1998

Wff

Iowa Turfgrass

D epartm ent of H orticulture
D epartm ent of Plant Pathology
D epartm ent of Entomology
Cooperative Extension
IOWA STATE UNIVERSITY

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In Cooperation with the
Iowa Turfgrass Institute
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Io w a State U n iv e r sit y
University Extension
A m es, Io w a

FG-466 | July 1998

Field Day Program - July 16,1998
9:00 a.m.

Introductory Remarks - R egistration Tent

9:15 a.m.

CHOICE OF FIVE TOURS
All tours start from registration area. See following two pages for
specific topics, speakers, times, and locations.

Tour #1

Lawn Care & Grounds -- Turfgrass varieties, fertilizers, plant growth
regulators, herbicides, application demonstration.

Tour #2

G olf Course —Turfgrass varieties, sand green management, disease control,
topdressing, SubAir demonstration, cmmb rubber.

Tour #3

Sports Thrf —Turfgrass varieties, SportGrass, Enkamat, pregermination and
divot mix demonstration, cmmb mbber.

Tour #4

M owing Equipm ent -- Safety, summer maintenance, and mowing equipment
demonstration.

Tour #5

Tree Care — Selection, planting demonstration, and care of trees for Iowa’s
landscape.

11:30-12:00 Exhibit Displays

12:00 noon

Lunch Served in Exhibit Area

1:30 p.m. Educational Sessions and Demonstrations
♦

Pesticide R ecertification Cont. Ed. Course (2 hours) —Main Building

♦

Turf I.D . and Weed, D isease & Insect Control Tour —Dave Minner,
Nick Christians, Mark Gleason, and Donald Lewis

♦ Vendors and Equipm ent -- Exhibit Area - Jim Dickson

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Introduction
Nick E. Christians and D avid D. Minner
The following research report is the 19th yearly publication of the results of turfgrass research
projects performed at Iowa State University. Copies of information in earlier reports are available
from most of the county extension offices in Iowa. This is the second year that the entire report is
available on the Internet. It can be accessed at:
http://www.hort.iastate.edu/hort/Frames/pubs/pframe.html
The 1997 season was mild with sufficient rainfall during most of the summer. The fall was very dry.
Several new sand-based golf and athletic field research plots are under construction on the south end
of the Turf Facility at the Horticulture Research Station. Various products and technologies
associated with sand-based systems will be evaluated such as: SportGrass - a combination of natural
grass and synthetic turf, Heatway - a water circulated soil heating system, SubAir - a subsurface forced
air system, several organic and inorganic sand amendments, and a sloped area to study temperature
and moisture stress on putting greens.
We would like to acknowledge Richard Moore, superintendent of the ISU Horticulture Research
Station; Jim Dickson, manager of the turf research area; Barbara Bingaman, Postdoctoral researcher;
Doug Campbell, research associate; Jeff Salmond, Mike Faust, and Melissa Weinhold, graduate
students; and all others employed at the field research area in the past year for their efforts in
building the turf program.
Special thanks to Lois Benning for her work in typing and helping to edit this publication.
Edited by Nick Christians and David Minner, Iowa State University, Department of Horticulture,
Ames, IA 50011-1100.

Dr. Nick Christians
Phone: 515/294-0036
Fax: 515/294-0730
E-mail: nchris@iastate.edu

Dr. David Minner
Phone: 515/294-5726
Fax: 515/294-0730
E-mail: dminner@iastate.edu

IV

Table of Contents
Environm ental D a ta ..........................................................................................................................

1

Species and C ultivar Trials
Results of Regional Kentucky Bluegrass Cultivar Trials...........................................................

5

Regional Tall Fescue Cultivar Evaluation..................................................................................

12

Regional Fine Fescue Cultivar Evaluation..................................................................................

16

Perennial Ryegrass Study.............................................................................................................

18

Shade Adaptation Study................................................................................................................

21

Fairway Height Bentgrass Study...................................................................................................

24

Green Height Bentgrass Cultivar Trial (Native Soil).................................................................

25

H erbicide and Growth R egulator Studies
Preemergence Annual Weed Control Study...............................................................................

26

Preemergence Annual Grass Control Study................................................................................

33

Postemergence Broadleaf Weed Control Study.........................................................................

37

Effect of Beacon on Kentucky Bluegrass Cultivars...................................................................

47

Effect of Primo on Kentucky Bluegrass Sod Establishment.....................................................

52

Effects of Primo and Beacon on
Poaannua Populations in Creeping B
Maintained at Green Height................................................................................................ 54
Effects of Primo on Poa annua Populations in Creeping Bentgrass Maintained
at Fairway Height.................................................................................................................

57

Effect of Primo on the Establishment of Kentucky Bluegrass in a Mature Grass Stand........

59

Postemergence Ground Ivy Control Study.................................................................................

60

Effect of Beacon on the Germination of Kentucky Bluegrass and Creeping Bentgrass.........

61

Non-selective Herbicide Study.....................................................................................................

63

Turfgrass Disease Research
Growth of Agrostis palustris in Response to Adventitious Root Infection by Species
Of
Acrem
onium
....................................................................................................................

65

Evaluation of Fungicides for Control of Dollar Spot in Penncross Creeping Bentgrass.........

68

Radiometric Assessment of Dollar Spot Severity on a Creeping Bentgrass Green..................

70

Evaluation of Fungicides for Control of Pythium Blight in Perennial Ryegrass.....................

72

Evaluation of Fungicides for Control of Brown Patch in Creeping Bentgrass........................

73

Fertilizer Trials
Kentucky Bluegrass Fertility Study...................................................................... ......................

77

Aquatrols Creeping Bentgrass Fertilizer Study...........................................................................

81

Creeping Bentgrass Fertility Trial Results..................................................................................

85

v

Kentucky Bluegrass Slow Release Fertilizer Study......................................................................

87

Creeping Bentgrass Establishment on Sand Greens.....................................................................

89

Environm ental Research
1991 Com Gluten Meal Crabgrass Control Study - Year 7 .......................................................

95

1995 Com Gluten Meal Rate Weed Control Study - Year 3 .....................................................

99

1995 Com Gluten Hydrolysate Weed Control Study - Year 3 .................................................. 103
Carriers for Com Gluten Hydrolysate......................................................................................... 105
T u rf M anagem ent
Evaluating Turfgrass Species for Use Over Buried Steam Lines................................................ 106
Rubber Tire Particles as a Topdressing Amendment for Intensely Trafficked Grass............. 110
The Effect of Topdressing with Rubber Buffings on Intensely Trafficked Football Turf...... 116
The Effect of Deicing Chemicals on Turfgrass.......................................................................... 119
Soil M odification and Sand-based Systems
Stabilizing Sand-based Athletic Fields With Enkamat................................................................ 127
Managing Cool-season Grasses as Part of a SportGrass® System.............................................. 131
Managing Bentgrass Stress on Putting Green Slopes.................................................................. 136
Effects of Soil Amendments on the Chemical and Physical Soil Parameters of a
Sand-based Golf Green........................................................................................................... 138
Effects of Bio-Flex-A-Clay on Creeping Bentgrass Establishment and Growth..................... 141
Responses of Creeping Bentgrass to Organic and Inorganic Soil Amendments Under
Stressed Conditions............................................................................................................... 145
Rubber Particles for Vehicular and Foot Traffic Areas - Demonstration Plot....................... 150
Modifying Athletic Field Soils With Calcined Clay and Tillage................................................ 151
Athletic Field Turfgrass Response to Calcined Clay Topdressing............................................ 153
O rnam ental Studies
10 Reasons for Landscape Plant Failure..................................................................................... 154
Trees Can Reduce Energy Consumption..................................................................................... 155
Fertilizing Trees and Shrubs.......................................................................................................... 157
Prairie Demonstration................................................................................................... :............. 160
Introducing
The Iowa State University personnel affiliated with the Turfgrass Research Program.......... 161
Companies and Organizations that made donations or supplied products to the Iowa
State University Turfgrass Research Program............................................................................ 162

vi

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Environm ental Data

4

Species and C ultivar Trials

Results of Regional Kentucky Bluegrass Cultivar Trials
N ick E. Christians, David D. Minner, and James R. Dickson
The National Turfgrass Evaluation Program (NTEP) has sponsored several regional Kentucky
bluegrass cultivar trials conducted at most of the northern agricultural experiment stations. The
current tests at Iowa State University include a high-maintenance trial with 103 cultivars, a second
high-maintenance trial with the same cultivars that is subjected to compaction treatments, and a lowmaintenance study with 21 cultivars. The high-maintenance trials receive 4 lb. N/1000 ft2/yr, and
are irrigated as needed. The low maintenance trial is not irrigated and receives 1 lb. N/1000 fr/yr.
All three trials are mowed at two inches. The objective of the high-maintenance study is to
investigate cultivar performance under a cultural regime similar to that used on irrigated home lawns
in Iowa. The objective of the low-maintenance study is to observe the cultivar response under
conditions similar to those found in non-irrigated lawns that receive a standard lawn care program.
The objective of the traffic study is determine what cultivars perform better on intense traffic areas
such as sports fields. Traffic treatments will begin in 1998. A non-traffic recovery period will
immediately follow each traffic period. Traffic will be applied using a differential slip-type traffic
simulator (Brouwer model). One pass over the entire plot area will be made every Monday,
Wednesday, and Friday during the traffic period with the traffic simulator.
The values listed under each month in Tables 1, 2, and 3 are the averages of visual quality ratings
made on three replicated plots for the three studies. Visual quality was based on a 9 to 1 scale: 9 =
best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Yearly means of monthly data
were taken and are listed in the last column. The first cultivar received the highest average rating for
the entire 1997 season. The cultivars are listed in descending order of average quality.
Data for genetic color (Gcol), spring greenup (Gm), leaf texture (Leaf), and leaf spot (Lspot) also are
included for the high-maintenance, irrigated trial. Genetic color (Gcol), spring greenup (Gm), and
leaf texture (Leaf) ratings are listed for the low-maintenance trial. Genetic color (Gcol), spring
greenup (Gm), leaf texture (Leaf), spring density (Sden), summer density (Suden), fall density (Fden),
and percentage spring ground cover (% cov) data are listed for the high-maintenance, irrigated traffic
trial.
The 1997 season began with high rainfall and cool temperatures and ended cool and dry.
Table 1. The 1997 ratings for the 1995 high-maintenance, irrigated Kentucky bluegrass trial.
Turf Quality
Gcol
Gm
Leaf Lspot May June July Aug Sept
Cultivar
6.0
6.0
5.3
7.0
5.7
6.7
6.7
8.0
1 ZPS-2572
7.3
6.0
4.7
5.7
7.0
6.0
7.3
7.7
6.3
7.3
2 Absolute (MED-1497)
6.0
5.7
5.0
6.0
6.0
6.3
7.3
6.3
7.7
3 Award
7.0
4 PST-B2-42
4.7
5.3
5.7
6.7
7.0
6.3
6.3
7.3
3.7
7.0
5.7
6.7
6.3
5 NJ 1190
5.3
6.7
7.3
7.3
4.3
6.7
4.3
5.0
7.0
6.3
6.3
6.3
7.0
6 Unique
5.7
6.7
5.3
5.3
6.0
6.3
7.0
6.0
7.3
7 Arcadia (J-1936)
5.0
6.0
5.3
7.0
6.0
6.3
6.7
8 Blacksburg
6.3
7.3
5.7
6.0
6.0
6.0
7.7
6.0
5.3
6.7
6.0
9 J-1576
6.7
5.0
5.3
6.3
6.0
6.3
7.0
6.3
7.0
10 Midnight
5.0
5.7
5.0
7.0
5.3
6.7
6.3
6.7
7.3
11 Quantum Leap (J-1567)
6.7
4.7
8.0
5.0
6.3
7.0
6.0
6.7
6.7
12 ZPS-2183
4.0
6.0
4.3
6.0
5.7
6.7
6.3
6.7
6.7
13 BAR VB 3115B

5

Oct
7.7
7.0
7.7
7.3
7.3
7.0
7.0
7.0
7.3
7.0
7.0
7.0
7.0

Mean
7.0
6.9
6.9
6.8
6.7
6.7
6.6
6.6
6.6
6.6
6.6
6.6
6.5

Species and C ultivar Trials

14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
33
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60

Cultivar
Baron
Bartitia
Caliber
Coventry
BA 81-058
BA 81-270
BAR VB 233
Challenger
Explorer (Pick-3561)
PST-BO-141
Total Eclipse (Tcr-1738)
Limousine
NJ-54
Pick 8
Platini
PST-BO-165
Seabrmg (BA 79-260)
Sodnet
SRX 2205
A88-744
America
BA 73-373
BAR VB 6820
H86-690
LKB-95
NJ-GD
PST-A7-245A
Shamrock
Wildwood
ZPS-309
Abbey
BA 81-113
BAR VB 5649
Bluechip (MED-1991)
Cardiff
Goldrush (BA 87-102)
Jefferson
Livingston
MED-1580
Nimbus
Nuglade
Nustar
Raven
SR 2000
Blackstone (PST-638)
Chicago (J-2582)
Classic

Gcol
5.0
4.0
4.3
5.0
5.0
4.0
4.3
5.0
5.0
4.7
5.7
4.0
4.7
5.0
4.7
4.0
5.7
5.7
4.7
5.7
4.0
4.7
4.7
6.0
4.0
5.3
4.0
5.3
5.3
5.0
4.3
5.3
5.0
4.3
5.0
5.0
4.7
4.7
4.7
4.0
5.7
4.3
4.7
5.7
6.0
5.0
5.0

Gm
6.0
5.0
6.7
7.7
7.0
7.3
6.0
6.3
5.7
6.7
5.3
4.3
7.0
6.0
6.0
7.3
6.0
6.0
5.3
6.7
7.0
5.7
4.3
6.3
5.7
7.0
6.7
7.0
5.3
5.3
5.7
5.0
6.0
5.7
5.7
4.3
5.7
6.0
6.0
5.3
6.3
5.7
5.3
6.7
6.3
6.0
6.0

Lspot
6.0
7.0
5.3
5.3
5.3
5.7
6.3
6.7
5.7
5.7
6.7
6.7
5.3
6.7
6.0
4.7
5.7
5.7
7.3
5.3
5.3
5.3
7.7
5.0
6.0
4.3
5.7
5.3
7.3
7.0
5.3
4.3
6.0
6.3
6.3
5.3
4.0
5.0
6.7
6.3
6.7
6.3
6.0
6.3
7.0
5.3
4.0

Leaf
5.0
4.7
5.7
4.3
5.3
4.0
5.3
5.0
4.7
5.3
5.0
5.3
5.0
5.0
5.0
4.3
5.3
5.7
5.3
4.3
6.0
4.3
5.7
4.7
5.3
5.0
4.7
5.0
6.0
5.0
4.7
5.3
4.3
5.7
5.7
5.3
5.0
4.7
5.0
5.0
5.0
5.3
5.0
4.7
5.0
5.3
5.0

6

May
5.3
5.3
6.3
6.0
5.3
6.0
6.3
5.3
5.7
6.7
5.3
4.7
5.7
6.0
5.3
6.3
5.7
5.3
5.0
6.3
6.3
5.7
4.3
5.7
5.7
5.0
6.0
6.0
5.7
5.3
5.3
5.3
6.0
5.7
5.3
5.3
6.0
5.7
5.3
6.0
4.7
6.0
5.3
5.7
5.0
5.0
5.3

June
6.7
6.7
6.3
6.3
6.0
6.0
7.0
6.3
6.3
7.0
6.3
6.7
5.7
6.0
6.3
5.3
6.0
6.3
6.0
6.0
6.0
6.0
6.7
5.7
6.0
5.3
5.7
6.0
6.0
6.7
6.0
5.3
5.7
6.3
6.0
6.3
5.3
5.7
6.3
6.0
6.3
5.7
6.0
5.7
6.0
5.3
5.7

Turf Quality
July Aug Sept
6.3
6.7
7.0
6.7
6.3
7.0
6.3
6.7
6.7
5.3
6.3
7.7
6.3
6.3
7.3
5.7
6.3
7.3
6.3
5.7
6.3
6.7
6.3
6.7
6.0
6.7
7.0
5.3
6.0
6.7
6.7
6.0
7.0
7.0
7.0
5.3
6.7
6.7
6.3
5.7
6.3
7.0
6.7
6.3
6.7
6.0
6.0
7.0
6.0
6.0
6.7
6.0
6.0
7.0
6.3
6.7
7.0
6.0
6.0
6.3
5.7
6.3
6.3
6.0
6.7
6.3
6.0
6.0
7.0
6.3
6.3
6.3
6.3
6.0
6.7
5.7
6.7
7.0
5.7
6.7
6.7
5.7
6.0
6.7
6.0
6.0
6.7
6.0
6.0
6.3
6.0
6.0
6.7
6.0
6.3
6.3
6.0
6.3
6.3
6.0
5.7
6.3
6.0
6.0
6.7
6.3
5.7
6.3
6.0
6.0
6.7
6.0
5.7
6.7
6.3
6.0
6.3
5.7
6.0
6.3
6.3
5.7
6.7
6.0
6.0
6.3
6.3
6.0
6.3
5.7
6.0
6.7
6.0
6.0
6.3
6.0
6.0
7.0
5.3
5.7
7.0

Oct
7.0
7.0
6.7
7.3
7.3
7.0
7.0
7.0
7.0
6.7
7.0
7.0
7.0
6.7
6.7
7.0
7.3
7.0
6.7
6.7
6.3
6.3
7.0
6.7
6.7
7.3
6.7
7.0
6.7
7.0
6.7
7.0
6.3
6.3
6.7
6.3
6.7
7.0
6.3
6.3
6.7
6.7
6.3
6.7
6.7
6.7
7.0

Mean
6.5
6.5
6.5
6.5
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.0
6.0
6.0

Species and C u ltivar Trials

61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103

Cultivar
Haga
Odyssey (J-1561)
Ascot
BA 75-490
Baronie
Marquis
PST-B3-180
Rambo (J-2579)
BA 81-220
BA 81-227
Glade
HV 130
Kenblue
Princeton 105
PST-A7-60
Allure
Conni
Eclipse
SR 2100
BA 70-060
BA 76-197
Chateau
J-1555
Misty (BA 76-372)
Rugby II (MED-18)
Sidekick
VB 16015
BA 77-702
Dragon (ZPS-429)
Pick 855
PST-P46
SR 2109
BA 75-163
Fortuna
HV 242
Lipoa
Pepaya (DP 37-192)
BA 75-173
Baruzo
Moonlight (PST-A418)
Champagne (LTP-621)
LTP-620
Compact
L S D ( o.o5>

Gcol
4.0
6.0
5.3
5.0
4.0
5.0
4.3
4.0
4.7
4.3
5.0
4.0
4.0
5.7
5.3
4.7
3.7
5.3
5.0
5.0
3.7
4.3
5.0
4.3
5.0
4.3
6.3
4.3
5.0
4.7
5.7
4.7
5.7
5.0
4.3
5.7
4.7
5.0
5.7
6.0
5.3
5.0
4.0
1.0

Gm
7.0
5.7
5.0
6.0
7.3
6.0
6.7
5.7
4.7
6.3
5.7
4.7
5.0
6.0
4.0
6.7
5.0
5.7
6.0
5.3
5.3
6.7
6.3
5.7
6.0
7.0
5.3
5.7
6.7
5.7
5.0
5.7
6.7
5.0
5.0
5.0
4.0
5.3
5.0
7.0
6.3
6.7
5.3
1.7

Leaf
5.3
5.0
5.0
5.0
5.7
4.7
5.0
5.3
4.7
4.3
5.7
5.0
5.3
5.7
6.7
4.0
4.7
5.0
4.7
4.7
4.3
3.7
5.3
5.0
4.7
4.7
5.3
4.7
5.0
4.7
5.7
5.3
5.0
5.0
5.3
6.3
5.0
4.3
5.7
4.0
5.0
5.0
5.7
1.5

Lspot
4.7
6.0
7.0
4.3
3.7
5.3
5.3
6.3
5.7
6.0
6.0
5.7
4.0
6.7
7.3
6.0
6.3
5.0
5.3
6.0
3.3
5.7
5.7
6.0
6.7
4.7
6.7
6.0
5.7
5.3
6.3
6.7
5.0
6.3
6.0
6.0
6.3
4.0
4.7
6.3
5.0
5.7
4.0
1.5

May
6.3
4.7
4.7
5.0
6.0
5.3
5.7
5.0
5.3
5.3
5.0
5.0
5.3
5.3
4.3
5.7
5.3
5.0
5.7
5.3
4.7
5.3
5.0
4.3
5.0
5.0
4.3
4.7
5.0
4.7
4.7
4.0
4.7
4.3
5.0
4.0
4.0
4.7
4.7
4.0
5.0
4.0
4.3
2.3

June
6.0
5.3
6.0
5.0
5.7
6.0
6.0
6.7
5.0
5.3
5.3
5.0
5.0
6.0
5.0
5.7
6.0
5.7
5.3
5.7
4.7
5.0
5.0
5.3
5.3
5.7
5.3
5.7
5.3
5.3
5.3
5.3
4.7
5.7
5.3
5.3
5.3
4.3
5.0
5.3
4.7
5.3
5.0
2.0

Turf Quality
July Aug Sept
5.3
5.3
6.3
6.3
6.0
6.7
6.3
5.3
6.3
6.3
6.7
5.7
5.0
5.7
6.7
6.0
5.7
6.3
5.7
6.0
6.0
5.7
6.0
6.0
5.7
6.0
6.3
5.7
5.3
6.7
6.0
5.7
6.3
6.0
6.3
6.3
6.0
6.0
6.0
5.0
6.7
5.3
6.0
6.3
6.3
5.0
5.0
6.3
6.0
5.3
5.7
5.3
5.7
6.3
5.3
5.3
6.0
6.0
5.3
5.3
5.7
5.7
6.3
5.0
5.7
6.3
5.7
5.7
6.0
5.7
5.7
6.3
6.0
5.7
6.0
5.0
5.7
6.0
5.0
6.7
5.3
5.7
5.0
6.0
6.0
5.3
5.0
5.0
5.7
6.0
5.7
6.0
5.3
5.7
5.7
6.0
5.0
5.3
6.3
5.7
5.7
5.3
5.7
6.0
4.7
5.7
5.7
6.0
5.7
6.0
5.7
5.3
5.0
6.0
4.7
4.7
6.0
5.3
5.0
5.7
4.7
4.7
5.7
5.0
4.7
5.7
5.0
5.0
5.0
1.8
2.8
2.7

Gcol (Genetic color): 9 = dark green and 1 = light green. Leaf (Leaf texture): 9 = fine and 1 = coarse.
Gm (Greenup): 9 = best and 1 = poorest greenup.
Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.

7

Oct
6.7
7.0
6.7
7.0
6.7
6.3
6.0
6.3
6.3
6.7
6.3
6.3
6.3
6.7
6.7
6.7
6.0
6.3
6.3
6.0
6.3
6.3
6.3
6.3
5.7
6.0
6.7
6.0
6.3
6.3
6.0
6.3
6.3
6.0
6.0
6.0
5.7
6.0
6.3
6.0
5.7
5.7
5.3
2.6

Mean
6.0
6.0
5.9
5.9
5.9
5.9
5.9
5.9
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.7
5.7
5.7
5.7
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.6
5.5
5.5
5.5
5.5
5.5
5.4
5.4
5.4
5.4
5.4
5.2
5.2
5.2
5.1
5.1
4.9
1.6

Species and C ultivar Trials

Table 2. The 1997 ratings for the 1995 low-maintenance, non-irrigated Kentucky bluegrass trial.
Gm
Leaf
May
Gcol
6.3
7.0
7.0
5.7
6.0
6.0
5.7
6.3
5.7
7.7
6.7
7.0
5.0
6.0
6.0
4.3
5.7
6.0
6.0
5.7
6.7
5.0
6.7
4.7
5.7
5.7
6.3
5.7
5.7
6.7
7.0
6.3
5.3
6.0
6.0
5.3
7.0
4.7
7.0
4.0
5.7
6.0
4.3
6.7
7.0
6.0
5.7
5.3
5.0
4.7
6.0
4.3
6.0
5.0
5.7
5.0
7.0
4.0
6.3
3.7
5.7
5.7
7.3
4.3
6.7
4.7
6.3
4.3
6.7
5.0
7.3
3.7
7.0
4.0
6.0
3.3
6.7
5.3
6.0
3.7
6.7
5.0
5.3
2.7
1.2
0.8
1.2
1.3
LSDo.os
Gcol (Genetic color): 9 = dark green and 1 = light green.
Leaf (Leaf texture): 9 = fine and 1 = coarse.
Gm (Greenup): 9 = best and 1 = poorest greenup.
Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

Cultivar
BAR VB 3115B
Eagleton
South Dakota
BAR VB 233
Caliber
Baron
Canterbury
Kenblue
Baronie
Bartitia
BAR VB 5649
BH 95-199
Blue Star
Baruzo
PST-A7-60
Dragon (ZPS-429)
PST-B9-196
VB 16015
MTT 683
Lipoa
BAR VB 6820

8

June
6.3
5.7
5.7
6.3
5.7
5.0
6.0
5.0
6.3
4.3
5.0
4.3
5.0
4.3
3.7
3.7
5.0
3.7
3.7
3.3
3.0
1.4

July
6.3
6.3
6.0
6.3
5.7
5.7
6.3
5.7
6.0
5.7
4.7
5.3
5.3
4.7
5.3
5.3
5.0
4.3
4.7
4.0
3.3
1.3

Aug
6.7
6.3
5.7
6.0
6.3
6.3
5.3
6.0
5.0
7.0
5.7
5.3
5.0
5.0
6.3
5.7
4.7
5.0
5.3
4.3
4.0
1.5

Sept
7.3
7.3
6.0
6.7
6.7
6.7
6.0
6.0
5.3
6.3
6.3
6.0
5.3
5.3
6.0
5.7
5.3
5.3
5.3
4.7
4.7
1.4

Oct
6.3
6.7
6.0
6.3
6.0
6.3
5.7
5.7
5.3
6.7
5.7
5.7
6.0
6.3
5.7
5.3
5.0
6.0
4.7
5.3
4.7
2.2

acceptable quality, and 1 = poorest quality.

Mean
6.4
6.3
6.1
6.0
6.0
5.8
5.8
5.8
5.7
5.7
5.3
5.3
5.2
5.1
5.1
5.0
4.9
4.7
4.5
4.2
3.7
0.9

Mean

Species and C u ltivar Trials

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Species and Cultivar Trials

Regional Tall Fescue Cultivar Evaluation - Established 1996
Nick. E. Christians and James R. Dickson
This was the first year of data collection from the new tall fescue trial. This is a National Turfgrass
Evaluation Program (NTEP) trial. It is being conducted at many locations around the U.S. The
purpose of the trial is to study the regional adaptation of 129 tall fescue cultivars. Cultivars were
evaluated for seedling vigor in October. The study is established in full sun. Three replications of the
3 x 5 ft (15 ft2) plots were established for each cultivar in the spring of 1996. The trial is maintained
at a 2-inch mowing height, 3 lbs N/1000 ft2 were applied during the growing season, and the area was
irrigated when needed to prevent drought. Preemergence herbicide was applied once in the spring.
Seedling vigor (Svig) was rated on a 9 to 1 scale: 9 = best vigor and 1 = worst vigor. Turf quality was
evaluated for May through October and was assessed on a 9 to 1 scale: 9 = best quality, 6 = lowest
acceptable, and 1 = poorest quality. Genetic color (Gcol), greenup (Gmp), and leaf texture (Ltex)
data also are included.
Initial establishment was poor due to damage in the winter of 1996-97 and none of the cultivars had
a satisfactory quality rating for the entire season. The September and October ratings show that
several of the varieties were well established by the fall of 1997.
Table 1. The 1997 ratings for the tall fescue regional cultivar trial.__________
Cultivar
1
2

3
4
5

Titan 2
Shenandoah
Arid
Renegade
Kentucky-31

Quality
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Aug

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Ltex

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June

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6.7
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4.7

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5.7
5.3
7.0
6.3
5.0
5.3

4.7
4.7
5.0
4.7
5.0
4.7
4.3
5.0
5.0
5.0
5.0
4.7
4.7
4.7

4.7
3.7
3.7
4.0
4.3
4.0
3.7
4.3
4.3
4.0
4.0
3.7
3.7
3.7

5.0
5.3
5.0
5.3
5.3
5.0
5.3
5.3
4.7
5.3
5.0
5.3
4.7
5.3

5.0
5.3
5.3
5.3
5.3
5.0
5.0
5.0
4.7
4.3
4.3
4.7
4.3
4.3

5.0
5.7
5.3
5.7
5.3
5.0
5.7
4.7
4.7
5.3
5.0
5.3
5.7
5.0

5.1
4.9
4.9
4.9
4.9
4.8
4.8
4.8
4.8
4.8
4.8
4.8
4.7
4.7

4.0
4.3
4.7
4.0

4.0
4.0
3.7
63.7

5.0
5.3
5.0
4.7

4.7
4.7
5.3
4.7

5.7
5.0
4.7
5.3

4.7
4.7
4.6
4.6

6 .0

5.7
5.7

w/endo

10

Safari
CU9501T
DLF-1
ISI-TF11
Pixie E+

11

A A -A 91

7.7
7.0
7.3
7.0
7.3

12

Crossfire II
Marksman
PST-523
Regiment
Southern Choice
WVPB-1D
Duster
Milleniun (Tm i -

7.3
7.0
7.3
7.7
6.3
7.0
7.7

6

7
8

9

13
14
15
16
17
18
19

8.0

6.0

7.3
6.3
6.0

6.7
6.7
7.0
7.0
7.0
6.0

6.3
6.7
6.7
7.0
6.7

6.0

5.3

7.7
6.3
7.3
7.3

5.7
5.3
6.3

5.7
5.0
5.3
4.7
4.3
5.3
4.7
4.7
5.3
4.7
5.7
5.0
5.0
5.3

5.7
6.3
5.7
5.3

5.0
5.0
4.3
5.3

6.0

7.0
6.7
7.0
7.3
7.3
7.0
7.3
6.7

6 .0
6 .0

RBR)

20
21
22

23

Pennington-1901
PST-R5AE
DP 7952
Finelawn Petite

7.3
7.0
7.3
6.7

6.3
7.0
5.7
7.0

7.3
6.7
6.0

6.7

12

Species and Cultivar Trials

Cultivar
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66

67

Genesis
MB 216
MB 28
TMI-AZ
Falcon II
Mustang II
PC-AO
Shortstop II
SR 8210
WVPB-1C
Bar FA6 US6 F
Coronado
JTTFA-96
JTTFC-96
MB 29
OF1-96-31
Pick FA B-93
RG-93
ATF-038
AV-1
EC-101
Equinox (Bullet)
Gazelle
J-101
Leprchaun
MB 210
MB 212
OFI-931
OFI-96-32
PSII-TF-9
PST-R5TK
TA-7
TMI-FMN
Tulsa
WRS2
ZPS-5LZ
AA-989
Alamo E+
ATF-253
Coyote
EA 41
Jaguar 3
MB 213
MB 214

Svig

Gcol

Gmp

Ltex

7.7
7.0
7.7
7.0
7.7
7.0
7.3
7.0
7.3
7.3
6.7
6.3
7.3
7.0
6.7
6.7

7.0
7.3
7.0
6.3
6.3
6.7
6.7
6.7
6.7
6.3
6.7
7.0
6.3
6.3
7.0
7.0
6.7
7.0
6.7
6.3
6.3
6.7
7.0
7.0
6.7
7.0
7.0
6.7
7.0
6.7
6.7
7.3
6.3
7.3
6.7
7.3
7.0
6.3

6.7
7.3
6.7
6.7
7.3

6 .0

6.7
7.3
7.0
7.0
7.3
6.3
6.3
7.0
7.3
7.0
6.7

6.0

6.0

7.3
7.0
6.7
7.0
7.3

7.7
6.3
7.3
7.7
7.0

6.0

6.3
5.7
6.3
7.3
6.7
7.0
6.7
6.7
7.3
7.3
7.0
6.3
7.7
7.3
7.0
7.0
6.7
7.0
6.7
7.3
7.3
6.3
6.7
6.3
6.3
6.7
7.0

5.7
6 .0
6 .0

6.3

6.7
5.7
6.3
6.7
5.3
5.7
5.7
6.7
5.7
5.7

8.0

6 .0

6.0

7.0
7.0
7.0
6.7
7.3
7.0
6.0

6.7
6.3
7.3
7.0
6.0

7.7
7.0
7.3
7.0
6.3
7.0
6.0

6 .0

5.7
5.3
5.7
5.3
6 .0
6 .0

5.7
5.7
6 .0

6.3
6.3
5.7
6 .0

5.3
5.3
6.3
5.3
6 .0

5.7
6.3
5.3
5.7
5.3
6.7
5.7
6 .0
6 .0
6 .0

13

May
4.07
5.0
5.0
4.3
5.0
4.7
4.7
4.0
4.7
5.0
4.3
4.7
4.7
4.7
4.7
4.7
4.3
5.0
4.3
4.3
4.3
4.3
4.7
4.3
4.7
4.7
4.3
4.3
4.7
4.0
4.3
4.3
4.0
4.3
4.3
4.7
4.7
4.0
4.3
4.7
4.3
4.0
4.3
4.3

June
5.0
4.3
4.7
4.3
4.7
5.0
4.3
4.7
4.0
4.7
4.0
4.3
4.3
4.7
4.3
4.0
4.3
4.7
4.3
4.3
4..3
3.7
3.7
4.7
4.0
4.3
4.3
4.3
4.3
4.7
4.3
4.0
4.0
4.0
4.0
3.3
4.0
4.3
4.7
4.0
4.3
4.0
4.0
4.3

Quality
July
Aug
4.0
3.7
4.0
4.0
3.7
3.3
4.0
4.0
3.7
3.3
3.3
3.7
3.7
3.3
3.7
3.0
3.0
3.7
3.3
3.3
3.7
3.3
3.3
3.3
3.7
3.7
3.3
3.7
3.3
3.7
3.0
3.3
4.0
3.3
3.7
4.0
3.3
3.7
3.3
3.3
3.7
3.7
3.3
3.3

4.7
4.7
4.3
5.0
5.0
5.0
4.7
5.0
5.3
4.7
4.3
4.7
4.7
4.7
4.3
4.3
5.3
4.3
4.3
4.7
4.3
4.3
4.7
4.3
4.3
4.7
5.0
4.7
4.7
5.0
4.7
5.0
5.0
5.0
4.7
5.0
4.3
4.3
4.0
4.7
4.3
4.3
4.7
4.3

Sept

Oct

Mean

4.7
5.0
4.7
4.7
4.0
4.0
4.7
4.3
4.7
4.3
4.7
4.7
4.3
4.7
4.3
4.7
4.3
4.3
4.3
4.7
4.3
5.0
4.3
4.3
4.7
3.7
4.0
4.3
4.0
4.0
4.7
4.3
4.3
4.0
4.3
4.0
4.0
4.3
4.3
4.3
4.0
4.3
4.0
4.0

4.7
5.0
5.0
5.0
4.7
5.0
4.7
5.0
4.7
5.0
5.7
4.3
4.7
4.7
5.3
5.7
5.0
4.7
5.0
4.3
5.0
5.0
5.3
4.7
4.7
5.0
5.0
4.7
4.7
4.7
4.7
5.0
4.3
5.0
4.7
5.0
4.7
4.3
4.3
4.3
4.3
4.7
4.7
4.7

4.6
4.6
4.6
4.6
4.5
4.5
4.5
4.5
4.5
4.5
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.4
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.2

Species and C ultivar Trials

68

69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84

Cultivar
OFI-FWY
PSII-TF-10
SRX 8084
SRX 8500
SS45DW
TMI-TW
WX3-275
ATF-020
ATF-192
ATF-196
BAR FA 6 LV
BAR FA6 US2U
CU9502T
Empress
JSC-1
KOOS 96-14
Masterpiece

Svig
6.0

7.0
7.3
7.0
7.0
6.3
6.7
6.0

6.3
7.0
7.0
6.3
7.3
6.3
6.3
7.0
6.0

Gcol
7.0
7.0
6.0

7.0
6.3
7.0
6.7
6.3
6.3
7.0
7.0
7.0

Gmp

Ltex

7.0
6.7
7.0
7.0
7.3
7.0
6.7

6.3
5.7
6.3
7.0
6.3
5.0

6.0

7.0
6.3
7.0
6.7

6.7
7.3
6.7
7.0
6.7
7.3
6.3
7.0
7.3

6.7
7.3
7.0
7.0
6.7

7.3
7.3
7.0
6.7
6.7

6.0

6 .0

6.3
5.3
7.0
6.7
7.3
7.0
6.3
5.3
5.7
6.3

Quality
July
Aug

May
3.7
4.3
4.3
3.7
5.0
4.0
4.3
4.3
3.7
4.0
4.7
4.3
4.3
4.0
4.3
4.0
4.0

June

3.7
3.3
3.7
3.7
3.3
3.7
3.7
3.3
3.3
3.7
3.7
3.3
3.7
3.0
3.3
3.3
3.3

4.7
4.7
4.0
4.7
4.7
4.7
4.7
4.3
1.7
4.3
4.3
4.3
4.0
4.7
4.3
4.3
4.3

Sept
4.0
4.3
4.0
4.3
4.0
4.3
4.7
3.7
4.0
4.3
4.0
4.3
4.3
4.3
4.0
4.0
4.0

Oct
5.0
4.7
4.7
5.0
4.3
5.0
4.0
4.7
5.0
4.0
3.7
4.0
4.3
4.7
4.7
4.7
4.7

Mean

4.0
4.0
4.3
4.0
4.0
3.3
4.0
4.0
4.0
4.0
4.3
4.0
4.0
4.0
4.0
4.0
4.3

4.3
3.7
4.0
4.3
4.3
3.7
4.0
4.0
3.7

4.3
3.3
4.3
3.3
3.7
3.7
3.7
4.0
3.7

3.0
3.3
3.3
3.3
3.3
3.7
3.3
3.7
3.3

4.3
4.7
4.3
4.7
4.3
4.3
4.3
4.0
4.3

3.7
4.3
4.3
4.3
4.0
4.0
4.3
4.0
4.3

4.7
5.0
4.0
4.3
4.3
4.7
4.3
4.3
4.7

4.1
4.1
4.1
4.1
4.0
4.0
4.0
4.0
4.0

4.0
4.0
4.0
3.7
3.7
3.7
3.3
4.7
4.3
3.7
4.0
4.0
3.7
4.0
3.7
4.0

3.7
3.7
3.3
3.7
4.0
4.0
4.3
4.3
4.0
3.3
3.7
3.3
4.0
3.0
3.7
3.7

3.3
3.0
3.3
3.0
3.3
3.3
3.0
3.3
3.0
3.3
3.0
3.3
3.0
2.7
3.3
3.0

4.7
4.3
4.3
4.3
4.3
4.3
4.0
4.3
4.0
4.3
4.3
4.0
4.3
4.3
4.0
4.0

4.0
3.7
4.0
3.7
4.0
3.7
4.7
3.0
3.7
4.0
3.7
4.0
3.7
4.3
3.7
3.3

4.3
4.7
4.3
5.0
4.3
4.3
4.3
3.7
4.0
4.3
4.3
4.3
4.0
4.3
4.7
4.3

4.0
3.9
3.9
3.9
3.9
3.9
3.9
3.9
3.8
3.8
3.8
3.8
3.8
3.8
3.8
3.7

4.2
4.2
4.2
4.2
4.2
4.2
4.2
4.1
4.1
4.1
4.1
4.1
4.1
4.1
4.1
4.1
4.1

(LTP-SD-TF)

85
86

87
88

89
90
91
92
93

MB 215
PST-5M5
PST-5RT
ZPS-2PTF
ATF-257
Bonsai
Lion
PST-5E5
Rmbrandt

6.3
6.3
7.3
6.0

7.0
6.3
6.3
7.0
6.7

5.3
5.7
6 .0
6 .0

5.3

6.0

6.0

6 .0

7.0
6.7
7.0

7.3
6.3
7.3

6 .0

6.3
7.0
7.0
6.7
7.0
6.7
7.0
6.7
7.3
7.3
6.7
7.3
6.3
7.0
7.0
7.0

6.7
7.3
7.3
6.7
7.0
7.0
6.3
6.3
6.7
6.7
6.7
6.7
6.7
7.3
6.3
7.0

6 .0

6.7

(LTP-4026 E+)

94
95
96
97
98
99
100
101
102

103
104
105
106
107
108
109

Tarheel
Apache II
ATF-022
ATF-188
J-98
Pick FA 6-91
PRO 8430
SSDE31
BAR FA 6 D USA
ISI-TF10
ISI-TF9
R5AU
TNI-N91
Tomahwak -E
WVPB-1B
BAR FA 6 D

7.7
7.3
6.0

6.3
6.3
6.3
6.3
7.0
6.3
5.7
7.0
7.3
6.3
6.7
5.7
6.3

6.3
6 .0

5.0
6.3
6.7
6 .0
6 .0
6 .0
6 .0

5.3
5.0
6.3
6 .0

6.7
6 .0

6.7

14

S pecies and C u ltivar Trials

110
111
112

113
114
115
116
117
118
119
120
121
122

123
124
125
126
127
128
129

Cultivar
BAR FA6 US1
BAR FA6 US3
Cochise II
MB 211
MB 26
DP 50-9011
OFI-951
Pick GA-96
Pick RT-95
ATF-182
Pick FA XK-95
Pick FA 15-92
Pick FA 20-92
Sunpro
J-5
AA-983
Pick FA UT-93
PST-5TO
J-3
Pick FA N-93
LSD0.05

Svig
6.7
6.0
6.0
6.0

6.7
6.3
6.0
6.0
6.0

6.3
6.3
5.7
6.3
5.7
5.7
6.0

5.7
5.7
5.7
6.0

Gcol
6.7
7.0
6.7
7.0
7.3
6.3
7.0
7.0
6.7
6.0

7.3
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.3
0.9

Gmp
6.7
7.3
6.7
7.0
7.0
7.0
6.7
7.3
7.0
6.7
7.3
6.3
7.0
7.0
7.3
6.7
7.3
6.3
7.0
6.7
1.3

Ltex
7.0
6.3
6 .0
6.0

6.3
5.7
6.7
6.3
6.7
5.7
6.7
6.7
7.0
5.7
6.3
6.7
7.3
6 .0

5.7
6.7
1.6

15

May
3.7
4.3
3.3
4.3
4.0
4.0
3.7
3.3
3.3
3.7
3.3
3.3
3.7
3.3
3.3
3.0
3.0
2.7
3.0
2.7
1.4

June
4.0
3.3
3.3
3.7
3.7
3.3
3.7
3.0
3.3
4.0
3.0
3.7
3.3
3.7
3.3
3.0
2.7
3.0
3.3
3.0
1.7

Quality
Aug
July
3.3
4.3
3.7
4.3
3.3
4.0
3.0
3.7
3.3
4.0
2.7
4.3
3.0
4.0
3.3
3.7
3.7
3.3
2.3
4.0
3.0
3.7
3.0
4.0
3.0
4.0
2.7
4.0
2.7
3.7
2.7
4.0
2.7
3.7
2.7
3.7
2.0
3.0
2.3
3.3
1.8

2 .0

Sept
3.3
3.7
4.0
3.7
3.7
3.3
3.3
4.3
4.0
3.3
4.0
3.0
3.3
3.3
3.3
3.0
3.7
3.3
3.0
3.0
1.7

Oct
3.7
3.0
4.3
3.7
3.7
3.7
4.0
4.0
4.0
3.7
4.0
3.3
3.3
3.7
3.3
3.3
3.3
3.3
3.3
3.3

Mean
3.7
3.7
3.7
3.7
3.7
3.6
3.6
3.6
3.6
3.5
3.5
3.4
3.4
3.4
3.3
3.2
3.2
3.1
2.9
2.9

2.1

1.1

Species and Cultivar Trials

Regional Fine Fescue Cultivar Evaluation - 1993
Nick. E. Christians and James R. Dickson
This was the second year of data from the new fíne fescue trial. This is a National Turfgrass
Evaluation Program (NTEP) trial. It is being conducted at many locations around the U.S. The
purpose of the trial is to study the regional adaptation of 59 fine fescue cultivars. Cultivars were
evaluated for quality each month of the growing season through October. The study is established in
full sun. Three replications of the 3 x 5 ft (15 ft2) plots were established for each cultivar in
September of 1993. The trial is maintained at a 2-inch mowing height, 3.5 lbs N/1000 ft2 were
applied during the growing season, and the area was irrigated when needed to prevent drought.
Preemergence herbicide was applied once in the spring.
Visual quality was based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 =
worst quality. Data on spring greenup are also included.
Table 1. The 1998 quality ratings for the fmeleaf fescue regional cultivar trial.
Species Greenup
May June July
Cultivar
STC
7.7
8.0
6.3
7.7
1 PST-4VB Endo.
STC
6.0
6.3
6.7
7.0
2 Rondo
CF
6.7
6.3
6.3
3 Shadow II (PST-44D)
6.3
STC
7.3
7.0
6.7
4 Jasper (E)
6.7
STC
7.0
7.3
6.0
7.0
5 PST-4ST
CF
7.3
6.0
8.0
6.3
6 K-2 (MB 65-93)
CF
6.7
6.3
6.7
6.3
7 Victory (E)
CF
6.3
6.7
5.7
8 Victory II (PICK 4-91W)
5.7
STC
6.7
6.3
6.3
8.0
9 Aruba
CF
7.0
6.7
5.3
5.7
10 Banner III (MB 61-93)
11 BAR UR 204
STC
6.0
6.3
5.7
7.0
12 Shademaster II
STC
7.0
6.7
6.7
6.7
CF
6.0
6.3
5.7
13 Banner II
5.7
CF
14 Columbra (MB 64-93)
7.7
6.7
5.7
6.0
CF
6.3
6.7
6.0
15 Jamestown II
5.7
CF
7.3
6.7
16 Medina
6.3
5.3
STC
7.0
6.7
7.0
7.0
17 PST-4DT
Tiffany
CF
6.7
6.0
5.7
6.7
18
CF
6.3
7.0
5.7
5.7
19 WX3-FF54
CF
6.7
7.0
5.7
6.0
20 Brittany
STC
7.7
6.7
5.7
21 CAS-FR13
6.3
STC
7.3
22 Flyer II (ZPS-4BN)
6.3
6.3
6.7
CF
7.0
6.7
5.7
5.7
23 Shadow (E)
CF
6.7
5.7
5.7
7.3
24 Treazure (ZPS-MG)
CF
6.0
6.7
5.3
5.7
25 ECO (MB 63-93)
6.7
6.3
6.7
HF
6.0
26 Discovery
HF
7.0
6.3
6.0
5.3
27 MB 82-93
STC
7.7
6.7
5.3
6 .0
28 Common Creeping
SLC
5.3
5.3
6.3
6.7
29 Dawson
6.7
CF
7.3
5.7
5.3
30 ISI-FC-62
6.0
CF
6.7
6.3
5.7
31 Bridgeport
6
.0
5.7
5.3
CF
6.7
32 Molinda

16

Aug
4.7
7.0
6.3
6 .0

6.3
5.7
6.7
5.3
4.7
5.7

Sept
7.3
6.7
7.7
7.0
7.0
6.3
6.3
6.7
6.0

6.0

6.7
6.3
6.3
6.3
6.7

6.0

6.0

5.7
4.0
5.3

6.3
6.7
6.3

6 .0

6.0

6.0

5.3
6.3

6.0

4.7
6.3

5.3
5.0
5.7
5.0
5.3
4.0
5.3
4.3
4.7
5.3
5.0
6.3

6.0

6.7
6.7
6.7
5.7
5.3
6.0

5.3
6.3
5.3
5.3

Oct
7.0
7.3
7.7
6.7
6.3
6.3
6 .0

7.7
5.7
7.3

Mean
6 .8
6 .8
6 .8

6.7
6.7
6.4
6.4
6.3
6 .2
6 .2

6 .0

6.2

6 .0

6 .2

6 .0

6.1

5.3
6.3
6.3
5.3
6.3
6.3

6.1

6 .0

6 .0

5.7
5.7
5.7
5.7

6 .0

6 .0

5.9
5.8
5.8
5.7
5.7
5.7
5.6
5.6

5.7
6.7
5.7
5.7
4.7
5.3
5.0

6.1
6.1
6.1
6.1
6.1

6 .0
6 .0
6.0

Species and C ultivar Trials

33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59

Cultivar
NJ F-93
SR 5100
BAR FRR 4ZBD
Flyer
Darwin
Ecostar
MB 66-93
Osprey (PRO 92/24)
Quatro
Seabreeze
WX3-FFG6
Sandpiper (PRO 92/20)
Defiant (MB 81-93)
Jamestown
TMI-3CE
Reliant II
SR 3100
Aurora w/endo
Pamela
Brigade
Vernon (MB 83-93)
Nordic
Silverlawn (WVPB-STCR-ioi)
Spartan
Cascade
Scaldis
67135

Species
CF
CF
STC
STC
CF
HF
CF
HF
SF
SLC
STC
CF
HF
CF
CF
HF
HF
HF
HF
HF
HF
HF
HF
HF
CF
HF
SF

Mean
6.0
5.6
6.0
5.7
5.6
4.3
4.0
5.5
6 .0
4.7
5.3
5.5
6 .0
6.0
5.4
6.7
6 .0
5.7
4.3
5.4
6.7
5.7
4.3
6.3
5.4
4.3
5.0
6 .0
6.3
5.4
5.3
4.7
6 .0
6.7
6.0
5.7
5.4
4.3
5.3
6 .0
5.7
4.7
5.4
4.7
5.7
6.3
6.0
5.4
6.0
4.0
6.0
5.7
5.7
4.7
4.7
5.2
5.3
5.3
6.0
5.3
5.7
5.3
4.3
5.0
5.3
5.7
4.7
4.7
5.0
6.0
5.3
5.3
5.0
5.0
5.0
5.3
5.0
4.7
4.9
5.0
5.7
6.0
4.3
4.7
6.0
4.7
4.3
4.9
6.3
4.7
4.0
4.7
5.3
5.3
5.0
4.0
4.0
4.7
5.3
5.7
4.7
5.0
4.3
4.0
4.6
5.0
5.0
5.3
5.3
5.3
3.3
4.6
4.3
4.0
5.0
5.0
4.0
4.5
4.7
4.7
4.3
3.7
4.5
5.3
4.7
4.0
4.4
5.3
4.7
5.0
3.3
3.3
4.7
5.0
5.0
4.0
4.3
4.2
5.0
4.7
5.3
3.7
3.0
4.3
3.0
4.1
4.7
4.7
4.3
2 .2
1.9
1.7
0.7
1.3
2.7
1.0
SF = Sheep Fescue, SLC = Slender Creeping Fescue,

Greenup
6.0

5.7
7.7
6.3
7.3
5.7
5.3
5.7
6.0

6.3
6.7
6.3
6.0
6.0

6.3
5.0
5.3
5.3
5.7
5.7
5.3
5.0
6.7
6.0

May
5.3
5.7
6.7
6.3
5.0
5.7
5.3

June
5.3
5.7

July
5.3
5.7
6.3

Aug
5.3
4.7
5.7
4.7
4.7
4.0
5.0
3.7
5.3
5.0
5.0
5.0
4.0
3.7
4.3
4.0
3.3
3.7
4.3
4.3
3.7
4.3
4.3
4.3
4.0
3.7
3.3

Sept
6.3

Oct

5.7
5.7
4.7
1.4
L S D ( o.o5)
Species: CF = Chewings Fescue, HF = Hard Fescue,
STC = Strong Creeping Fescue
Spring greenup (Greenup): 9 = dark green and 1 = light green.
Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
NS = not significant at the 0.05 level.

17

Species and Cultivar Trials

Perennial Ryegrass Study - Established 1994
James R. Dickson and N ick E. Christians
This trial began in the fall of 1994 with the establishment of 96 cultivars of perennial ryegrass at the
Iowa State University Horticulture Research Station. The study was established on an irrigated area
that was maintained at a 2-inch mowing height and fertilized with 3 to 4 lb. N/1000 ft2/yr. The area
receives preemergence herbicide in the spring and was treated with a broadleaf herbicide in September
of 1994.
Cultivars were evaluated for turf quality each month of the growing season. Visual quality was based
on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. The values
listed under each month in Table 1 are the averages of ratings made on three replicated plots for the
three studies. Yearly means of data from each month are listed in the last column. The cultivars are
listed in descending order of average quality. Data on genetic color (Gcol), greenup (Gm), and leaf
texture (Leaf) also are included.
Notice that the first 77 cultivars received mean ratings of 6 or above for the 1997 season. There is
now a wide selection of high-quality perennial ryegrass varieties to choose from for this region.
Perennial ryegrass is quite susceptible to winter damage. There was no winter damage in the spring of
1997. Last year’s report contains information on the effect of winter damage.
Table 1. The 1997 quality and other ratings for the national perennial ryegrass study established in 1994.
Gcol

Gm

1 Premier II (Bar USA 94-11)
2 Riviera II
3 Secretariat (RPBD)

6.0
5.0

6.3
6.3

5.7

6.3

5.0
5.7

4

Manhattan 3

5.7

5.7

5

5.7

6.3

6

Divine
Line Drive (MB 47)

6.3

7
8

Majesty (MB 43)
Palmer III (LRF-94-MPRH)

5.7
5.7

Cultivar

Wind Star (PST-28M)

Leaf

May

5.7

6.0
6.7
6.3

5.0

6.3

6.7

4.7

6.7

6.3

6.0
6.7

6.3
6.7
7.0

5.3
5.7
5.0

Mean

8.0

7.3
7.3

6.9

7.7
7.0

7.3

6.9
6.9

7.7

7.7

6.8

7.0
8.0

7.0

6.7

7.7

6.7

7.3
7.0

6.7

5.7
7.0

6.0

6.3

6.3
7.0

6.3
6.3

7.0
7.0

7.3
7.3
7.0

6.0

6.0
5.3

5.0
5.0

6.3
5.7

5.0

6.0
6.0

5.3

6.0

6.0

6.3

6.0

7.7

4.7

5.3
5.7

5.0
5.3

6.3
6.3

7.0
6.0

6.3
7.0

6.7

6.7
6.7

5.7

5.0

6.3

6.3

13
14

MB 45
Passport (PST-2FF)

5.0

6.3

5.0

6.7

15

Prizm

5.3

6.0

5.3

6.0

16
17

Assure
Blackhawk (TMI-EXFLP94)

5.0
4.7

7.0
5.7

5.3
5.0

18

Caddieshack (MED 5071)

5.3
5.7

6.0
7.0

5.3

22

Oct

6.3
6.3

4.7
6.0

SR 4200
Stallion Select

7.0

Sept

5.7

ISI-MHB
Mardigras (ZPS-2NV)

21

7.0
6.7

6.3
6.7
6.7

Calypso II

Elf
J-1706

Aug

7.0

11
12

19

July

6.3
7.0

9
10

20

June

7.0

5.3
6.0

6.3
6.0

6.7

6.0

6.7
6.7

5.7

6.3
6.3

6.3
6.7

5.0
6.0

5.7
6.3

6.3

5.7

5.3

5.0

6.3
6.7
5.7

4.7

6.3

5.0

6.7

5.0
5.0

6.3
6.0

18

6.7
7.3
6.7

6.7
6.7
6.6
6.6
6.6

7.7

7.0
7.7

6.6

6.7

6.7

6.7

6.6

7.0

7.0
7.0

7.0

6.6
6.5
6.5

6.7

7.0
6.7

6.7

6.7

6.0
6.3

7.3
6.7
6.7

6.7
7.7

6.7
7.7

6.5
6.5
6.5

6.7

5.7

7.0

6.3

6.7

6.3

7.0

6.3

7.0
6.7

6.5
6.5

6.0

Species and C ultivar Trials

Cultivar

Gcol

Gm

Leaf

May

June

July

Aug

Sept

Oct

Mean

Wizard (MB 41)

5.7

7.0

5.3

6.3

7.0

6.0

6.3

6.7

6.7

DLP 1305
Excel (MB 1-5)
Express
MB 44
Omega3 (ZPS-2DR-94)

4.0
5.7
4.0
6.0
5.7

6.3
7.0

5.0

6.3

6.7

7.0

6.7
6.3

6.4

6.3
6.3
6.3

7.0
7.0
7.0

6.4

6.7
6.0

6.0
6.0
6.0

7.3
6.7
7.0
7.0

7.3

6.0
5.7
6.0

6.0
6.0
5.3
6.0

5.7
6.0

6.7

5.3
5.0
5.7
5.3

6.0
5.0

6.5
6.4

6.4
6.4

5.3

5.7

5.7

6.0

6.3

5.7

7.3

6.7

6.3

6.4

30

Panther (ZPS-PR1)
Pennant II (MB 42)

6.0

5.3

5.0

5.7

5.3

6.0

6.3

7.7

7.7

6.4

31

R2 (ISI-R2)

4.3

5.7

5.0

5.7

6.0

7.0

6.3

7.3

6.4

32

Sonata (PST-2R3)

5.0

6.0

6.7

7.7

7.3

6.4

SR 4400 (SRX 4400)

5.3
5.7

5.7

33
34

5.3
4.3

6.3
5.7

5.0

5.7

6.0

7.0

6.3

7.0

6.7

6.4

5.0
4.3

5.7
6.0

5.7
5.0

6.3
5.7

6.3
6.7

6.7
6.7

7.0
6.0

6.0
6.7

6.3
6.7

6.4
6.4

5.0

6.0

6.3
5.7

6.3
6.3

6.7
6.7

6.4

6.3

5.7
6.0

6.3

5.3

5.0
5.0

7.3

5.0
4.3

5.0

5.3
5.3

6.3
6.0

6.0

6.7
7.0

6.3

5.3

6.3
6.3

6.3
6.3

7.3
6.7

23
24
25
26
27
28
29

37

Top Hat
WVPB 92-4
WVPB-PR-C-2
Accent

38

APR 106

39
40

Blazer III (Pick 928)
Brightstar

4.7

5.7
5.7

5.3

5.0

5.0

5.3

5.7

6.3

5.7

7.3

41

5.3
5.7

6.3
5.3

5.3
5.0

6.0
6.0

6.0
5.7

6.0

42

CAS-LP23
Legacy II (Lesco-TWF)

43

Night Hawk

5.0

6.0

5.0

6.0

6.0

44

Nobility

45
46
47

Omni
Precision
PS-D-9
Saturn II (ZPS-2ST)
WX3-93
Academy (PC-93-1)
Achiever

4.7
5.0

5.0
5.7

4.3
5.3
5.7

6.0
5.3

5.0
5.3
5.0
5.3
5.0

5.3
5.7
6.3
5.7

6.3
6.0
6.0
6.0

35
36

48
49
50
51
52

6.7

6.3

6.3
6.3
6.3

6.3
6.3
6.7

6.3
6.7

7.0
7.0

6.0
6.0
6.0

5.7
6.0
5.7

6.3
6.0

6.3

5.7

5.3

5.0

5.0
5.3
5.7

5.7

5.3

5.7
6.0

6.7
5.7

5.0
5.3

6.3
6.0

5.0

5.0

5.7

55

Esquire

5.0

5.7

5.0
5.0

56
57

4.7
5.0

6.3
6.7

6.0

59

MVF-4-1
Navajo
Pick LP 102-92
SR 4010 (SRX 4010)

4.7

5.7
5.7

60
61
62

Stallion Supreme (PSI-E-1)
Stardance (PST-2FE)
Top Gun (J-1703)

5.0
5.3

5.7
5.7

5.0

6.0

5.3
5.0
5.0

63
64

Williamsburg
WVPB-93-KFK

4.3
5.0

6.3
6.0

5.3
5.0

58

6.7

5.7

5.3

19

5.7

6.3

5.0

5.7

6.0

7.0

5.7
5.0

5.0

7.0
6.7
6.7

5.0
5.0
5.3

Cutter

6.0
6.7

6.3
6.3
6.3

6.3
5.7
5.3

53
54

5.7
6.0

7.0

6.3

7.0

6.3
5.0
5.3
6.0

Advantage
Catalina (PST-GH-94)

7.0
6.7

6.3
6.7

6.3
7.0
7.0

6.3
6.3
6.3
6.3

6.0

6.3
5.7

7.0
6.7
6.7

6.7

6.3
6.2
6.2

6.0

5.7

6.7

7.0

6.7

6.2

5.3

6.0
6.7

6.3
6.0

7.3
6.3

7.0
7.0

6.2

6.0

6.0

6.0

6.7

6.2

6.0

6.3

5.7
5.3

6.3
5.3
5.7

6.0
6.7

7.0
6.7

6.7
7.0

6.2
6.2

6.7

5.3

5.3

6.7

7.3

6.3

6.3

6.2
6.2

5.7

5.7

5.7

6.0

7.0

6.2

5.0
5.3

5.7
6.0

6.0
6.0

6.0
6.3

7.3
6.7

7.0
7.3
7.0

5.7
6.0

7.0

5.7
5.7

6.3
6.0

6.3
6.3

6.3
6.7

6.2
6.2

6.7

7.0
7.0

6.2

6.2
6.2

Species and Cultivar Trials

Cultivar

Gcol

Gm

Leaf

May

June

July

Aug

Sept

Oct

Mean

65

APR 066

4.7

5.0

5.3

6.3

6.0

6.7

6.1

BARER 5813
Brightstar II (PST-2M3)
Citation III (PST-2DGR)
Edge
Head Start (Pick PR 84-91)

4.7
6.0
5.7
5.0

5.0
5.0
5.7
5.7

5.3
5.0
6.3

5.0
5.3
5.7
6.0

6.0
6.3
6.0
5.3

7.0
7.3
7.0

7.0
7.0

5.0
5.3

5.0
5.7

5.7
6.0

6.0
6.0

5.3
6.0

6.3
7.3
6.3

7.3
6.7

6.1
6.1
6.1
6.1

5.0
4.7

6.0
6.3
4.7
5.3

5.0
5.3
5.3
5.0

5.7
6.7

6.3

66
67
68
69

5.0
5.0
5.3

7.0
6.3

6.1
6.1

70
71

Koos 93-6
Pegasus
Quickstart

4.7

6.0

5.0

5.7

5.7

6.0

6.0

6.7

6.7

6.1

4.7

6.3

5.0

5.3

5.7

6.3

6.7

6.3

6.3

6.1

Vivid

5.0

4.7

5.0

5.3

5.3

6.3

6.0

6.3

7.0

6.1

5.7
5.0

5.0

5.3

5.7

6.7

6.3

PST-2CB
APR 124

5.0

6.7
6.7

6.7
6.7

6.0

5.0

6.0

6.7

5.9

APR 131

5.3
5.7

5.0

79

5.3
4.7
4.7

5.3
6.0

6.1
6.0

77
78

5.3
5.0

6.3
6.0

6.3

5.3
6.7

5.3
5.0

6.0

76

Wind Dancer (MB 46)
Dancer

5.0

5.7

5.3

5.7

6.3

6.3

6.3

5.9

80

Chaparral (PST-2DLM)
Imagine

6.0

5.7

5.0

4.7

5.7

6.0

6.7

5.3

4.7

4.3

6.0

7.0

Koos 93-3
Morning Star

4.7
4.7

5.7
5.7

5.0

4.7

5.7
6.0

6.3
7.0

5.9

5.7

6.0
5.7

5.0

6.0

6.7
6.3

6.3
5.7

6.3
6.0

5.9

Repell III (LRF-94-C7)

6.0

5.3

5.7

5.3
4.7

5.3
6.3

5.7

5.3

6.0

7.0

5.9

4.0

6.3
5.3

5.0
5.3

5.7
4.7

5.3
6.0

5.3

5.7

6.7

5.9

86

Saturn
Figaro

7.0
6.7

5.3

5.7

6.3

6.7

5.8

87
88

Laredo
LRF-94-CB

6.3
6.0

89
90

Prelude III (LRF-94-86)
WX3-91

6.0
6.0
4.7

5.8
5.8
5.8

91
92

Roadrunner (PST-2ET)

72
73
74
75

81
82
83
84
85

93
94
95

4.7
5.7

5.3
6.0

6.3

6.3
5.7

5.3

5.3

4.7

5.3

5.7

6.0
5.7
6.3

5.0
5.3
4.7

5.3
5.0
5.3

6.0
5.7
6.0

5.0
5.3
5.0

5.7
5.7

5.3

6.0

Nine-o-one
DSVNA9401

5.3
4.0

6.0
4.7

5.0
5.7

5.0
4.7

4.7
4.7

5.3
5.3

5.0

5.0

5.0

DSV NA 9402
Pennfine

4.0
4.0

4.7
5.3

5.0
4.7

4.3
4.3
3.0

6.3

6.7

6.3
6.0
6.0

6.3
7.0
6.0

5.7

5.7

6.3
6.0

6.3
6.7

5.5

3.7

5.7

5.3

5.7

5.1

5.7

4.0

5.0

5.3

6.0

5.1

4.3
3.0
2.1

6.3
3.0
1.4

4.3
3.0

4.3
4.0

4.3
4.0

4.7
3.3
0.7

6.0

3.3
3.0
4.3
0.7
2.6
1.1
1.9
1.3
0.9
1.0
LSD(o.os)
Gcolor (Genetic color): 9 = dark green and 1 = light green.
Ltex (Leaf texture): 9 = fine and 1 = coarse.
Gmup (Greenup): 9 = best and 1 = poorest greenup.
Quality based on 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.
96

Linn

20

5.9
5.9

5.6

Species and C u ltivar Trials

Shade Adaptation Study - 1997
N ick E. Christians, Barbara R. Bingaman, and Gary M. Peterson
The first shade adaptation study was established in the fall of 1987 to evaluate the performance of
35 species and cultivars of grasses. The data included below is from the 10th complete season. The
species include chewings fescue (C.F.), creeping red fescue (C.R.F.), hard fescue (H.F.), tall fescue
(T.F.), Kentucky bluegrass (K.B., and rough bluegrass (Poa
).
The area was located under the canopy of a mature stand of Siberian elm trees (
pumila) at the
Iowa State University Horticulture Research Station north of Ames, Iowa. Grasses are mowed at a 2inch height and receive 2 lb N/1000 ft2/year. No weed control has been required on the area, but the
grass was irrigated during extended droughts.
Monthly quality data are collected from May through October (Table 1). Visual quality was based on
a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality. This trial has
been observed through the extremes of the drought year 1988 and the very wet conditions of 1993.
Turf quality among species varied greatly with moisture conditions. In dry weather, the fine fescues,
especially the hard fescues, do well, whereas rough bluegrass quickly deteriorates. In extended wet
periods, rough bluegrass does very well. Some of the tall fescues and chewings fescues also tend to
perform better in wet conditions. The 1997 season began with high rainfall and cool temperatures
and ended cool and dry.
A second shade trial was added adjacent to the original trial in the fall of 1994 to evaluate the
performance of cultivars of chewings fescue (C.F.), creeping red fescue (C.R.F.), hard fescue (H.F.),
tall fescue (T.F.), Kentucky bluegrass (K.B., and rough bluegrass (
trivialis), and Poa supina.
Data are collected in the same way (Table 2). The lower ratings in this trial are due to a greater
shade in the second trial. Overhanging branches were trimmed late in the 1997 season to improve
turf quality.
Table 1. 1997 Visual quality1 data for turfgrass culitvars in the Shade Trial established in 1987.
Cultivar
Sept
May
June
July
Aug
Oct
1. Victor (C.F.)
7.7
6.3
7.0
6.0
7.7
7.7
2. Shadow (C.F.)
7.7
6.0
6.0
6.0
6.3
7.3
3. Atlanta (C.F.)
5.7
7.3
6.3
6.3
7.0
6.7
4. Waldorf (C.F.)
6.0
6.3
6.3
6.7
7.3
7.0
5. Banner (C.F.)
5.7
6.0
6.3
6.0
7.0
6.7
6. Pennlawn (C.R.F.)
5.7
6.0
6.7
6.7
6.3
5.7
7. Mary (C.F.)
6.3
6.0
5.7
6.0
6.7
6.7
8. Jamestown (C.F.)
6.7
6.0
6.7
5.0
5.3
6.7
9. Wintergreen (C.F.)
5.3
6.0
6.0
6.0
6.3
6.0
10. Waldina (H.F.)
4.7
5.0
5.7
7.0
6.3
6.7
11. Bar Fo 81-225 (H.F.)
6.0
5.0
5.7
6.0
6.3
6.7
12. St-2 (SR3000) (H.F.)
4.7
5.7
6.0
6.0
6.3
6.3
13. Agram (C.F.)
5.3
5.7
5.3
5.3
6.0
6.0
14. Koket (C.F.)
4.7
4.7
5.7
5.3
6.3
5.7
15. Biljart (H.F.)
4.0
4.7
5.3
5.3
5.3
5.7
16. Highlight (C.F.)
4.7
4.7
5.0
5.0
5.7
5.7
17. Sabre {P oa trivialis)
4.0
5.7
6.3
5.0
5.3
3.7
18. Reliant (H.F.)
5.0
5.0
4.3
5.0
5.3
5.3
19. Ensylva (C.R.F.)
4.3
4.3
4.7
4.3
6.0
5.7
20. Spartan (H.F.)
3.7
4.0
5.7
5.0
5.0
5.7
21. Scaldis (H.F.)
4.3
5.0
3.7
4.7
4.3
5.3
22. Rebel (T.F.)
3.7
4.7
4.7
4.0
4.7
5.3

21

Mean
7.1
6.6
6.6
6.6
6.3
6.2
6.2
6.1
5.9
5.9
5.9
5.8
5.6
5.4
5.1
5.1
5.0
5.0
4.9
4.8
4.6
4.5

Species and Cultivar Trials

23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
Visual

Cultivar
Estica (C.R.F.)
Falcon (T.F.)
Rebel II (T.F.)
Bonanza (T.F.)
Midnight (K.B.)
Coventry (K.B.)
Apache (T.F.)
Ram I (K.B.)
Arid (T.F.)
Bristol (K.B.)
Glade (K.B.)
Nassau (K.B.)
Chateau (K.B.)

May
June
July
Aug
3.0
4.0
3.7
4.7
3.7
5.7
3.7
3.7
3.3
4.3
4.3
3.7
2.7
4.7
4.0
3.7
2.3
4.3
3.7
4.0
2.7
4.0
3.7
3.3
2.3
3.3
3.0
3.0
2.0
2.7
3.0
2.3
3.0
3.0
3.0
2.7
2.3
3.0
2.7
2.0
2.0
2.7
2.7
2.0
2.0
2.3
2.0
1.7
2.0
2.0
1.7
1.7
1.5
2.1
2.0
2.3
LSDo.os
quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and

Sept
Mean
Oct
5.0
5.3
4.3
4.3
4.3
4.2
5.0
4.1
4.0
5.0
4.1
4.3
4.7
4.3
3.9
3.3
4.0
3.5
4.0
3.7
3.2
2.7
3.7
2.7
2.3
2.0
2.7
2.7
2.0
2.4
2.3
2.3
2.3
2.0
2.0
2.0
2.0
2.0
1.9
2.2
1.8
1.7
1l = worst turf quality.

Table 2. 1997 Visual quality1data for turfgrass culitvars in the Shade Trial established in 1994.
Cultivar
May
June
July
Aug
Sept
Mean
Oct
i. SR 5100 (C.F.)
5.0
5.7
4.7
5.0
5.3
5.3
5.2
2. Bridgeport (C.F.)
5.0
5.0
4.3
4.7
5.7
5.7
5.1
3. Saber (P oa trivialis)
5.7
5.3
5.0
4.7
5.0
4.0
4.9
4. Waldina (H.F.)
4.7
5.3
4.7
4.7
5.0
5.0
4.9
4.7
5. Banner (C.F.)
4.7
4.3
4.7
4.7
5.3
4.7
4.7
6. Molinda (C.F.)
4.3
4.0
4.0
5.0
5.3
4.6
7. Nordic (H.F.)
3.7
4.3
4.0
4.7
4.7
5.3
4.4
4.7
8. Shadow (C.F.)
5.0
4.3
4.0
4.4
4.0
4.7
9. Banner II (C.F.)
4.3
5.0
4.4
4.3
3.7
4.7
4.3
4.7
{Poa trivialis)
4.0
4.7
4.0
4.3
4.0
10. Cypress
4.3
11. Polder {P oa trivialis)
4.7
4.0
4.7
4.0
5.0
3.7
4.3
4.0
12. Silvana (H.F.)
4.3
4.0
4.0
5.0
4.3
4.3
3.7
13. Southport (C.F.)
4.3
4.0
4.7
4.7
4.7
4.3
14. Flyer (C.R.F.)
3.7
4.7
3.7
4.3
4.7
4.3
4.2
4.3
15. Victory (C.F.)
3.7
3.3
3.7
5.0
4.1
4.3
16. Spartan (H.F.)
3.3
4.0
4.0
3.3
4.3
3.9
4.3
17. Bonanza (T.F.)
2.7
4.3
3.7
3.3
4.0
5.0
3.8
2.7
18. Midnight (K.B.)
4.0
3.3
2.3
4.7
5.0
3.7
2.7
19. Ascot (K.B.)
3.7
3.3
3.3
4.7
4.0
3.6
20. Glade (K.B.)
3.0
4.3
3.0
3.0
3.7
4.0
3.5
21. Shenandoah (T.F.)
2.3
4.3
3.0
3.4
3.0
3.7
4.3
22. Bonanza II (T.F.)
2.7
2.7
3.0
3.7
3.3
3.7
3.2
3.3
23. Rebel II (T.F.)
3.3
2.3
2.7
3.0
4.0
3.1
24. Coventry (K.B.)
2.3
3.7
3.0
3.0
3.0
3.0
3.0
25. Arid (T.F.)
3.0
3.3
2.7
2.0
2.7
3.3
2.8
26. Bristol (K.B.)
2.7
2.3
3.0
2.3
2.7
3.3
2.7
27. Adobe (T.F.)
2.3
2.3
2.3
2.3
2.7
2.4
2.3
28. Buckingham (K.B.)
2.0
2.7
2.7
1.7
2.7
2.3
2.3
29. Brigade (H.F.)
2.0
2.3
2.0
2.2
1.7
2.3
2.7
30. Rebel (T.F.)
1.3
3.3
1.7
1.3
2.3
2.7
2.1
2.0
2.7
31. Bonsai (T.F.)
2.0
1.3
2.0
2.1
2.3
32. Falcon II (T.F.)
2.0
2.3
1.7
1.3
2.7
2.1
2.3
33. Aztec (T.F.)
1.7
2.3
1.7
1.7
2.1
3.0
2.3
34. Mirage (T.F.)
1.7
2.3
2.0
1.3
2.3
2.7
2.1
1.7
35. Supranova {P oa supina)
1.3
1.7
1.3
1.7
1.7
1.6
2.4
1.9
1.7
1.9
2.3
2.1
1.8
LSDo.os
Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf quality.

22

Species and C u ltivar Trials

Table 3. The average quality ratings for grasses in the Shade Trial: 1990 - 1997.
1994
Cultivar
1990
1991
1992
1993
1995
1 Victor (C.F.)
2 ST-2 (SR 3000) (H.F.)
3 Waldorf (C.F.)
4 Mary (C.F.)

6.1
7.3
6.2

5 BAR FO 81-225 (H.F.)

1996

1997

Ave.*

6.6

7.1

6.45

5.8
6.6

6.25

4.3
5.1

5.9

7.2

7.1

6.3

5.7

6.1

7.3
6.4

5.9
6.7

6.2
6.6

5.8

6.3

5.5
3.9

5.5
6.1

6.7

6.3

6.2

7.1

4.9

6.5

5.5

6.1

6.5

5.7

5.9

6 Jamestown (C.F.)

6.0

4.2

6.0

6.5

6.2

5.9

6.1

7 Shadow (C.F.)

5.2

4.7

6.0

6.6

6.6
6.6

6.08
6.02

5.9

6.6

5.99

6.6

5.93
5.88

6.6
6.1

6.19
6.16

5.7

4.9

6.1

5.8

5.7

5.5

5.9
6.7

9 Rebel (T.F.)
10 Pennlawn (C.R.F.)

6.6

5.3

6.0

6.9

5.9

5.7

4.6

4.5

5.6

4.7

6.2

6.9
4.1

6.2

5.5
4.8

5.9

5.0

6.3
7.4

5.5

11 Sabre (Poa trivialis)
12 Waldina (H.F.)

6.2
6.4

4.9

5.0

5.84
5.84

5.5

5.5

5.8

5.8

5.9

5.84

5.6
6.9

6.6
6.3

6.1
6.2

5.6
5.2

5.1
4.3
4.2

4.3
4.1

5.83
5.79

5.0
6.0

5.1

5.1
5.3

4.8
6.2

5.1

5.75
5.74

8 Atlanta (C.F.)

13 Estica (C.R.F.)
14 Bonanza (T.F.)
15 Biljart (H.F.)
16 Banner (C.F.)
17 Falcon (T.F.)
18 Rebel II (T.F.)
19 Apache (T.F.)

6.8
7.0
6.4

4.1
6.5
5.1

7.0
6.0

4.5

6.1
5.0

5.6

6.3
4.2
4.1

6.3

5.3

6.0

6.5

6.8
6.8

5.3
6.0

5.6
6.0

6.1
6.3

5.5
5.3

4.6
3.9

5.9
5.9

5.0
5.4

5.0
5.3

5.1

5.5

5.9
5.6

6.3
7.2

6.0
3.5

7.1
4.2

6.7
4.7

4.7
4.9

2.9
5.0

2.7
4.8

5.2

4.0

5.1

5.9

5.6
5.1
5.4

4.4

5.3

4.9

5.39
5.27

4.9

4.2
3.7

5.2
5.2

5.2
4.6

5.7
4.4

4.6
4.8

4.6
4.1

5.4

5.15

5.7
3.5

5.4
4.6

6.0
5.0

3.8
4.7

5.0
5.5

5.9
6.4

3.3
4.4

5.5

5.2

4.6
4.1

3.9
4.9
2.8
4.0

5.5

5.0
5.9
6.2

4.7
4.8
4.3

3.0

32 Reliant (H.F.)

3.9

3.1

3.5

4.2

4.9

33 Glade (K.B.)
34 Bristol (K.B.)
35 Nassau (K.B.)

5.4

5.5

4.8

5.3

4.3

3.9
3.4

3.9

5.0

3.3
4.1

3.8

4.3

3.3

20 Wintergreen (C.F.)
21 Agram (C.F.)
22 Arid (T.F.)
23 Spartan (H.F.)
24 Ensylva (C.R.F.)
25 Koket (C.F.)
26 Scaldis (H.F.)
27 Coventry (K.B.)
28 Highlight (C.F.)
29 RAM I (K.B.)
30 Midnight (K.B.)
31

Chateau (K.B.)

5.8
5.3
4.8
5.2
4.7

3.7

6.3
6.2
5.4

5.2
5.1
5.3
5.0

4.2
4.3
3.7
6.0

5.46
5.43
5.41

4.6

5.02

3.5
5.1
2.7

4.85
4.74

2.2

3.9
1.9

4.56
4.48

4.8

4.9

5.0

4.33

2.8

2.8

2.3

4.26

3.6
2.4

2.8

2.4

2.1

2.0

3.95
3.34

Quality Based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.
*Average includes 1988 and 1989 data (not listed).
Compiled by Gary Peterson, ISU Extension Commercial Horticulture Field Specialist

23

3.2

5.70
5.61
5.60

4.65

Species and C ultivar Trials

Fairway Height Bentgrass Study - Established 1993
Nick E. Christians and James R. Dickson
This is the fourth year of data from the Fairway Height Bentgrass Cultivar trial established in the fall
of 1993. The last season for this trial will be 1998 and it is scheduled for replacement in the fall of
that year. Data collection began after the cultivars were fully established in July, 1994. The area is
maintained at a 0.5-inch mowing height. This is a National Turfgrass Evaluation (NTEP) trial and is
being conducted at several research stations in the U.S. It contains 21 of the newest seeded cultivars
and a number of expérimentais.
The cultivars are maintained with 4 lb. of N/1000 fP/growing season. Fungicides are used as needed
in a preventative program. Herbicides and insecticides are applied as needed.
Table 1 contains monthly visual quality ratings for the 1997 season. Visual quality is based on a 9 to
1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality. Data on genetic
color (Gcolor), leaf texture (Ltex), and greenup (Gmup) ratings are also included.
Southshore was the highest rated cultivar in 1997, followed by Cato and Crenshaw. There are no
statistically significant differences among the first 13 cultivars.
Table 1. The 1997 quality ratings for the fairway height bentgrass study.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21

Cultivar
Southshore
Cato
Crenshaw
Lopez
Bar WS 42102
Penn G-6 (G-6)
Penneagle
Pro/Cup
Trueline
Providenxe
Seaside II (DF-1)
18th Green
Penn G-2 (G-2)
Penncross
Seaside
ISI-AT-90162*
Bar AS 492
Exeter*
Pebble (OM-AT-90163)*
Tendenz*
SR 7100*
LSD(0.05)

Gcolor
6.3
7.7
7.3
7.3
6.7
6.7
6.7
7.3
6.7
7.0
6.3
7.3
6.7
7.0
6.0
5.7
6.7
6.7
6.0
6.3
5.7
1.9

Ltex
7.0
6.7
6.7
6.0
8.0
7.0
7.3
6.3
6.3
6.7
7.3
6.7
6.0
5.7
5.0
6.0
6.3
6.0
6.0
5.3
6.7
1.1

Gmup
7.0
7.0
6.0
6.7
6.3
7.0
6.7
6.7
7.0
7.0
6.3
7.3
6.3
6.7
6.3
7.0
6.0
6.0
6.3
6.7
7.3
1.2

May
6.3
6.3
5.7
6.3
5.3
6.0
6.0
6.3
6.7
6.0
5.3
5.7
5.7
5.7
5.0
4.7
5.3
5.0
5.0
5.0
4.7
1.6

June
7.7
6.3
7.0
7.0
7.0
6.3
6.7
6.7
7.3
6.0
6.3
5.7
6.0
6.3
5.7
5.7
5.3
5.3
5.3
5.0
5.3
1.0

July
6.7
6.3
6.7
6.0
6.3
7.0
6.0
6.0
6.3
6.0
6.0
6.3
6.0
5.7
5.3
5.7
5.0
5.0
5.0
4.7
4.7
1.9

Quality
Aug
7.0
7.0
6.7
7.0
7.0
6.3
7.3
6.3
6.3
6.3
6.7
7.0
6.3
6.0
5.7
5.3
5.7
5.3
5.0
5.7
4.7
1.8

Sept
7.3
7.3
7.7
7.0
6.7
7.0
6.7
7.0
6.7
6.7
6.7
6.7
6.0
6.0
6.3
6.0
5.7
5.7
6.0
5.3
4.7
2.0

* Colonial Bentgrass
Gcolor (Genetic color): 9 = dark green and 1 = light green.
Ltex (Leaf texture): 9 = fine and 1 = coarse.
Gmup (Greenup): 9 = best and 1 = poorest greenup.
Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.
NS = means are not significantly different at the 0.05 level.

24

Oct
7.7
8.0
8.0
7.0
7.0
7.0
7.0
7.0
6.3
7.0
6.7
6.0
7.3
5.7
5.7
5.0
5.0
5.7
5.7
5.7
5.3
1.2

Mean
7.1
6.9
6.9
6.7
6.6
6.6
6.6
6.6
6.6
6.3
6.3
6.2
6.2
5.9
5.6
5.4
5.3
5.3
5.3
5.2
4.9
0.9

Species and C ultivar Trials

Green Height Bentgrass Cultivar Trial (Native Soil) - Established 1993
Nick E. Christians and James R. Dickson
This is the fourth year of data from the Green Height Bentgrass Cultivar trial established in the fall
of 1993. The area was maintained at a 3/16-inch mowing height. This is a National Turfgrass
Evaluation Program (NTEP) trial and is being conducted at several research stations in the U.S. It
contains 28 seeded cultivars including a number of experimentáis. This trial will be replaced with a
new study at the end of the 1998 season.
The cultivars are maintained with a fertilizer program of 1/4 to 1/2 lb. N applied at 14-day intervals
with a total of 3 to 4 lb. N/1000 ft2/growing season. Fungicides are used as needed in a preventive
program. Herbicides and insecticides are applied as needed.
Penn A-4 (A-4) was the highest rated cultivar in 1997 (Table 1). Penncross, which has traditionally
been a good performer at the ISU research area fell to 23rd place this year. The reason for that drop
is unknown. The first 13 cultivars are statistically the same. Data on genetic color (Gcolor), leaf
texture (Ltex), and green up (Gmup), ratings are also included in Table 1. This was the fourth full
year of data.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Cultivar
Penn A-4(A-4)
Century (Syn 92-1)
Penn G-2 (G-2)
Imperial (Syn 92-5)
Penn A-1 (A-l)
Crenshaw
Penn G-6 (G-6)
Backspin (Syn 92-2)
Cato
Lofts L-93(l-93)
SR 1020
Bar WS 42102
Pennlinks
18th Green
Regent
DG-P
Pro/Cup
Providenco
ISI-AP-89150
Lopez
Trueline
Mariner (Syn-1-88)
Penncross
Msueb
Southshore
Bar AS 492
Seaside
Tendenz
LSD(o.os)

Gcolor
7.7
6.3
6.7
7.0
7.3
7.3
7.0
6.7
7.7
7.0
6.3
6.3
6.3
7.3
6.0
6.7
6.7
7.7
6.7
6.0
6.3
6.3
6.0
5.7
6.3
6.0
5.7
5.7
1.3

Ltex
7.7
7.3
7.7
7.0
7.7
7.3
6.7
7.0
7.0
6.7
6.7
7.0
6.0
5.7
6.0
6.3
6.3
6.0
6.0
6.0
6.0
6.0
5.7
6.0
6.7
6.0
5.3
5.7
0.9

Gmup
6.0
6.0
6.7
6.7
6.3
6.7
6.3
5.0
6.0
6.7
6.3
6.0
6.3
6.3
6.3
5.3
6.0
6.3
6.0
5.7
6.3
6.3
6.0
6.0
6.0
6.7
5.7
5.7
2.5

May
5.7
5.7
6.3
6.0
5.7
5.3
6.0
5.3
6.0
5.7
5.7
6.0
6.3
6.0
6.3
5.7
5.3
5.7
6.0
6.0
6.0
5.3
5.7
6.0
5.3
5.3
5.3
4.7
2.0

June
6.7
6.0
6.3
6.0
6.3
6.3
6.3
6.0
6.0
6.3
6.7
6.0
6.0
5.3
6.0
6.0
6.0
5.3
5.7
5.7
5.7
6.0
5.3
4.7
5.0
5.3
5.0
4.0
1.9

July
7.0
7.0
6.7
6.7
7.0
6.0
6.3
6.3
5.7
6.3
6.0
6.0
5.7
6.3
5.7
5.7
6.3
6.0
6.0
5.3
5.3
5.3
5.0
5.0
5.3
5.0
4.7
4.0
1.2

l it

Table 1. The 1997 ratings for the green height bentgrass trial.

8.0
7.7
6.7
7.0
7.3
7.0
6.7
6.3
6.7
6.7
6.7
6.7
6.3
6.3
6.0
6.7
6.0
6.7
5.7
6.3
6.3
5.7
5.7
5.3
5.3
5.3
4.7
4.7
1.3

Sept
7.7
8.0
8.0
7.3
6.7
7.7
7.0
7.3
7.0
6.7
6.0
6.3
6.0
6.3
6.0
6.0
6.3
6.3
5.7
6.7
6.0
6.0
6.0
6.0
6.0
4.7
5.0
4.7
1.0

Gcolor (Genetic color): 9 = dark green and 1 = light green.
Ltex (Leaf texture): 9 = fine and 1 = coarse.
Gmup(Greenup): 9 = best and 1 = poorest greenup.
Quality based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.

25

Oct
6.7
6.3
6.7
7.3
7.0
7.0
6.3
6.7
6.3
6.0
7.0
6.0
6.0
5.7
6.0
5.3
5.7
5.7
5.7
5.0
5.3
6.0
6.0
5.3
5.7
4.7
5.3
5.0
1.4

Mean
6.9
6.8
6.8
6.7
6.7
6.6
6.4
6.3
6.3
6.3
6.3
6.2
6.1
6.0
6.0
5.9
5.9
5.9
5.8
5.8
5.8
5.7
5.6
5.4
5.4
5.1
5.0
4.5
0.8

Herbicide and G row th Regulator Studies

1997 Preemergence Annual Weed Control Study
Barbara R. Bingaman, Nick E. Christians, and Michael B. Faust
The objective of this study was to screen various preemergent (PRE) and postemergent (POST)
herbicides for their efficacy in controlling annual weeds in turfgrass. The study was conducted at the
Iowa State University Horticulture Research Station north of Ames, IA. The experimental plot was
in ‘common’ Kentucky bluegrass. The soil in this area was a Nicollet (fine-loamy, mixed, mesic
Aquic Hapludoll) with 2.4% organic matter, a pH of 6.5, 7 ppm P, and 97 ppm K.
The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft
with three replications. There were 38 treatments including an untreated control (Table 1). Eleven
of the treatments were screened in combination with methylene urea (39-0-0). Barricade 65WG,
Pendimethalin 60WDG, and Dimension 1EC were screened at various rates in single preemergent
(PRE) and split PRE and postemergent (POST) applications in combination with fertilizer. Three
granular Dimension plus fertilizer formulations (AND444, AND445, and AND442) and a fertilized
control also were included. Turf that received treatments two through twelve was given an equivalent
amount of nitrogen at the time of both PRE and POST applications.
Three granular herbicides from The Scotts Company (S-7135, S-6619, and S-2452) were included.
These materials were applied in single PRE and split PRE plus POST treatments. Preclaim 3.09EC
was screened as an early-post and mid-postemergence material at two different rates for AgrEvo.
Acclaim Extra 0.57EW also was included as an early-postemergence treatment and Pendimethalin
60WDG was applied as a PRE material. An experimental formulation from Rhone-Poulenc, MY100, was applied as a PRE treatment at three different rates. Barricade 65WG was screened at
various rates in single PRE and in split PRE and POST applications for Novartis. In addition,
Pendimethalin and Dimension 1EC were applied in single PRE and split PRE and POST treatments.
Ronstar 2G was screened as a PRE material.
Granular formulations were applied using ‘shaker dispensers’. Liquids were applied at 30 psi using a
C 0 2backpack sprayer equipped with TeeJet™ #8006 flat fan nozzles. Preemergent (PRE)
treatments were made on May 1. Crabgrass germination was noted on June 7. This was considerably
later than usual for this location. Sequential applications of treatments 2 - 1 2 were made on July 3,
60 days after the initial application (Table 1). Postemergent applications of treatments 14, 16, and
18 were made on June 18, six to eight weeks after the initials. Early-postemergence applications of
treatments 19, 20, and 23 were made on June 11 when the crabgrass was in the 1- to 4-leaf stage.
Mid-postemergence applications of treatments 21 and 22 were made on July 10 when the crabgrass
had one to three tillers. Postemergent applications of treatments 35 - 38 were made on July 3, 60
days after the initial application.
Visual turf quality data were taken May 12 through August 20 (Tables 2 and 3). Visual quality was
assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf quality. Crabgrass
control was reported as the percentage of area per plot covered by crabgrass. Crabgrass data were
taken on July 2, July 10, July 15, July 30, and August 20 (Table 4). In addition, these data were
converted to express percentage reduction in crabgrass cover as compared with the untreated control
(Table 5).
All data were analyzed with the Statistical Analysis System (SAS, Version 6.10) and the Analysis of
Variance (ANOVA) procedure. Fisher’s Least Significant Difference (LSD) test was used to compare
visual quality and crabgrass control means.
Turf that received the herbicide plus methylene urea treatments (Barricade 65WG, Pendimethalin
60WDG, and Dimension 1EC), the ‘AND’ Dimension plus fertilizer formulations (AND444,

26

H erbicide and G row th Regulator Studies

AND445, and AND442), and the fertilized control had significantly better quality than the untreated
control and turf treated with the other herbicides for the entire season (Tables 2 and 3). Bluegrass
treated with the other materials exhibited quality similar to the untreated control.
Throughout the season on each data collection date, at least 36 of the herbicides significantly reduced
crabgrass cover when compared with the untreated control (Table 4). Crabgrass cover reductions >
90% (when compared with the untreated control) were reported in turf treated with 20 herbicides on
July 2, 23 on July 10, and 15 on July 15 (Table 5). By August 20, only 11 materials produced
crabgrass reductions at this same level. Seven treatments produced reductions > 90% for the entire
season.

Table 1. Materials, rates, and application dates for herbicides and fertilizers used in the 1997 Pre- & Postemergence

Initial Application
(PRE)2

1
2
3
4
5
6
7
8
9
10
11
12

13
14
15
16
17
18

Materials

Rate
lb a.i./A.

Untreated control
Barricade 65WG1
Pendimethalin 60WDG1
Dimension 1EC1
Dimension 1EC1
Dimension 1EC1
Dimension 1EC1
AND444 Dimension FG 0.072 + fertilizer1
AND445 Dimension FG 0.164 + fertilizer1
AND442 Dimension FG 0.035 + fertilizer1
AND444 Dimension FG 0.072 + fertilizer1
Fertilized control1

NA
0.650
1.500
0.250
0.380
0.125
0.250
0.125
0.250
0.060
0.125
NA

S-71353
S-71353
S-66193
S-66193
S-24523
S-24523

Fertilizer
blank/plot
(39-0-0)
NA
45.20 g
45.20 g
45.20 g
45.20 g
45.20 g
45.20 g
none
5.52 g
0.57 g
none
45.20 g

Sequential Application
45-60 DAT (POST)2
Rate
lb a.i./A.

NA
none
none
none
none
0.125
0.125
none
none
0.060
0.125
NA

Fertilizer
blank/plot
(39-0-0)
NA
45.20
45.20
45.20
45.20
45.20
45.20
45.20
45.20
0.57
none
45.20

g
g
g
g
g
g
g
g
g
g

Initial Application
(PRET

Sequential Application
(POST)4

Rate
grams product /ft

Rate
grams product /ft2

1.19
1.19
1.14
1.14
0.92
0.92

none
1.19
none
1.14
none
0.92

(Table 1 continued on next page)

27

Herbicide and G row th Regulator Studies

Table 1. (continued)
Materials

Rate
lb a.i./A

Timing of
application6

19
20
21
22
23

Preclaim 3.09 EC5
Preclaim 3.09 EC5
Preclaim 3.09 EC5
Preclaim 3.09 EC5
Acclaim Extra 0.57 EW5

1.54
2.06
2.06
3.09
0.06

EARLY POST
EARLY POST
MID POST
MID POST
EARLY POST

24

Pendimethalin 60WDG5&7

1.50

PRE

product/
1000 ft2 (ml)

Timing of
application8

3.00
4.50
6.00

PRE
PRE
PRE

Initial Application
(PRE)9

Sequential Application
60 DAT (POST)9

Rate
lb a.i./A.

Rate
Ib a.i./A.

25
26
27

MY - 100 (30% SC)7
MY - 100 (30% SC)7
MY - 100 (30% SC)7

0.32
0.38
0.48
0.65
1.50
2.00
0.25
0.25
0.33
0.75
0.125

28 Barricade 65WG10
29 Barricade 65WG10
30 Barricade 65WG10
31 Barricade 65WG10
32 Pendimethalin 60WDG10&"
33 Ronstar 2G10
34 Dimension 1EC10
35 Barricade 65WG10
36 Barricade 65WG10
37 Pendimethalin 60WDG,o&"
38 Dimension 1EC10

none
none
none
none
none
none
none
0.25
0.17
0.75
0.125

materials and was used as the fertilizer blank. Fertilizers were applied at 4 lb product/1000 ft for each of 2
applications.
initial applications (PRE) were made on May 1 before crabgrass germination and POST applications were applied
45 to 60 days later on June 30.
3These products were screened for The Scotts Company.
4PRE applications were made on May 1 before crabgrass emergence and POST applications were made 6 - 8 weeks
later on June 18.
5These materials were screened for AgrEvo.
6PRE applications were made on May 1 before crabgrass germination, EARLY POST on June 11 when the
crabgrass was in the 1- to 4-leaf stage, and MID POST on July 10 when the crabgrass had 1 to 3 tillers.
7These materials were screened for Rhone-Poulenc Ag Company.
8PRE applications were made on May 1 before crabgrass germination.
9PRE applications were made on May 1 before crabgrass germination and Post were made 60 days later on July 3.
10These materials were screened for Novartis.
1Pendimethalin 60WDG was substituted for Pendulum 60DG.
PRE applications were made on May 1 (treatments 1-18, 24-27, and 28-38). Crabgrass germination was on June 7.

28

H erbicide and G row th Regulator Studies

Table 2. Visual turf quality1of Kentucky bluegrass treated with herbicide materials in the 1997 Pre- &
Postemergence Annual Grass Control Study (May 12 through July 2).

1
2
3
4
5

Material

Rate
lb a.i./A
(unless noted)

May
12

May
21

June
5

June
18

June
25

July
2

Untreated control
Barricade 65WG + fertilizer
Pendimethalin 60WDG + fertilizer
Dimension 1EC + fertilizer
Dimension 1EC + fertilizer

NA
0.650
1.500
0.250
0.380
0.125 fb
0.125
0.250 fb
0.125
0.125
0.250
0.060 fb
0.060
0.125 fb
0.125
NA
1.192
1.192
1.142
1.142
0.922
0.922
1.54
2.06
2.06
3.09
0.06
1.50
3.003
4.503
6.003
0.32
0.38
0.48
0.65
1.50
2.00
0.25
0.25 fb 0.25
0.33 fb 0.17
0.75 fb 0.75
0.125 fb
0.125

7
9
8
8
9

6
8
8
9
7

5
7
7
7
7

5
8
8
9
9

7
9
8
9
9

5
9
9
9
9

9

8

7

9

9

9

8
8
9

8
8
8

7
7
7

9
9
9

9
9
9

9
9
9

8

8

7

9

8

9

8
8
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7

9
8
6
6
6
6
7
6
6
7
6
6
6
6
6
6
6
6
6
6
6
6
6
7
6
6
6

7
7
5
5
5
5
5
5
5
5
5
5
5
5
5
5
6
5
5
5
5
6
5
5
5
5
5

9
9
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5

9
9
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7

9
8
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5
5

7

6

5

5

7

5

6 Dimension 1EC + fertilizer
7 Dimension 1EC + fertilizer
8 AND444 Dimension FG 0.072
9 AND445 Dimension FG 0.164
10 AND442 Dimension FG 0.035
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

AND444 Dimension FG 0.072
Fertilized control
S-7135
S-7135
S-6619
S-6619
S-2452 Pendimethalin 1.71% GR
S-2452 Pendimethalin 1.71% GR
Preclaim 3.09EC (early post)
Preclaim 3.09EC (early post)
Preclaim 3.09EC (mid post)
Preclaim 3.09EC (mid post)
Acclaim Extra 0.57EW
Pendimethalin 60WDG
MY - 100 (30% SC)
MY - 100 (30% SC)
MY - 100 (30% SC)
Barricade 65WG
Barricade 65WG
Barricade 65WG
Barricade 65 WG
Pendimethalin 60WDG
Ronstar 2G
Dimension 1EC
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG

38 Dimension 1EC

1
1
1
1
1
L SD 0 .05
‘Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, & 1 = worst quality.
2The rate for these products is in grams product/fit2.
3The rate for these products is in ml product/1000 ft2.

29

1

Herbicide and Grow th Regulator Studies

Table 3. Visual turf quality1of Kentucky bluegrass treated with herbicide materials in the 1997 Pre- &
________ Postemergence Annual Grass Control Study (July 10 through August 20)._______________
Material

1
2
3
4
5

Untreated control
Barricade 65WG + fertilizer
Pendimethalin 60WDG + fertilizer
Dimension 1EC + fertilizer
Dimension 1EC + fertilizer

6 Dimension 1EC + fertilizer
7 Dimension 1EC + fertilizer
8 AND444 Dimension FG 0.072
9 AND445 Dimension FG 0.164
10 AND442 Dimension FG 0.035
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

AND444 Dimension FG 0.072
Fertilized control
S-7135
S-7135
S-6619
S-6619
S-2452 Pendimethalin 1.71% GR
S-2452 Pendimethalin 1.71% GR
Preclaim 3.09EC (early post)
Preclaim 3.09EC (early post)
Preclaim 3.09EC (mid post)
Preclaim 3.09EC (mid post)
Acclaim Extra 0.57EW
Pendimethalin 60WDG
MY - 100 (30% SC)
M Y- 100 (30% SC)
MY - 100 (30% SC)
Barricade 65WG
Barricade 65WG
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG
Ronstar 2G
Dimension 1EC
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG

38 Dimension 1EC

Rate
lb a.i./A
(unless noted)
NA
0.650
1.500
0.250
0.380
0.125 fb
0.125
0.250 fb
0.125
0.125
0.250
0.060 fb
0.060
0.125 fb
0.125
NA
1.192

1.192
1.14*
1.14*
0.922
0.922
1.54
2.06
2.06
3.09
0.06
1.50
3.003
4.503
6.003
0.32
0.38
0.48
0.65
1.50
2.00
0.25
0.25 fb 0.25
0.33 fb 0.17
0.75 fb 0.75
0.125 fb
0.125

July
10

July
15

July
30

August
20

Mean

7
9
9
9
9

7
9
9
9
9

6
8
8
8
8

6
8
8
8
8

6
8
8
9
8

9

9

8

8

8

9
9
9

9
9
9

8
8
8

8
8
8

8
8
8

9

9

8

8

8

9
9
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
8
7

9
9
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
7
8
7

8
8
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
6

8
8
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
7
6

8
8
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6
6

7

7

6

6

6

1
1
1
1
LSDo.05
‘Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, & 1 = worst quality.
2The rate for these products is in grams product/ft2.
3The rate for these products is in ml product/1000 ft2.

30

1

Herbicide and G row th Regulator Studies

Table 4. Percentage crabgrass cover1in Kentucky bluegrass treated with herbicide materials in the 1997 Pre- &
Postemergence Annual Grass Control Study.
Material

Rate
lb a.i./A
(unless noted)

July
2

July
10

July
15

July
30

August
20

Mean
cover

°/n
NA
0.650
1.500
0.250
0.380
0.125 fb
0.125
0.250 fb
0.125
0.125
0.250
0.060 fb
0.060
0.125 fb
0.125
NA
1.192
1.192
1.142
1.142
0.922
0.922
1.54
2.06
2.06
3.09
0.06
1.50
3.003
4.503
6.003
0.32
0.38
0.48
0.65
1.50
2.00
0.25
0.25 fb 0.25
0.33 fb 0.17
0.75 fb 0.75
0.125 fb
0.125

33
1
1
4
1

62
4
5
10
5

55
2
5
5
8

87
5
18
20
15

92
9
13
25
15

66
4
8
13
9

2

10

5

25

35

15

1
1
1

1
7
2

1
2
1

3
12
4

3
12
7

2
7
3

4

6

3

12

15

8

1
15
1
3
4
1
2
4
0
0
22
27
22
2
13
13
7
2
2
2
3
2
5
4
15
2
13

2
30
9
7
9
1
10
7
2
2
42
50
40
4
30
23
15
12
1
8
7
6
17
8
22
10
22

1
30
2
3
7
0
5
1
2
1
35
22
45
5
37
25
10
5
0
4
2
3
15
2
15
7
17

1
60
8
2
10
1
17
4
7
2
1
0
72
13
60
42
27
18
7
12
7
35
20
25
13
33

2
68
12
5
14
3
18
4
17
5
1
1
83
25
78
60
33
22
5
17
13
20
60
27
47
15
53

1
41
6
4
9
1
10
4
5
2
20
20
52
10
44
33
18
12
3
9
7
8
26
12
25
9
28

8

15

12

30

27

18

8
L S D o os
15
19
1Percent crabgrass cover was estimated as the area per plot occupied by crabgrass.
2The rate for these products is in grams product/fit2.
3The rate for these products is in ml product/1000 ft2.

20

23

14

1
2
3
4
5

Untreated control
Barricade 65WG + fertilizer
Pendimethalin 60WDG + fertilizer
Dimension 1EC + fertilizer
Dimension 1EC + fertilizer

6 Dimension 1EC + fertilizer
7 Dimension 1EC + fertilizer
8 AND444 Dimension FG 0.072
9 AND445 Dimension FG 0.164
10 AND442 Dimension FG 0.035
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

AND444 Dimension FG 0.072
Fertilized control
S-7135
S-7135
S-6619
S-6619
S-2452 Pendimethalin 1.71% GR
S-2452 Pendimethalin 1.71% GR
Preclaim 3.09 EC (early-post)
Preclaim 3.09 EC (early-post)
Preclaim 3.09 EC (mid-post)
Preclaim 3.09 EC (mid-post)
Acclaim Extra 0.57 EW
Pendimethalin 60WDG
MY - 100 (30% SC)
MY - 100 (30% SC)
MY - 100 (30% SC)
Barricade 65WG
Barricade 65WG
Barricade 65 WG
Barricade 65WG
Pendimethalin 60WDG
Ronstar 2G
Dimension 1EC
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG

38 Dimension 1EC
t t :—

31

>

8

Herbicide and Growth Regulator Studies

Table 5. Percentage reductions in crabgrass cover1in Kentucky bluegrass treated with herbicide materials in the
1997 Pre- & Postemergence Annual Grass Control Study.
Material

Rate
lb a.i./A
(unless noted)

July
2

July
10

July
15

Untreated control
Barricade 65WG + fertilizer
Pendimethalin 60WDG + fertilizer
Dimension 1EC + fertilizer
Dimension 1EC + fertilizer

NA
0.650
1.500
0.250
0.380
0.125 fb
0.125
0.250 fb
0.125
0.125
0.250
0.060 fb
0.060
0.125 fb
0.125
NA
1.192
1.19*
1.142
1.142
0.922
0.922
1.54
2.06
2.06
3.09
0.06
1.50
3.003
4.503
6.003
0.32
0.38
0.48
0.65
1.50
2.00
0.25
0.25 fb 0.25
0.33 fb 0.17
0.75 fb 0.75
0.125 fb
0.125

0
99
99
89
97

0
94
91
83
91

0
97
91
91
85

94

84

99
97
98

July
30

August
20

Mean
reduction

0
94
79
77
83

0
91
86
72
83

0
94
87
81
86

90

71

62

77

99
89
96

99
96
99

96
87
96

96
87
93

98
90
96

88

91

94

87

84

88

98
55
97
90
89
98
93
89
100
100
34
19
34
94
60
60
80
94
93
93
90
94
84
88
55
93
60

97
52
86
89
86
99
84
89
97
97
33
19
35
94
52
62
76
81
98
87
89
91
73
87
65
84
65

99
45
96
94
88
100
91
99
97
99
36
61
18
90
33
55
81
91
100
93
97
94
73
96
73
88
70

99
31
90
97
88
99
81
96
92
97
99
100
18
85
31
52
69
79
92
87
90
92
60
77
71
85
62

98
26
87
94
85
96
80
96
82
95
99
99
9
73
15
35
64
76
94
82
86
78
35
71
49
84
42

98
38
90
94
87
98
84
94
92
97
70
70
21
85
34
51
72
82
95
87
90
88
60
81
63
86
58

75

76

79

66

71

72

24
34
23
23
25
LSDo.oi
Reductions in percent crabgrass cover was estimated as the area per plot occupied by crabgrass.
2The rate for these products is in grams product/ft2.
3The rate for these products is in ml product/1000 ft2.

21

%
1
2
3
4
5

6 Dimension 1EC + fertilizer
7 Dimension 1EC + fertilizer
8 AND444 Dimension FG 0.072
9 AND445 Dimension FG 0.164
10 AND442 Dimension FG 0.035
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37

AND444 Dimension FG 0.072
Fertilized control
S-7135
S-7135
S-6619
S-6619
S-2452 Pendimethalin 1.71% GR
S-2452 Pendimethalin 1.71 % GR
Preclaim 3.09 EC (early post)
Preclaim 3.09 EC (early post)
Preclaim 3.09 EC (mid post)
Preclaim 3.09 EC (mid post)
Acclaim Extra 0.57 EW
Pendimethalin 60WDG
MY - 100 (30% SC)
M Y- 100 (30% SC)
MY - 100 (30% SC)
Barricade 65WG
Barricade 65WG
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG
Ronstar 2G
Dimension 1EC
Barricade 65WG
Barricade 65WG
Pendimethalin 60WDG

38 Dimension 1EC

32

Herbicide and Growth Regulator Studies

1997 Preemergence Annual Grass Control Study
Barbara R. Bingaman, Nick E. Christians, and Michael B. Faust
The objective of this study was to evaluate the efficacy of Team Pro as a preemergent annual weed
herbicide in turfgrass. This study was conducted at the Iowa State University Horticulture Research
Station north of Ames, IA. The experimental plot was in ‘Nassau’ Kentucky bluegrass. The soil in
this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 2.2% organic matter, a pH
of 6.7, 3 ppm P, and 54 ppm K. Irrigation was used to supplement rainfall and maintain the turf in
good growing condition.
The study design was a randomized complete block. Individual plot size was 5 x 5 ft with three
replications and one row per replication. DowElanco furnished five herbicide + fertilizer granular
formulations for this study. Team Pro 0.86GR (0.43% benefin and 0.43% trifluralin) + fertilizer
(NAF-324), Team 0.87GR (0.58% benefin and 0.29% trifluralin) + fertilizer (NAF-323), and
Pendimethalin 0.86GR + fertilizer were applied in single preemergence (PRE) applications at 2.0 lb
a.i./A and in split PRE and postemergence (POST) applications at 1.5 lb a.i./A. Dimension 0.09GR +
fertilizer was applied in a single PRE application at 0.38 lb a.i./A and Barricade 0.22GR + fertilizer
was applied in a single PRE application at 0.50 lb a.i./A. There were a total of nine treatments
including an untreated control (Table 1).
The herbicides were applied with ‘shaker dispensers’ to ensure uniform distribution. Following the
PRE applications, the materials were ‘watered in’ with the irrigation system. The plot was mowed
regularly at 2 inches.
Initial applications were made preemergently on May 7 before crabgrass germination. Crabgrass
germination was detected in the untreated control plots on June 18. Sequential (postemergent)
applications were made on June 2, eight weeks after the initial applications.
Phytotoxicity data were taken on May 12 and May 15. Phytotoxicity was assessed using a 9 to 1
scale: 9 = no damage and 1 = dead grass (Table 1). Visual quality data were taken on May 21, June 5,
June 10, June 18, and June 25 (Table 2). Visual turf quality was evaluated with a 9 to 1 scale: 9 =
best, 6 = lowest acceptable, and 1 = worst turf quality. Crabgrass control was determined by
estimating percentage crabgrass cover per plot and subsequently calculating percent reduction as
compared with the untreated controls. Percentage cover data were taken on July 2, July 10, July 15,
July 30, and August 20 (Table 3). Percentage crabgrass reduction data were calculated for each of
these collection dates (Table 4)
Data were analyzed with the Statistical Analysis System (SAS, version 6.10) using the Analysis of
Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference
(LSD) test.
There were no phytotoxicity symptoms on treated bluegrass (Table 1). The visual quality of all
treated bluegrass was significantly better from May 21 through August 20. The quality of treated
bluegrass was the same from June 10 through July 2. After the sequential applications, significant
quality differences were evident among the treatments for July 10 and July 15 (Table 2).
The mean quality of all treated bluegrass was significantly better than the untreated control. The
best mean quality was for bluegrass treated with Team Pro (NAF-324) at 1.50 lb a.i./A followed by
1.50 lb a.i./A, Team Pro (NAF-324) at 2.00 lb a.i./A, Team (NAF-323) at 1.50 lb a.i./A followed by
1.50 lb a.i./A, and Pendimethalin 0.86GR at 1.50 lb a.i./A followed by 1.50 lb a.i./A (Table 2).

33

Herbicide and G row th Regulator Studies

All herbicides significantly reduced percentage crabgrass cover from July 2 through August 20 when
compared with the untreated control (Table 3). The mean percentage cover of all treated bluegrass
was significantly lower than the untreated control. All products except Pendimethalin 0.86GR at
2.00 lb a.i./A maintained crabgrass cover below 20% through August 20. Bluegrass treated with Team
Pro (NAF-324) at 2.00 lb a.i./A, Team (NAF-323) at 2.00 lb a.i./A, Dimension 0.09GR at 0.38 lb
a.i./, and Barricade 0.22 GR at 0.50 lb a.i./A had the least percentage crabgrass cover as compared to
other treated and untreated turf.
There were significant reductions in crabgrass cover from July 2 through August 20 in all treated
bluegrass when compared with the untreated control (Table 4). Bluegrass treated with Dimension
0.09GR at 0.38 lb a.i./A, Team Pro (NAF-324) at 2.00 lb a.i./A, Team (NAF-323) at 2.00 lb a.i./A,
and Barricade 0.22GR at 0.50 lb a.i./A maintained at least 85% reduction in crabgrass cover
throughout the duration of the study.
Table 1. Kentucky bluegrass phytotoxicity1 for the 1997 Preemergence Annual Grass Control Study.
Initial
Sequential
application
application
Phytotxicity1
[preemergentl
Materials
1
2
3
4
5
6
7
8
9

Untreated control
Team Pro 0.86GR + fertilizer NAF-324
Team Pro 0.86GR + fertilizer NAF-324
Team 0.87GR + fertilizer NAF-323
Team 0.87GR + fertilizer NAF-323
Pendimethalin 0.86GR + fertilizer
Pendimethalin 0.86GR + fertilizer
Dimension 0.09GR + fertilizer
Barricade 0.22GR + fertilizer

Rate
(lb a.i./A)

Rate
(lb a.i./A)

May 12

May 15

NA
1.5
2.0
1.5
2.0
1.5
2.0
0.38
0.50

NA
1.5
none
1.5
none
1.5
none
none
none

9
9
9
9
9
9
9
9
9

9
9
9
9
9
9
9
9
9

NS
NS
LSD 0.05
‘Phytotoxicity was assessed using a 9 to 1 scale: 9 = no damage and 1 = dead turf.
Initial (preemergent) applications were made on May 7 and sequentials (postemergent) on July 2, 1997 (8 WAT).
NS = means are not significantly different at the 0.05 level.

34

H erbicide and G row th Regulator Studies

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Aug
20

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21
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Materials

Table 2. Visual quality1of Kentucky bluegrass treated with herbicide + fertilizer formulations for the 1997 Preemergence Annual Weed Control Study.

T3

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Herbicide and Growth Regulator Studies

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36

Herbicide and G row th Regulator Studies

1997 Postemergence Broadleaf Weed Control Study

NickE. Christians, and M icha

Barbara R. Bingaman,

The objective of this study was to evaluate the efficacy of various postemergence broadleaf
herbicides in turfgrass. This study was conducted at the Iowa State University Horticulture Research
Station north of Ames, IA. The plot was located in ‘common’ Kentucky bluegrass. The soil was a
Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.2% organic matter, a pH of 7.9, 17 ppm
P, and 109 ppm K. Rainfall was sporadic throughout the test so irrigation was used to maintain the
bluegrass in good growing condition.
The study was designed as a randomized complete block. Individual plot size was 5 x 10 ft with three
replications.
Four granular weed and feed products were included: DCDA20, DTDA20, MCDA20 and Turf Builder
+ 2 (Table 1). For these products the 5 x 10 ft plots were split into two-2.5 x 10 ft subplots and the
north subplot was moistened with water prior to treatment and the south subplot was kept dry. One
half of the material allotted for the whole plot was applied to each of the two subplots.
The balance of the herbicides were applied as liquids (Table 1). Tri-Power and Triplet were applied at
1.19, Horsepower at 0.98, Millennium at 1.10, DCDA at 0.98, DTDA at 0.98, and MCDA at 0.98 oz
product/1000 ft2. Gallery 75WG was applied at 0.75 lb a.i./A as an early spring material followed by
a postemergent application of either Confront 3SL at 0.75 lb a.i./A or Trimec Classic 3.4SL at 1.66
lb a.i./A. Trimec Classic 3.4SL and Confront 3SL also were applied alone postemergently at these
same rates. CGA #136872 (Beacon) was applied at 20.0 g product/A and at 10.0 g product/A in split
applications. SCOIL MSO, a methylated seed oil spreader, was added to the tank mix of CGA
#136872 (Beacon) at 0.25% V/V. Two experimental products, EH1312 and EH1342 were applied at
two different rates: EH1312 at 1.0 and 1.2 and EH1342 at 0.8 and 1.0 fl oz product/1000 fir. Super
Trimec was included at 1.1 fl oz product/1000 ft2 for comparisons. An untreated control also was
included.
Liquid materials were applied at 30 psi using a C 02 backpack sprayer equipped with TeeJet™ #8006
flat fan nozzles. The materials were applied in 380 ml of water. This translates to a rate of 2
gallon/1000 ft2. Granular materials were applied with a cardboard container used as a ‘shaker
dispenser’.
Early spring applications (treatments 13 and 14) were made on May 15. Spring postemergent
applications were made on May 22, after broadleaf weed species were established. Sequential
applications (treatments 17 and 18) were made on June 19, three weeks after the initial applications.
Throughout the study, the turf was examined for phytotoxic symptoms. Phytotoxicity data were
taken on July 7 and July 15 (Table 2).
Weed damage was characterized on May 30 (8 DAT) as to the type and severity of phytotoxic
symptoms (Table 3). Data were taken for dandelion and clover, the two predominate broadleaf
species. Damage was estimated by using a 4 to 1 scale: 4 = no damage, 3 = slight leaf curling and
discoloration, 2 = moderate leaf curling and sporadic discoloration, and 1 = severe leaf curling and
uniform discoloration. Additional weed damage data were taken on June 10 (19 DAT), June 19 (28
DAT), and June 26 (35 DAT). These data were assessed using a 9 to 1 scale: 9 = no damage, 8 =
slight damage & no mortality, 7 = some damage & no mortality, 6 = moderate damage & 10%
mortality, 5 = uniform moderate damage & 25% mortality, 4 = severe damage & 50% mortality, 3 =
uniform severe damage & 75% mortality, 2 = severe damage & 90% mortality and 1 = 100%
mortality (Table 4). The mortality estimations represent the reduction in all broadleaf species in

37

H erbicide and G row th Regulator Studies

each plot as compared to the untreated control plots (Table 5). Counts of the surviving weeds in
each plot were taken on July 3, 1997. The number of dandelion and oxalis plants per plot were
counted and the percentage of area per plot covered by clover and black medic was estimated (Table
6). These counts were converted to express percent reductions in number of plants per plot when
compared with the untreated controls (Table 7).
Data were analyzed with the Statistical Analysis System (SAS, version 6.10) and the Analysis of
Variance (ANOVA) procedure. Means comparisons were made using Fisher’s Least Significant
Difference (LSD) tests.
On July 7, phytotoxicity was noted on turf treated with CGA #136872 Beacon + SCOIL MSO (Table
2). These symptoms were still present on July 15 but were gone by July 22.
By May 30, all treated dandelion and clover plants were beginning to exhibit damage (Table 3). The
observed symptoms ranged from slight leaf curling and slight discoloration to severe leaf curling and a
uniform discoloration. For most herbicides, the treated dandelions had more severe damage than the
clover.
All treated broadleaves were exhibiting significant levels of damage by June 19 when compared with
the untreated control (Table 4). There also was some level of weed mortality in all treated plots.
There was severe mortality among the broadleaves treated with Triplet, Millenium, Trimec Classic
3.4SL, and Super Trimec by June 26 (Table 5). On this date, 25 herbicides produced significant
reductions in broadleaf cover when compared with the untreated control (Table 5). Reductions were
> 70% for seven herbicides and there was a 90% broadleaf reduction in turf treated with Super
Trimec.
Treatment with 21 of the herbicides resulted in dandelion numbers that were significantly less than
the untreated control (Table 6). Percentage reductions in dandelions were > 80% in turf treated with
either Triplet, MCDA, Gallery 75WG + Confront 3SL, Confront 3SL, Super Trimec, and MCDA20
(on wet foliage) (Table 7). Control of dandelions was better for DCDA20, DTDA20, MCDA20, and
Turf Builder + 2 applied to wet foliage than applied to dry foliage.
Populations of the annual broadleaf, oxalis, were quite high this year. Oxalis numbers were higher in
some of the treated plots than in the untreated control (Table 6). When compared to the untreated
control, Super Trimec produced an 80% numerical reduction in the oxalis population, although
statistically this reduction was not significant (Table 7).
Some of the treated turf had a higher percentage clover cover than the untreated control (Table 6).
Millenium, Gallery 75WG + Confront 3SL, Confront 3SL, and Super Trimec treated turf contained
no clover. Turf treated with either Tri-Power, Triplet, Horsepower, CGA #13872 (Beacon) at 10 g
product/A in split applications, DCDA20 (on wet foliage), or MCDA20 (on wet foliage) had
percentage clover reductions > 90% (Table 7).
All but one of the herbicides produced significant reductions in black medic percentage cover when
compared with the untreated control (Table 7). Treatment with 22 of the materials resulted in
reductions in black medic populations > 93% (Table 7).

38

Herbicide and G row th Regulator Studies

Table 1. Rates and timing of application for broadleaf herbicides used in the 1997 Postemergence Broadleaf Weed
Control Study.
Spring application
(POST)
Rate
mi water
product/1000 ft2
/plot

Materials
1
2
3
4
5
6
7
8
9
10
11
12

Untreated control
Tri-Power [60.36%]'
Triplet [49.67%]'
Horsepower [59.40%]'
Millenium[55.80%]'
DCDA [47.06%]'
DTDA [47.33%]'
MCDA [58.04%]'
DCDA201*2[dry foliage]
DTDA201*2[dry foliage]
MCDA201&2[dry foliage]
Turf Builder + 21&2[dry foliage]

NA
1.19 oz
1.19 oz
0.98 oz
1.10 oz
0.98 oz
0.98 oz
0.98 oz
4.00 lb
4.00 lb
4.00 lb
2.94 lb

Early spring application
(PRE)
Rate
lb a.i./A
13
14
15
16

Gallery 75WG [FN-3133]
+ Confront 3SL [XRM-5085]3
Gallery 75WG [FN-3133]
+ Trimec Classic 3.4SL3
Trimec Classic 3.4SL3
Confront 3SL [XRM-5085]3

ml water
/plot2

0.75
none
0.75
none
none
none

380
380

Spring application
(POST)
Rate
product/A
17
18

CGA #136872 (Beacon)
+ SCOIL MSO4
CGA #136872 (Beacon)
+ SCOIL MSO4

20.00 g
+ .25% v/v
10.00 g
+ .25% v/v

NA
380
380
380
380
380
380
380
none
none
none
none

Spring application
(POST)
Rate
(lb a.i./A)
none
0.75
none
1.66
1.66
0.75

ml water
/plot

380
380
380
380

Sequential application
(3 weeks after initial)5

ml water
/plot2

Rate
product/A

ml water
/plot

380

none
10.00 g
+.25%v/v5

380

380

380

(Table 1 continued on next page)

39

Herbicide and G row th Regulator Studies

Table 1.

(Continued)
Spring application
(POST)

Materials

19
20
21
22
23
24

Rate
fl oz product/1000 ft2

Trimec Classic 3.4SL6
EH13126
EH13126
EH13426
EH13426
Super Trimec

1.0
1.0
1.2
0.8
1.0
1.1

Rate
product/1000 ft2
25
26
27
28

DCDA20l&2 [wet foliage]
DTDA201&2[wet foliage]
MCDA201&2[wet foliage]
Turf Builder + 21&2[wet foliage]

4.00
4.00
4.00
2.94

lb
lb
lb
lb

ml water/plot

380
380
380
380
380
380

ml water/plot
enough to wet the foliage
enough to wet the foliage
enough to wet the foliage
enough to wet the foliage

1These materials were screened for Riverdale Chemical Co.
2Test plots receiving these materials were divided into two - 2.5 x 10 ft [25 ft2] subplots and the north subplot was
moistened before application and the south subplot was kept dry.
These materials were screened for DowElanco3, and Novartis [Ciba]4.
Sequential applications were made on June 19 approximately 3 weeks after the initials.
6These materials were screened for PBI/Gordon.
Early spring applications (PRE) (trts 13 & 14) made on May 15; Spring applications (POST) made on May 22.
Sequential (3 WAT) materials (trts 17 & 18) were applied June 19.
380 ml water per plot is equivalent to 2 gal/1000 ft2.

40

Herbicide and G row th Regulator Studies

Table 2. Phytotoxicity1on July 15 on turf treated with broadleaf herbicides in the 1997 Postemergence Broadleaf
Weed Control Study.
Rate
lb a.i./A
(unless noted)

Materials

July 7

July 15

NA
9
Untreated control
9
Tri-Power [60.36%]
1.19 floz2
Triplet [49.67%]
1.19 fl oz2
9
Horsepower [59.40%]
0.98 fl oz2
9
9
1.10 fl oz2
Millenium[55.80%]
0.98 fl oz2
9
DCDA [47-.06%]
0.98 fl oz2
9
DTDA [47.33%]
9
0.98 fl oz2
MCDA [58.04%]
9
4.00 lb3
DCDA20 [dry foliage]
4.00 lb3
9
DTDA20 [dry foliage]
4.00 lb3
9
MCDA20 [dry foliage]
2.94 lb3
Turf Builder + 2 [dry foliage]
9
Gallery 75WG [FN-3133] (PRE)
0.75 lb
+ 0.75 lb
9
+ Confront 3SL [XRM-5085] (POST)
14 Gallery 75WG [FN-3133] (PRE)
0.75 lb
9
+ Trimec Classic 3.4SL (POST)
+ 1.66 lb
9
1.66 lb
15 Trimec Classic 3.4SL3 (POST)
0.75 lb
9
16 Confront 3SL [XRM-5085] (POST)
20.00 g4
5
17 CGA #136872 (Beacon) + SCOIL MSO
10.0 fb 10.0 g4
5
18 CGA #136872 (Beacon) + SCOIL MSO
1.00 fl oz2
9
19 Trimec Classic 3.4SL
1.00 floz2
9
20 EH1312
1.20 floz2
9
21 EH1312
0.80 fl oz2
9
22 EH 1342
9
1.00 floz2
23 EH 1342
9
1.10 fl oz2
24 Super Trimec
9
4.00 lb3
25 DCDA20 [wet foliage]
4.00 lb3
9
26 DTDA20 [wet foliage]
4.00 lb3
9
27 MCDA20 [wet foliage]
2.94 lb3
9
28 Turf Builder + 2 [wet foliage]
‘Phytotoxicity was assessed using a 9 to 1 scale: 9 = no damage, 7 = slight discoloration, 5 = moderate
discoloration and tip bum, and 3 = severe damage.
2These rates are in fl oz product/1000 ft2. 3These rates are in lb product/1000 ft2. 4These rates are in grams
product/A.
1
2
3
4
5
6
7
8
9
10
11
12
13

41

9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
9
5
5
9
9
9
9
9
9
9
9
9
9

Herbicide and Grow th Regulator Studies

Table 3. Weed damage1from May 30 (8 DAT) for dandelion and clover treated with herbicides in the 1997
Postemergence Broadleaf Weed Control Study.

Materials

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Untreated control
Tri-Power [60.36%]
Triplet [49.67%]
Horsepower [59.40%]
Millenium[55.80%]
DCDA [47-.06%]
DTDA [47.33%]
MCDA [58.04%]
DCDA20 [dry foliage]
DTDA20 [dry foliage]
MCDA20 [dry foliage]
Turf Builder + 2 [diy foliage]
Gallery 75WG [FN-3133] (PRE)
+ Confront 3SL [XRM-5085] (POST)
Gallery 75WG [FN-3133] (PRE)
+ Trimec Classic 3.4SL (POST)
Trimec Classic 3.4SL3 (POST)
Confront 3SL [XRM-5085] (POST)
CGA #136872 (Beacon) + SCOIL MSO
CGA #136872 (Beacon) + SCOIL MSO
Trimec Classic 3.4SL
EH1312
EH1312
EH1342
EH 1342
Super Trimec
DCDA20 [wet foliage]
DTDA20 [wet foliage]
MCDA20 [wet foliage]
Turf Builder + 2 [wet foliage]

Rate
lb a.i./A
(unless noted)

Dandelion
damage

Clover
damage

NA
1.19 floz2
1.19 floz2
0.98 fl oz2
1.10 floz2
0.98 fl oz2
0.98 fl oz2
0.98 fl oz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3
0.75 lb
+ 0.75 lb
0.75 lb
+ 1.66 lb
1.66 lb
0.75 lb
20.00 g
10.0 fb 10.0 g4
1.00 floz2
1.00 floz2
1.20 floz2
0.80 fl oz2
1.00 floz2
1.10 floz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3

4
1
2
3
2
1
2
1
2
3
2
2

4
2
2
3
2
2
2
2
1
3
3
3

2

3

2
2
2
3
3
2
1
2
3
2
1
2
3
2
1

2
2
2
3
3
3
2
2
3
2
1
1
3
3
3

dam age was assessed using a 4 to 1 scale: 4 = no damage, 3 = slight leaf curling and discoloration, 2 = moderate
leaf curling and sporadic discoloration, and 1 = severe leaf curling and uniform discoloration.
Ratings are based on data from 3 replications.
2These rates are in fl oz product/1000 ft2.
3These rates are in lb product/1000 fit2.
4These rates are in grams product/A.

42

H erbicide and G row th R egulator Studies

Table 4. Weed damage1from June 10(19 DAT), June 19 (28 DAT) and June 26 (35 DAT) for dandelion and
clover treated with herbicides in the 1997 Broadleaf Weed Control Study.

Materials
i
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Untreated control
Tri-Power [60.36%]
Triplet [49.67%]
Horsepower [59.40%]
Millenium[55.80%]
DCDA [47-.06%]
DTDA [47.33%]
MCDA [58.04%]
DCDA20
DTDA20
MCDA20
Turf Builder + 2
Gallery 75 WG[FN-3133]
+ Confront 3SL [XRM-5085]
Gallery 75WG [FN-3133]
+ Trimec Classic 3.4SL
Trimec Classic 3.4SL3
Confront 3SL [XRM-5085]
CGA #136872 (Beacon) + SCOIL MSO
CGA #136872 (Beacon) + SCOIL MSO
Trimec Classic 3.4SL
EH1312
EH1312
EH 1342
EH 1342
Super Trimec
DCDA20
DTDA20
MCDA20
Turf Builder + 2

Rate
lb a.i./A
(unless noted)

June 10

June 19

June 26

Mean
damage

NA
1.19 floz2
1.19 floz2
0.98 fl oz2
1.10 floz2
0.98 fl oz2
0.98 fl oz2
0.98 fl oz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3
0.75 lb
+ 0.75 lb
0.75 lb
+ 1.66 lb
1.66 lb
0.75 lb
20.00 g4
10.0 fb 10.0 g4
1.00 fl oz2
1.00 floz2
1.20 floz2
0.80 fl oz2
1.00 floz2
1.10 floz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3

9
8
6
8
5
8
7
5
7
7
8
8

9
4
3
4
3
4
4
4
4
5
4
5

7
3
3
4
3
4
4
3
5
6
4
5

8
5
4
5
4
5
5
4
5
6
5
6

6

4

3

4

8
7
5
8
8
8
6
8
7
8
6
7
7
8
8

4
3
4
5
5
4
4
4
5
5
2
4
5
4
5

3
3
4
5
6
5
4
4
6
6
2
4
6
4
4

5
5
4
6
6
6
5
5
6
6
3
5
6
5
6

NS

2

2

2

LSD0.05

Damage ratings were assessed according to a 9 to 1 scale: 9 = no damage, 7 = little damage & will survive, 5
damage & only a few dead, 3 = uniform severe damage & moderate mortality, 1 = most weeds dead.
2These rates are in fl oz product/1000 ft2.
3These rates are in lb product/1000 ft2.
4These rates are in grams product/A.
NS = means not significantly different at the 0.05 level.

43

Herbicide and Grow th Regulator Studies

Table 5. Percentage cover reductions1from June 10 (19 DAT), June 19 (28 DAT), and June 26 (35 DAT) for
broadleaf weeds treated with herbicides in the 1997 Broadleaf Weed Control Study.
June 26

Mean

0
50
67
55
63
50
58
58
42
33
58
37

0
67
80
63
68
58
58
72
58
33
58
50

0
39
57
39
58
36
39
60
33
22
39
29

25

42

72

46

0
0
30
0
0
0
25
0
0
0
25
0
0
0
0

58
72
55
20
25
42
58
58
25
33
85
42
33
58
37

72
77
72
25
25
42
58
67
25
33
90
58
33
58
63

43
49
52
15
17
28
47
42
17
22
67
33
22
39
33

NS

37

31

29

Materials

Rate
lb a.i./A
(unless noted)

June 10

Untreated control
Tri-Power [60.36%]
Triplet [49.67%]
Horsepower [59.40%]
Millenium[55.80%]
DCDA [47-.06%]
DTDA [47.33%]
MCDA [58.04%]
DCDA20 (dry foliage)
DTDA20 (dry foliage)
MCDA20 (dry foliage)
Turf Builder + 2 (dry foliage)
Gallery 75WG [FN-3133]
+ Confront 3SL [XRM-5085]
Gallery 75WG [FN-3133]
+ Trimec Classic 3.4SL
Trimec Classic 3.4SL3
Confront 3SL [XRM-5085]
CGA #136872 (Beacon) + SCOIL MSO
CGA #136872 (Beacon) + SCOIL MSO
Trimec Classic 3.4SL
EH1312
EH1312
EH 1342
EH 1342
Super Trimec
DCDA20 (wet foliage)
DTDA20 (wet foliage)
MCDA20 (wet foliage)
Turf Builder + 2 (wet foliage)

NA
1.19 floz2
1.19 floz2
0.98 fl oz2
1.10 floz2
0.98 fl oz2
0.98 fl oz2
0.98 fl oz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3
0.75 lb
+ 0.75 lb
0.75 lb
+ 1.66 lb
1.66 lb
0.75 lb
20.00 g4
10.0 fb 10.0 g4
1.00 fl oz2
1.00 floz2
1.20 floz2
0.80 fl oz2
1.00 floz2
1.10 floz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3

0
0
25
0
42
0
0
50
0
0
0
0

June 19
............. _ o z .

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

LSDo.os

Percentage reductions represent reductions in the area per plot covered by broadleaf weed species and are expressed
as percent of the untreated controls.
2These rates are in fl oz product/1000 ft2.
3These rates are in lb product/1000 ft2.
4These rates are in grams product/A.
NS = means not significantly different at the 0.05 level.

44

H erbicide and G row th Regulator Studies

Table 6. Weed counts1taken on July 3, 1997 from Kentucky bluegrass treated with herbicides in the 1997
________ Postemergence Broadleaf Weed Control Study, ___________________________________ _
_Numb»

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Materials

Rate
lb a.i./A
(unless noted)

Untreated control
Tri-Power [60.36%]
Triplet [49.67%]
Horsepower [59.40%]
Millenium [55.80%]
DCDA [47-.06%]
DTDA [47.33%]
MCDA [58.04%]
DCDA20 [dry foliage]
DTDA20 [dry foliage]
MCDA20 [diy foliage]
Turf Builder + 2 [dry foliage]
Gallery 75WG [FN-3133]
+ Confront 3SL [XRM-5085]
Gallery 75WG [FN-3133]
+ Trimec Classic 3.4SL
Trimec Classic 3.4SL3
Confront 3SL [XRM-5085]
CGA #136872 (Beacon) + SCOIL MSO
CGA #136872 (Beacon) + SCOIL MSO
Trimec Classic 3.4SL
EH1312
EH1312
EH 1342
EH 1342
Super Trimec
DCDA20 [wet foliage]
DTDA20 [wet foliage]
MCDA20 [wet foliage]
Turf Builder + 2 [wet foliage]

NA
1.19 floz2
1.19 fl oz2
0.98 fl oz2
1.10 floz2
0.98 fl oz2
0.98 fl oz2
0.98 fl oz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3
0.75 lb
+ 0.75 lb
0.75 lb
+ 1.66 lb
1.66 lb
0.75 lb
20.00 g4
10.0 fb 10.0 g4
1.00 floz2
1.00 floz2
1.20 floz2
0.80 fl oz2
1.00 floz2
1.10 floz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3

......

Dandelion

Oxalis

Clover

Black
Medic

92
40
16
44
24
21
34
9
47
83
54
73

8
6
31
10
31
21
7
22
21
9
16
11

7
1
1
1
0
1
7
2
1
16
2
17

9
0
1
0
0
0
0
0
0
1
1
1

12

23

0

1

29
16
17
38
22
39
24
25
69
66
4
27
56
10
37

14
30
7
4
7
27
10
8
12
14
2
11
6
16
12

5
10
0
20
1
15
2
1
20
4
0
1
17
1
12

1
1
0
1
5
1
1
3
2
1
0
0
3
0
1

[Pr > 0.06]
40
14
NS
LSDo.os
_______________________________________________________________________________________ 4___
1These figures represent the number of dandelion and oxalis plants per plot and the percent of area per plot covered
by clover and black medic.
2These rates are in fl oz product/1000 ft2.
3These rates are in lb product/1000 ft2.
4These rates are in grams product/A.
NS = means are not significantly different at the 0.05 level

45

Herbicide and Growth Regulator Studies

Table 7. Percentage reductions in broadleaf weed counts and weed cover1taken on July 3, 1997 from Kentucky
________ bluegrass treated with herbicides in the 1997 Postemergence Broadleaf Weed Control Study._______

Materials

Percent reductions in
number of plants

Percent reductions in
weed cover (%)

Dandelion

Clover

Oxalis

Black
Medic
%

i
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28

Untreated control
Tri-Power [60.36%]
Triplet [49.67%]
Horsepower [59.40%]
Millenium [55.80%]
DCDA [47-.06%]
DTDA [47.33%]
MCDA [58.04%]
DCDA20 [dry foliage]
DTDA20 [dry foliage]
MCDA20 [dry foliage]
Turf Builder + 2 [dry foliage]
Gallery 75WG [FN-3133]
+ Confront 3SL [XRM-5085]
Gallery 75WG [FN-3133]
+ Trimec Classic 3.4SL
Trimec Classic 3.4SL
Confront 3SL [XRM-5085]
CGA #136872 (Beacon) + SCOIL MSO
CGA #136872 (Beacon) + SCOIL MSO
Trimec Classic
EH1312
EH1312
EH 1342
EH 1342
Super Trimec
DCDA20 [wet foliage]
DTDA20 [wet foliage]
MCDA20 [wet foliage]
Turf Builder + 2 [wet foliage]

NA
1.19 floz2
1.19 fl oz2
0.98 fl oz2
1.10 floz2
0.98 fl oz2
0.98 fl oz2
0.98 fl oz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3
0.75 lb
+ 0.75 lb
0.75 lb
+ 1.66 lb
1.66 lb
0.75 lb
20.00
g
10.0 fb 10.0 g4
1.00 floz2
1.00 floz2
1.20 floz2
0.80 fl oz2
1.00 floz2
1.10 floz2
4.00 lb3
4.00 lb3
4.00 lb3
2.94 lb3

0
57
83
53
74
78
63
90
49
10
41
21

0
25
0
0
0
0
17
0
0
0
0
0

0
95
90
90
100
85
0
70
85
0
70
0

0
100
93
100
100
100
100
100
100
96
96
93

87

0

100

96

68
83
82
59
76
58
74
73
25
28
95
71
39
89
60

0
0
8
46
8
0
0
0
0
0
80
0
25
0
0

20
0
100
0
95
0
65
80
0
40
100
95
0
95
0

96
96
100
96
41
89
96
63
78
96
100
100
67
100
96

43

46

NS

50

[Pr > 0.06]
49
‘Percentage reductions represent reductions in the number of dandelion and oxalis plants per plot and reductions in
the area per plot covered by clover and black medic. They are expressed as percent of the untreated controls.
2These rates are in fl oz product/1000 ft2.
3These rates are in lb product/1000 ft2.
4These rates are in grams product/A.
NS = means are not significantly different at the 0.05 level
LSDo.05

Herbicide and Growth Regulator Studies

Effect of Beacon on Kentucky Bluegrass Cultivars

NickE. Christians, & Micha

Barbara R. Bingaman,

The objective of this study was to evaluate CGA #136872 (Beacon) for phytotoxicity on four
Kentucky bluegrass cultivars. This study was conducted at the ISU Horticulture Research Station
north of Ames, IA. Identical studies were conducted in four Kentucky bluegrass cultivars:
‘common’, ‘Glade’, ‘Park’, and ‘Ram I’. The soil in all four plots was a Nicollet (fine-loamy, mixed,
mesic Aquic Hapludoll). The ‘common’ plot had 3.65% organic matter, a pH of 5.42, 3 ppm P, and
93 ppm K and the ‘Glade’ plot had 4.0% organic matter, a pH of 6.85, 5 ppm P, and 76 ppm K.
The ‘Park’ plot had 3.6% organic matter, a pH of 7.03, 17 ppm P, and 93 ppm K and the ‘Ram I’
plot had 3.9% organic matter, a pH of 7.00, 3 ppm P, and 76 ppm K.
Rainfall was sporadic during the study. Supplemental irrigation was used in all plots except the
‘common’ plot to keep the bluegrass in good growing condition.
These studies were designed as randomized complete blocks with three replications. There were four
treatments including an untreated control. Novartis CGA #136872 (Beacon) was applied in single
applications at 20 g and 40 g product/A. CGA #136872 (Beacon) also was applied in split
applications at 10 g product/A. A methylated seed oil, SCOIL MSO, was added to all treatments at
0.25% V/V except the untreated control (Table 2). The treatments were applied at 30 psi using a
C 0 2 backpack sprayer equipped with TeeJet #8006 flat fan nozzles. Initial treatments were made on
July 11. Sequential treatments were applied on July 24, 1997.
Phytotoxicity and visual quality data were taken weekly from July 15, 1997 through September 18.
Phytotoxicity was assessed using a 9 to 1 scale: 9 = no damage, 7 = slight chlorosis, 5 = serious
chlorosis, and 1 = dead turf (Tables 1-4). Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 =
lowest acceptable, and 1 = worst quality (Tables 5-8). Data were analyzed with the Statistical
Analysis System (SAS, version 6.10) and the Analysis of Variance (ANOVA) procedure. Means were
compared using Fisher’s Least Significant Difference (LSD) test. No phytotoxicity was detected on
the ‘common’ bluegrass following the initial and sequential applications (Table 1). There was a slight
chlorosis on ‘Glade’ bluegrass on July 30 following the sequential treatment of CGA #136872
(Beacon) at 10 g product/A on July 24 (Table 2). This discoloration was gone by August 6. On July
24, there was a general slight chlorosis on all treated ‘Park’ bluegrass (Table 3). By July 30, the
quality of the treated ‘Park’ was the same as the untreated. The ‘Ram I’ bluegrass that received a
sequential treatment on July 24 showed a moderate chlorotic effect on July 30. Bluegrass treated
with an initial application of CGA #136872 (Beacon) at 40 g product/A had a slight chlorosis on this
same date. By August 6, these symptoms were no longer present.
Turf quality was the same for treated and untreated ‘common’ bluegrass (Table 5). Because this plot
was not irrigated, the sporadic rainfall can probably explain the poor quality in this plot during the
summer. Turf quality of ‘Glade’ treated with CGA #136872 (Beacon) at 10 g product/A in split
applications was lower than the other treated and untreated bluegrass on July 30 as a result of the
sequential application on July 24 (Table 6). This difference was not evident on August 6. On July
24, ‘Park’ bluegrass treated with CGA #136872 (Beacon) had poorer quality than the untreated turf
(Table 7). Turf quality was the same for treated and untreated ‘Park’ by July 30 and no other quality
differences were noted throughout the season. Treatment with CGA #136872 (Beacon) resulted in
lower turf quality of ‘Ram I’ bluegrass on July 24 (Table 8). On July 30, there also was a further
quality decrease in ‘Ram I’ bluegrass that received a sequential treatment of CGA #136872 (Beacon)
on July 24. The quality differences among the treated and untreated plots had disappeared by August
6.
In treated plots where decreases in quality occurred, they were not intensified by increases in the rate
of CGA #136872 (Beacon). This would indicate that the phytotoxicity may have been due to the
SCOIL rather than the CGA #136872 (Beacon). Future studies should include a SCOIL treatment
with no CGA #136872 (Beacon) included.

47

Herbicide and G row th Regulator Studies

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Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality.

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Initial treatments were applied July 11 and sequential were applied on July 24, 1997.
NS = means are not significantly different at the 0.05 level.
‘Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality.

Mean
quality

VO

Material

Table 7. Visual quality1 of ‘Park’ Kentucky bluegrass treated in the 1997 Cultivar Phytotoxicity Study.___________________________________________

Herbicide and G row th Regulator Studies

Herbicide and G row th Regulator Studies

Effect of Primo on Kentucky Bluegrass Sod Establishment
Barbara R. Bingaman, N ick E. Christians, and M ichael B. Faust
The objective of this study was to determine the impact of the growth regulator, Trinexapac-ethyl
(Primo), on the establishment of ‘Majestic’ Kentucky bluegrass sod. This study was conducted at the
Iowa State University Horticulture Research Station north of Ames, Iowa. The soil in this area was a
Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 4.0% organic matter, a pH of 7.30, 2 ppm
P, and 79 ppm K. This study was a repeat of a 1996 study. Rainfall was sporadic throughout the
duration of this study. Supplemental irrigation was used to maintain the bluegrass in good growing
condition and to facilitate sod root development
The study was designed as a randomized complete block with four replications. Individual plots were
5 x 5 ft. Primo 1EC was applied at three treatment regimes. All Primo 1EC applications were made
at 0.75 fl oz/1000 ft2, the label rate for Kentucky bluegrass. The four treatments included an
untreated control, applications of Primo 1EC two weeks prior to sod harvest, two weeks after sod
establishment, and a combination treatment of two weeks prior plus two weeks after establishment
(Table 1). Primo 1EC was applied at 30 psi with a C 02 powered backpack sprayer equipped with
TeeJet™ #8006 flat fan nozzles. The Primo was mixed in 283 ml of water which translates to an
application rate of 3 gal/1000 ft2. The two weeks before sod cutting treatments were made on June
11. The two weeks after sod cutting treatments were applied on July 10.
The bluegrass on the entire experimental plot was cut on June 26 using an 18-inch sod cutter.
Within each individual plot, sod pieces were cut that matched the outside diameter of 12 x 12 in.
wooden frames with 18 mesh bottom screens. The pieces were trimmed and transplanted into the
frames. The frames with the sod pieces were returned to the holes and placed flush with the soil
surface. There were four frames per individual plot, one in each of four quadrants.
The study was watered thoroughly upon completion and was watered on a regular basis to prevent the
sod from drying. One frame per plot was sampled on each of four collection dates beginning July 10,
two weeks after establishment. The other frames were harvested at two week intervals on July 21,
August 6, and August 20 (Table 1).
Root development was measured using a hydraulic sod pulling apparatus equipped with steel cables
that could be attached to screw hooks on the comers of wooden frames (Figure 1). The tensile
strength required to ‘pull’ a frame from the soil was measured in pounds per square inch (psi).
Visual quality data were taken on June 18, June 25, July 2, July 9, July 15, July 21, July 30, August 6,
and August 20 (Table 2). Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest
acceptable, and 1 = worst quality.
Data were analyzed using the Statistical Analysis System (SAS, Version 6.10) and the Analysis of
Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference
(LSD) test.
There were no differences in turf quality between the treated and untreated plots (Table 2). No
bluegrass phytotoxicity was detected during the study. There were no tensile strength differences in
sod harvested on either July 10, July 21, or August 6 (Table 1). On August 20, the sod treated with
Primo 1EC two weeks before cutting had significantly more root development than sod receiving the
other Primo treatment regimes and the untreated control.

52

H erbicide and G row th Regulator Studies

Table 1. Root tensile strength and knitting of Kentucky bluegrass sod growing in frames in the 1997 sod
________ production study measured by the number of pounds per square inch (PSI) required to pull 1 ft2 frames.
Rate oz
product/
1000 ft2

Material

Timing of
application

July
9

July
21

August
6

August
20

Mean
strength

213
321
225
226

172
223
181
190

------psi---1
2
3
4

Untreated control
Primo 1EC
Primo 1EC
Primo 1EC

NA
0.75
0.75
0.75
0.75

NA
2 wks before
2 wks after
2 wks before
+ 2 wks after

104
116
125
100

214
244
193
241

159
213
180
194

NS
NS
NS
57
32
LSD 0.05
Two weeks prior to cutting sod treatments were applied on June 11. Sod was cut and put into frames on June 26.
Two weeks after sod establishment treatments were made on July 10. Sod frames were pulled on July 10, July 22,
August 6, and August 20.
NS = means are not significantly different at the 0.05 level.

Table 2. Visual quality1 of Kentucky bluegrass sod growing in frames in the 1997 sod production study.
Material
1
2
3
4

Untreated control
Primo 1EC
Primo 1EC
Primo 1EC

Rate oz
product/
1000 ft2

Timing of
applications

June
18

June
25

July
2

July
9

July
15

July
30

Aug
6

Aug
20

NA
0.75
0.75
0.75
0.75

NA
2 wks before
2 wks after
2 wks before
+ 2 wks after

9
9
9
9

9
9
9
9

7
7
7
7

6
6
6
6

7
7
7
7

6
6
6
6

6
6
6
6

6
6
6
6

NS
NS
NS
NS
NS
NS
NS
NS
L S D oos
Two weeks prior to cutting sod treatments were applied on June 11. Sod was cut and put into frames on June 26.
Two weeks after sod establishment treatments were made on July 10.
Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality.
Figure 1. The hydraulic sod pulling apparatus used in the 1997 sod production study.

53

Herbicide and Grow th Regulator Studies

Effects of Primo and Beacon on
an nu a Populations
in Creeping Bentgrass Maintained at Green Height

NickE. Christians, and M icha

Barbara R. Bingaman,

The objective of this control study was to evaluate CGA #136872 (Beacon) and the growth regulator,
Trinexapac-ethyl (Primo) as Poa annua controls in green height creeping bentgrass.
This study was conducted on a practice green at Veenker Memorial Golf Course in Ames, IA. The
turf in this area consisted of creeping bentgrass with an infestation of Poa annua that ranged from
33 to 65% through the season.
The study was a randomized complete block design with three replications. Individual plot size was 5
x 5 ft. There were five treatments including an untreated control, CGA #136872 (Beacon), and
Primo. CGA #136872 (Beacon) was applied in single applications at 10 and 20 g product/A and at
10 g product/A in split applications. A methylated seed oil surfactant, SCOIL MSO, was added to
CGA #136872 (Beacon) at 0.25% V/V for all applications. Primo 1EC was applied at 0.3 fl oz/1000
ft2 monthly from June through September.
Initial applications of all materials were made on June 5. The sequential application of CGA
#136872 (Beacon) was made on June 26. Additional Primo 1EC applications were made on July 10,
August 13, and September 4. The materials were mixed with 283 ml of water (3 gal/1000 fit2) and
were applied at 30 psi with a C 02 backpack sprayer equipped with TeeJet™ #8006 flat fan nozzles.
All applications were made between 6:30 and 7:00 a.m. Following applications, the plot was watered
with the normal watering schedule in the late afternoon.
Phytotoxicity data were taken on June 10, June 19, June 26, and July 2. Phytotoxicity was assessed
using a 9 to 1 scale: 9 = no damage, 6 = moderate tip bum (browning) and 4 = severe tip bum (Table
1). Visual turf quality data were taken weekly beginning June 10 and ending September 16 (Table 2).
Visual turf quality was assessed with a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf
quality. Poa annua control was represented by estimating the percentage of area per plot covered by
Poa annua. Percentage cover data were taken on June 19, June 26, July 15, July 21, and August 21
(Table 3). The presence of Poa annua seedheads also was recorded on July 2, July 15, July 21, and
August 21 (Table 4). Seedhead numbers were estimated using many = a large number of uniformly
distributed seedheads, moderate = a moderate number with a uniform distribution, few = a small
number with a sporadic distribution, and none = no seedheads within the plot. Additional percentage
cover data will be taken spring 1998 beginning at greenup. Winter damage also will be assessed in
early spring.
There was severe phytotoxicity on bentgrass treated with CGA #136872 (Beacon) on June 10
through July 2 (Table 1). This material caused significant levels of phytotoxicity when compared
with Primo 1EC-treated and untreated bentgrass. In addition, this phytotoxicity translated into
significant brown areas in bentgrass treated with CGA #136872 (Beacon) on June 19, June 26, and
July 2 when compared with Primo 1EC-treated and untreated bentgrass. There was no phytotoxicity
detected after July 2.
There were no significant visual quality differences from July 21 through September 11 (Table 2).
Primo lEC-treated bentgrass had a darker green color than the CGA #136872 (Beacon)-treated and
the untreated bentgrass from August 7 through September 11 but the difference was not significant.
Bentgrass treated with CGA #136872 (Beacon) showed reductions in percentage Poa annua cover
for July 15 and July 21 but the percentages were not different from the Primo-treated and the
untreated bentgrass (Table 3). On August 21, there were significantly lower Poa annua populations

54

H erbicide and G row th R egulator Studies

in bentgrass treated with CGA #136872 (Beacon) at 10 g and 20 g product/A and with Primo 1EC
when compared with the other treated and untreated bentgrass.
Seedhead formation on Poa annua was suppressed by treatment with CGA #136872 (Beacon) and
Primo 1EC. There were fewer seedheads in treated bentgrass than in untreated on July 2, July 15,
July 21, and August 21.
Table 1. Phytotoxicity1and percent brown area2 in plots of creeping bentgrass in the 1997 P o a annua control

Phytotoxicity1
Material

1 Untreated control
2 136872
+ SCOIL MSO
3 136872
+ SCOIL MSO
4 136872
+ SCOIL MSO
5 Primo 1EC

Percent brown area2

Rate
product/A.
(initial)

Rate
product/A.
(sequential)

June
10

June
19

July
2

June
19

June
26

July
2

NA
10.0 g
+ 0.25% V/V
20.0 g
+ 0.25% V/V
10.0 g
+ 0.25% V/V
0.3 fl oz/
1000 ft2

NA

9

9

9

0

0

0

none

7

4

9

17

8

0

none
10.0 g
+ 0.25% V/V
0.3 fl oz/
1000 ft2

7

3

9

32

20

0

7

4

3

10

7

28

9

9

9

0

0

0

1

1

1

13

9

6

LSDo.os

Phytotoxicity was assessed with a 9 to 1 scale: 9 = no damage, 6 = moderate tip bum (browning) and 4 = severe
tip bum.
2Percent brown area per plot represents the total area with dying P oa annua and bentgrass with tip bum.
Initial applications were made on June 5 and sequentials on June 26, 1997. Primo was applied June 5, July 10,
August 13, and September 4.
Table 2. Visual quality1 in plots of creeping bentgrass in the 1997 P o a annua control study.
Rate
Rate
Material
product/A.
product/A.
July July Aug Aug Aug Aug
(initial)
(sequential)
21
14
31
7
21
28
1 Untreated control
2 136872
+ SCOIL MSO
3 136872
+ SCOIL MSO
4 136872
+ SCOIL MSO
5 Primo 1EC

LSDo.os

NA
NA
10.0 g
none
+ 0.25% V/V
20.0 g
none
+ 0.25% V/V
10.0 g
10.0 g
+ 0.25% V/V + 0.25% V/V
0.3 fl oz/
0.3 fl oz/
1000 ft2
1000 ft2

Sept
4

Sept
11

7

9

8

8

8

8

9

9

8

9

8

8

8

8

9

9

7

9

8

8

8

8

9

9

8

9

8

8

8

8

9

9

8

9

9

9

9

9

9

NS

NS

NS

NS

NS

NS

NS

9
NS

u>
Initial applications were made on June 5 and sequentials on June 26, 1997. Primo was applied June 5, July 10,
August 13, and September 4.
NS = means are not significantly different at the 0.05 level.

55

Herbicide and G row th Regulator Studies

Table 3. Percentage P oa annua cover in plots of creeping bentgrass in the 1997 P o a annua control study.
Material

Rate
product/A.
(initial)

Rate
product/A.
(sequential)

July
15

July
21

August
21

Mean

NA
10.0 g
+ 0.25% V/V
20.0 g
+ 0.25% V/V
10.0 g
+ 0.25% V/V
0.3 fl oz/1000 ft:2

NA

45.0

33.3

65.0

47.8

none

31.7

28.3

56.7

38.9

none
10.0 g
+ 0.25% V/V
0.3 fl oz/1000 ft2

33.3

23.3

53.3

36.7

35.0
53.3

23.3
30.0

58.3
35.0

38.9
39.4

NS

NS

8.6

NS

0/n

i
2

Untreated control
136872
+ SCOIL MSO
3 136872
+ SCOIL MSO
4 136872
+ SCOIL MSO
5 Primo 1EC2
LSD

o.05

‘Percent P oa annua cover represents the area per plot covered by P o a annua .
Initial applications were made on June 5 and sequentials on June 26, 1997. Primo was applied June 5, July 10,
August 13, and September 4.
NS = means are not significantly different at the 0.05 level.
Table 4. Presence of P oa annua seedheads1in plots of creeping bentgrass in the 1997 P o a annua control study.
Seedhead numbers

Material

1 Untreated control
2 136872
+ SCOIL MSO
3 136872
+ SCOIL MSO
4 136872
+ SCOIL MSO

Rate
product/A.
(initial)

Rate
product/A.
(sequential)

July
2

July
15

July
21

August
21

NA
10.0 g
+ 0.25% V/V
20.0 g
+ 0.25% V/V
10.0 g
+ 0.25% V/V

NA

moderate

moderate

moderate

many

none

few

moderate

few

few

none
10.0 g
+ 0.25% V/V

none

none

none

few

none

few

none

none

few
5 Primo 1EC
0.3 fl oz/1000 ft2 0.3 fl oz/1000 ft2 moderate
moderate
none
The presence of P o a annua seedheads was estimated as: many = a large number uniformly distributed, moderate =
a moderate number with a uniform distribution, few = small number with a sporadic distribution, and none = no
seedheads within the plot.
Initial applications were made on June 5 and sequentials on June 26, 1997. Primo was applied June 5, July 10,
August 13, and September 4.
NS = means are not significantly different at the 0.05 level.

56

H erbicide and G row th Regulator Studies

Effects of Primo on
in Creeping Bentgrass Maintained at Fairway Height

Poaannua Po

Barbara R. Bingaman, N ick E. Christians, and M ichael B. Faust
The objective of this study was to monitor Poa annua populations through the season in fairway
height turf following a routine application program with the growth regulator, Trinexapac-ethyl
(Primo).
This study was conducted in a turf area maintained at 1/2-inch mowing height surrounding a practice
green at Veenker Golf Course in Ames, IA. The turf in this area consists of Perennial ryegrass and
Kentucky bluegrass with a uniform infestation of Poa annua.
The experiment was a completely randomized design. Individual plot size was 5 x 5 ft with three
replications. Untreated plots and Primo treated plots were randomly placed in a single row. Primo
was applied at 0.5 fl oz/1000 fit2.
Monthly applications were made on June 5, July 10, August 13, and September 4. The liquid was
applied at 30-35 psi with a C 0 2 backpack sprayer equipped with TeeJet™ #8006 flat fan nozzles.
All applications were made between 6:30 and 7:00 a.m. The plot was watered with the normal
watering schedule in the late afternoon.
Visual turf quality data were taken weekly beginning June 10 and ending September 16, 1997 (Table 1
and 2). Visual quality was assessed on a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst
quality. Poa annua control was measured by estimating the percentage cover per plot. Percentage
cover data were assessed by estimating the percent area per plot covered by Poa annua (Table 3).
Percentage cover data were taken on June 5 and September 11. Additional percentage cover data will
be taken in spring, 1998 beginning at greenup. Winter damage also will be assessed in early spring.
The plot and the surrounding area were overseeded with perennial ryegrass twice between late August
and early September. By September 11, germinating ryegrass plants were quite numerous throughout
the plot.
Throughout the season no Poa annua seedheads were visible in the plot or in the surrounding turf
area. Beginning on August 20, the Primo treated plots had a darker blue-green color when compared
with the untreated plots and the surrounding area. This color difference was detected through
September 11. On September 16, no color differences were detected.
Percentage Poa annua cover data were taken on June 5 and September 11. There was a uniform Poa
annua population among the treated and untreated plots on June 5. There were significantly smaller
Poa annua populations in Primo treated plots on September 11 when compared with the untreated
controls (Table 3). There was a large population of young ryegrass plants in all of the plots.

57

Herbicide and G row th Regulator Studies

Table 1. Visual quality of fairway height Perennial iyegrass in the 1997-98 Postemergence
________
annua Conversion Study (Junes 10
r ,, through
v. — July
.„y;31, 1997).________________
Material
1 Untreated control
2 Primo

Rate
fl oz/1000 ft2

June
10

June
19

June
26

July
2

July
15

July
21

July
31

NA
0.5

9
9

9
9

9
9

9
9

9
9

8
8

9
9

NS

NS

NS

NS

NS

NS

NS

LSD0.o5

Applications were made on June 5, July 10, August 13, and September 4.
NS = means are not significantly different at the 0.05 level.

Table 2. Visual quality of fairway height Perennial ryegrass in the 1997-98 Postemergence Poa
annua Conversion Study (August 6 through September 16, 1997).

Material
1 Untreated control
2 Primo

Rate
fl oz/1000 ft2

Aug
6

Aug
12

Aug
20

Aug
28

Sept
4

Sept
11

Sept
16

NA
0.5

9
9

9
9

8
9

8
9

8
9

8
9

8
9

NS

NS

NS

NS

NS

NS

NS

LSDo.o5

Applications were made on June 5, July 10, August 13, and September 4.
NS = means are not significantly different at the 0.05 level.

Table 3. Percentage Poa annua cover in fairway height Perennial ryegrass in the 1997
Postemergence Poa annua Conversion Study.
Material
1 Untreated control
2 Primo

Rate
fl oz/1000 ft2

June
5

September
11

NA
0.5

35
35

30
3

NS

9

LSDo.os

Applications were made on June 5, July 10, August 13, and September 4.
NS = means are not significantly different at the 0.05 level.

58

H erbicide and G row th Regulator Studies

Effect of Primo on the Establishment of Kentucky Bluegrass
in a Mature Grass Stand
Barbara R. Bingaman, N ick E. Christians, and M ichael B. Faust
The objective of this study was to determine if application of the growth regulator, Trinexapac-ethyl
(Primo), would enhance the incorporation of new cultivars into existing stands of turf. This study
was conducted at the Iowa State University Horticulture Research Station. The study was in an
established area of ‘Park’ Kentucky bluegrass that was not fertilized in 1997. The soil in this plot
was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with an organic matter content of 3.2%, a
pH of 7.8, 3 ppm P, and 75 ppm K. It was overseeded with ‘Baron’ Kentucky bluegrass, a cultivar
that has dark green seedlings. The color difference between ‘Baron’ and ‘Park’ should enable
percentage cover estimations to be made for each cultivar..
Individual plot size was 5 x 5 ft with three replications and 3 ft barrier rows between replications.
There were four treatments including an untreated and unseeded control and an untreated and seeded
control. Primo was applied at 0.5 fl oz/1000 ft2 to overseeded and unseeded plots. Primo
applications were made two weeks before overseeding (Table 1). The Primo was mixed with 283 ml
of water per plot and was applied at 30 psi using a C 02 backpack sprayer equipped with TeeJet™
#8006 flat fan nozzles. This rate translates to 3 gal/1000 ft2.
Rainfall was quite sporadic following overseeding. Irrigation was used to keep the bluegrass in good
growing condition and to enhance germination.
Visual turf quality data were taken weekly beginning on August 21 when the Primo was applied. Data
were taken on September 5, September 12, September 18, September 26, October 2, October 9, and
October 14 (Table 1). Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable,
and 1 = worst quality.
Overseeding was performed on September 12. At the time of overseeding, the entire plot was sliced
with a vertical mower in three directions. The plot was raked to remove thatch and debris. ‘Baron’
Kentucky bluegrass was seeded by hand into individual plots at 1.5 lb/1000 ft2 and raked into the slits.
On September 12, the plots treated with Primo had less growth and were not as green when compared
with the untreated plots. By September 18, the quality differences were gone and there were no
further quality differences through October 14 (Table 1).
The plots were monitored weekly for germination after September 12. Seedlings were first observed
on September 26 in the overseeded plots. The seedlings were still too small to take % cover data by
October 14. On October 9 and October 14, we confirmed that there were young seedlings in both the
Primo treated and untreated, overseeded plots. The seedlings were so small that estimations of
populations could not be made at this time. The plot was monitored weekly through November 12.
At this time, the temperatures were prohibitive for further seedling growth so we ceased monitoring
the plot. Percent cover data will be taken for both cultivars in the early spring. The color
differences between the ‘Baron’ and ‘Park’ should be quite visible at spring greenup.
Table 1. Visual quality o f ‘Park’ Kentucky bluegrass.
Rate (fl oz
Sept
Sept Sept Sept
Materials
Oct
product/1000 ft2) Overseeded
5
12
18
26
2
1 Untreated control
NA
no
6
6
6
6
6
2 Primo
no
0.5
6
6
6
6
6
yes
3 Primo
0.5
6
5
6
6
6
4 Seeded control
NA
yes
6
5
6
6
6
NS
NS
NS
NS
NS
LSDoos
Primo treatments were made on August 21 and the plots were overseeded on September 12, 1997.
NS = means are not significantly different at the 0.05 level.

59

Oct
9
6
6
6
6
NS

Oct
14
6
6
6
6
NS

Herbicide and Grow th Regulator Studies

1997 Postemergence Ground Ivy Control Study
Barbara R. Bingaman, N ick E. Christians, and M ichael B. Faust
The purpose of this study was to evaluate herbicide formulations for their efficacy on ground ivy in
turfgrass. The study was conducted on the Iowa State University campus in ‘common’ Kentucky
bluegrass heavily infested with ground ivy. The soil in this area was a Nicollet (fine-loamy, mixed,
mesic Aquic Hapludoll) with 5.3% organic matter, a pH of 7.5, 12 ppm P, and 165 ppm K.
The study was designed as a randomized complete block. Individual plot size was 5 x 5 ft with three
replications. There were five treatments plus an untreated control (Table 1). Experimental
formulations EH1312 and EH1342 were applied at two different rates. EH1312 was applied at 1.0
and 1.2 fl oz product/1000 ft2 and EH1342 at 0.8 and 1.0 fl oz/1000 ft2. Trimec Classic was applied
at 1.5 fl oz/1000 ft2.
Applications were made postemergently on June 5 after the ground ivy was well established. The
materials were diluted in 189 ml water and applied at 30 psi using a C 0 2 backpack sprayer equipped
with #8006 nozzles. This rate translates to 2 gal/1000 ft2.
Damage to ground ivy plants was evaluated using a 9 to 1 scale: 9 = no damage, 7 = slight curling and
discoloration, 5 = moderate curling and discoloration, 3 = severe discoloration & curling, 1 = all
plants dead. Ground ivy control was assessed using a 9 to 1 scale: 9 = healthy plants, 3 = most plants
dead, 1 = all ground ivy plants dead.
Data were analyzed with the Statistical Analysis System (SAS, version 6.10) and the Analysis of
Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference
(LSD) test.
There was no bluegrass phytotoxicity. Ground ivy damage data were taken on June 10 and June 19
(Table 1). On June 10, all herbicide treated ground ivy had some damage. On June 19, the most
severe damage was on ground ivy treated with EH1312 at 1.0 fl oz product/1000 ft2 and EH1342 at
0.8 fl oz product/1000 ft2. Mean damage for these two dates showed that all herbicides produced
significant damage when compared with the untreated control.
By June 26, there was high ground ivy mortality in all treated bluegrass. Most of the treated ground
ivy plants were dead by July 2. All treated ground ivy plants treated with EH1342 at 0.8 fl oz
product/1000 ft2 were dead on July 2. The plot was monitored through September and there was no
regrowth of ground ivy in the treated turf.
Table 1. Ground ivy control with various herbicides used in the 1997 Postemergence Ground Ivy Control Study.
T*___
___1
r'
___ j ivy control2
__ ,_I2
Degree_ofFAdamage1
Ground
Rate (fl oz
Mean
product
June
June
June
July
Materials
Mean
damage
/1000 ft2
10
19
26
2
control
1 Untreated control
NA
9.0
9.0
9.0
9.0
9.0
9.0
1.0
6.5
5.0
5.8
3.5
1.5
2 Trimec Classic
2.5
1.0
6.0
3.0
4.5
4.0
2.0
3 EH1312
3.0
4 EH1312
1.2
4.0
5.3
4.0
6.5
2.0
3.0
0.8
6.0
2.5
4.3
2.0
1.0
1.5
5 EH 1342
1.0
6.5
5.0
5.8
4.5
2.0
3.3
6 EH 1342
NS
NS
NS
2.5
2.9
NS
LSDoos
degree of damage was evaluated using a 9 to 1 scale: 9 = no damage, 7 = slight curling and discoloration, 5 =
moderate curling and discoloration, 3 = severe discoloration & curling, 1 = all plants dead.
2Ground ivy control was assessed using a 9 to 1 scale: 9 = healthy plants, 3 = most plants dead, 1 = all plants
dead.
Materials were applied on June 5, 1997
NS = means are not significantly different at the 0.05 level.

60

H erbicide and G row th Regulator Studies

Effect of Beacon on the Germination of
Kentucky Bluegrass and Creeping Bentgrass

NickE. Christians, and M icha

Barbara R. Bingaman,

The objective of this study was to evaluate the effect of CGA #136872 (Beacon) on seed
germination and establishment of Kentucky bluegrass and creeping bentgrass. This study was
conducted at the Iowa State University Horticulture Research Station located north of Ames, IA.
The experimental plot was a bare soil area that had been tilled, raked, and prepared for seeding. The
soil in this plot was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with an organic matter
content of 3.9%, a pH of 7.0, 3 ppm P, and 76 ppm K.
Individual plot size was 5 x 6 ft. There were three replications with 3 ft barrier rows between
replications. CGA #136872 (Beacon) was applied at 20 and 40 g product/acre. Applications were
made eight, four, and two weeks, and one day before seeding. The liquid materials were applied at 30
psi using a C 0 2 backpack sprayer equipped with TeeJet ™ #8006 flat fan nozzles. A methylated seed
oil spreader (SCOIL MSO) was added at 0.25% V/V to all treatments except the control. CGA
#136872 (Beacon) was mixed in 283 ml of water per plot which translates to an application rate of 3
gal/1000 ft2.
The ‘eight weeks before seeding’ treatments were applied on July 14, the ‘four weeks before seeding’
on August 15, the ‘two weeks before seeding’ on August 28, and the ‘one day before seeding’ on
September 11. Seeding took place on September 12.
There was a heavy infestation of weeds in the plots and border rows at the time of seeding. All weeds
were cut off with a hoe and removed. The soil from individual plots was not mixed with adjacent
plots. Light raking was performed to make shallow grooves in the soil for the seeds. The plots were
split into two 5 x 3 ft subplots. One of these was seeded with ‘Penneagle’ creeping bentgrass at 1
lb/1000 ft2 and the other with ‘Award’ Kentucky bluegrass at 1.5 lb/1000 ft2. The seeding was done
using a drop seeder. The plots were lightly raked following seeding to partially cover the seeds.
Rainfall was sporadic during this period so the plot was irrigated daily.
Bentgrass seedlings were first observed on September 18. Kentucky bluegrass germination was noted
on September 26. By October 2, differences in bentgrass cover were beginning to appear but the
plants were so small that data were not taken. Germination was determined as the percentage of area
per plot covered by each species. Percentage cover data were taken on October 9, October 14, and
November 11 (Tables 1 and 2). Final 1997 data for this study were taken on November 11 because
winter weather conditions had already set in. At this time, the bentgrass plants had matured but the
bluegrass plants were still quite small.
Data were analyzed with the Statistical Analysis System (SAS, version 6.10) and the Analysis of
Variance (ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference
(LSD) test.
There were observable reductions in percentage cover of creeping bentgrass on October 9 and 14
even though the differences were not significant. The November 11 data show that the ‘one day
before seeding’ treatment of CGA #136872 (Beacon) at 40 g product/A significantly reduced the
percentage cover of bentgrass when compared with the untreated control. Although the ‘one day
before seeding’ treatment of CGA #136872 (Beacon) at 20 g product/A did numerically reduce the
bentgrass cover, the percentage cover was not significantly reduced from the untreated control
(Table 1).

61

Herbicide and Grow th Regulator Studies

Because o f the weather conditions in October, the bluegrass did not mature. The plants were still
quite small when the final data were taken. There were significant differences (P > 0.06) in bluegrass
cover on N ovem ber 11. The percentage cover o f bluegrass treated with 20.0 g product/A at eight
weeks, two weeks, and one day before seeding was significantly reduced when compared with the
untreated control. In addition, significant reductions were recorded for bluegrass treated two weeks
before seeding at 40 g product/A (Table 2). These were unusual results for the Kentucky bluegrass
and observations will be made in the spring to confirm these results.

Table 1. Percentage cover1o f ‘Penneagle’ creeping bentgrass in the 1997 carryover seedling study.
Rate
product/A.

Material

1
2
3
4
5
6
7
8
9

Untreated Control
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO
CGA #136872 + SCOIL MSO

20.0
20.0
20.0
20.0
40.0
40.0
40.0
40.0

Timing of
application
(before seeding)

NA
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%

V/V
V/V
V/V
V/V
V/V
V/V
V/V
V/V

NA
8 weeks
4 weeks
2 weeks
1 day
8 weeks
4 weeks
2 weeks
1 day

Oct
9

32
40
43
30
22
33
20
20
5

Oct
14

Nov
11

35
45
43
32
27
35
20
23
5

- oz
/ o------55
73
75
72
40
65
45
53
12

Mean
cover

41
53
54
44
29
44
28
32
7

NS
NS
38
NS
LSDoos
'Percentage cover was estimated as the area per plot covered by creeping bentgrass.
‘Eight weeks before seeding’ materials were applied on July 14, ‘four weeks’ on August 15, ‘two weeks’ on
August 28, and one day on September 11. Seeding took place on September 12.
NS = means are not significantly different at the 0.05 level.
Table 2. Percentage cover1of ‘Award’ Kentucky bluegrass in the 1997 carryover seedling study.

Material

i
2
3
4
5
6
7
8
9

"X T "

Untreated Control
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL
CGA #136872 + SCOIL

MSO
MSO
MSO
MSO
MSO
MSO
MSO
MSO

20.0
20.0
20.0
20.0
40.0
40.0
40.0
40.0

Rate
product/A.

Timing of
application
(before seeding)

Oct
9

Oct
14

Nov
11

Mean
cover

NA
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%
g + 0.25%

NA
8 weeks
4 weeks
2 weeks
1 day
8 weeks
4 weeks
2 weeks
1 day

13
12
17
12
12
15
12
12
10

15
17
18
15
12
17
15
15
10

OZ
53
32
48
25
35
50
40
35
40
(p > 0.06)

27
20
28
17
19
27
22
21
20

NS

NS

18

NS

V/V
V/V
V/V
V/V
V/V
V/V
V/V
V/V

LSDo os

‘Eight weeks before seeding’ materials were applied on July 14, ‘four weeks’ on August 15, ‘two weeks’ on
August 28, and one day on September 11. Seeding took place on September 12.
NS = means are not significantly different at the 0.05 level.

62

Herbicide and G row th R egulator Studies

1997 Non-selective Herbicide Study
Barbara R. Bingaman, N ick E. Christians, and M ichael B. Faust
The objective of this study was to demonstrate trim and edging of cool season turfgrasses with nonselective herbicides. This study was designed as a demonstration plot for the 1997 Iowa State
University Turfgrass Field Day on August 14 at the Horticulture Research Station north of Ames, IA.
The plot was in an area of ‘common’ Kentucky bluegrass adjacent to an ornamental grass bed.
The study was designed with the treated plots in a single row. Each plot was a 0.5 x 8.0 ft. (4 ft2)
strip with 0.5 x 1.0 ft. barrier strips between plots. This study was not replicated and the treatments
were applied once. There were seven treatments including an untreated control (Table 1). Reward
was applied alone at 2.0 pt. product/A and at 0.5, 1.0 and 1.5 pt. product/A in combination with
Roundup Pro at 2 qt. product/A. Fusilade II at 4, 8, and 16 oz. product/A was combined with Reward
at 1.0 pt. product/A. LESCO spreader/sticker was added to all treatments at 0.25% V/V.
The herbicides were mixed in 60 ml of water and applied at 30 psi using a C 02 backpack sprayer
equipped with one TeeJet™ #8006 flat fan nozzle. Applications were made to ensure that there was
no herbicide drift. Water was withheld from the plot for at least 24 hours post-treatment.
Plots were rated for plant damage using a 9 to 1 scale: 9 = 100% brown, 5 = 35-50% brown, and 1 =
100% green. Ratings were taken on August 1, August 4, August 6, August 14, August 21, August 28,
September 5, September 12, September 18, and September 26 (Table 1). The percentage of damaged
and dead plants per plot was also recorded on these dates. These data were recorded as the percent
brown area per plot (Table 2). In addition, notes on species affected, species regrowth, and spreading
of the herbicide affected areas were made on each collection day.
On August 1, broadleaf plants were slightly discolored (bleached) in turf treated with Reward alone at
2.0 pt. product/A and at 0.5 and 1.0 pt product/A in combination with Roundup Pro (Table 1).
There was no discoloration of any treated turfgrass.
Turfgrass and broadleaves were damaged and turning brown in all treated plots by August 4. There
were a few redroot pigweed plants treated with Reward at 1.0 pt product/A plus Fusilade II at 16 oz.
product/A that were undamaged. There was still 25 - 40% green cover in plots treated with Reward
alone, Reward at 0.5 pt. plus Roundup Pro at 2 qt. product/A, and Reward at 1.0 pt. product/A plus
Fusilade II at 4 oz. product/A. In the other treated plots, 80 - 90% of the grass was brown (Table 2).
On August 6, 40% of the cover was still green within the plot treated with Reward at 0.5 pt.
product/A plus Roundup Pro at 2 qt. product/A and 30% of the cover was green in the plot treated
with Reward at 1.0 pt. product/A plus Fusilade II at 4 oz product/A. In other treated plots there was
< 20% green cover.
By August 14, in those plots treated with Reward + Roundup Pro the herbicide affected area had
begun to widen. There was > 70% dead plants in all treated plots. In addition, there was 100% brown
cover in plots treated with Reward at 1.0 and 1.5 pt. product/A plus Roundup Pro at 2 qt. product/A.
On August 21, all herbicides had produced at least 80% brown plants except Reward alone at 2.0 pt.
product/A. The pigweeds treated with Reward at 1.0 pt. product/A plus Fusilade II at 16 oz.
product/A were still undamaged.
By August 28, the grass had begun to spread back into some of the treated plots. The plot treated
with Reward at 2.0 pt. product/A was 50% overgrown with grass and the Reward + Fusilade II plots
were beginning to fill in with grass. The plots treated with Reward at 0.5, 1.0, and 1.5 pt. product/A
plus Roundup Pro at 2.0 qt. product/A were completely brown.
By September 5 (5 WAT), there was 75% green cover in the plot treated with Reward at 1.0 pt.
product/A plus Fusilade II at 4 oz. product/A. Regrowth of 50% was recorded in plots treated with

63

Herbicide and G row th Regulator Studies

either Reward at 20 pt. product/A or Reward at 1.0 pt. product/A plus Fusilade II at 8.0 oz.
product/A. There was < 5% grass regrowth in plots receiving Reward at 0.5, 1.0, and 1.5 pt.
product/A plus Roundup Pro at 2 qt. product/A.
The turf plots treated with Reward at 0.5, 1.0, and 1.5 pt. product/A plus Roundup Pro at 2 qt.
product/A still had very little regrowth on September 12 (6 WAT). There was 90% regrowth in the
plot treated with Reward at 1.0 pt. product/A plus Fusilade II at 4 oz. product/A.
Table 1. Damage ratings1 for grass and broadleaf species in Kentucky bluegrass treated for the 1997
Nonselective Herbicide Study.
Treatments
1 Reward
2 Reward
+ Roundup Pro
3 Reward
+ Roundup Pro
4 Reward
+ Roundup Pro
5 Reward
+ Fusilade II
6 Reward
+ Fusilade II
7 Reward
+ Fusilade II

Rate
product/A

Aug

Aug
4

Aug

21

Aug
28

Sept
5

Sept

6

Aug
14

Aug

1

2.0 pt

2

7

7

7

6

5

5

5

2

6

6

7

8

9

8

8

2

7

8

9

9

9

8

8

1

8

8

9

9

9

9

8

i

6

6

6

7

6

3

2

1

8

7

8

8

8

5

4

1

8

7

8

8

8

8

7

0.5 pt
2.0 qt.
1.0 pt
2.0 qt.
1.5 pt
2.0 qt.
1.0 pt
4.0 oz
1.0 pt
8.0 oz
1.0 pt
16.0 oz

12

LESCO Spreader/Sticker was added to all treatments at 0.25% v/v = 0.15 ml/plot.
Damage was assessed using a 9 to 1 scale: 9 = 100% brown, 5 = 50% brown and 1 = 100% green.

Table 2. Percentage brown plant cover per plot1 in Kentucky bluegrass treated for the 1997
Nonselective Herbicide Study.
Treatments

Rate
product/A

Aug

1

Aug
4

Aug

6

Aug
14

Aug

Aug
28

Sept
5

Sept

21

12

OX.

1 Reward
2 Reward
+ Roundup Pro
3 Reward
+ Roundup Pro
4 Reward
+ Roundup Pro
5 Reward
+ Fusilade II
6 Reward
+ Fusilade II
7 Reward
+ Fusilade II

2.0 pt
0.5 pt
2.0 qt.
1.0 pt
2.0 qt.
1.5 pt
2.0 qt.
1.0 pt
4.0 oz
1.0 pt
8.0 oz
1.0 pt
16.0 oz

5

75

80

80

60

50

50

40

5

60

60

75

90

100

95

90

5

80

90

100

100

100

95

95

0

90

90

100

100

100

100

95

0

70

70

70

80

70

25

10

0

90

80

85

90

90

50

30

0

90

80

85

95

95

90

80

LESCO Spreader/Sticker was added to all treatments at 0.25% v/v = 0.15 ml/plot.
'Percentage brown cover represents the area covered by brown damaged and dead plants per plot.

64

Turfgrass Disease Research

Growth of

Agrostispalustris in Response to Adventitious Root
Infection by Species of A crem o n iu m
Clinton.

F.Hodges and Douglas Campbell

The form genus Acremonium is recognized primarily for its endophytic associations with numerous
grass species (11, 13, 14) that range from mutualistic to pathogenic (16). The economic
consequences of endophyte-infected grasses are both positive and negative. Negative effects include
Fescue toxicosis and ryegrass staggers in livestock (2,6). Positive effects include increased insect,
nematode, and pathogen tolerance (3, 11, 13, 14). Other positive effects include enhanced seed
germination, growth, and drought resistance (1, 4, 5). Naturally occurring endophytes have not been
reported in association with Agrostis palustris, but inoculations of A. palustris with a group of
Acremonium isolates suggest that stolons can be infected (15). In recent years, research has focused
primarily on the potential benefits afforded turfgrasses infected by Acremoniun endophytes.
Over the last 10 to 12 years isolation of Acremonium rutilum and A. alternatum from the roots and
leaves of diseased A. palustris growing on high-sand-content golf greens has increased. Symptoms are
expressed differently depending on whether the plants are on the closely mowed greens or on the
collar of the green at higher mowing levels. Closely mowed greens show irregular areas of unthrifty,
thinning turf due to mild undercover chlorosis and tanning of the older leaves. The higher mowed
grasses of the collars show distinct brown, irregular patches of turf with living plants interspersed
through the patches. The affected areas in the collar enlarge very slowly during the growing season
and seem to be perennial in that they recur in the same location from season to season. Isolation of
Acremonium species from A. palustris with these symptoms is most common during cool, wet
periods of the spring and fall. The expression of symptoms, however, is most prevalent in the
warmer periods of the summer.
Shoot and Root Growth
Inoculation of adventitious roots of A. palustris with three isolates of A. rutilum and one isolate of A.
alternatum under high (95° day/75° night) and low (75° day/60° night) temperature regimes decreased
the growth of the plants, but no plants were killed. Under high temperatures, the various isolates of
A. rutilum examined decreased shoot growth 13 to 58%; root growth was decreased 23 to 47%. A.
alternatum induced a 68% decreased in shoot growth and a 56% decrease in root growth under the
high temperatures. Under low temperatures, the isolates of A. rutilum decreased shoot growth 60 to
69% and root growth 51 to 62%. A. alternatum decreased shoot growth by 71% and root growth by
58% under the low temperatures. The observations show that growth of plants infected by A.
rutilum is inhibited more under low temperatures than under high temperatures, and that the negative
effect on growth by A. alternatum is temperature neutral.
Stolon Numbers
The number of stolons produced by A. palustris infected by the Acremonium species decreased in
response to high and low temperatures. Under high temperatures, stolon numbers per plant were
reduced 21 to 35% in response to the isolates of A. rutilum and 36% in response to A. alternatum.
The decrease in stolon numbers was more severe under the low temperatures; isolates of A. rutilum
decreased stolon numbers in a range of 48 to 54% and A. alternatum decreased stolons by 60%.
A c re m o n iu m Development on Roots

Inoculated roots from both the high and low temperature regimes were typically tan colored without
any evidence of lesions or rot and no visible signs of hyphae or spores. Vascular cylinders of some

65

Turfgrass Disease Research

inoculated roots were cream colored, and some root tips were swollen. Some roots that were cleared
and stained showed fine hyphal growth on and within the cortex from the low temperature study;
visible hyphae on the surface of roots from the high temperature regime were rare. Among plants
subjected to the high temperature regime, reisolation of the isolates of A. rutilum from roots ranged
from 63 to 77%; A. alternation was reisolated from 81% of the inoculated roots. Reisolation of A.
rutilum isolates from inoculated roots of plants subjected to the low temperature regime ranged from
73 to 83%; A. alternatum was reisolated from 73% of the inoculated roots.
Significance of A c r e m o n iu m Species as Root-Borne Pathogens
Decreases in shoot and root growth in response to isolates of A. rutilum and A. alternatum and their
reisolation from inoculated roots establishes a degree of pathogenicity. Inoculated roots, however,
showed only slight tanning, some yellowing of the vascular cylinder and scant hyphal development in
the cortex. Also, reisolation of the Acremonium isolates from inoculated roots ranged only from 63
to 83%. These characteristics coupled with the inability of the Acremonium isolates to induce shoot
symptoms suggest that they do not function as strong primary pathogens.
The developmental characteristics of A. rutilum and A. alternatum on roots of A. palustris suggest
that these species may be emerging pathogens and/or constituents of root disease complexes. The
modem high-sand-content green and the management practices applied to it are especially stressful
and may predispose A. palustris roots to infection by weak pathogens and/or minor root pathogens
(12). Evidence is growing that close moving and abrasion of roots by sand particles are predisposing
roots to infection by relatively weak pathogens like A. rutilum and A. aternatum. Other weak and
minor root pathogens showing similar characteristics on A. palustris roots include Idriella bolleyi,
Curvularia lunata, and various species of Pythium (7, 8, 9, 10). All of these organisms, including the
Acremonium species, are commonly isolated from the adventitious roots of the same plant. Each
organism alone can induce some symptoms when they infect adventitious roots, but individually they
cannot reproduce the field symptoms. These responses suggest that organisms like A. rutilum, A.
alternatum, I. bolleyi, C. lunata, and some Pythium species are responding to the stressful conditions
applied to A. palustris as a root-disease complex. It is also possible that the stressful management
conditions are contributing to the emergence of pathogens from organisms that are typically benign
under less stressful growing conditions.
Acknowledgments
The research presented was funded in part by grants from the Iowa Turfgrass Institute and the Iowa
Golf Course Superintendents Association.
References
1. Arachevaleta, M., C. W. Bacon, C. S. Hoveland, D. E. Radcliffe. 1989. Effect of the tall fescue
endophyte on plant response to environmental stress. Agron. J. 81: 83-90.
2. Bacon, C. W., J. K. Porter, J. D. Robins, E. S. Luttrell. 1977. Epichloe typhina from toxic tall
fescue grasses. Appl. Environ. Microbiol. 34: 576-581.
3. Clay, K. 1991. Endophytes as antagonists of plant pests. In: Andrews, J. H., S. S. Hirano (eds.),
Microbial Ecology of Leaves, pp. 331-357. Springer-Verlag, New York.
4. Clay, K. 1988. Fungal endophytes of grasses: a defensive mutualism between plants and fungi.
Ecology 69: 10-16.
5. Clay, K. 1987. Effects of fungal endophytes on the seed and seedling biology of Lolium
perenne and Festuca arundinacea. Oecologia 73: 358-362.
6. Fletcher, L. R., I. C. Harvey. 1981. An association of a Lolium endophyte with ryegrass
staggers. N. Z. Vet. J. 29: 185-186.
7. Hodges, C. F., D. A. Campbell. 1996. Infection of adventitious roots of
palustris by
Idriella bolleyi. J. Phytopathol. 144: 265-271.
66

Turfgrass Disease Research

8. Hodges, C. F., D. A. Campbell. 1995. Growth of Agrostis palustris in response to adventitious
root infection by Curvularia lunata. J. Phytopathol. 143: 639-642.
9. Hodges, C. F., D. A. Campbell. 1994. Infection of adventitious roots of Agrostis palustris by
Pythium species at different temperature regimes. Can. J. Bot. 72: 378- 383.
10. Hodges, C. F., L. W. Coleman. 1985. Pythium-induced root dysfunction of secondary roots of
Agrostis palustris. Plant Dis. 69: 336-340.
11. Latch, G. C. M. 1993. Physiological interactions of endophytic fungi and their hosts. Biotic
stress tolerance imparted to grasses by endophytes. Agric., Ecosystems, Environ. 44: 143-156.
12. Salt, G. A. 1979. The increasing interest in 'minor pathogens'. In: Schippers, B., W. Gams
(eds.), Soil-Borne Plant Pathogens, pp. 289-312. Academic Press, New York.
13. Siegel, M. R., C. L. Schardl. 1991. Fungal endophytes of grasses: Detrimental and beneficial
associations. In: Andrews, J. H., S. S. Hirano (eds.), Microbial Ecology of Leaves, pp. 198-221.
Springer-Verlag, New York.
14. Siegel, M. R., G. C. M. Latch, M. C. Johnson. 1987. Fungal endophytes of grasses. Ann. Rev.
Phytopathol. 25: 293-315.
15. Sun, S., A. D. Brede. 1997. Inoculation of creeping bent with Acremonium endophyte. Int.
Turfgrass Soc. Res. J. 8: 925-929.
16. White, J. F., Jr. 1988. Endophyte-host associations in forage grasses. XI. A proposal
concerning the origin and evolution. Mycologia 80: 442-446.

67

Turfgrass Disease Research

Evaluation of Fungicides for Control of Dollar Spot
in Penncross Creeping Bentgrass - 1997
M arkL. Gleason
Trials were conducted at the turfgrass research area of Iowa State University’s Horticulture Research
Station north of Ames, Iowa. Fungicides were applied to Penncross creeping bentgrass maintained at
5/32-inch cutting height, using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000
ft2. The experimental design was a randomized complete block with four replications. All plots
measured 4 ft x 5 ft.
Initial inoculation with the dollar spot pathogen was not fully successful, so fungicide applications
were suspended July 2. After inoculation of the entire plot with pathogen-infested iye grain on
August 4, spray applications began on August 8. Subsequent applications were made at specified
intervals on August 27, August 29, September 5, and September 10.
Dollar spot symptoms appeared in the plot by August 18. Disease development was severe during
late August and early September. Most, but not all, treatments exhibited significantly better dollar
spot control than the untreated check on all three rating dates (see Table 1). No phytotoxicity
symptoms were observed during the trial.
Table 1. 1997 Dollar Spot Trial at ISU Horticulture Station. Plot size 20 ft2, 4 plots/trt; 80 ft2 per
treatment.
Interval
% plot infected1
Trt. Product
Rate/1000 ft2
(days)
Aug 29 Sept 7 Sept 14
—
1 Check
42.5
42.5
40.0
2 Lynx 25 DF
0.5 oz
14
2.8
1.1
1.9
+ chlorothalonil 4 F
3.0 fl oz
3 Lynx 25 DF
0.5 oz
21
19.3
4.5
11.8
+ Heritage 50 DF
0.2 oz
4 Lynx 1% G
24.0 oz
28
18.0
13.0
8.3
5 Bayleton 25 DF
0.5 oz
14
8.0
2.8
9.5
+ Chlorothalonil 4 F
3.0 fl oz
6 Bayleton 25 DF
0.5 oz
21
16.8
8.3
22.5
+ Heritage 50 DF
0.2 oz
7 Bayleton 25 DF
0.5 oz
14
25.0
8.3
19.3
8 Thalonil 4 L
4.0 fl oz
14
37.5
23.8
26.3
+ Heritage 50 WG
0.2 oz
9 Thalonil 4 L
6.0 fl oz
14
9.8
4.3
10.0
+ Heritage 50 WG
0.2 oz
10 Thalonil 4 L
4.0 fl oz
14
40.0
31.8
41.3
11 Thalonil 4 L
6.0 fl oz
14
22.0
7.3
13.8
—
12 CONFIDENTIAL
20.0
23.8
30.0
—
13 CONFIDENTIAL
16.3
9.0
18.8
—
14 CONFIDENTIAL
30.3
16.3
24.0
—
15 CONFIDENTIAL
1.0
0.0
0.1
—
16 CONFIDENTIAL
11.3
3.5
9.5
—
17 CONFIDENTIAL
3.5
0.5
1.1
—
18 CONFIDENTIAL
1.5
0.1
0.1
19 Daconil Ultrex 82.5 WDG
3.8 oz
14
6.5
2.5
5.5
20 IB 11522
4.1 oz
14
18.3
8.3
14.5

68

Turfgrass Disease Research

Trt.
21
22
23

24

25

26

28
29
30
31
32
33
34
35
36
37
38
39

Product
Daconil Ultrex 82.5 WDG
+ Heritage 50 WG
Heritage 50 WG
EXP 10790 (26 GT) 2 SC
ALTERNATE WITH
Heritage 50 WG
+EXP 10790(26 GT) 2 SC
Daconil Ultrex 82.5 WDG
ALTERNATE WITH
Heritage 50 WG
+ Daconil Ultrex 82.5 WDG
Chipco Aliette Signature 80 WG
+ EXP 10790 (26 GT) 2 SC
ALTERNATE WITH
Heritage 50 WG
+ Chipco Aliette Signature 80 WC
+ EXP 10790 (26 GT) 2 SC
Chipco Aliette Signature 80 WC
+ EXP 10790 (26 GT) 2 SC
3336 F
+ Chipco 26019 FLO
CTM 90 WDG
CTM 90 WDG
Turfcide 400
Turfcide 75 WC
Turfcide 75 WC
+ Daconil Ultrex 82.5 WDG
Daconil Ultrex 82.5 WDG
Turfcide 75 WG
+ Spotrete 75 WDC
Spotrete 75 WDG
Turfcide 75 WG
+ Terraguard 50 W
Terraguard 50 W
Eagle 40 W
Eagle 40 W
ALTERNATE WITH
Fore 75 DG

Rate/1000 ft2
3.0 oz
0.2 oz
0.2 oz
3.0 fl oz

Interval
(days)
14
28
14

31.3
33.3

36.3
22.8

41.3
23.0

12.3

5.0

11.8

37.5

25.0

37.5

14

31.3

21.5

20.0

14

2.0

0.0

0.0

14
14
14
14
14

0.9
0.03
45.0
30.0
13.8

0.0
0.0
23.8
22.0
9.0

0.0
0.0
21.3
25.0
11.3

14
14

27.5
23.8

21.8
14.0

28.8
21.8

14
14

30.0
18.8

31.3
5.3

37.5
20.0

14
21
14

6.9
4.0
1.8

3.5
1.4
0.3

9.3
5.3
2.0

1637

10.5

11.9

0.2 oz
3.0 fl oz
3.1 oz

28

0.2
3.1
4.0
3.0

oz
oz
oz
fl oz

28

0.2
4.0
3.0
4.0
3.0
2.0
2.0
4.0
8.0
4.5
3.0
3.0
2.0
2.0
3.0
3.0
3.0
3.0
2.0
2.0
0.6
0.6

oz
oz
fl oz
oz
fl oz
fl oz
fl oz
oz
oz
fl oz
oz
oz
oz
oz
oz
oz
oz
oz
oz
oz
oz
oz

28

6.0 oz

LSD2
‘n = 4
2Least Significant Difference, P=0.05.

69

% plot infected1
Aug 29 Sept 7 Sept 14
4.4
10.8
7.8

14

14

14

Turfgrass Disease Research

Radiometric Assessment of Dollar Spot Severity
on a Creeping Bentgrass Green
M ark L. Gleason, Forrest W. Nutter, Jr., and Nick E. Christians
Introduction
Few guidelines are available to help researchers, consultants, and agrichemical industry personnel to
select a “best” method for assessing the severity of turfgrass diseases. The “best” method should be
easy to use, offer reproducible results, and provide a fast and accurate measure of disease severity.
Rating systems for turfgrass diseases - usually based on visual assessment of test plots - are highly
subjective and vary greatly from person to person. This crazy quilt of methods slows the
development of new disease control products because assessment errors and variability can mask or
distort differences between treatments.
Radiometers have shown promise for improving assessment of some turf diseases. Research in the
early 1990’s by our group (Nutter et al., Phytopathology 83:806-812, 1993) showed that
assessments of dollar spot severity using a commercially available radiometer (Crop Scan Inc.) were
not only more accurate than visual assessments but also faster to make.
This report summarizes a 1997 project to test radiometric assessment against visual assessment in
the “real world” context of fungicide trials. The purpose of the trial was to evaluate radiometry’s
potential to improve the quality of research in new product evaluation.
Procedures
A field trial was conducted in September 1997 on green-height Penncross creeping bentgrass at the
ISU Horticulture Research Farm. Plot design was a randomized complete block with 39 fungicide
treatments (38 treatments selected by agrichemical companies plus one untreated check treatment)
and four replications per treatment. The entire plot was inoculated with rye grain infested with the
dollar spot pathogen, Sclerotinia homeocarpa, approximately one month before plot ratings were
made, and fiingicide treatments began five days after inoculation. Applications of fungicides were
made with a bicycle sprayer using flat fan nozzles at 30 psi, using 5 gal water/1000 ft2.
By the first week of September, plots displayed a wide range of dollar spot severity, from disease-free
to severely infected. On 9 September, all plots were rated visually and radiometrically by four
individuals. Radiometric readings, using a CropScan radiometer at 610 and 810 nm wavelengths, were
made in full sun between 11 am and 2 pm. Both visual and radiometric assessments were made on the
central 1 m2 of each plot.
Results
Statistical analysis of the data showed that:
1. There was a significant interaction between the fungicide treatment and the person doing the
visual assessment, but not the radiometric assessment.
2. The coefficient of variation (a measure of the precision of the measurements; the lower the
number, the more precise the measurements) was 31.5 for visual ratings and 1.4 for radiometric
ratings.
3. For visual ratings, the slope of the graphs comparing one rater’s ratings to that of another rater an indicator of systematic bias (varies with disease severity) among the raters - was significant for
10 of the 12 combinations of four raters; for radiometric ratings, none of the 12 combinations
was significant.
4. The intercept of the graphs comparing one rater’s ratings with another’s - an indicator of a
constant bias (does not vary with disease severity) was significant for 8 of the 12 comparisons
for visual assessment but for none of the radiometric assessment comparisons.

70

Turfgrass Disease Research

5. Rank correlation of treatments between visual and radiometric assessments was relatively high
(91%). However, preliminary analysis of the data suggested that the rank order of several
treatments was significantly different between visual and radiometric methods. This means that
the rating of the relative success of at least some of the fungicide treatments at controlling dollar
spot would have been different with the two methods.
Interpretation
1. Radiometric assessment of dollar spot severity was more precise and less subject to bias by
individual raters than visual assessment.
2. Although the rankings of treatments were fairly similar by the two methods, some treatments
were ranked significantly different by these methods.
3. An earlier study (Nutter et al., 1993) showed that radiometric ratings of dollar spot severity were
also more accurate (i.e., closer to the true level of disease) than visual ratings, and required only
2/3 the time to complete.
Bottom line
The study demonstrated that radiometric assessment has excellent potential for improving the
accuracy, precision, and speed of dollar spot ratings. The method may also have potential to
improve ratings of other turfgrass diseases.

71

Turfgrass D isease Research

Evaluation of Fungicides for Control of Pythium Blight
in Perennial Ryegrass - 1997
M ark L. Gleason
Trials were conducted on a perennial ryegrass fairway at Veenker Memorial Golf Course in Ames, IA.
Fungicides were applied with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1,000 fit2.
Experimental design was a randomized complete block with 4- x 5-ft subplots and 4 replications per
treatment. All treatments began on June 13, when active Pythium mycelium was noted in the grass.
Additional applications were made on June 20 and 27 and July 4, 11, 18, and 25.
Weather during late June, and again in late July, was moderately conducive to Pythium blight
(daytime temperatures 80-95° F, nights 70-80° F, prolonged periods of high relative humidity).
Disease development in the untreated check plots was light on both rating dates (July 24 and 31).
Most treatments showed no symptoms, and had significantly less disease than the check treatment.
No symptoms of phytoptoxicity were observed during the course of the study.

Table 1. 1997 Pythium Blight Trial. Perennial ryegrass fairway at Iowa State University’s Veenker
________ Memorial Golf Course, Ames, Iowa. Plot size = 20 ft2, 4 plots/trt; 80 ft2 per treatment
Interval
Number of infection centers per plot1
Rate/1000 ft2
(days)
Trt. Product
July 24
July 31
—
1 Check
2.0
1.8
0.4 oz
2 Heritage 50 WG
14
0.0
0.0
0.3 oz
14
3 Heritage 50 WG
0.0
0.0
4 Heritage 50 WG
0.2 oz
14
0.0
0.3
2.0 oz
5 Terrazole 35 W
7
0.0
0.0
6 Terrazole 35 W
4.0 oz
7
0.0
0.8
7 Terrazole 35 W
6.0 oz
7
0.0
0.0
—
8 Confidential 1
0.3
0.0
—
9 Confidential 2
1.0
0.0
—
10 Confidential 3
1.3
2.5
—
11 Confidential 4
0.0
1.0
—
12 Confidential 5
0.0
0.0
13 Heritage 50 WG
600 g ai/ha
10
0.0
0.0
14 Aliette 80 WP
9,765 g ai/ha
10
0.0
0.0
LSD2
1.01
1.60
'n = 3.
2Least significant difference (P = 0.05).

72

Turfgrass Disease Research

Evaluation of Fungicides for Control of Brown Patch
in Creeping Bentgrass - 1997
M arkL. Gleason

Trials were conducted at Veenker Memorial Golf Course on the campus of Iowa State
University. Fungicides were applied to creeping bentgrass maintained at 5/32-inch cutting height,
using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental
design was a randomized complete block with three replications. All plots measured 4 ft x 5 ft.
All plots were surrounded by 1-ft-wide strips of untreated turf in order to help create uniform
disease pressure.
Fungicide applications began on June 11. Subsequent applications were made at specified
intervals on June 18 and 25 and July 2, 9, 16, 23, and 30.
Brown patch symptoms were first observed on July 1. Disease development on untreated check

plots, expressed on a 0-5 scale (0=no disease, 1=1-5%. 2=5-10%, 3=10-25%, 4=25-50%,
5=>50% diseased area per plot), was moderately severe on July 4,10, and 24, and severe on July
18. Many, but not all, fungicide treatments exhibited significantly (LSD, P< 0.05) less disease
than the untreated check.
Severe dollar spot developed during the brown patch trial. Dollar spot was rated as the number
of infection centers per plot. NOTE: The trial was organized with brown patch as the target
disease.

No phytotoxicity symptoms were observed during the trial.

73

Turfgrass Disease Research

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76

Fertilizer Trials

1997 Kentucky Bluegrass Fertility Study
Barbara R. Bingaman, Nick E. Christians, & Michael B. Faust
The purpose of this study was to evaluate the response of Kentucky bluegrass to various natural
organic and commercial fertilizers. The experimental plot was an established area of ‘Park’
Kentucky bluegrass at the Iowa State University Horticulture Station north of Ames, Iowa. The soil
in this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 3.3% organic matter, a
pH of 6.5, 3 ppm P, and 80 ppm K. Irrigation was used to supplement rainfall and maintain the turf
in good growing condition.
The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft
and three replications were conducted. Three-foot barrier rows were placed between replications to
facilitate taking clippings.
All fertilizers were applied in the spring and late summer at a yearly rate of 4 lb N/1000 ft2 (Table 1).
There were 11 treatments including eight different fertilizers and an untreated control. Two
soybean-based natural products from Renaissance Fertilizer Co. (6-0-6 and 8-2-6) were applied at 2
lbs N/1000 ft2 followed by 2 lbs N/1000 ft2, and at 3 lbs N/1000 ft2 followed by 1 lb N/1000 ft2.
Com gluten meal from Grain Processing Inc., Safe & Simple (a different particle configuration of
com gluten meal) from Blue Seal Feeds, Milorganite (processed sewage sludge), Poly Plus™ sulfur
coated urea (39-0-0) from LESCO Inc., and Proturf (32-3-10) from The Scotts Company also were
included. These products were applied in split applications at 2 lbs N/1000 ft2. In addition, a liquid
product, Green Lawn, was applied monthly May through September (5 applications) at 0.8 lb N/1000
ft2.
Prior to treatment the plot was mowed to a uniform height of 2 inches A survey of the area was
made before application and turf quality was uniform. Granular fertilizers were applied using ‘shaker
dispensers’. Green Lawn was applied at 30 psi using a C 02 backpack sprayer equipped with TeeJet
#8006 flat fan nozzles. It was mixed in 283 ml of water which translates to an application rate of 3
gal/1000 ft2.
Initial applications were made on May 15. Late summer sequential applications were made on July
31. Green Lawn was applied on May 15, June 11, July 10, July 31, and September 5.
It was a very cool and dry spring. In April, there was only one substantial rainfall with total rainfall
for the month under 1.5 inches. In May and June, the rainfall events were sporadic. This trend
continued in July and August. Because of this, irrigation was heavily relied on to keep the bluegrass in
good growing condition.
Visual turf quality and fresh clipping weight data were taken weekly from May 21 through October 2.
Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf
quality (Tables 2 and 3). Mowing height for taking clippings was 2 inches (Tables 3 and 4).
Data were analyzed with the Statistical Analysis System (SAS) version 6.10 and the Analysis of
Variance Procedure (ANOVA). Fisher’s Least Significant Difference test (LSD) was used to compare
means.
There was no phytotoxicity on the treated bluegrass. The visual quality of all fertilized bluegrass was
significantly better than the untreated control from May 30 through October 2 (Table 2 and 3). The
quality of all fertilized turf did not fall below the acceptable quality level (a rating of 6) for the entire
season. Sulfur coated urea, Proturf, and Renaissance (6-0-6) at 3 lb N followed by 1 lb N/1000 ft2

77

Fertilizer Trials

(treatment 4) produced the best mean quality. The effects of these treatments were not different
from those of com gluten meal, Renaissance (6-0-6) at 2 lb N followed by 2 lb N/1000 ft2 (treatment
3), Renaissance (8-2-6) at 3 lb N followed by 1 lb N/1000 ft2 (treatment 6), and Safe & Simple.
Two commercial fertilizers, Proturf and sulfur coated urea, caused rapid bluegrass quality
improvements following initial and sequential applications. The response to the natural product
fertilizers, com gluten meal, Renaissance (6-0-6 and 8-2-6), and Safe & Simple, generally was slower
but was maintained longer. After the initial treatments, the best quality through May 30 was found in
bluegrass treated with Proturf and sulfur coated urea. By June 4, the visual quality of bluegrass treated
with the soybean products (Renaissance 6-0-6 and 8-2-6) applied at 3 lb N followed by 1 lb N/1000
ft2 was similar to bluegrass treated with Poly-Plus (Table 2 and 3).
Untreated bluegrass produced the least fresh clippings from June 4 through the end of the study. For
the period from June 4 through July 30, the most clippings were from bluegrass treated with
Renaissance (8-2-6) at 3 lb N followed by 1 lb N/1000 ft2 (treatment 6). During this period, similar
weights were produced by Poly-Plus on June 4, June 10, July 9, July 22, and July 30; by Proturf on
June 4; and by Renaissance (6-0-6) at 3 lb N followed by 1 lb N/1000 ft2 (treatment 4) on June 18,
June 25, July 9, July 15, July 22, and July 30. On July 2, com gluten meal had comparable clipping
weights. On July 22 and July 30, the clipping weights in bluegrass treated with Green Lawn and Safe
& Simple were similarly high.
Mean and total clipping weights from untreated bluegrass were significantly less than clippings from
treated bluegrass (Table 4). The largest mean and total clipping weights were from bluegrass treated
with Renaissance (8-2-6) at 3 lb N followed by 1 lb N 1000 ft2 (treatment 6) but they were similar to
those weights from all other fertilizers except Milorganite.
Table 1. Application rates for fertilizer materials used in the 1997 Kentucky Bluegrass Fertility Study.

Materials
Untreated control
Com gluten meal (10% N)
Renaissance (6-0-6)3
Renaissance (6-0-6)3
Renaissance (8-2-6)3
Renaissance (8-2-6)3
Milorganite (6-2-0)
Proturf (32-3-10)4
Safe & Simple (10% N)
Sulfur coated urea (39-0-0)5
Green Lawn (26-4-2)6

1
2
3
4
5
6
7
8
9
10
11
1-r

yearly lbs
N/1000 ft2

initial
application1
Rate
lbs N /1000 ft2

Sequential
application2
Rate
lbs N/1000 ft2

NA
4
4
4
4
4
4
4
4
4
4

NA
2.0
2.0
3.0
2.0
3.0
2.0
2.0
2.0
2.0
0.8

NA
2.0
2.0
1.0
2.0
1.0
2.0
2.0
2.0
2.0
0.8

,

Sequential applications were made on July 30, 1997. Green Lawn fertilizer was applied 5 times (May 15, June 11,
July 10, July 30, and September 5.
These products are being screened for Renaissance Fertilizer Company, 4The Scotts Company, 5LESCO,and
6Green Lawn (applied monthly for a total yearly rate of 4.0 lb N/1000 frj.

78

Fertilizer Trials

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H

Fertilizer Trials

1996-97 Aquatrols Creeping Bentgrass Fertilizer Study
Barbara R. Bingaman, Nick E. Christians, and Michael B. Faust
The purpose of this study was to compare several different fertilizers in a fall fertilization program
on creeping bentgrass maintained at fairway height. The experimental plot was in an established
fairway height area of ‘Penneagle’ Creeping Bentgrass grown on native soil at the Iowa State
University Horticulture Research Station north of Ames, Iowa. The pH of the soil was 8.0, the P
level was 14 lb/A and the K level was 140 lb/A.
The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft
with three replications. Three-foot barrier rows were placed between replications to facilitate taking
clippings. Fertilizers were applied in the fall of 1996 shortly before the bentgrass ceased actively
growing for the season (15-30 days).
The reason for the timing of application was that in the fall photosynthesis was still occurring and
the plants would use the nutrients to increase root growth and carbohydrate levels. The resulting turf
stand, therefore, should have better winter hardiness and an improved response (earlier greenup and
higher quality) in the spring.
Single applications of five fertilizer formulations were made on October 24, 1996. Untreated Urea
(46-0-0), Fertilizer Plus 0.5% (46-0-0), and Fertilizer Plus 1.0% (46-0-0) were applied at 0.5 and 1.0
lb N/1000 ft2. Fertilizer A (17-10-12) and Fertilizer B (22-4-14) were applied at 0.6 lb N/1000 ft2.
An untreated control will be included for a total of 10 treatments (Table 1). The fertilizers were
applied using plastic coated containers as ‘shaker dispensers’.
Post treatment observations were made in the fall of 1996. The plots were checked on October 28
and periodically throughout the fall for phytotoxicity and quality differences. Greenup began on
March 13 and all plots were green by April 18, 1997. Greenup data were recorded using a 9 to 1
scale: 9 = 100% green, 6 = 50% green, 1 = 100% brown turf (Table 1). Visual quality data were
taken on April 18, May 22, and May 30 (Table 1). Visual quality was assessed using a 9 to 1 scale: 9
= best, 6 = lowest acceptable, and 1 = worst quality.
On May 22, the plots were mowed to 3/8” and clippings were collected. Fresh clipping weights were
taken (Table 1). The clippings were dried for 96 hours at 67° C and dry weights were measured (Table
1). The dry tissue was ground to 40 mesh using a Wiley Laboratory Mill and submitted for tissue
nutrient and carbohydrate analysis.
Tissue nutrient analyses were conducted by the Plant Nutrition Lab in the Department of
Horticulture at Iowa State University using an IRIS - AP - Duo, Inductively Coupled Argon Plasma
Analyzer (ICAP). Nitrogen was determined as percent N on a dry weight basis. Tissue content of
boron, copper, manganese, molybdenum, nickel, and zinc were determined in ppm. The percent
content in leaf tissue levels of calcium, potassium, magnesium, and phosphorus also were evaluated
(Tables 2 and 3).
Total non-structural carbohydrate content (TNC) analyses was conducted by the Agronomy Forage
Lab in the Department of Agronomy at Iowa State University. The acid extraction procedure for
removing total non-structural carbohydrate and the phenol-sulfuric acid calorimetric method for
total carbohydrate analysis were used. This methodology followed the guidelines in Chemical &
Biological Methods for Grain & Forage Sorghum, Department of Agronomy, International Programs
in Agriculture, Purdue University. The carbohydrate levels were determined as percent by weight on
a dry matter basis (Table 3).

81

Fertilizer Trials

Root cores were taken on May 29. Five cores were taken from each plot. The cores were split into
three sections by depth (0-5, 5-10, and 10-15 cm). The roots were extracted from the soil using
water and a series of screens with various mesh sizes. The roots were dried at 100° C and dry weights
were taken. The roots were ‘ashed’ in a muffle furnace at 500° C to bum off the root tissue. The
residue was weighed and root weights were calculated by subtracting the ashed remnants from the dry
root weights (Table 4).
Data were analyzed with the Statistical Analysis System (SAS) version 6.10 and the Analysis of
Variance (ANOVA) procedure. Fisher’s least significant difference tests (LSD) were used to compare
means.
There was a difference in spring greenup between the grass in the control and all other treatments.
The grass treated with the fertilizer plus 1% treatment at 1 lb N/1000 ft2 had the highest rating
(Table 1). The fresh clipping and dry clipping weights were also highest for that treatment.
There were significant differences in tissue N content (Table 2). The grass in the control had the
lowest N content as would be expected. The grass treated with the fertilizer plus 1% treatment at 1
lb N/1000 ft2 contained the highest N content.
Phosphorus tissue content was highest in the grass treated with the 17-10-12 fertilizer (Table 3).
This again would be expected because of the lack of P in most of the other treatments. There were
no differences in carbohydrate content among the treatments.
Root weight of the grass varied among the treatments at the 0-5 cm depth only (Table 4). It was
generally the grass treated with the 0.5 lb N/1000 ft2 treatment levels that had the highest rooting.
The exception was treatment 6, the 1 lb N/1000 fit2 treatment with the 0.5% fertilizer plus
treatment.
Table 1. Spring 1997 greenup1, visual quality2 and clipping weight3 data for creeping bentgrass in the 1996-97
Bentgrass Fertilizer Study.
Greenup
Materials
1.
2.
3.
4.
5.
6.
7.
8.
9.

Untreated control
Untreated urea (46-0-0)
Untreated urea (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer A (17-10-12)
Fertilizer B (22-4-14)
LSD 0.05

Visual quality

Clipping weights
from May 22
Fresh
Dry
weights
weights

Rate
lb N/1000 ft2

March
13

May
22

May
30

NA
0.5
1.0
0.5
0.5
1.0
1.0
0.6
0.6

5
6
7
6
6
7
7
6
6

6
6
7
7
7
7
7
6
7

9
9
9
9
9
9
9
9
9

278.5
341.3
355.4
302.2
333.6
341.5
412.9
351.4
341.5

95.1
113.4
115.5
99.1
108.1
111.8
134.5
114.0
110.8

1

NS

NS

74.6
(p>0.08)

22.9
(P>-10)

Fertilizers applied on October 24, 1996.
NS = means not significantly different at the 0.05 level.
‘Greenup was assessed using a 9 to 1 scale: 9 = 100% green, 6 = 50% green, and 1 = 100% brown turf.
Visual quality ratings were based on a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality.
3Height for clippings was 3/8”.

82

Fertilizer Trials

Table 2. Tissue nutrient data for creeping bentgrass clippings1taken May 22, 1997 for the 1996-97 Aquatrols
Bentgrass Fertilizer Study.
% dry
weight

1.
2.
3.
4.
5.
6.
7.
8.
9.

Tissue content (ppm)

Materials

lb N/
1000 ft2

N

B

Cu

Mn

Mo

Untreated control
Untreated urea (46-0-0)
Untreated urea (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer A (17-10-12)
Fertilizer B (22-4-14)

NA
0.5
1.0
0.5
0.5
1.0
1.0
0.6
0.6

2.11
2.18
2.35
2.17
2.30
2.30
2.37
2.27
2.24

7.96
7.09
6.99
6.97
7.18
7.39
7.11
7.37
6.90

5.43
4.71
4.52
5.22
5.27
6.11
5.41
5.31
6.15

46.07
45.47
44.00
43.43
45.20
52.30
48.87
48.50
43.67

2.42
2.15
2.26
2.24
2.28
2.03
1.96
2.43
1.89

0.700
0.700
0.700
0.700
0.823
0.700
0.700
0.700
0.700

21.23
21.20
21.23
20.80
22.47
21.13
21.60
21.67
21.73

NS

1.00

5.25

NS

NS

0.87

0.10
L S D o.05
Fertilizers applied on October 24, 1996.
NS = means not significantly different at the 0.05 level,
lo w in g height for clippings was 3/8”.
2Nickel tissue concentrations were < 0.700 ppm.

Ni2

Z

Table 3. Tissue nutrient and tissue total carbohydrate data for creeping bentgrass clippings1taken May 22, 1997 for
________ the 1996-97 Aquatrols Bentgrass Fertilizer Study.________________________________
Percent by weight
on dry matter basis

Percent Tissue content (%)

Materials
1.
2.
3.
4.
5.
6.
7.
8.
9.

Untreated control
Untreated urea (46-0-0)
Untreated urea (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer A (17-10-12)
Fertilizer B (22-4-14)
L SD 0 .05

lb N/
1000 ft2

Ca

K

Mg

P

Total
carbohydrates

NA
0.5
1.0
0.5
0.5
1.0
1.0
0.6
0.6

1.00
0.98
0.96
0.94
0.96
0.99
0.99
0.98
0.96

1.18
1.19
1.15
1.20
1.14
1.17
1.20
1.22
1.25

0.34
0.35
0.35
0.33
0.36
0.35
0.36
0.35
0.34

0.249
0.247
0.243
0.243
0.261
0.237
0.249
0.275
0.252

29.25
28.99
29.00
29.87
29.92
29.76
29.19
29.16
29.43

NS

NS

NS

0.020

NS

Fertilizers applied on October 24, 1996.
NS = means not significantly different at the 0.05 level,
lo w in g height for clippings was 3/8”.

Fertilizer Trials

Table 4. Root weights1for creeping bentgrass in the 1996-97 Aquatrols Bentgrass Fertilizer Study.
Root weight (g)
Materials
1.
2.
3.
4.
5.
6.
7.
8.
9.

Untreated control
Untreated urea (46-0-0)
Untreated urea (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer Plus 0.5 (46-0-0)
Fertilizer Plus 1.0 (46-0-0)
Fertilizer A (17-10-12)
Fertilizer B (22-4-14)

Rate
lb N /1000 ft2

0 - 5 cm

5 - 10 cm

10 - 15 cm

NA
0.5
1.0
0.5
0.5
1.0
1.0
0.6
0.6

0.37
0.48
0.37
0.36
0.52
0.51
0.43
0.33
0.36

0.08
0.11
0.09
0.09
0.23
0.12
0.08
0.10
0.10

0.02
0.06
0.03
0.03
0.05
0.05
0.04
0.04
0.03

0.12

NS

NS

LSDoos
Fertilizers applied on October 24, 1996.
NS = means not significantly different at the 0.05 level,
^ o o t cores were taken on May 30, 1997.

84

Fertilizer Trials

Creeping Bentgrass Fertility Trial Results - 1997
James R. Dickson and Nick E. Christians
Introduction
Two liquid products and one granular product from the Ringer Corp. were tested against Plant Marvel
(20-5-30) and a control of urea. All treatments were applied at the rate of 4 lbs N per 1000 sq. ft. per
year. The applications were made at two-week intervals over a period of 20 weeks (ten applications)
between May 26 and September 29, 1997. They were applied on Penncross creeping bentgrass growing
on a sand-based golf green which was constructed to USGA specifications.
This report summarizes information on turf visual quality, shoot clipping yield, and root growth. The
clipping yield data were collected once per month beginning July 29th. These clippings were collected
one week after treatment application. Visual quality data were collected, beginning July 7th, during the
weeks when no treatments were applied. Roots samples were collected September 17, 1997.
Methods and Materials
The treatments in this trial were applied in a randomized complete block design with 3 replications on 5 x
5 ft plots (Figure 1). All treatments were diluted in deionized water to yield a volume of 560 ml. They
were then applied to the plots through a C 02 pressurized 3-nozzle wand with TeeJet XR 8005 nozzles.
Visual quality ratings were based on turf color and density. A 9 to 1 scale was employed with 9 being the
best possible quality and 1 representing dead turf.
A non-motorized, Ransom greens mower was used for obtaining clippings. The clippings were placed in
paper sacks and dried at 70” C for at least 48-hours. Their weights were then measured to the nearest
0.01-g.
Six 2 x 15 cm cores were collected from each plot for root weight measurements. These cores were
divided into three 5 cm increments and all six cores within a 5 cm depth interval were combined. The
roots were washed by hand and collected on a No. 40 U.S.A. standard sieve. They were then dried at 70”
C for at least 48 hours. The oven-diy weights were measured to the nearest 0.0001-g prior to ashing at
500° C for at least 24 hours. The ash weights were then measured to the nearest 0.0001-g, and subtracted
from the oven-dry weight.
A statistical analysis of the treatment results for visual quality, the shoot weights (by event and
cumulative) and root weights (by treatment and depth) was conducted using the Statistical Analysis
System (SAS) to determine treatment effects.
Results and Discussion
Significant treatment differences in clipping weight (Table 1) were observed in September data only.
There were no treatment differences for the annual average clipping weights.
There were no treatment differences observed in the data from the root samples (Table 2).
There were no apparent visual quality differences between the treatments until late-September (Table 3).
At that date, it became apparent that the grass receiving the Ringer “C2” treatment and the urea (control)
treatment were producing a darker green color.

85

Fertilizer Trials

Table 1. 1997 mean clipping yields (g)
Date
Treatment

7/29

Ringer[C-l]
C-l +Ringer (5-2-10)
Ringer[C-2]
Plant Marvel (20-5-30)
Control (urea)

31.1
37.3
35.3
35.4
32.6
NS

___________________ LSDq.qs__

8/27

9/24

10/9

32.4
40.7
33.6
32.6
33.0

5.22
6.6
5.1
6.5
5.0

9.9
14.5
11.6
13.0
12.2

NS

NS

Average
19.6
24.8
21.4
21.9
20.7

2.50

NS

Table 2. 1997 mean root yields (g) at three depth intervals
Depth (cm)
Treatment
0-5
5-10

10-15

Average

Ringer[C-l]
C-l +Ringer (5-2-10)
Ringer[C-2]
Plant Marvel (20-5-30)
Control (urea)
___________________ LSDoos___

1.112
1.125
1.240
1.152
1.089

0.481
0.411
0.401
0.448
0.218

0.179
0.230
0.240
0.370
0.193

0.591
0.588
0.627
0.657
0.592

NS

NS

NS

NS

Table 3. 1997 mean visual quality ratings
Date
Treatment

7/07

7/16

7/30

8/13

8/27

9/10

Ringer[C-l]
C-l +Ringer (5-2-10)
Ringer[C-2]
Plant Marvel (20-5-30)
Control (urea)

5.7
6.0
6.0
6.0
6.0

6.7
7.0
7.0
7.0
7.0

6.7
7.0
7.0
7.0
7.0

6.7
7.3
7.3
7.0
7.7

6.7
7.0
7.0
7.0
7.0

NS

NS

NS

NS

NS

L S D o os

86

9/24

10/9

Average

7.0
7.3
7.7
7.0
7.7

6.3
7.0
7.7
7.3
8.0

6.0
7.0
7.7
7.0
8.0

6.45
6.96
7.17
6.92
7.29

NS

0.69

0.49

0.31

Fertilizer Trials

1997 Kentucky Bluegrass Slow Release Fertilizer Study
Barbara R. Bingaman, Nick E. Christians, and Michael B. Faust
The purpose of this study was to evaluate the response of Kentucky bluegrass to various commercial
fertilizers. The experimental plot was an established area of ‘Park’ Kentucky bluegrass at the Iowa
State University Horticulture Station north of Ames, Iowa. The soil in this area was a Nicollet (fineloamy, mixed, mesic Aquic Hapludoll) with 3.0% organic matter, a pH of 6.75, 4.5 ppm P, and 107
ppm K. Irrigation was used to supplement rainfall and maintain the turf in good growing condition.
The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft
and three replications were conducted. All fertilizers were applied in a single application at 2 lb.
N/1000 ft2 (Table 1). There were nine treatments including eight different fertilizers and an
untreated control. Three experimental formulations (44-0-0), sulfur coated urea (39-0-0), Polyon
(42-0-0). ESN (41-0-0), and Nutralene (40-0-0) were supplied by LESCO. In addition, IBDU (31-00) was included.
The fertilizers were applied on May 29, 1997. A pre-treatment survey of the plot showed that the
bluegrass was uniform throughout. The materials were applied using ‘shaker dispensers’. The
materials were ‘watered in’ with the irrigation system. There was no substantial rainfall until midJune so irrigation was used to maintain the plot.
Visual turf quality data were taken weekly beginning on June 4. Quality was assessed using a 9 to 1
scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf quality. Subsequent data were taken weekly
through September 26.
Data were analyzed using the Statistical Analysis System (SAS, version 6.10) and the Analysis of
Variance (ANOVA) procedure. Means comparisons were made with Fisher’s Least Significant
Difference (LSD) test.
Differences in turf quality were detected among the treated and untreated plots from June 4 through
June 25 (Table 1). On June 10, bluegrass treated with either sulfur coated urea or Nutralene had
significantly better quality than the other treated and untreated turf. The quality of bluegrass treated
with the other fertilizers was the same as the untreated turf. By June 18, the quality of all treated
bluegrass, except turf treated with Exp. 1, was better than the untreated control. The quality of
bluegrass fertilized with sulfur coated urea, ESN, and Nutralene was better than the other treated and
untreated turf. On June 25, all fertilized turf had significantly better quality than the untreated turf.
Sulfur coated urea, Exp. 3, ESN, Nutralene, Polyon, and IBDU produced the best quality. From July 2
through September 5, there were generally no quality differences among the fertilized bluegrass but all
fertilized turf had better quality than the untreated control. After September 5, the fertilizer effects
were no longer detected.

87

Mean

Fertilizer Trials

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88

Fertilizer Trials

Creeping Bentgrass Establishment on Sand Greens
Michael B. Faust, Nick E. Christians, and Barbara R. Bingaman
Introduction
This creeping bentgrass establishment trial was initiated 1 Sept. 1996 at the Iowa State University
Horticulture Research Station. The study was conducted to observe the development of creeping
bentgrass from seed grown in a sand-based golf course green.
Sand has become a popular growing medium for golf course greens. The popularity of sand is due to
its physical characteristics. Sand-based greens are more resistant to heavy compaction and provide
increased water infiltration through the subsurface of the green. However, high sand content greens
have drawbacks. Greens constructed of high sand mixes are inefficient recyclers of nutrients due to
low levels of organic matter which results in reduced microbial activity. Nutrient and water retention
is minimal because of low quantities of humus and clay. Essential elements required by turfgrass are
easily leached through the sand medium.
Organic-based nutrient products containing humic substances and soluble carbohydrates were tested to
increase the stability and efficiency of sand-based greens. The sand medium is enhanced through
increased microbial activity, and by growth stimulating compounds supplied by the organic products.
The objectives of the study were i) to compare the effects of five different combinations of organicbased fertilizer products and a control on the establishment of creeping bentgrass (Agrostis palustris
Huds. cv. Crenshaw), and ii) to compare the effects of two different application frequency schedules
on the development of creeping bentgrass.
Materials and Methods
The research was conducted on a 100% sand-based golf green. The rooting material contained 10%
calcium carbonate (CaC03) and had a pH of 8.2. Physical analysis of the sand particles showed the
rooting medium to be within the standards set by the United States Golf Association (USGA) for golf
course green construction. A 900 ft2 area was used to conduct the research. The research was
conducted as a randomized complete block design using six treatments in three replications. Each
experimental plot had an area of 50 ft2.
The list of treatments and application sequences can be found in the treatment protocol section.
Five of the treatments used in the study were liquid fertilizer products, and the sixth treatment was a
granular fertilizer material. Four of the liquid treatments, excluding the control, were general use soil
conditioners designed to stimulate microbial activity and to provide overall improved soil fertility.
The granular treatment was a ground feather meal product containing 56% WIN. All of the liquid
treatments were applied to the turf using a C 0 2 tank and hand-held spray boom. The granular
treatment was applied with a hand-held shaker.
Application of the treatments followed a four-week cycle in September and October of 1996. Week
one was a 1:1:1 (N,P,K) application with 0.5 lb N, P, and K/1000 ft2 being applied to the turf.
Weeks 2-4 used a 2:0:1 (N,P,K) application with 0.5 lb N, and 0.25 lb K/1000 ft2. The treatments
were irrigated after application. A single four-week cycle was completed in 1996. The study was
covered by a tarp in November to protect the newly emerged seedlings during the winter months.
Treatments were resumed in the spring of 1997. Changes were made to the research at this time.
The plots were split into two 25 ft2 sections, doubling the number of individual plots in the trial. A
randomized split block design was used for the 1997 growing season.

89

Fertilizer Trials

The first application in the spring of 1997 was a 1:1:1 starter fertilizer containing 0.5 lb N, P, and
K/1000 ft2. This starter fertilizer application occurred on 1 May 1997. It was applied to both
sections of the split 50 ft2 plot. Application frequency and product quantity changes were initiated
two weeks following the 1:1:1 application. At that time, a switch was made to 2:0:1 treatments.
These treatments were applied for the remainder of the season.
Half of the experimental plots received one 0.5 lb N/1000 ft2 application every two weeks (2
applications per month). The other half of the plot received two 0.125 lb N/1000 ft2 applications
per week (8 applications per month). The high frequency of applications was designed to imitate
fertigation treatments. A total of 1 lb N/1000 ft2 and 0.5 lb K/1000 ft2 was applied each month
from 15 May through 18 July. On 18 July, another change was made concerning the rates of N and
K that were applied through the treatment applications. The N and K rates were reduced by onehalf. This change resulted in 0.5 lb N/1000 ft2 and 0.25 lb K/1000 ft2 being applied to each
experimental plot in a one-month period. The new rates were used for the remainder of the season.
All treatments were irrigated following application.
Clipping tissue samples were removed and collected seven times throughout the 1997 season
following improved maturity of the plots. Individual collection dates were 25 July, 8 and 22 August,
5 and 19 September, 3 October, and 3 November. Clippings were taken 3 to 4 days following the
fourth and eighth 0.0625 lb N/1000 ft2 treatment application when all plots had received identical N
and K rates. The clippings were dried at 68 °C for 48-h, dry-ashed, diluted with acid, and analyzed for
nutrient content by inductively coupled argon plasma spectrometry (ICAP). Plant tissue nitrogen
content was determined using the total Kjeldahl nitrogen procedure (TKN).
Root samples were taken twice during the 1997 growing season. Five one-inch diameter cores were
removed from random locations on each plot at a depth of 6 inches. The roots were washed from the
sand media using a screening technique. The extracted root material was dried at 78 °C for 48-h. An
oven-dry root mass was taken and the samples were placed into a muffle furnace for 12-h at a
temperature of 500 °C. A second root weight was taken following the ashing procedure. The actual
dry root mass of plants grown on each experimental plot was determined by subtracting the dry-ashed
root mass from the oven-dry root mass.
Percentage cover data were taken throughout the duration of the research. One set of data was taken
in the fall of 1996 and the remainder occurred in 1997. Ratings for percentage cover of grass were
between 1 and 100%; where 1% = no grass and 100% = total grass coverage. Visual quality data rating
density and color of each plot was taken in the fall of 1997. Quality was rated on a 1 to 9 scale: 1 =
poor quality and 9 = highest quality.
Results and Discussion
Results from clipping analysis are shown in Tables 1 and 2. The tables have been divided into
macronutrient (Table 1), and micronutrient (Table 2) concentrations of turfgrass tissue.
Differences in tissue concentration between treatments were shown for phosphorus (P) and sulfur (S)
(Table 1). The granular product (Treatment 6) provided significantly higher tissue P and S
concentrations compared to the five liquid treatments. Tissue concentrations of the plants grown
with the granular treatment were on average 18% and 10% higher for P and S, respectively, than
plants supplied with the liquid treatments. Tissue P concentrations were probably higher because the
granular product contained 3% P20 5 (12-3-9 formulation). P was not supplied to plots receiving the
liquid treatments throughout the 1997 growing season.

90

Fertilizer Trials

Application frequency differences occurred for the macronutrients nitrogen (N), Phosphorus (P), and
Sulfur (S) (Table 1). Tissue concentrations were 5%, 7%, and 5% higher for N, P, and S,
respectively, in plots receiving 8 applications/month compared to those receiving 2 applications/
month.
Treatment differences were shown for the following micronutrients: molybdenum (Mo), nickel (Ni),
and zinc (Zn) (Table 2). The molasses product (Treatment 4) provided plants with the highest tissue
Mo and Ni concentrations. Turfgrass grown on the granular treated plots had the lowest tissue Mo
and Ni concentrations. Highest Zn concentrations for plants grown with the granular treatment were
on average 20% higher than plants supplied with the liquid treatments.
The micronutrients Mo and Zn showed differences in application frequency (Table 2). Tissue
concentrations were 8% and 7% higher for Mo and Zn, respectively in plots receiving 8 applications/
month compared to the plots that received 2 applications/month.
A treatment effect developed between treatments for percentage turf cover (Table 3). Data taken 4
and 18 June 1997 showed a 28% average lower percentage turf cover value for grass grown on the
plots treated with the granular material compared to the grass grown on plots receiving the liquid
treatments. Turf coverage was initially slow because nutrients were not immediately available for
plant uptake. The granular treatment was a slow release fertilizer containing 56% water insoluble
nitrogen for sustained plant response. As nutrients were released for plant uptake, differences in
percentage turf cover disappeared. A mean significant difference in percentage turf cover between
treatments was shown for the 1997 growing season because of the slow development of grass plants
supplied by the granular treatment early in the season. Application frequency did not have an effect
on how quickly the grass developed on each plot (Table 3).
Visual quality data taken on 17 Oct. 1997 showed no differences among fertilizer treatments (Table
3). However, plots receiving 8 applications per month had an 8% better quality rating than plots
receiving 2 applications/month. The average quality of turfgrass was highest on granular treated
plots and lowest on plots receiving the 22% humic acid treatment.
No differences occurred between treatments or application frequency for root development of the
grass plants (Table 3). A trend was shown where plants grown on plots treated with molasses had the
highest dry root mass, but this was not a significant difference. Plots treated with the 6-0-0, with
compost derived organic acids, had the lowest dry root mass.
Concl usions
Consistent differences between the organic-based fertilizer products and the control, which contained
no organic material, were not observed in the study. For quicker establishment of ‘Crenshaw’
creeping bentgrass, liquid fertilizers tended to work better than the granular fertilizer. However,
quality was highest at the end of the growing season for plants treated with the granular product.
Plants grown on plots treated with lighter, more frequent applications provided higher visual quality
ratings. This could be attributed to the higher N, P, S, Mo, and Zn concentrations in tissue of plants
grown on plots treated eight times per month compared to those treated only twice. Significant
differences in root growth as affected by the treatments or application frequency did not occur in this
study. Treatments and application frequency schedules will be resumed in the spring of 1998 to
attain second year results.

91

Fertilizer Trials

Treatment Protocol for the Bentgrass Establishment Trial 1996-1997

•

Objectives
-Compare the effects of five different combinations of soil conditioner fertilizers and
control on the establishment of creeping bentgrass.
-Compare the effects of two different application frequency schedules on the growth and
development of creeping bentgrass.

•

Post Germination Treatments (1996)
-Weekly applications at a rate of 0.51b N/1000 ft123456
-Week 1- 1:1:1 N, P, & K
-Weeks 2, 3, & 4- 2:0:1 N, P, & K
-One 4-week cycle was completed in the fall of 1996

•

Post Germination Treatments (1997)
-Initial 1:1:1 treatment application with 0.5 lb N, 0.5 lb P, and 0.5 lb K/1000
-2:0:1 treatment applications were used for the remainder of the season
-Half of the plots received one 0.5 lb N/1000 ft2 application every two weeks (2
applications/month), the other half of the experimental plots received two 0.125 lb
N/1000 ft2 applications per week (8 applications/month)-These rates were used May 15
through July 18. On July 18 the application rates were reduced by one-half.
-All experimental plots received 1.0 lb N/1000 ft2 and 0.5 lb K/1000 ft2per month from
May 15 to July 18.
-Experimental plots received 0.5 lb N/1000 ft2and 0.25 lb K/1000 ft2 per month from
July 18 to end of the 1997 growing season.

•

1:1:1 Treatments (N,P,K)
*1:1:1 treatment applications were made on 15 September 1996, and 15 May 1997.
These treatments contained phosphorus and were applied as a starter fertilizer.
1. 7-24-0 w/5%o humic acid as P source; KN03as K source; remaining N from NH3N 0 4
2. 8-16-4 w/compost-derived organic acids as P source; KN03 as K source; and
remaining N from NH4N 0 3
3. 15% humic a cid; H3P 0 4 as primary P source; KN03 as primary K source; and
remaining N from NH4N 0 3
4. 5-3-2 w/molasses ; H3P 0 4 as primary P source; KN03 as primary K source; remaining
N from NH4N 0 3
5. (Control) H3P 0 4 as P source; KN03 as K source; remaining N from NH4N 0 3.
6. 12-16-8 granular & 12-3-9 granular at 0.51b N/1000 ft2

•

2:0:1 Treatments (N,P,K)
*2:0:1 treatment applications were made 22 September through 6 October
completing a four-week application cycle in 1996. The 2:0:1 treatments
were resumed 15 May 1997 and were continued the entire 1997 growing
season.
1. 22% humic a cid ; KN03as K source; remaining N from NH4N 0 3
2. 6-0-0 w/compost derived organic acids ; KN03 as K source; remaining N from
NH4N 0 3
3. 15% humic a cid; KN03 as K source; remaining N from NH4N 0 3
4. 5-3-2 w/molasses ; KN03 as primary K source; remaining N from NH4N 0 3
5. (Control) KN03 as K source; remaining N from NH4N 0 3
6. 12-3-9 granular ground feather meal product
92

Fertilizer Trials

Table 1. Mean macronutrient tissue concentration and analysis of variance.______________________________
Macronutrients2
Nitrogen
Phosphorus
Potassium
Calcium
Magnesium
Sulfur
Treatment"________ (N)__________ (P)__________ (K)__________ (Ça)_________ (Mg)__________(S}_
------------------------------------------------ % of dry tissue--------------------------------------------1
3.07
0.27bw
1.64
0.22b
0.86
0.40
2
3.02
0.26b
1.61
0.93
0.42
0.21b
3
3.16
0.28b
1.70
0.82
0.39
0.22b
4
3.09
0.28b
1.66
0.84
0.39
0.22b
3.06
0.27b
1.65
5
0.86
0.40
0.21b
6
3.18
0.33a
1.71
0.92
0.42
0.24a
Application
Frequency
3.02b
1.64
2 apps/month
0.27b
0.89
0.41
0.22b
3.17a
0.29a
8 apps/month
1.69
0.85
0.23a
0.40
Anova*
Prob > F
Treatment
App. Freq.
Trt*App. Freq

0.2920
0.0022
0.2540

0.0002
0.0253
0.2883

0.4337
0.1210
0.4189

0.5202
0.3034
0.5964

0.4920
0.2215
0.7605

0.0054
0.0337
0.0762

zData shown are the mean of seven tissue collection dates during the 1997 growing season. Individual collection dates were
25 July, 8 and 22 August, 5 and 19 September, 3 October, and 3 November.
y2:0:l (N,P,K) treatments are described on the Treatment Protocol page in this report.
Significant differences occur at the P < 0.05 level.
wMean separation within columns and parameters by Fisher’s LSD, P < 0.05

Table 2. Mean micronutrient tissue concentration and analysis of variance.
Micronutrients2
Treatment"

1
2
3
4
5
6
Application
Frequency
2 apps/month
8 apps/month
Anova*
Prob > F
Treatment
App. Freq.
Trt*App. Freq

Boron
(B)

Copper
(Cu)

Iron
(Fe)

Manganese
(Mn)

Mdybdamm
(Mo)

Nickel
(Ni)

Zinc
(Zn)

7.20
7.39
7.45
7.38
7.25
6.73

8.99
9.18
9.15
8.90
8.85
8.40

220
255
192
197
212
283

138
135
132
138
133
127

2.84aw
2.70b
2.89a
3.01a
2.73b
2.26c

7.52a
7.12b
7.63a
7.68a
7.66a
6.84b

40.07b
40.20b
41.11b
41.90b
39.09b
49.67a

7.32
7.15

8.80
9.01

229
224

134
134

2.63b
2.85a

7.38
7.44

40.40b
43.62a

0.2465
0.3445
0.9292

0.2884
0.3048
0.5393

0.1795
0.8316
0.2355

0.5162
0.9001
0.7057

0.0001

0.0098
0.6595
0.7526

0.0001

0.0012
0.1250

0.0009
0.0327

zData shown are the mean of seven tissue collection dates during the 1997 growing season. Individual collection dates were
25 July, 8 and 22 August, 5 and 19 September, 3 October, and 3 November.
y2:0:l (N,P,K) treatments are described on the Treatment Protocol page in this report.
Significant differences occur at the P < 0.05 level.
wMean separation within columns and parameters by Fisher’s LSD, P < 0.05

93

Fertilizer Trials

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aq

Environm ental Research

1991 Corn Gluten Meal Crabgrass Control Study - Year 7

NickE. Christians, and Micha

Barbara R. Bingaman,

A study screening com gluten meal (CGM) for efficacy as a natural product herbicide and fertilizer in turf
was begun in 1991 and has been continued on the same plot for seven consecutive years. It is being
conducted at the Iowa State University Research Station north of Ames, IA. The experiment is located in
an area of'Parade' Kentucky bluegrass. The soil in this experimental area is a Nicollet (fine-loamy,
mixed, mesic Aquic Hapludoll) with an organic matter content of 3.6% a pH of 7.1, 4.5 ppm P, and 101
ppm K.
The experimental design is a randomized complete block. Individual experimental plots are 5 x 5 ft with
three replications. There are seven treatments including CGM at 20, 40, 60, 80,100, and 120 lbs/1000 ft2
and an untreated control (Table 1). Because com gluten meal is 10% N, these rates are equivalent to 2, 4,
6, 8, 10, and 12 lb N/1000 ft2. All treatments were made to the same plots as in previous years. The
CGM was applied in a single, early spring preemergence application on April 18, 1997 using 'shaker
dispensers'.
The materials were watered-in with the irrigation system. Supplemental irrigation was used to provide
adequate moisture to maintain the grass in good growing condition.
The plot was monitored throughout the season for turf quality, and weed control. Visual turf quality was
assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf quality. Quality data
were taken on June 5, June 25, July 21, July 30, and August 20 (Table 1).
Weed control was measured by either counting the number of plants or estimating the percentage cover
per individual plot. Broadleaf species (dandelion and clover) and annual grasses (crabgrass) were
surveyed. Data were taken for dandelion and clover on June 5, July 30, and August 20. Crabgrass data
were taken on July 30 and August 20. Crabgrass germination was noted on June 6.
Data were analyzed with the Statistical Analysis System version 6.10 (SAS Institute, 1989) and the
Analysis of Variance (ANOVA) procedure. Fisher’s Least Significant Difference (LSD) means
comparison tests were used to assess CGM effects on bluegrass quality and weed control. Weed control
data were converted to percentage reductions as compared with the untreated controls.
It was an unusually cool, dry, and windy spring. The usual greenup was more subtle this year. Bluegrass
did not respond to CGM treatments as dramatically as in the past. The nitrogen response was slower and
was not uniform within individual plots.
There was no phytotoxicity observed in the Kentucky bluegrass treated with CGM. Turf quality was
significantly better in CGM treated bluegrass than the untreated control for the entire season (Table 1).
The best quality was in turf receiving the highest level of CGM.
Crabgrass populations were low in the untreated controls because the dandelion and clover infestations
were large and well established before crabgrass germination. Com gluten meal at 40, 60, 80, 100, and
120 lb resulted in numerical reductions in the number of crabgrass plants as compared with the untreated
control on August 2 (Table 2). Crabgrass reductions were lower in 1997 when compared with data over
the previous six years (Table 5).
Percentage reductions of dandelion numbers and clover cover were similar to those found in previous
years (Table 6). Treatment with CGM at all levels in 1997 except at 20 lb significantly reduced dandelion
populations (Table 3). Clover cover was significantly reduced by all levels of CGM as compared with the
untreated control (Table 4).

95

Environm ental Research

Table 1. Visual quality1of Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control StudyMaterial
1 Untreated control

lbs CGM
/1000 ft2

lbs N
/1000 ft2

June
5

June
25

July
21

July
30

August
20

Mean
quality

0

0

5

5

5

6

5

5

2

Com gluten meal

20

2

6

6

6

7

6

6

3

Com gluten meal

40

4

7

7

7

7

7

7

4

Com gluten meal

60

6

8

7

8

7

7

8

5

Com gluten meal

80

8

8

8

9

8

8

8

6

Com gluten meal

100

10

8

8

9

8

8

8

7

Com gluten meal

120

12

9

8

9

8

9

9

1

1

1

NS

1

1

LSD 005

Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = poorest turf quality.
NS = means are not significantly different at the 0.05 level.
Table 2. Number of crabgrass plants1in Kentucky bluegrass plots treated in the 1991 Com Gluten Meal Weed
________ Control Study.____________________________________________________________________
Crabgrass counts

Material

1 Untreated control

Percentage Reduction2

lbs CGM
/1000 ft2

July
30

Aug
20

Mean

July
30

Aug
20

0

2

7

5

0

0

0

Mean

2

Com gluten meal

20

8

11

10

0

0

0

3

Com gluten meal

40

1

1

1

67

82

79

4

Com gluten meal

60

1

1

1

83

82

82

5

Com gluten meal

80

2

2

2

0

73

54

6

Com gluten meal

100

1

1

1

67

82

79

7

Com gluten meal

120

1

1

1

67

86

82

NS

6

(P > 0.06)
6

NS

NS

NS

LSDoos

‘These values represent the number of crabgrass plants per plot.
2These values represent percentage reductions in crabgrass plants per plot as compared with the untreated controls.
NS = means are not significantly different at the 0.05 level.

96

Environm ental Research

Table 3. Dandelion counts1in Kentucky bluegrass treated with com gluten meal in the 1991 Com Gluten Meal
Weed Control Study.
Percentage reduction2

Dandelion numbers
June
5

July
30

Aug
20

Mean

21

0

0

0

0

29

16

31

51

2

24

5

7

5

71

78

77

76

2

2

6

3

80

91

81

84

8

0

1

4

1

100

97

88

93

Com gluten meal

10

1

1

6

2

94

98

78

88

Com gluten meal

12

1

0

1

1

94

100

97

97

8

12

20

13

68

56

68

61

Material

lbs N
/1000 ft2

June
5

July
30

1.

Untreated control

0

12

21

29

2.

Com gluten meal

2

8

10

3.

Com gluten meal

4

3

4.

Com gluten meal

6

5.

Com gluten meal

6.
7.

L S D 0.05

Aug
20

Mean

1These counts represent the number of dandelions per plot.
2These values represent the percentage reductions in dandelions per plot as compared with the untreated controls.

Table 4. Percentage clover cover1and percentage reductions per plot2 in Kentucky bluegrass in the 1991 Com
________ Gluten Meal Weed Control Study.____________________________________________________
Percentage clover cover ( % ) 1

Material

lbs N
/1000 ft2

June
5

Percentage cover reduction (%)2

July
30

Aug
20

Mean

June
5

July
30

Aug
20

Mean

1 Untreated control

0

57

47

53

52

0

0

0

0

2

Com gluten meal

2

25

22

12

19

56

54

78

63

3

Com gluten meal

4

13

2

5

7

77

95

91

87

4

Com gluten meal

6

2

3

2

3

96

93

96

95

5

Com gluten meal

8

2

3

2

3

96

93

96

95

6

Com gluten meal

10

10

14

14

13

82

70

74

76

7

Com gluten meal

12

3

2

5

4

94

95

90

93

12

20

15

14

21

42

28

27

L S D ( o.o5)

1Percentage clover cover represents the area per plot covered by clover.
2These values represent the percentage reductions in clover cover per plot as compared with the untreated controls.

97

Environm ental Research

Table 5. Comparisons of the mean percentage crabgrass reductions1in Kentucky bluegrass in the 1991 Com Gluten
________ Meal Weed Control Study through 1997._________________________________________________
Percentage crabgrass reduction (%)

Material

lbs N
/1000 ft2

1991

1992

1993

1994

1995

1996

1997

Oc

1

OA

0

0

0

70

36

15

0

98

97

88

97

79

98

93

98

93

85

82

87

93

93

87

75

69

54

10

79

94

95

86

75

87

79

12

97

100

100

98

84

97

82

26

44

31

39

40

60

NS

1 Untreated control

0

0

0

0

2

Com gluten meal

2

58

85

91

3

Com gluten meal

4

86

98

4

Com gluten meal

6

97

5

Com gluten meal

8

6

Com gluten meal

7

Com gluten meal
LSDq.05

1These values represent the percentage reductions in crabgrass plants per plot as compared with the untreated
controls.
NS = means are not significantly different at the 0.05 level.

Table 6. Mean reductions in percentages clover cover1and number of dandelions per plot2 for 1994-1996 in
Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control Study.
Percentage clover cover
reduction (%)3
Material

lbs N
/1000 ft2

1994

1995

Reduction in
1
dandelion numbers

1996

1997

1994

1995

oz

1996

1997

oz

1 Untreated control

0

0

0

0

0

0

0

0

0

2

Com gluten meal

2

81

56

71

63

71

49

33

24

3

Com gluten meal

4

90

64

82

87

100

77

75

76

4

Com gluten meal

6

98

93

93

95

100

89

79

84

5 Com gluten meal

8

100

76

90

95

98

96

95

93

6 Com gluten meal

10

94

84

92

76

100

98

96

88

7

12

90

93

93

93

100

100

100

97

NS

48

29

26

50

65

60

61

Com gluten meal
L S D ( o.o5)

Percentage clover cover represent the area per plot covered by clover.
2Dandelion counts represent the number of dandelions per plot.
3These values represent the percentage reductions of either clover cover or dandelion counts per plot as compared
with the untreated controls.
NS = means are not significantly different at the 0.05 level.

98

Environm ental Research

1995 Corn Gluten Meal Rate Weed Control Study - Year 3
Barbara R. Bingaman, N ick E. Christians, and Michael B. Faust
Com gluten meal (CGM) was screened for efficacy as a natural product herbicide in turf. This trial is a
long-term study begun in 1995 that will be continued on the same area for several years. It is being
conducted at the Iowa State University Horticulture Research Station north of Ames, IA. The experiment
is in an area of'Ram T Kentucky bluegrass. The soil is a Nicollet (fine-loamy, mixed, mesic Aquic
Hapludoll) with an organic matter content of 3.8%, a pH of 7.0,3 ppm P, and 110 ppm K. The initial
broadleaf weed population exceeded 50% cover on most of the test area.
The experimental design is a randomized complete block. Individual experimental plots are 10 x 10 ft
with three replications. Com gluten meal will be applied at a yearly rate of 40 lb CGM/1000 ft2
(equivalent to 4 lb N/1000 ft2) using four different regimes of single and split applications (Table 1).
Four applications of 10 lb/1000 ft2, split applications of 20 lb/1000 ft2, an initial application of 30 lb plus
a sequential of 10 lb/1000 ft2, and a single application of 40 lb/1000 ft2 were included with an untreated
control.
Initial applications were made on April 18. The second application for treatment 2 was made on June 3,
the third on July 30, and the final on September 5. Sequential application of treatment 3 was made on
August 6.
The experimental plot was checked for phytotoxicity after applications. Visual quality was measured
using a 9 to 1 scale: 9 = best and 6 = lowest acceptable, and 1 = worst quality (Table 1). Visual quality
data were taken on May 21, June 5, June 10, June 18, July 2, July 21, July 30, and August 20. Crabgrass
control was assessed by estimating the percentage crabgrass cover per individual plot on July 30 and by
counting the number of plants per individual plot on August 20 (Table 2). Dandelion control was
measured by estimating the percentage of area covered in each plot on June 5 and by counting the number
of plants per plot on August 20 (Table 3). Clover control was recorded by estimating the percentage of
area covered in each plot on June 5, July 30, and August 20 (Table 4). Weed control data were converted
to express percentage reductions as compared with the untreated control (Tables 2, 3, and 4).
Data were analyzed with the Statistical Analysis System (SAS) version 6.10 and the Analysis of Variance
(ANOVA) procedure. Fisher’s Least Significant Difference test (LSD) was used to compare means.
There were no phytotoxic symptoms detected on the treated bluegrass. Visual turf quality was
significantly better in bluegrass treated with CGM than in the untreated control on each data collection
date except July 21 (Table 1).
Broadleaf weed species were well established when the crabgrass was emerging especially in the
untreated controls. Competition from the broadleaves and the mature turf probably prevented the
establishment of large crabgrass populations within the untreated plots. Consequently crabgrass cover
was low in the untreated turf. Com gluten meal did cause numerical reduction in crabgrass cover as
compared with the untreated control but the differences were not statistically different (Table 2).
Crabgrass numbers were decreased by CGM at 10 lb in four applications (treatment 2), by split
applications at 20 lb (treatment 3), and by an initial 30 lb application followed by 10 lb (treatment 4) as
compared with the untreated control (Table 3). There were more crabgrass plants in turf receiving an
initial application of CGM at 40 lb (treatment 5) than in the untreated control. The level of control with
CGM applied in split applications at 20 lb (treatment 3) was consistent for 1995, 1996, and 1997. In
1997, crabgrass control was better than 1995 and 1996 for CGM at 10 lb applied four times (treatment 2).

99

Environm ental Research

Percentage dandelion cover was reduced by all levels of CGM as compared with the untreated control
(Table 4). In 1997, CGM at all levels except at 30 lb followed by 10 lb (treatment 4) provided > 50%
reductions in cover as compared with the untreated control. In 1996, the CGM at these rates provided >
48% reductions.
Com gluten meal at all levels reduced the number of dandelions as compared with the untreated control
(Table 5). The best control was provided by CGM at 10 lb in four applications and CGM at 20 lb in split
applications.
Percentage clover cover was significantly reduced by CGM at all levels as compared with the untreated
control. Percentage reductions for 1997 were > 64% in all treated turf. Clover control was better in 1997
than 1996 in turf treated with CGM at 10 lb in four applications and CGM at 20 lb in split applications
(Table 7).

Table 1. Visual quality1of Kentucky bluegrass treated in the 1995 Com Gluten Meal Rate Weed Control Study.

1.
2.
3.
4.
5.

Rate
(lb product/1000 ft2)

May
21

June
5

June
10

June
18

July
2

July
21

July
30

Aug
20

Mean

Material

Untreated control
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal

0
10 fb 10 fb 10 fb 10
20 fb 20
30 fb 10
40

6
7
8
7
7

6
7
8
9
9

6
7
8
9
9

6
7
7
8
9

6
9
8
9
9

6
7
7
8
8

6
8
7
8
8

6
8
8
8
8

6
8
8
8
8

1

1

1

1

1

NS

1

2

1

LSD 0.05

'Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst turf quality.

Table 2. Percentage crabgrass cover per plot1in Kentucky bluegrass treated in the 1995 Com Gluten Meal Rate
________ Weed Control Study._________________________________________________________________
Material

Rate
(lb product/1000 ft2)

Percentage crabgrass
cover

Untreated control
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal

NA
10 fb 10 fb 10 fb 10
20 fb 20
30 fb 10
40

22
10
7
9
17

Percentage cover
reductions
%

1.
2.
3.
4.
5.

LSD

NS

o.05

0
54
66
60
22
NS

‘Percentage crabgrass cover data represent the area per plot covered by crabgrass.
2These values represent the percentage reduction in crabgrass cover per plot as compared with the untreated controls.
All treatments were at an annual rate of 4 lb N/1000 ft2. Initial applications were made on April 18. The second application o f
treatment 2 was made on June 3, the third on July 30, and the final on September 5. The sequential application of treatment 3
was made on August 6.
NS = means are not significantly different at the 0.05 level.

100

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Rate
Crabgrass
__________ Material_________(lb product/1000 ft2)______ reduction2

Table 3. Crabgrass counts per plot1 and percentage crabgrass reductions2 in Kentucky bluegrass treated in the 1995 Corn Gluten Meal Rate Weed Control Study for 1995, 1996,

________ and 1997._____________________________________________________________________________________________________________________________________

Environm ental Research

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E nvironm ental Research

1995 Corn Gluten Hydrolysate Weed Control Study - Year 3

NickE. Christians, and Mich

Barbara R. Bingaman,

Com gluten hydrolysate (CGH) was screened for efficacy as a natural herbicide in turf. This trial is a
long-term study started in 1995 that will be continued in the same experimental area for several years. It
is being conducted at the Iowa State University Research Station north of Ames, IA. The experiment is
located in an area of'Ram T Kentucky bluegrass. The soil in this area is a Nicollet (fine-loamy, mixed,
mesic Aquic Hapludoll) with an organic matter content of 3.7% a pH of 7.1, 5 ppm P, and 100 ppm K.
The experimental design is a randomized complete block. Individual experimental plots are 5 x 5 ft with
three replications. There are 3-ft barrier rows between replications. Com gluten hydrolysate was applied
at 5, 10, 15, and 20 lbs product/1000 ft2 (Table 1). These rates translate to 0.5, 1.0, 1.5, and 2.0 lbs
N/1000 ft2. The CGH was dissolved in water and the volumes applied were 700, 1400, 2100, and 2800
ml for the 5, 10, 15, and 20 lb rates, respectively. An untreated control was included for comparisons. A
liquid seaweed foliar feeding product (0.2-0-1), RL-37, from International Ag Labs, Inc. was applied to
the south half of the plots in replication 1 at 3 oz product/1000 ft2. This product is supposed to stabilize
the CGH and prolong the CGH effects. The CGH was applied at 20 psi using a carbon dioxide backpack
sprayer equipped with TeeJet™ #8006 flat fan nozzles.
All treated plots received a single application on May 9. A wind barrier was used as a windbreak to
prevent sprayer drift. The treatments were watered in with irrigation. Supplemental irrigation was used
throughout the season to maintain the grass in good growing condition.
Visual quality data were taken on May 21, June 5, June 10, June 18, July 21, July 30, and August 20.
Visual quality was measured using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality
(Table 1). Weed populations were very high especially in the untreated controls. The percentage of area
per plot covered by all weed species was estimated on May 12 and June 5 (Table 2). On July 30, the
percentage of area per plot covered by broadleaf weed species was determined (Table 2). Crabgrass
control was assessed by counting the number of crabgrass plants per plot on July 30 and August 20 (Table
3). In addition, weed control data were taken on August 20 for dandelion, clover, and black medic. The
number of dandelion plants per plot were counted and the percentages of clover and black medic cover
were estimated per plot (Table 4).
Data were analyzed with the Statistical Analysis System version 6.10 (SAS Institute, 1989) using the
Analysis of Variance (ANOVA) procedure. Fisher’s Least Significant Difference (LSD) means
comparisons were used to assess hydrolysate effects on bluegrass quality and weed control.
No phytotoxic symptoms were detected in any of the treated plots. Turf quality was improved by CGH as
compared with the untreated control plots through July 30. By August 20, there were no differences in
quality between the treated and untreated turf.
Total weed populations were not significantly reduced by CGH (Table 2). On some of the data collection
dates, weed cover was higher in bluegrass treated with CGH than in the untreated control. The majority
of the weed cover was dandelion and clover.
Crabgrass populations were reduced by CGH as compared with the untreated control (Table 3). The
higher rates of CGH provided the best control.
Com gluten hydrolysate at 10, 15, and 20 lb caused numerical reductions in the number of dandelions per
plot but the reductions were not statistically significant (Table 4). There were more dandelions in turf
treated with CGH at 5 lb than in the untreated control. Percentage clover cover was not reduced by CGH.
The percentage cover in all CGH treated turf was equal to or greater than the cover in the untreated
control. Black medic cover was numerically reduced by CGH at 15 and 20 lb but the differences as
compared to the untreated control and the other treated turf were not statistically significant. There was
more black medic in turf treated with CGH at 5 and 10 lb than in the untreated control.

103

Environm ental Research

Table 1. Visual quality1 of Kentucky bluegrass in the 1995 Com Gluten Hydrolysate Weed Control Study.

Untreated control
CGH
CGH
CGH
CGH

1
2
3
4
5

Rate
lb/1000 ft2
NA
5
10
15
20

L S D q.05

May
21
6
7
7
7
8

June
5
6
6
8
8
8

June
10
6
6
7
9
8

June
18
6
6
7
8
8

July
212
6
6
7
7
7

July
30
6
6
7
8
8

Aug
20
6
6
6
6
6

Mean
6
6
7
8
8

1

1

1

1

1

1

NS

1

T Visual quality was assessed using a 9 to 1 scale: 9 = best, 6 = lowest acceptable, and 1 = worst quality.

2Means are significantly different at the 0.07 level.
NS = means are not significantly different at the 0.05 level.

Table 2. Percentage total weed cover1and percentage broadleaf weed cover2 in Kentucky bluegrass in the 1995 Com Gluten
________ Hydrolysate Weed Control Study,
Percentage
Percentage
..... broadleaf coyer ^^
.yX££iLc.?.y.?.F..............................
Rate
May
June
Mean
July
lb/1000 ft2
12
5
30
1
2
3
4
5

Untreated control
CGH
CGH
CGH
CGH

NA
5
10
15
20

%
70
75
62
62
62

62
60
47
43
60

-------- %23
37
32
15
38

66
68
54
53
61

NS

NS
NS
NS
L S D o.05
1These figures represent the total percentage area per plot covered by all weed species.
2These figures represent the percentage are per plot covered by broadleaf weed species.
NS = Means are not significantly different at the 0.05 level.

Table 3. Crabgrass counts1in Kentucky bluegrass in the 1995 Com Gluten Hydrolysate Weed Control Study.

1
2
3
4
5

Untreated control
CGH
CGH
CGH
CGH

Rate
lb/1000 ft2
NA
5
10
15
20

LSDo.0 5
1These values represent the number of crabgrass plants per plot.

July
30
20
12
4
2
4

Crabgrass counts
August
20
27
20
10
13
4

10

10

Mean
24
16
8
7
4
8

Table 4. Dandelion counts, percentage clover cover, and percentage black medic cover1 in Kentucky bluegrass in the 1995 Com
Gluten Hydrolysate Weed Control Study.
Rate
lb/1000 ft2
1
2
3
4
5

Untreated control
CGH
CGH
CGH
CGH

NA
5
10
15
20

Dandelion
count

Clover
cover

Black medic
cover

76
96
64
60
61

%
13
15
15
13
17

------ % ------7
12
12
1
4

NS
NS
NS
LSDo.0 5
lThese figures represent the number of dandelions per plot and the percentage area per plot covered by clover and black medic.
NS = Means are not significantly different at the 0.05 level.

104

Environm ental Research

Carriers for Corn Gluten Hydrolysate
Melissa C. McDade and Nick E. Christians
Com gluten hydrolysate (CGH) is an effective natural preemergent control in growth chamber and
greenhouse environments. The use of a carrier is being considered to stabilize the hydrolysate and
improve its activity in a field situation. Two possible carriers for the CGH are being investigated in
this study, humic acid (RL 37, Liquid Seaweed Foliar from International Ag Labs, Inc., Fairmont,
MN) and a soybean oil (SprayTech Oil from Agro-K Corporation, Minneapolis, MN). The humic
acid is thought to bind with the CGH particles to slow degradation, while the oil is mixed with the
solution of CGH and water to encapsulate droplets of the solution, slowing its dispersal and
degradation in the soil.
This study is taking place at the Iowa State University Horticulture Research Station north of Ames,
Iowa. It is located in an area which has a mature stand of Kentucky bluegrass.
Three rates of CGH, three rates of humic acid, and three rates of oil are being used along with an
untreated control for each factor. The experiment is set up in a factorial design with the treatments
randomized in each of three replications. Each individual plot measures 5’x 5’. The rates used in
this experiment are based on previously effective rates of the CGH and suggested rates for both the
humic acid and the oil. The rates being used are:
CGH

Humic Acid

SprayTech Oil

0 lbs/1000ft2
10 lbs/1000ft2
20 lbs/1000ft2
40 lbs/1000ft2

0 gal/acre
1 gal/acre
2 gal/acre
4 gal/acre

0 pts/acre
0.5 pts/acre
1 pts/acre
2 pts/acre

Treatments were sprayed onto the plots in May. The study area is irrigated as needed to provide a
good growing condition for the turf.
Weed control will be determined by collecting data on percent cover of broadleaf and grass weeds
during the season. Visual quality will also be assessed during the season using a 9 to 1 scale: 9 = best
quality, 6 = lowest acceptable quality, 1 = poorest quality.
Analysis of data will utilize the Statistical Analysis System version 6.12 (SAS Institute, 1989-1996).
This study is ongoing and full data will be available in the 1999 Turfgrass Report.

105

Turfgrass M anagem ent

Evaluating Turfgrass Species for Use Over Buried Steam Lines 1996-98
David D. Minner, Jeffrey J Salmond, John E. Jordan, and Barbara R. Bingaman
This two-year study was initiated in the summer of 1996 to evaluate the performance of various
grass species planted in an area with elevated soil temperatures above a steam line. The 16-inch
diameter steam line has 3.5 inches of 400° F insulation and is buried 3.5 ft below the surface. The
400° F steam temperature has produced summer soil temperatures of 120° F at the 12-inch depth.
The performance of both warm and cool season grasses was monitored over a two-year period.
Kentucky bluegrass, perennial ryegrass, tall fescue, and combinations of these species represent the
cool season species. Three warm season species; zoysiagrass, bermudagrass, and buffalograss, were
used alone and in combination with cool season species. A total of 18 different grass combinations
were planted in the summer of 1996 from either seed or sod. In addition three cultivars, J-554, J-36,
and J-37, were added in nonreplicated plots.
The design of this trial was a randomized complete block with three replications. The experiment
was situated in a 320 x 10 ft area above a buried steam tunnel on the intramural recreational facility
of the ISU campus. Individual plot size was 5 x 10 ft and three replications were included. The
individual plots were placed perpendicular to the length of the steam line so that the middle of each
plot was directly over the steam line and received higher temperatures than either the east or west
section of each plot.
Turf establishment was assessed by rating visual quality, turf color, and percentage green cover. The
initial ratings were taken on October 10, 1996. Additional data were taken in 1997 on April 3 and
May 3 and in 1998 on March 25. Visual quality was assessed using a 10 to 1 scale: 10 = best quality,
6 = lowest acceptable quality, and 1 = worst quality (Table 1). Brown or dormant turf was considered
a negative aspect of overall turf quality. Therefore, winter dormant warm season grasses received
lower turf quality scores based primarily on poor turf color. Turf color was evaluated using a 9 to 1
scale: 9 = best color and 1 = worst color (Table 2). Percentage green turf cover represents the area
per plot covered by green turf (Table 3).
Soil temperatures were taken in 1996, 1997, and 1998 directly over the steam line and in the center
of each plot. Temperature was measured at the 2-, 6-, and 12-inch depths (Tables 4, 5, and 6).
Data were analyzed with the Statistical Analysis System version 6.10 (SAS Institute, 1989) using the
Analysis of Variance (ANOVA) and General Linear Methods (GLM) procedures. Fisher’s Least
Significant Difference test (LSD) was used to compare means where appropriate.

106

Turfgrass M anagem ent

Table 1. Visual turf quality of grass species established for the 1996-98 Steam Tunnel Turf Cultivar Study.
Started
Started
Oct
April
May
Grass Type_______________from sod from seed
1996
1997
1997
Mean
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

Perennial ryegrass
Kentucky bluegrass
Tall fescue
Kentucky bluegrass + p. ryegrass
Tall fescue + K. bluegrass
Zoysiagrass
Zoysiagrass + tall fescue/K. bluegrass
Buffalograss
Buffalograss + K. bluegrass/p. ryegrass
Bermudagrass
Bermudagrass + K. bluegrass/p. ryegrass
Zoysiagrass
Bermudagrass
Buffalograss
Zoysiagrass + tall fescue/K. bluegrass
Bermudagrass +K bluegrass/p. ryegrass
Buffalograss + K. bluegrass/p. ryegrass
Tolf Bermudagrass

X

7
10
4
3
10
10
10
10
9
9
2
5
5
2
5
5
4

X
X
X
X
X
X
X
X
X
X

X
X
X
X
X
X
X
X
X
X

1

LSDoos

5
7

6
8

6
8

-

-

-

6
4
5
5
5
5
5
5
1
1
1
1
1
1
1

7
5
2
2
5
5
4
4
1
1
3
1
1
3
1

5
4
6
6
7
7
6
6
1
2
3
1
3
3
2

1

1

1

‘Turf quality was assessed using a 10 to 1 scale: 10 = best, 6 = lowest acceptable, and 1 = worst quality.
2These grasses were not replicated, they were planted in Rep 2 only. Data from these treatments were not included
in the analyses.
Table 2. Color of grass species established for the 1996-98 Steam Tunnel Turf Cultivar Study.
Oct
Started
Started
April
May
1997
from sod from seed 1996
1997
Grass Type
1 Perennial ryegrass
2 Kentucky bluegrass
3 Tall fescue
4 Kentucky bluegrass + p . ryegrass
5 Tall fescue + K. bluegrass
6 Zoysiagrass
7 Zoysiagrass + tall fescue/K. bluegrass
8 Buffalograss
9 Buffalograss + K. bluegrass/p. ryegrass
10 Bermudagrass
11 Bermudagrass + K. bluegrass/p. ryegrass
12 Zoysiagrass
13 Bermudagrass
14 Buffalograss
15 Zoysiagrass + tall fescue/K. bluegrass
16 Bermudagrass +K bluegrass/p. ryegrass
17 Buffalograss + K. bluegrass/p. ryegrass
18 Tolf Bermudagrass

X
X
X

9
9
-

X
X
X
X
X
X
X
X

X
X
X
X
X
X
X
X
X
X

LSDo.os

March
1998

Mean

7
8

8
8

7
8

8
8

-

-

-

-

7
8
1
1
1
1
1
1
1

7
7
1
1
1
1
1
1
1
1
1
1
1
1
1

8
8
3
3
4
4
4
4
3
3
3
3
3
4
3

1

0.4

9
9
9
9
9
9
9
9
8
9
8
8
9
8
9

2
1
2
2
1

8
7
2
2
5
5
5
5
1
1
3
1
1
3
2

0.2

1

1

1

‘Turf color was assessed using a 10 to 1 scale: 10 = best, 6 = lowest acceptable, and 1 = worst color.
These treatments were not replicated, they were in Rep 2 only. Data for these treatments were not included in the
analyses.

107

Turfgrass M anagem ent

Table 3. Percentage turf cover in plots established for the 1996-98 Steam Tunnel Turf Cultivar Study.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18

Started
from
seed

Started
from
sod

Grass Type

Perennial ryegrass
Kentucky bluegrass
Tall fescue
Kentucky bluegrass + p. ryegrass
Tall fescue + K. bluegrass
Zoysiagrass
Zoysiagrass + tall fescue/K. bluegrass
Buffalograss
Buffalograss + K. bluegrass/p. ryegrass
Bermudagrass
Bermudagrass + K. bluegrass/p. ryegrass
Zoysiagrass
Bermudagrass
Buffalograss
Zoysiagrass + tall fescue/K. bluegrass
Bermudagrass +K bluegrass/p. ryegrass
Buffalograss + K. bluegrass/p. ryegrass
Tolf Bermudagrass

Oct
1996

May
1997

March
1998

Mean

63
90

%
72
93

45
40

65
81

-

—

X

78
100

X
X

40
28
100
100
100
100
100
100
5
60
57
5
63
57
33

80
53
3
3
5
5
10
10
2
2
2
2
5
7
2

77
55
100
100
100
100
100
100
2
4
48
2
11
67
9

33
40
37
35
98
98
100
98
82
85
97
48
83
88
85

58
44
60
60
76
76
78
77
23
38
51
14
41
55
32

12

13

14

33

12

X
X

—

X
X
X
X
X
X

April
1997

X
X
X
X
X
X
X
X
X
X

L S D 0.05

—

—

1^""
' Percentage turf cover was assessed as the area per plot covered by grass.
2These treatments were not replicated, they were in Rep 2 only. Data for these treatments were not included in the
analyses.
Table 4. Soil temperatures (F°) at 2-inch depth for selected grass species included in the 1996-98 Steam Tunnel Turf
Cultivar Study.
Grass Type

October
1996

March
1997

April
1997

December
1997

March
1998

Mean

Kentucky bluegrass
Kentucky bluegrass + p. ryegrass
Tall fescue + K. bluegrass
Zoysiagrass
Buffalograss
Bermudagrass

74
72
73
81
78
75

56
53
53
61
58
56

72
72
72
73
73
73

57
53
56
59
63
61

57
56
56
56
61
61

61
59
59
62
64
63

L S D 0.05

6

3

NS

6

1

2

F°
2
4
5
6
8
10

108

Turfgrass M anagem ent

Table 5. Soil temperatures (F°) at 6-inch depth for selected grass species included in the 1996-98 Steam Tunnel Turf
Cultivar Study.
Grass Type

October
1996

March
1997

April
1997

December
1997

March
1998

Mean

Kentucky bluegrass
Kentucky bluegrass + p. ryegrass
Tall fescue + K. bluegrass
Zoysiagrass
Buffalograss
Bermudagrass

82
78
78
88
86
84

63
58
57
67
64
63

74
73
72
75
75
74

64
60
63
67
69
69

60
57
58
59
64
65

65
62
63
67
68
68

LSDoos

7

4

NS

6

2

2

F°
2
4
5
6
8
10

Table 6. Soil temperatures (F°) at 12-inch depth for selected grass species included in thel996-98 Steam Tunnel
Turf Cultivar Study.
Grass Type

October
1996

March
1997

April
1997

December
1997

March
1998

Mean

Kentucky bluegrass
Kentucky bluegrass + p. ryegrass
Tall fescue + K. bluegrass
Zoysiagrass
Buffalograss
Bermudagrass

93
85
85
93
95

67
62
62
70
69
68

76
76
73
77
77
77

72
69
72
76
78
77

66
66
67
68
72
72

70
68
69
73
74
74

5

5

NS

6

2

3

F°
2
4
5
6
8
10

L S D 0.05

—

109

Turfgrass M anagem ent

Rubber Tire Particles as a Topdressing Amendment for
Intensely Trafficked Grass - 1996-97 data
Jeffrey J. Salmond and David D. Minner
The U.S. discards about 250 million tires a year. The rubber tire recycling industry produces several
grades, sizes, and shapes of processed rubber. All recycled rubber is not the same. Suitable materials
for athletic field use must be free of all metal fibers and slivers, and must be a size that is compatible
with hollow coring and can easily filter into the turf canopy. Some rubber particles may contain
nylon strands from “cord reinforced tires”. It is doubtful that the nylon will limit plant growth;
however, the effect of the nylon on water retention and plant growth is not known. To ensure a
consistent rubber product only a trace of nylon should be present.
Two recycled tire products for turfgrass use are crumb and buffing rubber. Crumb rubber is derived
from chipping whole tires and is available in screened particle sizes ranging from 2 to 50 mm. The
rubber must be screened to remove the metal and nylon cords. Buffing rubber comes from the retread
industry, and it originates when tire treads are ground before being recapped. Little effort has been
made to commercially produce screened buffing rubber due to the declining number of markets for
passenger retreads (U.S. EPA and PES, 1993). Buffing rubber has no metal or nylon because only the
tread is recycled. Particles range from 0.25 to 50 mm. Smaller particles are rounded. However,
many particles are shreds that have a length-to-width ratio of approximately 7:1.
Materials. Experiments were conducted in 1996 and 1997 at the Iowa State University Horticulture
Research Station north of Ames, Iowa, on a mature stand of Kentucky bluegrass. The soil was a
Nicolett series (fine-loamy, mixed, mesic Aquic Hapludoll) with a pH of 6.8. On 6 May 1995, before
treatment with rubber, the plot was mowed at 1.5 cm, solid-tine core aerified, and topdressed with ten
treatments. The topdressing treatments were two types and two depths of crumb rubber, two types
and two depths of buffings rubber, sand, and an untreated control. The size description of rubber
particles is generally expressed by two sieve numbers. For example, a 10/20 mesh rubber indicates
that the rubber passes through a 10 mesh U.S. Tyler sieve and is retained on a 20 mesh U.S. Tyler
sieve. The rubber treatments consist of a coarse crumb and medium crumb size, and a coarse buffing
and medium buffing size (Table 1). The rubber treatments were topdressed at depths of 1 cm and 2
cm. The sand was topdressed at 2 cm and was 92% 35/100 mesh (Table 1). The treatments were
arranged in a randomized complete block design. Each treatment was replicated three times. Overall
plot size was 27.5 m x 2.4 m, and the individual plots measured 1.2 m x 1.8 m (4 ft. x 6 ft.). The
thirty individual plots were split into two rows along the long axis, so that the traffic treatments
could be applied uniformly. The overall plot received 146.7 kg N ha'1 per year and was not supplied
with supplemental irrigation during the traffic periods.
Traffic and evaluations. The Brouwer Traffic Simulator (Brouwer Co., Dalton, Ohio) was used to
supply differential-slip type traffic on 0.3-m (1 ft.) centers across the plots. The double-roller,
traffic simulator was equipped with 1.5-cm football cleats. The width of each roller was 0.6-m.
Traffic was applied on each Monday, Wednesday, and Friday from 31 Mar. through 21 June 1996, to
simulate spring athletic activity. This traffic period was followed by a summer no-traffic period for
turfgrass recovery, from 21 June to 14 Aug. Traffic resumed on 14 Aug. through 8 Nov., to simulate
fall athletic activity. This traffic period was followed by a winter no-traffic period for turfgrass
recovery, 8 Nov. 1996 through 31 Mar. 1997, before a new traffic period was to begin. Treatments
for a second season resumed on 31 Mar. to 7 June for spring traffic, 7 June through 20 Aug. for
spring recovery, 20 Aug. through 20 Nov. for fall traffic, and 20 Nov. 1997 through 31 Mar. 1998
for fall recovery. Assessments of fall recovery were made on 31 Mar. 1998. An average of six
passes were performed each traffic day. A pass consisted of driving the simulator down the length of
the overall plot along 0.3-m centers over the width of the overall plot. The plots were evaluated

110

Turfgrass M anagem ent

after traffic treatments and recoveiy periods for quality, density, color, percentage living turfgrass
cover, percentage topdressing visible, and surface hardness. One traction assessment was taken on 15
May 1997.
Quality, density, and color. Turfgrass quality and density were rated visually on a scale of 1 to 10,
where 1 represented the poorest, 6 represented the lowest acceptable, and 10 represented the best for
each parameter. Turfgrass color was rated also on a scale of 1 to 10, where 1 represented
unresponsive turf (yellow or brown), 6 represented the lowest acceptable color, and 10 represented a
dark green color. Turf quality is an overall visual rating of turf color, density, and texture. Turf
density and retention of a vegetative mat or thatch were considered more important than color when
rating turf quality of treatments that received traffic. Turf density was a visual estimate of plants per
individual plot area. Traffic tolerance was assessed by visually estimating quality and percentage
turfgrass cover.
Turf cover and percentage topdressing showing. Throughout the traffic and recovery periods,
percentages of the following were observed: living turf cover, rubber or sand topdressing, and bare
soil. Percentage living turfgrass cover is the most important parameter for evaluating the
detrimental effects of traffic on athletic turf. Following traffic treatments, turf begins to decline and
the underlying materials, bare soil, sand, or rubber, become visible. The percentage cover values
estimate how much grass, bare soil, sand, or rubber is visible on the surface. Treatments with a high
percentage of turf cover and low percentage of bare soil, sand, or rubber topdressing visible are more
desirable.
Surface hardness and soil moisture. Surface hardness was measured by using a portable drop-hammer
apparatus described by Rogers and Waddington (1990). The 0.5 and 2.25-kg hammers, each with a
length of 0.67 m and a missile diameter of 5 cm, were used. Each hammer was fitted with a Bruel
and Kjaer Model #4393-1639904 accelerometer (Bruel and Kjaer, Decatur, Ga.). The hammers were
dropped from a height of 45.5 cm through a 5.5 cm diameter PVC tube. An accelerometer is
mounted inside the hammer. Upon impact, the accelerometer measures the negative acceleration
(deceleration,
g)of the hammer. A Bruel and Kjaer 2515 Vibration Analyzer was used to record the
impact measurements generated from the accelerometer. A harder, less resilient surface is indicated
by a higher gmax (peak deceleration) value. Five individual drops were taken in different locations
within each plot, averaged, and stored in the vibration analyzer. Gravimetric soil moisture was
measured on two core samples each time hardness was measured.
Traction. Traction measurements, recorded in torque (N-m), were taken with a studded torque wrench
device developed by Canaway and Bell (1986). The apparatus was equipped with 45 kg of weight
(100 lbs) and dropped from a height of 5 cm. Traction was estimated as the amount of torque
required to tear the underlying sod. Three traction assessments were made within each individual plot
on 15 May 1997.
Statistical Analyses. The Statistical Analysis System version 6.06 (SAS Institute, 1990) and Analysis
of Variance (ANOVA) were used to analyze the data. Least Significant Difference (LSD) means
comparisons were made to test between treatments effects on visual quality, density, color, percent
turf cover, and percent topdressing showing (Tables 2). LSD means comparisons were also made to
test between treatments effects on surface hardness (g-max) (Table 2).
Quality, density, and color. The 2-cm depth of medium buffings rubber provided the best overall
visual quality (7.7) and density (7.6) for all the treatments (Table 2). The 2-cm depth of medium
crumb rubber compared with the all crumb materials resulted in the best quality (7.0) and density
(6.8). We did not find any significant differences in color. A positive correlation (R2 = 0.94) existed
between turf quality and turf density. Results for turf density were similar to those found for turf
quality. The sand treatment, coarse crumb rubber at the 2-cm depth, and coarse buffing rubber at the

111

Turfgrass M anagem ent

1-cm depth did not increase the quality or density of turfgrass. The untreated control did not
improve quality and density, and the coarse crumb rubber at the 1-cm depth and the medium crumb
rubber at the 1-cm depth were considered unacceptable for quality and density. No differences were
found for quality and density between the control and the 1-cm depth of coarse crumb rubber.
Turf cover and percentage topdressing showing. The 2-cm depth of medium buffings was the best
treatment in providing turfgrass cover (87.7%)(Table 2). However, the 2-cm depth of medium
buffings rubber showed the least topdressing on the surface (10.2%)(Table 2). The 2-cm depth of
medium crumb rubber provided the best cover and least percentage of topdressing showing for the
crumb materials. Positive correlations existed between turf cover and quality (R2 = 0.9) and density
(R2 = 0.86). The untreated control did not improve. No differences were found for percentage cover
and percentage topdressing showing for the control and the 1-cm depth of coarse crumb rubber. A
negative correlation existed between topdressing showing and quality (R2 = -0.78) and density
(R* = -0.76).
Surface hardness. Many of the surface hardness measurements were out of the proposed range
suggested by Canaway et al. (1990) for the 0.5-kg hammer. All treatments reduced surface hardness
with the 0.5-kg and 2.25-kg hammers compared to the control (Table 2). The 2-cm depth of coarse
crumb rubber had the lowest surface hardness for the 2.25-kg hammer (67.7) and the 2-cm depth of
medium buffings rubber had the lowest surface hardness for the 0.5-kg hammer (80.3). For the twoyear average, the 2.25-kg hammer and soil moisture had a correlation coefficient of -0.704, whereas
the 0.5-kg hammer and soil moisture had a correlation coefficient of -0.598. The 2.25-kg hammer
was more correlated with soil moisture than the 0.5-kg hammer. A comparison between surface
hardness and soil moisture on an annual basis showed strong correlation.
Traction. All of the treatments resulted in traction above the preferred minimum limit of 25 N-m
proposed by Canaway et al. (1990). However, only medium buffings rubber at the 1-cm depth (43.9
N-m) and medium buffings rubber at the 2-cm depth (44.0 N m) had greater traction than the control
(38.4 N-m)(Table 2). The 2-cm depth of medium buffings rubber provided the greatest traction at
44.0 N-m (Table 2).
One of the interesting effects from rubber occurred on frozen ground (Table 3). During the winter
period, results indicate the sand treatment continued to show a higher, harder g-max with the 0.5 and
2.25 kg hammers. Furthermore, on the totally frozen conditions, the soil control is significantly
harder than the high rates of coarse crumb, medium buffing, and coarse buffing and lower rates of the
medium crumb and medium buffings with the 0.5-kg hammer. Using the 2.25-kg hammer on totally
frozen ground shows a significant difference between the sand and soil control as compared to the
high rates of coarse crumb and coarse buffings.
If you are considering using rubber particles for a turfgrass topdressing amendment, Table 4 gives
information pertaining to the amount of rubber needed for a particular area.
R eferences
Canaway, P.M. and M.J. Bell. 1986. Technical note: An apparatus for measuring traction and
friction on natural and artificial playing surfaces. J. Sports Turf Res. Inst. 62:211-214.
Canaway, P.M., M.J. Bell, G. Holmes, and S.W. Baker. 1990. Standards for the playing quality of
natural turf for association football, pgs. 29-47. In: R.C. Schmidt, E.F. Hoemer, E.M. Milner,
and C.A. Morehouse, (eds.). Natural and artificial playing fields: characteristics and safety
features. American Society for Testing and Materials, Philadelphia, Pa.
Rogers, J.N., III and D.V. Waddington. 1990. Portable apparatus for assessing impact characteristics
of athletic field surfaces, pgs. 96-110. In: R.C. Schmidt, E.F. Hoemer, E.M. Milner, and C.A.

112

Turfgrass M an agem ent

Morehouse, (eds.). Natural and artificial playing fields: characteristics and safety features.
American Society for Testing and Materials, Philadelphia, Pa.
U.S. Environmental Protection Agency and Pacific Environmental Services. 1993. Scrap tire
technology and markets. Noyes Data Corp., Park Ridge, N.J.

Table 1. Particle size analysis for sand,*5 crumb
and buffings rubber used as topdressing.
»»
«rubber,
«------? ------Sieve Diameter
Coarse
Medium
Medium
Course
Sand
Size
Mesh
mm
Crumb
Crumb
Buffing
Buffing
Gravel

1/4 in

6.3

0.0

0.0

0.0

0.0

0.0

Fine Gravel

10

2.0

0.4

85.0

23.7

4.5

13.9

Very Coarse

18

1.0

1.5

13.4

56.6

50.6

79.9

Coarse

35

0.5

17.2

0.5

9.1

35.1

6.1

Medium

60

0.25

55.7

0.4

7.1

7.7

0.1

100

0.15

19.1

0.1

2.4

1.6

0.0

<100

<0.15

4.2

0.1

1.0

0.3

0.1

Fine
Veiy Fine

113

Turfgrass M anagem ent

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3

Turfgrass M anagem ent

Table 3. Surface hardness measured with the 0.5-kg and 2.25-kg hammers under frozen field
conditions in 1996 and 1997.
0.5-kg hammer
Treatments

Depth
(cm)

3-9-96f

l-22-97f

2.25-kg hammer

2-23-97§

3-9-96f

l-22-97t

2-23-97§

iZmax
Coarse crumb

1

148

305

193

185

291

212

2

109

159

222

110

201

174

1

165

239

205

200

325

191

2

126

280

246

116

278

220

1

113

282

239

185

275

233

2

104

180

210

112

187

178

1

129

218

313

192

296

280

2

121

200

242

107

259

235

Sand

2

370

271

313

349

327

283

Control

—

162

346

163

241

301

187

56
105
NS
LSD(0.o5) If
t Frozen ground conditions throughout profile.
§ Top 1 cm of profile thawed, remaining profile frozen.
ÜLSD at P < 0.05 according to Fisher’s least significance difference test.
NS = not significant at P ^ 0.05.

65

69

73

Medium crumb
Coarse buffing
Medium buffing

Table 4. Volume and weight of rubber required for various topdressing depths. Data based on a
medium crumb rubber (24% 4/10 mesh; 57% 10/18 mesh) with a bulk density of 25 lbs/ft3.
Depth
Depth
Pounds per
Tons per
Cubic feet
1000 ft2
(cm)
(inches)
1000 ft2
per 1000 ft 2
0.64
0.25
0.32
639
20.8
1.00

0.38

959

0.48

31.2

1.27

0.50

1278

0.64

41.6

2.00

0.75

1918

0.96

62.5

2.54

1.00

2557

1.30

83.3

For example, an area to be topdressed with rubber particles on a football field, between the hash
marks and the twenty-yard lines, is approximately 9000 ft2. At the recommended depth for one
application at 0.25 in. at 639 lbs/1000 ft2, the amount of rubber needed for this area is 5750 lbs or
2.9 tons of rubber.
Equation:
at 0.25 in.

639 lbs =
1000 ft2

x amount of lbs, needed
y amount of ft2 in area

115

Turfgrass M anagem ent

The Effect of Topdressing with Rubber Buffings on
Intensely Trafficked Football Turf - 1996-97 data
Jeffrey J. Salmond and David D. Minner
The rubber recycling industry was introduced to the turfgrass industry about 15 years ago. Since then,
ways have been improved for the incorporation of the rubber into the soil profile. Crumb rubber is
typically the rubber particle used for topdressing turf. The spherical crumb rubber particle shape
allows for easier incorporation of the material into core aerification holes. Buffing rubber has a
length-to-width aspect ratio of 7:1. Buffing rubber, therefore, is not used as often for two reasons.
One, the number of passenger retreads have decreased (U.S. EPA and PES, 1993) and two, the longer
buffings do not filter into the turf canopy or core holes very easily. Other research reported in this
publication indicates that turf injury was less when topdressed with buffing rubber compared to crumb
rubber.
Traffic studies usually consist of a machine simulating a traffic pattern (i.e. Brinkman and Brouwer
traffic simulators). Our goal was to use football players to apply live traffic to buffing rubber. The
objectives of the two-year study were to evaluate buffing rubber as a topdressing and to determine its
effects on seed germination.
Materials. A study was initiated in the summer of 1996 at the Ames High School football field in
Ames, Iowa to evaluate the effects of buffings rubber on a intensely trafficked football turf for a twoyear study. The data were collected during a 5-day football training camp in August of 1996 and
August of 1997. The experimental plots were arranged on a mature stand of common Kentucky
bluegrass (
Poapratensis L.) overseeded with perennial ryegrass ( perenne L.) in an area just
off the playing field. Overall plot size was 1.8 m x 6.1 m (6 ft. x 20 ft.) with individual plots being
0.9 m x 0.6 m (2 ft. x 3 ft.) for a total of 18 plots, 2 rows of 9 plots each (Table 1). Each rubber
treatment was adjacent to a non-rubber control plot. The three medium buffing (MB) treatments
were arranged in a randomized complete block design. The rubber treatments were placed at 0.6, 1.3,
2 cm depths, (1/4”, 1/2” and 3/4” respectively), and replicated three times. The overall plot was
mowed at 1.5 cm and core aerified with 1.3 cm diameter hollow tines and topdressed with the rubber
treatments. Topdressing with the 2 cm treatment was excessive, therefore a remaining amount of
rubber was added later, after settling had occurred, to achieve the desired amount.
The particle size of the medium buffing rubber ranged from 1.0 mm diameter (18 mesh) to 0.5 mm
diameter (35 mesh). The average ratio of length to width for the longest shreds in the buffing rubber
was approximately 7:1.
Percent turfgrass cover was used to assess turf injury from traffic. Temperatures were recorded
within the grass canopy and at a 2.5 cm depth. The surface temperature was measured using a hand­
held infrared probe (Cole-Parmer, Type J, model # H-39652-00, Niles, IL) plugged into a
thermocouple thermometer held at a height of 61 cm above the plot. The effective diameter cone
measured was 15 cm with an area of 182.6 cm2. The 2.5 cm depth temperature was measured with a
30.5 cm, 0.64 cm diameter heavy-duty penetration probe (Cole-Parmer, Type T, model # H-9360126, Niles, IL).
Surface hardness was measured with the Briiel and Kjaer 2515 Vibration Analyzer (Briiel and Kjaer,
Decatur, GA) (Table 2).
The experimental plot was measured to the size of a football exercise apparatus called ‘ropes’. The
object of the exercise is to develop balance of the athlete and to teach foot and eye coordination.
Human athletes, wearing 1 cm high-density plastic cleats, were used to uniformly apply traffic to the
plots during the football practice exercise. The athlete runs through the ropes by placing his foot
into the desired square sector. The coach can instruct the athlete to do various exercises such as a
criss-cross, bunny-hop, side step, diagonal and others. The 1.8 m x 6.1 m apparatus was placed over
the experimental plot area such that each square of the apparatus was over the top of the 0.9 m x

116

Turfgrass M anagem ent

0.6 m treatments and controls. The number of feet to hit each plot was calculated with a hand-held
counter and later recorded to find the total number of feet placed into each individual plot.
Data were analyzed by using the general linear model (GLM) procedure of SAS (SAS Institute, 1990).
Data collected from the two-year experiment were pooled and analyzed using the method for
multiple year, single location as described by Steel and Torrie (1980). Fisher’s least significant
difference (LSD) test was used to compare main effect over-all treatment means for each collection
day and for the temperatures (P < 0.05).
The analysis showed no overall differences between the two years. The number of feet trafficked
into each plot increased from 1996 (Table 3) to 1997 (Table 4). Differences between the rubber
treatments and the untreated control were not apparent on three of the five collection days. The
rubber treatments, however, had a higher percentage of living turfgrass cover throughout the traffic
period than the controls (Table 5). The 0.6, 1.3, and 2 cm depths of medium buffing rubber showed a
57, 71, and 82% increase in turf cover compared to their respective untreated controls by the end of
the traffic treatments, respectively. On the fifth collection day, the medium buffing at 2 cm depth
had an average percent turf cover of 33 and the control had 6% turf cover. Likewise, the 1.3 cm
depth of rubber had an average turf cover of 32% and the control had 9% turf cover. The 1.3 and
2.0 cm depths showed a 50% increase in turf cover compared to the 0.6 depth of rubber by the end of
the traffic treatments (Table 5). The 0.6 cm depth of rubber had 15% turf cover compared to 32%
and 33% turf cover for the 1.3 and 2 cm depths, respectively. The 2 cm depth of rubber provided
more turfgrass cover on four of the five collection days (Table 5).
Rubber treatments did not result in a significant difference between subsurface temperatures compared
to control treatments. Surface temperature increased 0.4 to 2.4 °C for the rubber treatments versus
the controls (Table 6). Subsurface temperatures verily that the rubber treatments are slightly cooler
than the controls. Subsurface temperatures of the rubber treatments were slightly cooler (0.4 to 0.9
°C) than the control plots (Table 6).
Table 1. Treatments and the arrangement of treatments in the experimental plots.
2
3
C
1
1
C
C
C
2

c

3

C

1

Rep I

2

C

C

Rep II

3
Rep III

Depths
1. 1/4” medium rubber buffings (0.635 cm)
2. 1/2” medium rubber buffings (1.27 cm)
3. 3/4” medium rubber buffings (1.9 cm)
C = control

Table 2. Initial surface hardness (gmaY) before traffic.
Treatments
1. 0.6 cm MB
2. control for trt 1
3. 1.3 cm MB
4. control for trt 2
5. 2 cm MB
6. control for trt 3
MB = Medium rubber buffing.
§ Treatment means are the average of three replications.

117

62§
67
61
67
60
68

C

C

1
left over

Turfgrass M anagem ent

Table 3. Average number of feet in 1996 hit into each plot.
Collection day
1
2
3
Avg. feet per plot
130
330
550
Total number of feet
2,340
5,940
9,900
for 3 reps
Table 4. Average number of feet in 1997 hit into each plot.
Collection day
1
2
3
Avg. feet per plot
380
441
330
Total number of feet
for 3 reps

6,840

7,938

5,942

4
445
8,010

5
346
6,228

Total
1,801
32,418

4
587

5
431

Total
2,169

10,566

7,758

39,044

Table 5. Percentage turfgrass cover after each day of traffic. Data are the average of 1996 and
________ 1997.____________________________________________________________________
--------------------------- Collection d a y ----------------------------1
2
3
4
5

Treatments

Percentage turfgrass cover
0.6 cm MB
99
86
70
33
57
control for trt 1
91
75
27
1.3 cm MB
98
80
73
21
97
80
control for trt 2
59
23
2 cm MB
97
83
78
38
control for trt 3
96
72
47
20
6
NS
NS
NS
LSD(005) 1
MB = Medium rubber buffing.
LSD at P < 0.05 according to Fisher’s least significance difference test.
1.
2.
3.
4.
5.
6.

15
7
32
9
33
6
7

NS = not significant at P ^ 0.05.

Table 6. Surface and subsurface temperatures of the rubber treatments and their control plots. Data
are the average of 1996 and 1997.
Treatments
Surface!
Subsurface^
(canopy)
(2.5 cm)

— °c —
1.
2.
3.
4.
5.
6.

0.6 cm MB
control for trt 1
1.3 cm MB
control for trt 2
2 cm MB
control for trt 3
LSD(oos) f

32.1
31.7
31.8
31.4
33.7
31.3
NS

28.9
29.3
28.5
29.3
28.3
29.2
NS

MB = Medium rubber buffing.
f Surface temperature taken with hand-held infrared probe.
i Subsurface temperature took with heavy-duty penetration probe into soil at a 2.5 cm depth.
| LSD at P £ 0.05 according to Fisher’s least significance difference test.
NS = not significant at P ^ 0.05.

118

Turfgrass M anagem ent

The Effect of Deicing Chemicals on Turfgrass
D avid D. Minner and Barbara R. Bingaman
Runoff from deicing products applied to walkways and other hard surfaces can result in accumulation
of salts in turf borders. The purpose of this study was to assess the level of damage caused by several
common deicer products. Our approach was to simulate a brine runoff by spraying salt solution
directly on turf plots throughout the winter and evaluating injury during the growing season.
M ethods:
Year one of this field study was conducted from February through October, 1996 at the Iowa State
University Horticulture Research Station, Ames, Iowa. Year two was run from January through
October, 1997 at Iowa State University, Ames, Iowa. Individual experimental plots were 0.6 x 1.2 m
with three replications. Because of possible deicer runoff, each individual plot was completely
surrounded by a 0.3-meter border. The experimental design was a randomized complete block with
25 treatments.
Treatments containing potassium chloride (KC1), 30% urea + 70% calcium chloride (CaCl2), 50%
urea [CO(NH2)2] + 50% CaCl2, urea, rock salt (NaCl2), Safe Step (50% NaCl2 + 50% KC1), and
magnesium chloride(MgCl2)- hexahydrate (47% MgCl2 and 53 % water). A control, treated with
water, was included for comparison. Application rates of 68, 136, and 272 g m'2 were used for all ice
melt products, except MgCl2 - hexahydrate, to simulate typical amounts of product used by the ice
melt industry (Table 1). To keep the salt component of each ice melt product on an equal weight
basis, the rate of MgCl2 - hexahydrate was increased to compensate for the additional weight of the
water. The MgCl2 - hexahydrate rates at 136 and 306 g/m2 compare on an equal weight basis with the
other ice melt products at 136 and 272 g/m2.
The deicers were dissolved in water and applied as a brine solution using a carbon dioxide backpack
sprayer. One liter of brine solution applied to the 0.6 by 1.2 m. plots simulated the melting of
approximately 0.3 cm of ice. TeeJet flat fan EVS #8008, white nozzles were used at 45 psi.
Windbreak ‘cages’ were employed to prevent drift of the materials. Neither runoff nor drift was
observed after treatment differences became apparent.. The turf was mowed weekly at 6.4 cm and
no supplemental irrigation was supplied.
Nine sequential applications of each rate were made per season. Total amounts per season totaled
610, 1220, and 2440 g m‘2 for each ice melt product (1322, 2611, and 5188 g/m2for MgCl2 hexahydrate). Year one applications were made from 22 February through 19 March 1996 and year
two from 14 January through 26 February 1997.
Soil samples were taken from each plot spring and fall 1997. Samples were taken 4” deep and 10
samples were taken per plot. The soil was air dried, ground, and analyzed for electroconductivity by
the Plant Nutrition Lab in the Department of Horticulture (Table 5).
Phytotoxicity and percent living plant material data were taken at greenup and early spring 1996 and
1997 (Table 1). Phytotoxicity was assessed using a 10 to 1 scale: 10 = no turf injury and 1 = foliage
completely brown.
Turf cover, turf quality, and turf color data were collected in spring and summer of both years. Turf
cover was assessed as the percentage of area per plot covered by turfgrass species. Turf quality was
measured using a 10 to 1 scale: 10 = best quality, 2 = weeds only, and 1 = no green material. Turf
color was defined using a 9 to 1 scale: 9 = best, 1 = worst color, and 0 = no turf present.

119

Turfgrass M anagem ent

On 29 August 1996 and 1997, the study areas were treated with Roundup to kill all remaining
vegetation in preparation for fall seeding. The intent was to evaluate what effect residual salt levels
may have on seedling establishment of turf. The dead plant material was removed prior to seeding.
The plots were seeded with perennial ryegrass at 59 g-m'2 using a drop spreader. Ryegrass seedling
vigor and percentage ryegrass cover data were taken on 10 October 1996 and (Table 4). Ryegrass
seedling vigor was assessed using a 10 to 1 scale: 10 = best and 1 = worst vigor. Percentage ryegrass
cover was determined as the percentage of area per plot covered by ryegrass.
Data were analyzed using the Statistical Analysis System (SAS) version 6.12 and the Analysis of
Variance (ANOVA) procedure. Fisher’s least significant difference (LSD) tests were used to test for
treatment effects on turfgrass factors.
Results:
Deicer treatments applied during the winter caused a bleaching and light tan appearance to the
dormant turf. This appearance remained visible for some treatments during spring green-up and was
rated as phytotoxicity. The average of phytotoxicity on 10 April and 9 May indicated that all
treatments had significantly more turf injury than the untreated control (Table 1). There was a
significant increase in turf phytotoxicity as rate increased from 610 to 1220 g-m'2 for each ice melt
material except urea. Urea alone or in combination with CaCl2 67/33 caused severe phytotoxicity
even at the low rate of 610 g m'2. Urea-CaCl2 30/70 at 610 g-m'2 had significantly less phytotoxicity
and significantly more living green plant material than all other ice melt treatments. When MgCl2 hexahydrate is compared to other ice melt products at the same rate (i.e. approximately 1322 g m'2,
compare treatment 23 with treatments 3, 6, 9, 12, 15, 18, 21, and 27) it produced less phytotoxicity
than urea-CaCl2 combinations, KC1, urea, rock salt, and CaCl2, but was similar to Safe Step. However,
when MgCl2 and other deicers are compared on an equal weight basis, without the extra water present,
MgCl2causes more phytotoxicity than urea-CaCl2 combinations 30/70 or 50/50, KC1, rock salt, Safe
Step and CaCl2 (i.e. compare treatment 23 with treatments 2, 5, 8, 11, 14, 17, 20, and 26).
Percent turf and weed cover (Table 2) and turf quality and color (Table 3) were evaluated during the
summer to determine recovery following deicer affects. A reduction in percent turfgrass cover caused
by winter application of ice melt products was still noticeable during late summer. The untreated
control had 91 percent turf cover while other ice melt treatments ranged from zero to 89 percent
turf cover. The only treatments that had turf cover statistically similar to the untreated control
were at the low application rate, 610 g-m"2. These included urea-CaCl2 30/70 and 50/50, KC1, rock
salt, Safe Step, and CaCl2. Urea, urea-CaCl2 67/33, and MgCl2 - hexahydrate had significantly reduced
turf cover compared to the untreated control. The area of each field plot covered by turf, weeds, or
bare soil was evaluated with the sum of the three types of cover equal to 100%. High rates of urea
(treatments 7, 9, 10, 15, and 16) severely reduce turf and weed cover, and resulted in 50 to 97% bare
soil. It is veiy clear that urea should not be used alone or as a major component of an ice melt
product. However, it is apparent that moderate percentages of urea combined with CaCl2 (i.e. ureaCaCl2 30/70 or 50/50) and applied at 610 g-m'2 can enhance turf cover (Table 2), quality and color
(Table 3).
Deicer treatments that resulted in poor turf cover also had higher weed cover. Treatments with high
rates of urea (trts 7, 9, 10, 15, and 16) substantially reduced both turf and weed cover and resulted in
plots with mostly bare soil showing (Table 3).
Average turf quality and color for July and August, 1996 are presented in Table 4. At 610 g-m'2 all
urea + CaCl2 combinations, KC1, rock salt, Safe Step, and CaCl2 were statistically similar to the
untreated control. Urea and MgCl2 had inferior turf quality.

120

Turfgrass M anagem ent

At 1220 g m'2 all deicer treatments had significantly poorer turf quality than the untreated control,
however, urea + CaCl2, 30/70, KC1, and Safe Step were superior to urea + CaCl2 50/50 or 67/33, urea,
rock salt, and MgCl2 (Table 3). At 2440 g m'2 all deicer treatments were similar and had very poor
turf quality (Table 3).
The elements in some deicer compounds are also essential elements for plant growth. Turf color was
evaluated to determine if any beneficial color enhancement occurred, especially from urea treatments
containing nitrogen. Urea combinations with CaCl2 enhanced turf color. Urea + CaCl2 50/50
provided the best color enhancement and was superior to the untreated control (Table 3).
In the fall of 1996, the entire study area was killed with a non-selective herbicide and reseeded with
perennial ryegrass to determine if winter deicer products inhibit fall re-establishment. As indicated
earlier some ice melt treatments (treatments 6, 7, 9, 10, 14, 15, 16, and 19) caused a severe
reduction in turf and weed cover that resulted in a high percentage (20 to 97%) of the plot area
covered by bare ground (Table 2). This indicates that urea and rock salt, used at high rates, can
produce severe grass injury. Poor re-establishment of perennial ryegrass for the urea and rock salt
treatments (treatments 7, 9, 10, 14, 15, 16, and 19) indicated that there was a residual affect in the
soil that may prolong re-establishment of affected areas near sidewalks.
Summary:
Seven different deicer products were sprayed directly to turf on nine different dates during the winter
to evaluate possible injury to Kentucky bluegrass turf. Injury was dependent upon deicer type and
rate of application. On an equal weight basis, urea and rock salt produced more turf injury than Safe
Step, CaCl2, KC1, and combinations of urea + CaCl2 30/70. Urea at rates greater than 610 g m'2 yr,
and rock salt at rates greater than 2440 g-m'2 yr can cause severe vegetation loss and poor re­
establishment of turf from seeding. Calcium chloride combined with small amounts of urea (30%)
enhanced turf color.

121

Turfgrass M anagem ent

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55

Turfgrass M anagem ent

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Table 5. Electroconductivity for soil samples from field plots treated with deicer products for the 1997 Brine Deicer Study.
Electroconductivity
_____ [mmho/cm]_____
Deicer product

1
2
3
4
5

6
7

8
9

10
11
12
13
14
15
16
17
18
19

20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43

Rate
oz/yd

Total
applied
oz/yd

NA
NA
Untreated Control
2
18
30% Urea [CO(NH2)2] + 70% Calcium chloride (CaCl2)
4
30% Urea [CO(NH2)2] + 70% Calcium chloride (CaCl2)
36
30% Urea [CO(NH2)2] + 70% Calcium chloride (CaCl?)
8
72
50% Urea [CO(NH2)2] + 50% Calcium chloride (CaCl2)
2
18
4
36
50% Urea [CO(NH2)2] + 50% Calcium chloride (CaCl2)
8
72
50% Urea fCO(NH,),] + 50% Calcium chloride (CaCl,)
2
18
61% Magnesium chloride [MgCl2] (47% a.i.) + 39% Urea [CO(NH2)2]
4
61% Magnesium chloride [MgCl2] (47% a.i.) + 39% Urea [CO(NH2)2]
36
8
61% Magnesium chloride [MgCl2] (47% a.i.) + 39% Urea [CO(NH2)2]
72
2
Potassium chloride (KC1)
18
4
36
Potassium chloride (KC1)
__ 8 ...... ___ 72
Potassium chloride (KC1)
2
18
Urea [CO(NH2)2]
4
Urea [CO(NH2)2]
36
8
72
Urea [CO(NH,),]
2
18
Rock salt (NaCl2)
4
36
Rock salt (NaCl2)
8
72
Rock salt (NaCl2)
2
Safe Step [50% (NaCl2) + 50% Potassium chloride (KC1)]
18
4
Safe Step [50% (NaCl2) + 50% Potassium chloride (KC1)]
36
8
72
Safe Step [50% (NaCl2) + 50% Potassium chloride (KC1)]
4
Magnesium chloride (MgCl2) (47% a.i.)
39
Magnesium chloride (MgCl2) (47% a.i.)
9
77
Magnesium chloride (MgCl2) (47% a.i.)
17
153
2
18
Calcium chloride (CaCl2) pellets
4
Calcium chloride (CaCl2) pellets
36
Calcium chloride (CaCl?) pellets
8
72
42% Ammonium nitrate (NH4N 03)+58% Calicum chloride (CaCl2)
2
18
42% Ammonium nitrate (NH4N 03)+58% Calicum chloride (CaCl2)
4
36
42% Ammonium nitrate (NH4N 03)+58% Calicum chloride (CaCl^)
8
72
54% Ammonium sulfate [(NH4)2S04] + 46% Calicum chloride (CaCl2)
2
18
4
54% Ammonium sulfate [(NH4)2S04] + 46% Calicum chloride (CaCl2)
36
54% Ammonium sulfate [(NH4)2S04] + 46% Calicum chloride (CaCl2)
8
72
75% Rock Salt (NaCl2) + 25% Calicum chloride (CaCl2) flakes
2
18
75% Rock Salt (NaCl2) + 25% Calicum chloride (CaCl2) flakes
4
36
75% Rock Salt (NaCl2) + 25% Calicum chloride (CaCl2) flakes
8
72
67% Rock Salt (NaCl2) + 33% Calicum chloride (CaCl2) flakes
2
18
67% Rock Salt (NaCl2) + 33% Calicum chloride (CaCl2) flakes
4
36
67% Rock Salt (NaCl2) + 33% Calicum chloride (CaCl2) flakes
8
72
50% Rock Salt (NaCl2) + 50% Calicum chloride (CaCl2) flakes
2
18
4
50% Rock Salt (NaCl2) + 50% Calicum chloride (CaCl2) flakes
36
50% Rock Salt (NaCl2) + 50% Calicum chloride (CaCl2) flakes
8
72
LSDqo5____________________________________________________

126

Spring

Fall

0.97
0.88
2.91
0.99
4.50
0.95
2.15
1.06
2.45
0.95
0.97
4.00
5.27
1.44
2.33
0.95
0.98
3.08
3.23
0.85
1.43
1.11
1.85
1.07
...... 1.88 ......... 1.28....
"0*83*
2.60
1.51
3.50
5.32

1.88

0.88

4.20
6.75
2.16
3.68
3.80
1.47
3.13
2.87
1.67
1.58
1.55
1.70
2.58
3.03
2.47
3.13
4.97
0.99
2.76
1.43

1.19
1.58
0.89
1.03

1.10
1.10
1.18
1.06

1.12
0.88
0.97
0.96
0.75

0.86
0.86
0.72
0.89
0.84
0.82
1.04
1.62
0.63

0.68
0.71
0.65

0.66

1.15

0.69
0.55
0.55
0.59

1.70

0.76

1.11

Soil M odification and Sand-based System s

Stabilizing Sand-based Athletic Fields With Enkamat
David D. Minner and Jeffrey J. Salmond
O bjectives
The objectives of the study are to determine the proper placement depth for Enkamat and to
evaluate it as a stabilization material for sand-based systems.
Sand-based systems are widely used for sports fields to reduce compaction and promote rapid
drainage. Sand is an excellent media for drainage of the rootzone, but it can result in an unstable
surface, especially when the grass has worn away. New technologies are being developed to stabilize
sand-based fields. Fibrillated polypropylene fibers woven into a synthetic black backing
(SportGrass™), fibrillated fibers (TurfGrids®), and interlocking mesh elements (Netlon, Ltd.) are a
few of the products available for stabilizing sand-based athletic fields. Reinforcement material can be
grouped into two categories: those that form a horizontal layer at or near the turf surface and those
that are comprised of individual discrete units that are mixed into the rootzone layer (Baker, 1997).
Enkamat consists of a bulky mat made from nylon threads that are fused together where they cross.
The thickness of this three-dimensional mat ranges from 11/16- to 7/8-inch and has an open
construction leaving 90% of its volume to be filled with sand or soil (Baker, 1997). Enkamat has
been used in combination with other geotextile material (polyester covers, TurfArmor®, and
plywood) to protect the grass surface when special events are held on stadium fields.
Demonstration plots have shown that if the Enkamat is exposed to the surface, during field wear,
there is a potential for tripping with cleated shoes. We are interested in how deep Enkamat needs to
be placed to prevent exposure to the surface and if there is any benefit from field stabilization with
Enkamat.
M ethods
A 50 ft by 50 ft sand-based pad, six inches deep, was constructed in the fall of 1997 for evaluation of
Enkamat at the Horticulture Research Station, Ames, Iowa. The sand-based system was placed over a
4-inch gravel blanket with a network of 4-inch drain pipes. The sand rootzone is described below and
no other physical amendments were added. The study area is automatically watered and is part of our
new sand-based sports turf research facility. Table 1 shows the treatments that were installed to
evaluate Enkamat as a reinforcement material for sand-based athletic fields.
TREATMENTS
Table 1. Treatments used to compare the reinforcement capability of Enkamat on sand-based
athletic fields.
T rt

Synthetic

1
2
3

Sand
Enkamat
Enkamat

Depth of synthetic below sod
(sod contains 0.75 inches of soil)

Comments

—

Standard for the industry

0 (0.75 inches)
1 (175 inches)

127

Soil M odification and Sand-based System s

The experimental design is a randomized complete block with three treatments and three
replications. Individual treatment plots are 13 ft. by 16 ft. The large size of the plots will allow for
study of an additional factor by sub-dividing each treatment plot. Potential split plot treatments
could include typical field management factors such as topdressing or drill seeding. Enkamat will be
placed at two different depths to ensure that it will not become exposed during intense traffic. We
will determine if Enkamat provides any advantage for turf growth, even when placed deep enough in
the soil profile to avoid surface exposure. Enkamat will be placed at two depths, even with the
surface of the sand base or one inch below the surface of the sand base. In treatment #2 the top of
the Enkamat is even with the top of the sand surface. When sodded, the top of the Enkamat is then
covered by 0.75 inches of soil. In treatment #3 the top of the Enkamat is placed one inch below the
surface of the sand. When sodded, the top of the Enkamat is then covered by 1.75 inches of soil.
The study area was sodded on 7 November 1997 with ‘Midnight’ Kentucky bluegrass containing 0.75
inches of a Nicollet fine loam soil. Sod laid on sand-based fields is the current standard for the
industry. In northern climates sand-based fields are seldom established from seed. Enkamat
reinforced fields will need to show an improvement over the conventionally accepted sand fields that
are sodded. Turf will be mowed, watered, and fertilized to simulate a high maintenance sand-based
sports field. Turf will be mowed, without catching clippings, at a 1.5-inch height three times per
week. Water will be applied through an automatic watering system at the first sign of wilt.
Approximately 1.5 inches of water will be applied each week from May through September.
Nitrogen will be applied at 1 lb N/1000 sq. ft./growing month. Phosphorous, potassium, calcium,
magnesium, and micronutrients will be applied based on soil testing.
From May through August plots will be evaluated for turf appearance, surface hardness, and traction.
From mid-August through September all treatments will receive simulated traffic treatments. Traffic
will be applied every Monday, Wednesday, and Friday with a model T224 Brouwer roller that has
been converted into a riding traffic simulator. Both of the two-foot wide rollers on the traffic
simulator are fitted with 5/8-inch football cleats on 2-inch centers. The rollers are attached by chain
and sprocket to supply a differential-slip-type traffic that produces a tearing action of the grass
surface. Turf will be evaluated during a non-traffic recovery period from 1 October to midNovember. The entire study area will receive both hollow and solid coring in 1998 to determine if
Enkamat disrupts this routine management practice.
Literature Cited
Baker, S.W. 1997. The reinforcement of turfgrass areas using plastics and other synthetic materials:
a review. International Turfgrass Society Research Journal, 8:3-13.

128

Soil M odification and Sand-based System s

1997 Enkamat Study Plot Plan
<—N
Sodded November 7, 1997
‘Midnight’ Kentucky bluegrass
<—

13 ft.

—>

T
1

2

3
16 f t

i

3

1

2

2

3

1

Objective: To determine required depth of placement for Enkamat.
Treatments:
1. No Enkamat
2. Enkamat 0” below surface of sand.
3. Enkamat 1” below surface of sand.
Installation procedure:
1. Treatment 1—No Enkamat installed. Existing surface is considered top of sand.
2. Treatment 2—Loosen top one-half inch of surface with stiff rake. Press Enkamat into sand and
roll surface so that top of Enkamat is even with top of final sand surface.
3. Treatment 3~Remove the top one inch of sand. Loosen top one-half inch of surface with stiff
rake. Press Enkamat into sand and roll surface. Replace one inch of sand on top of Enkamat.
4. Roll entire surface area for all treatments.
5. Individual plots are 16’ by 13’. Overall plot size is 48’ by 39’.
6. All treatments were sodded with ‘Midnight’ Kentucky bluegrass containing 0.75 inches of soil
attached to the grass mat.

129

Soil M odification and Sand-based System s

Figure 1. Treatments to evaluate the placement depth of Enkamat.
Grass blades
0.75 inches of soil attached with sod
Trt. #1

.•

- • •

•/.

*.*.•*.* •/.

*.*•*.

Sand Rootzone

: •: •; •.*•.*•: •: .; .; .;

Grass blades
0.75 inches of soil attached with sod
1.0 inch of sand over Enkam at
Enkamat

Trt. #2
•\

; ■.*/■.; ■.’/ ’•V"•V*■V'•V'•*/'•'

:-,:*..*•„: •.•••„.•*.: •„.*•..*•.:•.
\

•.*.•/.•/.•/.

Sand Rootzone

•••

Grass blades
0.75 inches of soil attached with sod
Enkamat
Trt. #3
Sand Rootzone
.\v.y.V*V*V

130

Soil M odification and Sand-based System s

Managing Cool-season Grasses as Part of a SportGrass® System
David D. Minner and Jeffrey J. Salmond
New and innovative systems are being developed for natural grass fields. Coaches, athletes, and
trainers prefer natural grass to reduce physical stress on players. Artificial surfaces are known for
their durability and infrequent need for maintenance. SportGrass® is the first product that combines
the playability of natural grass with some of the more durable characteristics of synthetic turf.
The SportGrass® system is a synthetically reinforced layer of grass that is grown on a sand-based
rootzone. The system consists of natural grass growing in a synthetic matrix containing fibrillated
fibers (polypropylene blades) attached to a backing. Within the layer of sand are polypropylene
grass blades tufted into a woven backing (www.sportgrass.com). Roots can grow through the woven
backing and into the sand below. Since grass roots grow down through the synthetic fibers and
backing, the crown and roots of the plant are protected. SportGrass® is horizontally and vertically
stabilized by the combination of the polypropylene blades and the backing material. Grass can be
established by seeding or sprigging. Specialized methods have been developed to produce, harvest,
and install large-roll SportGrass® sod.
The SportGrass® system was designed to reduce divots, ruts, and bare spots due to heavy traffic. The
product claims to reduce the need for renovation and frequent repairs. Cool-season and warm-season
turfgrasses can be grown in the SportGrass® system. If the natural grass is briefly worn away, the
synthetic and sand portions of the SportGrass® system maintain a stable playing surface. SportGrass®
also aids in a quicker recovery of the turfgrass ('www.sportgrass.com').
The SportGrass® synthetic material is typically produced in 15 ft by 100 ft rolls. The synthetic turf
material is laid on top of the sand-based root zone. During installation, the seams of the synthetic
material are temporarily held to the rootzone with metal sod staples. Sand that matches the root
zone is then topdressed and brushed into the 3/4-inch polypropylene blade matrix. As an alternative,
a gunit gun has been used to blow dry sand into the polypropylene fibers. Once the matrix has been
filled, seeding or sprigging can take place. The seed is typically sliced into the surface so that the
plant crown develops within the sand/fiber matrix. SportGrass® can also be installed as sod.
SportGrass® sod is grown over a plastic sheet to impede root penetration. The sod is then sliced into
appropriate sizes in the sod field (usually 42 inches by 40 feet). A large roll harvester is used to roll
up the sod. SportGrass® has been used on football, baseball, and soccer fields and golf courses.
Most natural grass systems tend to become elevated above the surface where the grass was first
established. Over time the accumulation of thatch and the process of topdressing can add as much as
0.5 to 2.0 inches of material above the original soil line where the grass was first started. Stabilizing
materials that were once near the surface can be lowered in the profile as organic and mineral
material accumulates above the synthetic stabilizer. We are interested in finding out if this “burying”
of the stabilizer material reduces their effectiveness. We also want to know if current management
practices can be used to prevent accumulation of thatch above the synthetic stabilizer. Stabilizers
also tend to reduce surface resilience and increase surface hardness (as measured by Gmax). Two
separate studies were established in the fall of 1996 to evaluate mat management above the surface of
the stabilizers and to evaluate field hardness.
M ethods:
Study # 1 - Mat Management
The objective was to evaluate conventional methods of turfgrass management as they apply to
SportGrass®. Of particular interest is how grass management practices influence the accumulation of

131

Soil M odification and Sand-based System s

organic matter within and above the synthetically reinforced zone. Most grass systems tend to
increase in elevation as topdressing, thatch, and mat accumulate above the original surface where the
grass was first established. Moderate accumulation of thatch may improve surface characteristics by
increasing cushion and biomas cover. Eight treatments including two non-SportGrass® controls were
used to evaluate mat management in the SportGrass® System (Table la). The six SportGrass®
treatments consisted of catching clippings, returning clippings, verticutting, solid coring, Primo plant
growth regulator, and verticutting after thatch accumulation. Verticutting and coring treatments
were applied on 19 September 1997. Primo treatments will begin in 1998. Verticutting was applied
by making two passes over the plot in opposite directions using a Bluebird vertical mower set to cut
approximately 1/4-inch into the surface (even with the top of the synthetic grass blades). The
thatch litter was hand raked and removed from the surface. Hollow tine coring with 5/8-inch tines
was attempted on a border area containing SportGrass®. The GA30 Cushman aerifyer with 5/8-inch
hollow tines did not adequately penetrate the synthetic backing of the SportGrass® material. Pointed
3/8-inch solid tines easily penetrated the backing and were used in the study. Holes were punched on
2-inch centers at a rate of 36 holes/sq ft.
Study #2 - Grass Species
The objective was to evaluate how grass species, seeding rates, and traffic intensity influence the
performance of the natural grass and synthetic turf combination. (Tables 2a and 2b). Synthetically
stabilizing sand surfaces typically increases surface hardness. In some situations synthetic stabilizers
have been perceived as making fields too hard. When cleat penetration and traction are reduced the
field appears slippery. Fields dominated by a thick stand of perennial iyegrass have been described as
being more slippery than other types of grass. This study will evaluate the performance of a
SportGrass® system with respect to hardness and footing.
In both studies, surface hardness and traction measurements were taken on 12 November. Surface
hardness was measured with a 2.25-kg hammer attached to the Bruel and Kjaer 2515 Vibration
Analyzer. The hammer was dropped from a height of 18 inches. Soil moisture content was
performed on five plots in the mat management study. Traction was conducted with a torque wrench
apparatus attached to a cleated plate that was developed by Canaway and Bell, 1986. One hundred
pounds was the load bearing weight of the torque device and the weight was dropped from a height of
2 inches. Traction was assessed as the amount of torque (N m) required to tear the underlying sod.
Traction data represent the average of three individual measurements per plot.
The Statistical Analysis System version 6.06 (SAS Institute, 1989) and Analysis of Variance
(ANOVA) were used to analyze the data. Least Significant Difference (LSD) means comparisons
were made to test between treatments effects on surface hardness (Tables 3 and 4) and traction
(Table 3).
R esults:
Study # 1 Mat Management
Information is preliminary at this time since treatments just started in 1997 and thatch may take
two or more years to accumulate. However, there was a clear and significant difference in surface
hardness associated with solid tine coring on 12 November 1997, 54 days after treatment (Table 3a).
Solid tine coring of SportGrass® reduced surface hardness by approximately 18g (77g for solid tine vs.
approximately 95g for non-cored SportGrass® treatments). The solid tined SportGrass® plots had a
surface hardness that was similar to the seeded or sodded non-SportGrass® controls (Table 3a). The
sodded control had a significantly higher Gmax than the seeded control.
With respect to surface hardness of SportGrass®, the preliminary results in this study indicate that
solid tine coring can be used to effectively manage surface hardness.

132

Soil M odification and Sand-based System s

Traction was not affected by the treatments at this time. There was no difference in traction
between SportGrass® treatment and non-SportGrass® treatments.
Study # 2 Grass Species
Seeding rate did not affect surface hardness, although there was a slight trend showing reduced
hardness with higher seeding rates (Table 4). Perennial ryegrass alone or mixed with Kentucky
bluegrass significantly reduced surface hardness compared to Kentucky bluegrass used alone.
Research will continue for two more years before a final report is prepared, however, early
indications are that typical turfgrass management practices can be used to regulate surface hardness
on SportGrass® fields.
Literature Cited
Canaway, P.M. and M.J. Bell. 1986. Technical note: An apparatus for measuring traction and
friction on natural and artificial playing surfaces. J. Sports Turf Res. Inst. 62:211-214.
Table la . Treatments used to evaluate management of the grass mat within the SportGrass® system.
T rt Clippings
Cultivation
PGR
Other
with SportGrass®
1.

Catch

none

none

none

yes

2.

Return

none

none

none

yes

3.

Return

Verticut

none

none

yes

4.

Return

Solid core

none

none

yes

5.

Return

none

Primo

none

yes

6.

Return

none

none

7.

Return

none

none

after thatch accumulates,
begin thatch reduction
treatment
Seeded control

8.

Return

none

none

Sodded control

Table lb. Plot layout for mat management study.
extra plot
extra plot

yes
no
no

6

2

4

3

5

2

5

1

4

6

1

3

6

1

3

2

5

4

7

8

7

8

7

GRASS SPECIES STUDY AREA
North «
Rep 1
Rep 2
Rep 3

133

Soil M odification and Sand-based System s

Table 2a. Species layout for grass species study.
Grass species
Seeding rate
(whole plot trt)
T rt
lb/1000 ft2
1.

Kentucky bluegrass1

2

2.

Kentucky bluegrass

2

3.

Kentucky bluegrass

4

4.

Kentucky bluegrass

4

5.

Perennial ryegrass

7

6.

Perennial ryegrass

7

7.

Perennial ryegrass

14

8.

Perennial ryegrass

14

9.

KB & PR

2&7

10.

KB & PR

2&7

11.

KB & PR

4 & 14

12.

KB & PR

4 & 14

Traffic Intensity
(Split plot)
Low
yes
yes
yes
yes
yes
yes
yes
yes
jves
yes
yes
yes

1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ Perennial ryegrass
Table 2b. Plot plan of treatment arrangements for the grass species study.
MAT MANAGEMENT STUDY AREA
______
REP 1_______
4

North «

5

6

7

REP 2
8

9

7
(4a)
13

9
(5a)
14

11
(6a)
15

1
(la )
16

7
(4a)
17

9
(5a)
18

8
(4b)
REP 3
21
22

10
(5b)

12
(6b)

2
(lb)

8
___(4b)

10
(5b)

23

24

25

26

27

3
(2a)
31

1
(la )
32

9
(5a)
33

5
(3a)
34

11
(6a)
35

3
(2 a)
36

4
(2b)

2
(lb)

10
(5b)

6
(3b)

12
(6b)

4
(2b)

1

2

3

1
(la )
10

3
(2a)
11

5
(3a)
12

2
(lb )

4
(2b)

6
(3b)

19

20

7
(4a)
28

5
(3a)
29

11
(6a)
30

8
(4b)

6
(3b)

12
(6b)

134

Soil M odification and Sand-based System s

Table 3a. Surface hardness and traction measurements for the mat management study on 12
_________ November 1997. Three traction measurements were taken within each plot and averaged.
Treatments
Surface hardness (gmax)
Traction
2.25-kg hammer____________ (N-m)
1. Catch clippings

94.4

65.2

2. Return clippings

95.3

68.5

3. Verticut (prevent thatch)

94.3

67.3

4. Solid tine aerify

77.6

67.5

5. PGR (Primo)

93.5

67.0

6. Verticut (after thatch accumulates)

97.3

67.0

7. Control seeded

73.3

63.6

8. Control sodded

83.5

63.1

10.0

NS

LSDf0o5)
NS = not significant at P < 0.05.
Table 3b. Soil moisture taken on selected plots.

By weight
Treatment

Rep

extra plot

Sample description

% organic matter

% soil moisture

fibers in sample

3.4

0.7

8

3

fibers in sample

3.1

0.7

7

1

seeded KB

3.3

0.5

7

2

seeded KB

4.4

0.7

7

3

seeded KB

3.0

0.7

Table 4. Surface hardness measurements taken on 12 November 1997 on the grass species study.
The a and b parts of the individual plots were combined as an overall plot and surface
hardness was performed.
Seeding rate
Surface hardness
Treatments
lb/1000 sq.ft.
temax)
1. Kentucky bluegrass1

2

92.8

2. Kentucky bluegrass

4

88.2

3. Perennial ryegrass2

7

81.0

4. Perennial ryegrass

14

76.1

5. KB1 + PR2

2+7

78.5

6. KB + PR

4+14

77.4

7. KB Control seeded

4

73.3

8. KB Control sodded

—

83.5
6.1

LSDfo.osi
1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ perennial ryegrass

135

Soil M odification and Sand-based System s

Managing Bentgrass Stress on Putting Green Slopes
David D. Minner, Nick E. Christians, Iowa State University
Tom Verrips, Otter Creek G o lf Course, Ankeny, LA
Meaningful research is necessary if superintendents are to make confident changes in their golf
management program. A recent GCSAA survey showed that 82% of the respondents felt that
“research trials conducted on golf courses yield more accurate and usable information for the golf
industry than the same trials conducted on university field plots”. The actual research location may
not be so important but the take-home message here is that researchers must begin to manage field
plot facilities under the same level of stress that actually occurs under golfing conditions. For
example, intense traffic, extremely low mowing height, and excessive ball marks are seldom found in
research plots. Further more, research greens are usually perfectly flat, often deep rooted, and
seldom require a regiment of hand watering even during hot and dry summers.
Difficult summer growing conditions, such as high temperature and moisture extremes, can dictate
the fate of problem greens even when the best turf management practices are used. Excessive rain
followed by high humidity and heat leads to a shallow dysfunctional root system. Dry spots develop
and greens require more frequent watering. Summer diseases begin to show up and fungicide
application is increased. Some turf loss occurs and algae begins to invade the moist surface where
grass is thin. The amount of turf loss in any given year is unfortunately dependent upon the weather
and how long the adverse conditions persist. Turf management practices are usually applied
uniformly across a putting surface, however problem areas on a green are anything but uniform.
Severe turf loss occurs in high stress areas of putting greens, and therefore, it is important to evaluate
management practices and products under realistic conditions of high stress.
A sloped research green (SRG) was constructed at the Horticulture Research Station, Ames, IA, in
1997 to evaluate bentgrass management under difficult and variable growing conditions. The green
was seeded with Crenshaw creeping bentgrass in September 1997 and currently has 70% turf cover.
Treatments are scheduled to begin September 1998. Construction of the green was funded by Iowa
State University, Iowa Golf Course Superintendents Association, and the Golf Course Superintendents
Association of America. The SRG was erected to simulate the undulating topography that occurs on
many putting greens - as opposed to a typical flat research green. The sand-based portion of the SRG
is 100 ft by 40 ft by 1 ft. The subgrade, gravel blanket, and sand rootzone all follow the same
contour. The 12-inch sand rootzone contains no amendment and is positioned over a 4-inch gravel
blanket with 4-inch drain lines. The SRG has four distinct microenvironments that will be
simultaneously evaluated for nine different treatments. The microenvironments are:
1) cool slope - this 7.0% slope faces north and should be cooler in the summer but also
colder in the winter,
2) knoll - the crown of the green is expected to have the most potential for scalping and
dry spot injury in the summer,
3) hot slope - this
6.6%slope faces south and is expected to generate high surface
temperatures, and
4) swale - the low portion of the green is expected to have excessively wet conditions.
To our knowledge, the type of sloped green project that we are proposing has never been used for
putting green research.
No amendments, organic or inorganic, were used to construct the 12-inch rootzone. The sand has a
pH of 8.2 and is calcareous. Topdressing treatments will begin in 1998 and will be routinely applied
to 40 ft. by 3.5 ft plots. The long and narrow plots are situated so that each treatment covers all
four distinct micro-environments on the green. This plot arrangement allows for three replications

136

Soil Modification and Sand-based Systems

of nine topdressing treatments. The nine topdressing treatments include combinations of organic
(Dakota Peat or hypnum peat) and inorganic amendments (porous ceramic clay, diatomaceous earth,
and zeolite).
To evaluate treatments and simulate actual growing conditions, greens will receive routine traffic and
mowing at 0.135 inches (3.4 mm). Simulated traffic (18,000 rounds per year) will be applied with a
Brouwer TR224 cleated roller that was converted to apply differential slip type traffic (design by Dr.
Bob Carrow). Heavy spring rains will be simulated by excessive irrigation in May. Dry conditions
will be simulated by restricting irrigation on a temporary basis from June through August. A “spoon
feeding” fertility program will be applied based on soil and tissue testing results from the nonamended control plots.
We are not seeking subtle differences in turf quality, but instead seek the difference between survival
and complete loss of turf that may be related to stresses that accumulate on sloped areas of greens.

Fig 1. Sloped Research

137

Soil M odification and Sand-based System s

Effects of Soil Amendments on the Chemical and Physical
Soil Parameters of a Sand-based Golf Green
Young K. Joo, Nick E. Christians, Deying Li, and D avid D. Minner
The objective of this study is to investigate the effects of inorganic soil amendment materials Bio­
ceramic, Profile, Axis, and Bio-Flex-A-Clay on the chemical and physical soil parameters of a sandbased golf green. Bio-ceramic is a ceramic material from Korea. Axis is a diatomaceous earth and
Profile is a porous ceramic clay material. Bio-Flex-A-Clay is a polymer coated sand from a product
of True Pitch, Inc. of Altoona, Iowa. The Bio-Flex-A-Clay is the same product with a kelp material
incorporated on the Flex-A-Clay. A USGA type sand-based green was constructed in the summer of
1996. The green consisted of a 12-inch sand rootzone placed over a 4-inch gravel blanket. No
intermediate “choaker” layer was used between the sand and the gravel blanket. The sand and pea
gravel materials used in the plot met the particle size specifications of a USGA green. A network of
4-inch drain lines were trenched into the subsoil below the gravel blanket. No organic or inorganic
amendments were used in green construction since they were added at a later date as treatments. The
study area consisted of five treatments (Table 1) replicated six times. The 15 plots each measured 6
x 9 ft. The sand from each plot was removed to a 6-inch depth. The sand was combined with 5%
volume/volume Dakota peat and 10% of each of the amendments as outlined in Table 1. The
mixture was then replaced on the plot area and allowed to settle. The area was seeded with 1 lb.
‘Crenshaw’ creeping bentgrass/1000 ft2 in September of 1996. A 10-20-10 fertilizer was applied to
supply 1 lb. N/1000 ft2 as a starter fertilizer.
Table 1. The five treatments established in the sand green.
Sand %
Treatment
1
95
Control
85
2
Bio-ceramic
Profile
85
3
4
85
Axis
5
Bio-Flex-A-Clay
85

Amendment %
0
10
10
10
10

Dakota Peat %
5
5
5
5
5

The grass was severely damaged by winter kill and was reseeded with 1.5 lb. Crenshaw/1000 ft2 on
May 13, 1997. Starter fertilizer was reapplied at the same rate as that used in the fall.
The grass became fully established during the 1997 season. In November of 1997, soil samples were
collected for chemical testing. The samples were submitted to Harris Laboratory of Lincoln, NE and
a full set of chemical evaluations were conducted. Undisturbed-intact soil columns were collected in
November 1997 to develop a water release curve and test other soil physical parameters. These tests
included saturated water conductivity, water retention at 40 cm, and soil bulk density. Each
treatment was also sampled immediately after plot construction to develop soil physical
measurements on recompacted samples. The samples were recompacted according to United States
Golf Association specifications and each test was repeated.
Establishment data for May, July, and August demonstrated that the Bio-Flex-A-Clay had a very
positive effect on the growth of the creeping bentgrass during grow-in (Table 2). This material
contains kelp, which evidently affected establishment.
In chemical analysis, Profile was most effective in increasing cation exchange of the media (Table
3). Profile also doubled the amount of exchangeable potassium (K) and increased magnesium (Mg) by
nearly 50%.
Saturated water conductivity was reduced by Bio-Flex-A-Clay (Table 4). Profile and Axis increased
water retention and decreased bulk density as compared to the control.

138

Soil M odification and Sand-based System s

Water release curves were very similar for the control, Bio-ceramic, and Bio-Flex-A-Clay. The
Profile and Axis both resulted in higher water retention at each of the pressure treatments from 0 to
2 bars (Figure 1).
We would like to acknowledge the National Natural Science Foundation o f China fo r partial support of this
research.
Table 2. Establishment data (% cover) in May, July, and September of 1997.
July
Treatment
May
August
1
60
77
Control
10
2
60
80
Bio-ceramic
13
57
80
3
Profile
10
47
4
10
67
Axis
80
100
100
5
Bio-Flex-A-Clay
LSD

15

5

o.05

Table 3. Soil test results for the
Treatments
CEC
Control
8.8
Bio-ceramic
9.2
Profile
9.5
8.8
Axis
Bio-Flex-A-Clay
8.0

inorganic soil modification study.
Na
OM
PH
SS
0.4
8.3
1
16
8.3
1
17
0.4
0.4
8.2
1
20
0.4
8.3
1
17
14
8.3
1
0.5

October
100
100
100
100
100

13

-

NIT
1
1
1
1
1

P
7.7
6.3
7.7
8.7
7.3

K
25
27
51
25
24

103
114
145
105
1038

Ca
1551
1625
1604
1548
1394
49

0.4

NS'

NS

NS

NS

NS

NS

8

14

Control
Bio-ceramic
Profile
Axis
Bio-Flex-A-Clay

S
1.7
1.0
1.3
1.7
2.7

Zn
0.9
1.4
0.9
0.7
1.2

Mn
3.1
3.6
2.9
3.3
3.3

Cu
0.5
2.1
0.9
0.4
0.9

Fe
11.9
15.5
17.3
15.3
11.9

B
0.3
0.3
0.3
0.3
0.3

AK
0.7
0.8
1.4
0.7
0.8

AMg
9.8
10.3
12.8
10.0
11.3

ACa
88.7
88.1
84.9
88.4
87.2

LSDo.os

NS

NS

NS

NS

NS

NS

0.2

1.2

1.3

LSD

o.05

Table 4. Physical test for the inorganic modified soil.
Undisturbed
D*5
Treatment
kJ
w
Control
45.7
24.1
1.49
Bio-ceramic
23.7
1.48
43.9
1.44
Profile
46.8
27.2
1.42
Axis
44.5
27.3
Bio-Flex-A-Clay
39.5
23.6
1.55

J

...

3.8

NS

AK = Actual potassium ( % base saturation)
AMg = Actual magnesium (% base saturation)
ACa = Actual calcium ( % base saturation)
ANa = Actual sodium ( % base saturation)
All others units = ppm

*NS = Not significant at 0.05 level
CEC = Cation Exchange Capacity (meg/100g)
SS = Soluble salts (mmhos/cm)
Na = Sodium (ppm)
OM = Organic matter (% )
NIT = Nitrate N (ppm)

LSDoos

ANa
0.8
0.8
0.9
0.9
0.8

1.2

0.05

2Wre/=Water retention at -40cm water pressure (% of water based on dry soil)
3D*=Soil dry bulk density (g/cm3)
4Recompacted according the undisturbed value

139

Recompacted
kI

34.0
37.7
40.7
33.4
27.5

21.9
20.9
23.5
24.9
20.3

D*
1.49
1.48
1.44
1.42
1.55

3.5

2.2

0.04

Figure 1. Soil moisture release curve for undisturbed samples of each amendment treatment completed in November 1997.

Soil M odification and Sand-based System s

h- I— h- h- I—

l +Ht

(%) luaiuoo J8JBM

140

Soil M odification and Sand-based System s

Effects of Bio-FIex-A-Clay on Creeping Bentgrass Establishment and Growth
N ick E. Christians, M elissa C. McDade, David D. Minner, Deying Li, and Young K. Joo
Introduction:
Bio-Flex-A-Clay is a product of True Pitch, Inc. of Altoona, Iowa. Flex-A-Clay is a material
normally used for stabilization of pitching mounds and other athletic field areas. Bio-Flex-A-Clay is
the same product with a kelp material incorporated on the Flex-A-Clay. Preliminary field tests
conducted at Iowa State University in 1996 and 1997 demonstrated improved establishment of
creeping bentgrass in sand-based field plots that had been treated with Bio-Flex-A-Clay. The study
discussed in this report was designed to determine which of the components of this product were
responsible for the improved establishment observed in the field studies.
Objectives:
The objectives of the study were to observe the effects of Bio-Flex-A-Clay, each of its component
parts, and of equivalent amounts of nitrogen (N), phosphorus (P), and potassium (K), on the
establishment, growth, and root development of creeping bentgrass under controlled environmental
conditions in the greenhouse. Dakota peat, a standard used for rootzone modification, was also
included as a comparison.
Materials and Methods:
Pure sand that had been screened to meet United States Golf Association (USGA) standards for golf
course green construction was used as the growing media. The sand media was placed in plastic
sleeves with a 1.5-inch inside diameter, 1.77 sq. inch surface area, and length of 24 inches. The soil
profile followed USGA recommendations for putting green construction. Each profile had a 14-inch
rootzone, a 2-inch intermediate layer, and an 8-inch pea gravel subgrade. The plastic sleeve was then
inserted into a 2-inch diameter PVC pipe and placed on a 30° angle from vertical. Roots growing in a
downward direction intercepted the plastic sleeve and were visually measured using a non-destructive
technique. The sleeve was sealed on the bottom and punctured to provide drainage.
The amendments (Table 1) were incorporated into the upper six inches of mixture. The treatments
included pure sand as a control with no amendments, the Bio-Flex-A-Clay at 2.5, 5, and 10% v/v of
the mixture, N-P-K treatment that contained equivalent amounts of nutrients as supplied by the kelp
in the Bio-Flex-A-Clay treatment, Flex-A-Clay alone with no kelp, polymer alone, the clay alone,
the kelp alone, Clay+polymer+kelp, and Dakota peat at 10% v/v. Crenshaw creeping bentgrass was
seeded at 4.9 g/m2 to the surface. A randomized complete block design with four replications was
used. The study was initiated in October, 1997 and terminated on January 24, 1998. Data were
collected on the number of days required for plants to become established to the three-leaf stage,
shoot density, and total root biomass. Weekly evaluations of rooting depth were made by lifting the
plastic sleeves from the PVC pipe and measuring the longest root.

141

Soil M odification and Sand-based System s

Table 1. Bio-Flex-A-Clay Greenhouse Study -1997/98.
Treatment
Materials

Rate

1 Control

Pure sand

100%

2

Bio-Flex-A-Clay (BFAC)

BFAC 2.5% (v/v)

4.51 g dry wt. basis

3

Chemical Fertilizer. #1

same N, P, K for ‘Trt 2’

10.8 mg N, 0.4 mg P, 7.2 mg K

4

Bio-Flex-A-Clay (BFAC)

BFAC 5.0% (v/v)

9.03 g dry wt. basis

5

Chemical Fertilizer. #2

same N, P, K for ‘Trt 4’

21.7 mg N, 0.8 mg P, 14.3 mg K

6

Bio-Flex-A-Clay (BFAC)

BFAC 10% (v/v)

18.05 g dry wt. basis

7

Chemical Fertilizer. #3

same N, P, K for ‘Trt 6’

43.3 mg N, 1.59 mg P, 28.6 mg K

8

Flex-A-Clay (FAC)

FAC 10%

22.01 g same volume of ‘Trt 6’

9

Clay

Clay (20.2% w/w)

3.65 g same amount in ‘Trt 6’

10

Polymer

Polymer (7.1% w/w)

1.28 g same amount in ‘Trt 6’

11

Kelp

Kelp (6.6% w/w)

1.19 g same amount in ‘Trt 6’

12

Clay + Polymer + Kelp

Trt (9+10+11)

same amount in ‘Trt 6’

13

Peat

Dakota peat 10% (v/v)

14.67 cm3

There were no significant differences among the treatments in the number of days for the newly
established plants to reach the 3-leaf stage (Table 2). Root length increased from 19.2 cm in the
control to 37 cm in the 2.5% Bio-Flex-A-Clay treatments, to 43.8 cm in the 5% Bio-Flex-A-Clay,
to 63.7 cm in the 10% Bio-Flex-A-Clay treatment. The maximum root length observed at the end
of the project was greatest in the treatments that received the Bio-Flex-A-Clay at 10% v/v. This
root length in the 10% Bio-Flex-A-Clay treatment was 3.4 times greater than in treatments that
received an equivalent amount of N-P-K, was 2.8 times greater than the treatment that received an
equivalent amount of kelp to that included in the 10% Bio-Flex-A-Clay treatment, and 1.7 times
greater than Dakota peat.
Shoot density was highly variable. The Dakota peat had the highest shoot density at termination.
The Bio-Flex-A-Clay provided no apparent advantage in shoot density. The effect of the peat was
likely due to extra water holding capacity, which would improve seedling establishment in the sand
media.
Root biomass was 6.3 times higher in the 10% v/v Bio-Flex-A-Clay treatment than in the control
and nearly double any of the other treatments. The bentgrass treated with Bio-Flex-A-Clay had 8.3
times more roots than the sand treated with Flex-A-Clay alone. There were 3.7 times more roots in
the 10% v/v Bio-Flex-A-Clay treatment than in the 5% treatment. Treatments that included BioFlex-A-Clay at the 10% level had 1.9 times more root mass than units modified with the Dakota
peat.
Weekly evaluations of root growth taken during the study showed a clear advantage to the 10% v/v
Bio-Flex-A-Clay treatment (Figure 1). This was true from the first testing date and continued
throughout the study.

142

Soil M odification and Sand-based System s

CONCLUSION
There was a clear advantage in rooting of creeping bentgrass that was treated with the Bio-Flex-AClay. The 10% v/v treatment with this material was much better than the 2.5 or 5% Bio-Flex-AClay treatments. It also far exceeded the rooting in treatments that contained the same N-P-K rates
as that provided by the kelp contained in the Bio-Flex-A-Clay and it exceeded sand treated with
equivalent amounts of kelp without the Flex-A-Clay and treatments receiving Dakota peat. There
was no apparent advantage in shoot density in units treated with Bio-Flex-A-Clay in this greenhouse
trial although we did see a clear advantage in shoot density in early field trials.
More work should be conducted under field conditions to determine if topdressing with Bio-Flex-AClay provides any advantage in sand-based systems.
We w o u ld lik e to ackn ow ledge th e N ation al N atu ral Science F oundation o f C hina f o r p a rtia l su pp o rt
o f th is research.

Table 2. Effects of inorganic soil modification on bentgrass growth.
Treatments

Three-leaf
Stage2
(days after seeding)

Root
Length3
(cm)

Shoot
Density3
(# of shoot/cm2)

Root
Biomass4
(g/column)

1

Pure sand

36.3

19.2

2.80

0.025

2

Bio-Flex-A-Clay 2.5% (v/v)

37.3

37.0

2.23

0.047

3

10.8 mg N, 0.4mg P, 7.2 mg K

41.5

27.1

1.30

0.016

4

Bio-Flex-A-Clay 5.0% (v/v)

38.0

43.8

0.88

0.043

5

21.7 mg N, 0.8 mg P, 14.3 mg K

36.3

28.0

1.13

0.010

6

Bio-Flex-A-Clay 10% (v/v)

31.5

63.7

2.73

0.157

7

43.3 mg N, 1.59 mg P, 28.6 mg K

41.5

19.0

3.70

0.062

8

Flex-A-Clay 10% (v/v)

43.0

21.9

1.78

0.019

9

Clay 20.2% (w/w)

38.5

30.3

3.68

0.036

10

Polymer 7.1% (w/w)

33.3

10.9

0.40

0.003

11

Kelp 6.6% (w/w)

27.0

22.9

3.15

0.070

12

Clay, Polymer, Kelp

32.3

29.4

2.98

0.076

13

Dakota Peat 10% (v/v)

31.3

38.4

4.25

0.084

LSD 005

NS1

11.2

1.88

0.044

'NS = Not significant at 0.05 level
2Seeded Oct. 16, 1997
3Measured Jan. 15, 1998
4Measured Jan. 24, 1998. Column equals 11.1 cm2(1.77 inch2) X 60 cm

143

Soil M odification and Sand-based System s

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Responses of Creeping Bentgrass to Organic and Inorganic Soil
Amendments Under Stressed Conditions
Young K. Joo, J. P. Lee, David D. Minner, and Nick E. Christians
The objectives of this research were to investigate the effects of inorganic soil amendments on the
growth of creeping bentgrass established on a sand-based soil media under stressed conditions. The
organic amendments included hypnum, Dakota, and Irish peat at 10% v/v (volume/volume) of the
sand mix. The inorganic amendments included Axis (a diatomaceous earth), Profile (a porous
ceramic clay), Flex-A-Clay (a polymer coated sand), and Bio-ceramic (a ceramic material from
Korea). Following establishment, the grass was subjected to water, nutrient, and high temperature
stress. The study was initiated in June, 1996 and was terminated in January 1997.
The amendments were uniformly incoiporated into the upper 14 inches of the sand column. The
treatments included a pure sand control, and the amendments were mixed at 10% v/v of mixture.
Bio-ceramic was also included at 5% of the mixture. The sand and other materials used in the
columns were sieved to meet particle size specifications of a USGA green. Soil profiles in the
columns followed USGA recommendations for putting green construction. Each profile had an
intermediate 4-inch choker layer and a 6-inch pea gravel sub-layer. The 24-inch profiles were
established in a clear plastic sleeve with a 1.5 in2 surface area. The sleeves were placed in a PVC pipe
with 2 inch inside diameter. The sleeve was sealed on one end and punctured to provide drainage.
‘Crenshaw’ creeping bentgrass was seeded on the column surface at the equivalent of 1 lb seed/1000
ft2 . The grass was grown under normal conditions for four weeks. High pressure sodium lamps were
used as the light source and greenhouse temperature was maintained at 65 to 72° F. The tubes were
tilted on a 30° angel from vertical at the end of the 4-week establishment period to force the roots
to grow down the lower side of sleeve. This allowed for a biweekly, nondestructive measurement of
root growth. The study was designed as a randomized complete block with four replications.
The water and nutrient stress treatments were started at the 4th week and lasted three months. The
tubes were irrigated at least two times/week with a total of 2 inches of water for normal grass growth.
Water stress treatments received one-quarter of the water applied to the other normal units. The
normal fertilizer treatment received 0.5 lbs. N/1000 ft2 (1:1:1 N, P20 5, K20 ) every two weeks. The
nutrient stressed units received one-fourth of the normal fertilization fate. High temperature stress
treatments were started after three and one-half months of the normal growing conditions in the
greenhouse. The high temperatures were established in a growth chamber set at 95° F (day) and 85° F
(night). The high temperature treatments were maintained for 16 weeks.
Visual turf quality, dry weight of clippings, and root length were measured every two weeks. Root
weight data were collected at harvest.
Both organic and inorganic amendments produced better auality ratings than the control under
normal, moisture stressed, and low nutrient conditions. Tne organic treatments generally provided
higher quality than the inorganics (Table 1). The inorganic amendments did not produce greater
clipping yields than the control under normal and low nutrient conditions. They did, however,
improve growth under moisture stressed conditions. Organic amendments increased clipping yields
over the control and over the inorganic amendments under all three conditions (Table 2).
Root lengths generally increased for both inorganic and organic amended treatments for both normal
and moisture stressed conditions, with organic treatments generally exceeding inorganics. Neither
group of soil amendments improved root length in low nutrient conditions. Total root weights were
not improved by inorganic or organic amendments in normal and low nutrient conditions. Both
amendments improved total root mass under moisture stressed conditions (Table 3).
There were no significant effects of amendments on clipping production during the first three
months of high temperature treatment (Table 4). By the end of the 4th month, the grass grown on
columns with Dakota peat had much higher clipping weights than any of the other treatments. Turf
quality ratings were generally improved by inorganic and organic amendments, with Flex-A-Clay
(small) and Dakota peat providing the highest ratings. Total plant weight at termination (HTTW)
was enhanced by inorganic and organic amendments.

145

Soil M odification and Sand-based System s

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Soil M odification and Sand-based System s

Soil M odification and Sand-based System s

Rubber Particles for Vehicular and Foot Traffic Areas - Demonstration Plot
Jeffrey J. Salmond and D avid D. Minner
A demonstration area was initiated in June 1996 to evaluate the effects of rubber particles for
topdressing in areas that receive equipment traffic. Other experiments in this Research Report have
found beneficial results from rubber topdressing when small plots and artificial traffic are used. Golf
courses and other recreational areas where vehicles and mowers are repeatedly used typically develop
turf wear and soil compaction problems.
A 16 ft. x 64 ft. area receiving intense equipment traffic at the Horticulture Research Station was
arranged with four non-replicated treatments. The area was scalp-mowed, hollow core aerified, and
the cores were then removed. Topdressing treatments consisted of a coarse crumb rubber, medium
crumb rubber, and sand. All three topdressing materials were applied at a 0.5 in. depth, and an
untreated control received no topdressing. Individual plot size was 16’ x 16’ (Table 1).
The total plot area was roped off for turfgrass re-establishment. The evaluation plots did not
received traffic in 1996 or 1997. Traffic will begin in spring, 1998.
Table 1. Plot arrangement for topdressing treatments at 0.5 in. and an untreated control.

1------------------------------------------- 64’--------------------------------------------

untreated control

coarse crumb

sand

medium crumb

N -»

150

Soil M odification and Sand-based System s

Modifying Athletic Field Soils with Calcined Clay and Tillage
David D. Minner and Jeffrey J. Salmond
The objective of this study was to evaluate calcined clay in a tilling renovation process and its effects
on turfgrass growth.
A study was initiated in November 1997 at an Ames High School football practice field in Ames,
Iowa, to evaluate calcined clay (Turface® MVP) in a tilled renovation procedure. The study was
conducted on a separate irrigated practice field (different from the calcinedday topdressing study).
The 15,750 sq.ft, experimental plot area was arranged between the hash marks and the goal lines.
Each individual plot measured 15 ft. by 50 ft., and was centered on every yard line marker (goal line,
5, 10, 15, 20, etc.) (Table 1) such that 7.5 ft. was on one side of the yard line and 7.5 ft. was on the
other side of the same yard line. Treatments consisted of calcined clay at 1 ton/1000 sq.ft., calcined
clay at 2 tons/1000 sq.ft., and an untreated control (Table 2). Treatments were completely
randomized and replicated seven times. Each replication was 45 ft. by 50 ft. with three treatments.
Treatments were topdressed at their respective rate and tilled into the top 4 inches of soil with a
Rotadairon (Bryan Wood, Commercial Turf & Tractor). The Rotadairon is used to level a playing
surface and prepares the seed bed while burying roots, rocks, clods, clumps, or grass. The untreated
control contained no amendment and was tilled. The total plot area will be seeded in spring 1998
with a bluegrass blend containing ‘Nublue’, ‘Limousine’, and ‘Touchdown’.
The control will be topdressed with sand in 1998 and the calcined clay-amended plots will be
topdressed with Turface® MVP.

151

Soil M odification and Sand-based System s

Table 1. Experimental plot layout of calcined clay tilled renovation. Treatments were applied on November 13,
1997.

1
Goal Line

T

1
1
1—
1
1
1
1
1
1
1
1
1
1
1
1
1
1
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1
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2

1

5

Plot size is
50 x 15 ft
REP 1

Plots are centered
Between hash marks
REP 2

Each 5-yard line is the
Center of the plot
REP 3

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3

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3

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3

2
3

11

19

2

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20

1
1

------------1------------

REP 4

REP 5

REP 6

REP 7

21

Table 2. Treatment listing and respective rates.
Rate
(tons/1000 ft2)

Treatment

1
1
Turface
2
Turface
2
3
Untreated control*
NA
Turface applied to plots with topdresser and then tilled with Rotadairon to 4-inch depth.
*Untreated control received no amendment but was tilled with the Rotadairon.

152

Soil M odification and Sand-based System s

Athletic Field Turfgrass Response to Calcined Clay Topdressing
David D. Minner and Jeffrey J. Salmond
Calcined clay materials have been used to amend soils that are compacted by excessive traffic. Our
objective was to evaluate calcined clay as a topdressing material and its effects on turfgrass growth.
The study is being conducted on a local high school football/soccer practice field and the calcined
clay materials are being compared with sand treatments.
A study was initiated in August 1996 to evaluate calcined clay (Turface® MVP) as a topdressing
material. The study was conducted on an irrigated practice field containing native clay loam soil.
The 9000 sq.ft, experimental plot area was arranged between the hash marks and twenty-yard lines.
Each individual plot measured 15 ft. by 50 ft. for a total of 12 plots. Treatments consisted of two
topdressing materials, calcined clay or sand, with six replications. Six plots were topdressed with
calcined clay (4500 total sq.ft.) and six plots were topdressed with sand (4500 total sq.ft.). Plots
were core aerified with 3/4-inch tines at a 4-inch depth, materials (calcined clay or sand) topdressed,
core aerified again, seeded with a Gridiron blend of three Kentucky bluegrass cultivars and two
perennial ryegrass cultivars, and fertilized (Table 1). The sand was topdressed at the same depths as
the calcined clay. Plots were arranged every 5 yards. Core plugs were not removed and the plugs and
topdressing were mixed on the surface by separately dragging each plot.
The procedure for topdressing materials is presented in Table 1. To date, the calcined clay plots
contain a rate of 1785 lbs/ 1000 sq.ft, or 1339 lbs per plot area. One-quarter inch of topdressed
calcined clay on the individual plots is equivalent to a rate of 714 lbs/ 1000 sq.ft. The experimental
plot layout is presented in Table 2.
Plots will be evaluated each month on turfgrass quality and percent turfgrass cover. The study will be
continued through 1999.
Table 1. Renovation schedule for topdressed calcined clay.
Turface 1/4 in.
core aerify
core aerify
Sept. 1, 1996
(714 lbs/1000 sq. ft.)
Nov. 1, 1996
core aerify
Turface 1/4 in.
core aerify
(714 lbs/1000 sq. ft.)
core aerify
core aerify
April 1, 1996
Turface 1/8 in.
(357 lbs/1000 sq. ft.)

seed

fertilize

seed

fertilize

seed

fertilize

Table 2. Experimental plot layout for topdressed calcined clay and sand between the hash marks and
-------------------- ,----------------------- p -

T

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20

O rnam ental Studies

10 Reasons for Landscape Plant Failure
JejfUes
#1

Improper Site Selection - Most landscape plants have specific environmental and spatial
requirements that must be met if they are to have long and functional lives. Questions to ask
before plants are installed include, (1) will trees and shrubs outgrow the space allocated to them,
and (2) will they thrive given the unique environmental conditions present on the site (sun,
shade, wind, etc.)?

#2

Poor Soil Drainage - Roots, responsible for water and mineral element uptake, energy
storage, the synthesis of important organic compounds, and plant anchorage, require oxygen to
function. But heavy clay, waterlogged soils are frequently oxygen deficient which can lead to
poor growth and even death.

#3

Lack of Winter/Summer Hardiness - A plant’s ability to tolerate both high and low
temperatures must be a prime consideration when selecting it for a given region.

#4

Planting Problems - Planting too deep, either intentionally or unintentionally, can cause
landscape plants to die within months of installation, or lead to other chronic problems
(girdling roots, stem or trunk rots, etc.) that significantly shorten their lives.

#5

Improper Watering - Watering is the most important task for owners of newly planted trees
and shrubs, but proper frequency and amount needed will vary according to area rainfall,
moisture-holding capacity of the soil, and the site’s drainage characteristics. Too much water,
particularly if the planting area is poorly drained, can easily kill trees.

#6

Mechanical Injury - For trees and other landscape plants to perform as they were intended,
they must be afforded protection from all forms of “people pressure.” Wounds to trunks and
branches administered by vehicles, bicycles, hot charcoal, lawn mowers, and string-trimmers
can injure plants directly, and/or predispose them to secondary attack by insects and diseasecausing pathogens.

#7

Problem Plants - Plants poorly adapted to a region, and those with serious insect and disease
problems should be avoided.

#8

Construction Injury - As landscape plants mature, they attain a rather delicate balance with
their surrounding environment. In fact, woody plants grow best in an environment of minimal
change. Unfortunately, our urban, suburban, and even rural landscapes are places where drastic
changes occur with regularity. Construction activities like driveway and sidewalk installation,
grade changes, road widening, and utility trenching in the vicinity of trees and shrubs can cause
substantial root injury, and in some cases, death.

#9

Animals - Deer, rabbits, voles, horses, and dogs top the list of animals that cause problems for
landscape plants. Because repellents are often ineffective, high value plants should be
protected with fencing to prevent injury.

#10 Well-intentioned Maintenance Practices - Remember, anything you wrap around the
trunk or stem of a plant can cause problems if it is not inspected regularly.

I
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O rnam ental Studies

Trees Can Reduce Energy Consumption
J e ff lies
Trees planted in key positions around homes and businesses can reduce energy consumption and save
money. For example, properly placed trees can slash air-conditioning demand in summer by as much
as 50 percent. Thoughtfully placed trees also can reduce winter heating costs by 4 to 22 percent.
But to achieve maximum energy savings and environmental improvement, appropriate tree species
must be planted in strategic locations and in the correct relationship to the buildings or areas they are
designed to benefit. Simply stated, the goal is to get maximum shade in summer but minimum shade
in winter.
Highest priority should be given to planting shade trees due west of west-facing windows followed by
planting trees east of eastern windows. Trees located on the east and west sides of buildings offer the
most advantageous combination of solar control and energy savings by blocking early morning and
late evening sun in the summer but offering no obstruction to winter sunlight. Select trees that can
be planted within 20 feet of windows and will grow at least 10 feet taller than windows. If space
permits, use tree combinations to create a continuous planting opposite all major west and east­
facing windows. But don't waste time and financial resources planting trees on the south side of
buildings! A large tree oriented to the south will cast little, if any shade on buildings to the north in
summer. And in winter, the same tree will cast an undesirable shadow on structures to the north for
most of the day. If shade trees are already present on southern exposures, removing their lower
branches will permit more sunlight to reach the buildings to the north in winter.
Deciduous trees (those that drop their leaves in autumn) are the preferred natural heating and cooling
regulators in temperate climates. To obtain maximum benefit, the "ideal" shade tree should have a
broad crown and dense foliage in summer when shade is most desirable. Then when temperatures
begin to cool in fall, the ideal tree would lose its leaves, permitting the suns energy to penetrate a
sparsely-branched canopy. Trees meeting these criteria are classified as "solar friendly." Kentucky
coffeetree, ash, and sugar and red maples are good examples of solar friendly trees because they
provide dense summer shade and sparse winter branching.
In general, large-growing trees are best because they provide the maximum environmental benefit per
tree. But because "solar friendly" trees are most effective when planted close to the east and west
sides of buildings, only sturdy trees with good branching habits that resist damage from storms should
be planted. Do not plant large, fast-growing, weak-wooded species like silver maple and cottonwood
next to homes and businesses. Also avoid trees that drop their leaves late in the fall (Norway maple),
trees that retain their leaves throughout the winter (oaks), have exceptionally sparse branching
(ginkgo), or are densely-branched (littleleaf linden). To aid municipal tree managers in making tree
selection decisions, a list of recommended deciduous shade trees for energy conservation is provided
on the next page.

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O rnam ental Studies

Deciduous Shade Trees for Energy Conservation
Common name

Scientific Name

Red maple

Acer rubrum

40 - 60'

30 - 50'

Sugar maple

Acer saccharum

60 - 75’

40 - 60'

Black maple

Acer nigrum

60 - 15'

40 - 60'

Ohio buckeye

Aesculus glabra

40 - 60'

30 - 40’

Black alder

Alnus glutinosa

40 - 60'

20 - 40'

River birch

Betula nigra

40 - 70'

40 - 50'

Northern catalpa

Catalpa speciosa

40 - 60'

20 - 40'

Common hackberry

Celtis occidentalis

40 - 60'

40 - 60'

White ash

Fraxinus americana

50 - 80’

40 - 60'

Green ash

Fraxinus pennsylvanica

50 - 60'

30 - 40’

Blue ash

Fraxinus quadrangulata

50 - 70'

40 - 50’

Kentucky coffeetree

Gymnocladus dioicus

60 - 75'

40 - 50'

Tuliptree

Liriodendron tulipifera

70 - 90'

40 - 50'

Ironwood

Ostrya virginiana

30 - 40'

20 - 30'

Amur corktree

Phellodendron amurense

30 - 45’

40 - 50'

American linden

Tilia americana

60 - 80'

40 - 60'

Mature height

Mature spread

If a site isn’t large enough to accommodate large-growing tree species, you might consider using
woody plants to establish a zone of insulating dead air space along the walls of buildings. Plants like
arborvitae and juniper installed close to buildings will create a layer of still or slow-moving air that
can slow heat loss in winter and heat gain in summer. This technique is most effective when plants
are installed in a continuous line that extends along the walls to be protected and around the comers.
Landscape interest can be created by using a variety of plants, but take care to group like kinds
together.
In addition to shielding buildings from environmental extremes, plant materials can be used to
minimize the so-called “urban heat island effect.” Researchers have found that summer temperatures
in urban areas can be two to eight degrees (Fahrenheit) higher than in rural surroundings. To
moderate high temperatures during the summer months, large-growing trees can be carefully located
to shade paved surfaces during the hottest time of day, and nonpaved surfaces should be covered with
either turfgrass or another perennial groundcover, shrubs, and/or low-growing trees. The use of lightcolored parking lot surfaces also is recommended.
Energy-conserving landscapes do not happen by accident. Rather, careful planning and preparation
is required to realize environmental and financial benefits from strategically placed woody plants.
Before you plant that next tree, make certain it is positioned for aesthetic beauty and energy
conservation.

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O rnam ental Studies

Fertilizing Trees and Shrubs
J e ff lies
You would think after decades of research, thousands of anecdotal reports from the field, and the
endless procession of articles in print, there would be unanimous agreement regarding the importance
of tree and shrub fertilization. Instead, confusion, controversy, and heated words exchanged in
"letters to the editor" sections of trade journals indicate the apparent lack of consensus among
landscape maintenance professionals when it comes to applying fertilizers.
Some use fertilizers as preventive medicine, slinging mineral elements around the landscape in an
effort to ward off marauding insect and disease pests. Others use fertilizer as a rescue treatment for
plants besieged by any number of biotic and abiotic stresses. Still others adopt a policy of
nonintervention, avoiding all together the application of fertilizer. So, who's right? As is often the
case, everybody and nobody. Yes, vigorous plants supplied with optimal levels of mineral elements
are better equipped to handle stress, but fertilizer cannot remedy poor growth resulting from causes
other than nutrient deficiencies such as compacted soils, poor drainage, restricted rooting areas,
mechanical injury, or competition from turfgrass. In fact, the only valid reason to fertilize landscape
plants is to correct nutrient deficiencies.
Why Fertilize?
Have you ever been asked this one? "If trees in the forest are able to thrive without the addition of
fertilizer, why should I pay you to fertilize the trees and shrubs in my yard?" The difference is, trees
in their natural setting benefit from a layer of decayed leaves, twigs, and other organic matter that
accumulates on the forest floor. Small, absorbing roots of trees and other woody plants colonize this
rich, well-aerated, nutrient-laden soil, and derive everything they need from the cycling of organic
matter production and decomposition. But in urban and suburban landscapes where the environment
has been drastically altered from its original state, mineral cycling does not occur and supplemental
fertilization often becomes necessary.
What a Plant Needs
Fertilizers often are incorrectly referred to as "plant food." More precisely, fertilizers provide
essential mineral elements that trees and shrubs need to produce their own food (sugars) through the
process of photosynthesis, and to carry out other important biological functions.
For proper growth and development, woody plants must obtain 17 essential mineral elements from
their environment. The macronutrients, so called because plants require them in large amounts,
include hydrogen, carbon, oxygen, nitrogen, phosphorus, potassium, calcium, magnesium, and sulfur.
Micronutrients or trace elements are needed in smaller amounts and include iron, chlorine,
manganese, zinc, boron, copper, molybdenum, and cobalt. Throughout a plant's life, mineral
elements are required for growth and maintenance; however, all woody plants do not have the same
mineral requirements. For example, a beech tree requires more calcium, potassium, and phosphorus
than most pines.
Importance of Soil pH
The availability of a number of mineral elements, particularly phosphorus and the micronutrients, is
directly influenced by soil pH. Soil reaction, expressed as pFl, refers to the acidity or alkalinity of a
soil or the relative proportion of hydrogen (acid) and hydroxide (alkaline) ions. Equal
concentrations of the two produce a neutral reaction (pH 7.0). As a soil becomes more acid, its pH
decreases; as it becomes more alkaline, its pH increases.
Certain trees (pin oak, red maple, river birch, etc.) growing on high pH soils frequently display iron
or manganese deficiency symptoms (yellow leaves with green veins). Most woody plants tolerate a

157

O rnam ental Studies

wide range in pH (5.5 to 7.5) particularly if the soil is well-drained, but a soil pH between 6.0 and 6.5
is thought to be best. Soils with pH levels above 7.0 can be successfully treated with elemental sulfur
(96%) to lower soil pH and improve plant growth; however, a better solution might be to use plants
that grow naturally on alkaline soils. Trees like hackberry, sycamore, catalpa, honeylocust, blue ash,
Kentucky coffeetree, bur oak, and chinquapin oak are known to tolerate soils having a pH of 8.0 or
higher!
Knowing Which Plants to Fertilize
Soil tests can help determine when to fertilize trees and shrubs. Unfortunately, researchers have not
been able to determine optimum mineral element levels for many landscape plants. Therefore, the
landscape manager must rely on deficiency symptoms to identify nutritional problems. A few
common deficiency symptoms include, (1) unusually small leaves, (2) abnormal leaf color (light
green or yellow), (3) poor annual shoot elongation, (4) dead twigs at ends of branches, and (5)
general lack of vigor. If these symptoms are present and are not the result of other factors such as
drought, disease, root injury, herbicide damage, or mechanical injury, then fertilization is probably
warranted.
How Much Fertilizer to Apply?
The soil around woody plants is most commonly supplemented with nitrogen, phosphorus, and
potassium. But because nitrogen is so important to plant growth and is usually the element most
likely to be deficient, most fertilizer recommendations are keyed to this vital element.
Recently transplanted and/or poorly established plants have minimal fertilization needs. In fact, the
fate of recently installed landscape plants is more closely tied to proper water management than to
fertilization. But once established (the establishment period can last from months to years),
fertilization can stimulate growth and improve the appearance of landscape plants. A rate of 3
pounds of actual nitrogen/1,000 square feet/year will satisfy the nutritional needs of most trees and
shrubs. Dwarf and slow-growing trees and shrubs require only half this rate. Mature plants and those
compromised by root injury will benefit from fertilization, but rates are usually in the neighborhood
of 1 to 2 lbs. N/1,000 square feet/year. But remember, fertilizer is not a rescue treatment for
seriously injured or declining plants.
When to Apply?
Fertilizers should be applied when environmental conditions favor root activity. Of all the
environmental conditions, soil moisture and temperature have the greatest influence on root growth.
The most intense root growth occurs when soils are moist and when temperatures are between 68
and 84 F.
Of course, correct timing of fertilizer application varies with geographic region. But in general, late
summer or early autumn is usually the preferred time to apply fertilizer. At this time, vegetative
growth has ceased, the soil is warm, carbohydrate supplies are at their highest, daytime high
temperatures are moderating, and moisture is usually not limiting growth.
Another benefit to fall fertilization is early shoot growth in the spring depends almost entirely on
nitrogen absorbed the previous summer and autumn. Nitrogen can still be applied in the spring,
however, it must be in the root zone about one month before growth begins for it to have any effect
on early season growth. Fertilizer applied later in the spring isn't necessarily wasted, but it may not
produce the desired growth until the following year.
To prevent loss or leaching of nitrogen from the root zone of plants in sandy, well-drained soils,
split applications in spring and fall can be used. But if leaching is not a problem, no benefit has been
shown from applying the same total amount of fertilizer in more than one application.

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O rnam ental Studies

Other macronutrients can be applied when deficiencies are discovered, regardless of calendar date.
But when treating micronutrient deficiency symptoms (for example, iron or manganese), watersoluble chelates of iron or manganese should be applied to the soil in the fall to have a positive
impact on early season shoot growth.
Application Methods
Fertilizers can be, (1) broadcast on the soil surface, (2) placed in holes in the soil, (3) dissolved in
water and injected into the soil, (4) sprayed on the foliage, (5) driven into the soil in fiber
impregnated spikes, or (6) implanted or injected into the plant. The method chosen will depend on
the nature and slope of the soil surface, mineral elements being applied, presence of competing
vegetation (turfgrass most commonly), and equipment available. No single method is best suited for
every situation, but for the fertilizer to be effective, it must reach, or be placed near the root zone.
Because the root zone of most trees and shrubs lies just below the soil surface (4 to 12 inches deep),
surface application (broadcasting) is the easiest, least expensive, and most effective method for
applying mobile elements like nitrogen. But when applying immobile elements like phosphorus,
working on severe slopes, or trying to place mineral elements below a highly competitive
groundcover like turfgrass, granular or liquid formulations applied 8 to 12 inches deep are useful.
Fertilizers sprayed on the foliage are effective for correcting micronutrient imbalances (primarily
iron and manganese). Plant response is quick, but applications must be repeated, at the very least,
every season. Fertilizer stakes, spikes, and tablets driven into the soil at regular intervals around
plants are popular with homeowners because they are easy to apply, but they are expensive, cause
compaction where the spike is inserted, and provide poor lateral distribution of mineral elements in
the root zone.
Trunk implants and injections have become the method of choice for correcting micronutrient
deficiencies in trees over 4 inches in diameter when they have not previously responded to soil
treatments. These methods deliver mineral elements directly into the vascular system of the tree
and provide a quick and positive response. Implants and injections should be reserved for high value
trees because of the time and expense associated with these methods. Drilling holes also may cause
decay around the injection or implantation site.
A fertilization program tailored to the specific needs of every tree and shrub in the landscape is only
one piece of the maintenance puzzle for landscape technicians. Without proper plant selection and
installation techniques, timely watering, mulching, appropriate pruning, weed control, and a host of
other maintenance activities, the functional and aesthetic benefits of the landscape deteriorate.
Finally, fertilizers should be applied only when a nutrient deficiency has been identified. Fertilizing
"to be safe" wastes time, money, and could contribute to contamination of surface and groundwater
supplies.
F u rth er Reading
Dorr, B. 1996. Tree fertilization: A world of options. Arbor Age 16(2): 14-17.
Ferrandiz, L.S. 1990. Tree fertilization techniques. Grounds Maintenance 25(6): 10-14.
Gilman, E.F. 1990. Tree root growth and development. I. Form, spread, depth and periodicity. J.
Environ. Hort. 8(4):215-220.
Harris, R.W. 1992. Arboriculture: Integrated management of landscape trees, shrubs, and vines.
Prentice-Hall, Englewood Cliffs, NJ.
Lanphear, L.S. 1996. Stimulating healthy growth. Arbor Age 16(9): 12-14.
Shaw, M. 1998. Tree nutrition 101. Arbor Age 18(3): 16-19.
Ware, G. 1990. Constraints to tree growth imposed by urban soil alkalinity. J. Arboric. 16(2):3538.
Warren, S. 1995. Nitrogen fertilizer and beyond. Arbor Age 15(4): 10-12.
Watson, G.W. 1992. Trees and shrub fertilization. Grounds Maintenance 27(l):42-46.
159

O rnam ental Studies

Prairie Demonstration
Kevin Jones and D avid D. Minner

Table 1. Prairie plant identification plots.
________ Individual plots are 10 ft by 2 ft.

Iowa has two broad regions for potential
natural vegetation. Bluestem prairies are
found in the north half of Iowa while oakhickory forests dominate the southern half
of the state. Throughout the entire state
there are pockets of land that support a
mixture of both prairie and forest. The
term “bluestem prairie” can be somewhat
misleading since there is a wide variety of
forbes and grasses that make up Iowa’s
prairie plant community. There are usually
less than 10 different grasses found in most
prairies, while there may be 30 to 50
different forbes or wild flowers. This
demonstration area was initiated to show
the diversity of plants suitable for prairie
restoration in Iowa. Furthermore, many
turf managers are finding that the prairie
can provide an appealing and low
maintenance alternative for some turf
areas.

Sideoats
grama

Tall
boneset

Wild
bergamont

Sand love
grass

Mountain
mint

Little
bluestem

Purple
prairie
cone flw.
Boneset

Meadow
blazing
star
Prairie
smoke

Western
wheatgrass
Bottle
brush
Tall
dropseed

Individual species of prairie plants are
growing in labeled plots for easy
identification. The plants were started in
the greenhouse and then field transplanted
as plugs in the spring of 1997. A prairie
restoration area will be seeded in the fall of
1998 adjacent to the prairie plant
identification plots.

Canada
wild rye
Indian
grass
Big blue
stem

N orth

Fowl
mana
grass

Blue joint
grass
Prairie
cord grass

160

Long
headed
cone flw.
White
prairie
cone flw.
Purple
prairie
clover

False
dragon
head
Foxglove
bear
tongue

New
England
aster
Lance leaf
coreopsis
Slender
mountain
mint
Black
eyed
Susan
Sweet
black eyed
Susan
Prairie
alumroot
Yellow
cone
flower

Introducing
Iowa State University Personnel Affiliated with the Turfgrass Research Program
Barbara Bingaman, Ph.D.

Postdoctoral Research Associate, Horticulture Department

Doug Campbell

Research Associate, Horticulture Department

Nick Christians, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Department

Jason DePaepe

Field Technician, Horticulture Department

Jim Dickson

Field Manager, Horticulture Department

Mike Faust

Graduate Student and Research Associate, M.S. (Christians)

Mark Gleason, Ph.D.

Professor, Extension Plant Pathologist
Plant Pathology Department

Clinton Hodges, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Department

Jay Hudson

Graduate Student and Research Associate, M.S. (Minner)

Jeff lies, Ph.D.

Assistant Professor, Extension, Nursery Crops/Omamentals
Horticulture Department

Young K. Joo, Ph.D.

Visiting Scientist from Korea

Kevin Jones

Field Technician, Horticulture Department

Brian Kelting

Field Technician, Horticulture Department

Deying Li

Visiting Scientist from China

Melissa McDade

Graduate Student and Research Associate, M.S. (Christians)

Jason Miller

Field Technician, Horticulture Department

David Minner, Ph.D.

Associate Professor, Turfgrass Science Research and Extension
Horticulture Department

Richard Moore

Superintendent, Horticulture Research Station

Forrest Nutter, Ph.D.

Associate Professor, Plant Pathology Department

Chad Olsen

Field Technician, Horticulture Department

Gary Peterson

Commercial Horticulture Specialist

Phil Riedell

Field Technician, Horticulture Department

Jeff Salmond

Graduate Student and Research Associate, M.S. (Minner)
Graduated May 1998

Mark Semm

Field Technician, Horticulture Department

Brian Wehner

Field Technician, Horticulture Department

161

Companies and Organizations
That Made Donations or Supplied Products to
the Iowa State University Turfgrass Research Program
Special thanks are expressed to the Big Bear Turf Equipment Company and Cushman Turf for
providing a Cushman Turfgrass Truckster, a 15 cu. ft. topdresser, and Ryan GA30 aerifier; to TriState Turf and Irrigation for providing a Greensmaster 3100 Triplex Greensmower and a
Groundsmaster 325D rotary mower; and, to Great American Outdoor for providing a John Deere
2243 Triplex Greensmower for use at the research area.
We would also like to acknowledge Williams Lawn Seed Company of Maryville, MO for supplying a
Perma Lock Inc. pesticide storage building for use at the turfgrass research area.

Agr-Evo USA Company
5967 N. Winwood Drive
Johnston, IA 50131

Glen Oaks Country Club
1401 Glen Oaks Drive
West Des Moines, IA 50266

Milorganite
735 North Water Street
Milwaukee, WI 53200

AIMCOR-Profile
One Parkway North
Deerfield, IL 60015

Golf Course Superintendents
Association of America
1421 Research Park Drive
Lawrence, KS 66049-3859

Monsanto Company
Agricultural Products Division
800 North Lindbergh Boulevard
St. Louis, MO 63167

Grain Processing Corporation
PO Box 349
Muscatine, IA 52761

Novartis
Agriculture Division
Greensboro, NC 27049

Great American Outdoor
10100 Dennis Drive
Urbandale, IA 50322

Ossian Inc.
635 S. Elmwood Avenue
Davenport, IA 52808

Heatway
3131 W. Chestnut Expressway
Springfield, MO 65802

PBI/Gordon Corporation
1217 West 12th Street
PO Box 4090
Kansas City, MO 64101-9984

Akzo Nobel
Enkamat
Asheville, NC 28802
Aquatrols, Inc.
Cherry Hill, NJ 08002
Big Bear Turf Equipment
Company
10405 T Street
Omaha, NE 68127
Cushman Turf
5232 Cushman
Lincoln, NE 68501
D & K Turf Products
5191 NE 17th Street
Des Moines, IA 50313
Dakota Peat
PO Box 14088
Grand Forks, ND 58208
Dow Chemical Co.
S. Madison St.
Ledington, MI 49431
DowElanco
Midland, MI 48674

Hunter Industries, Inc.
1940 Diamond St.
San Marcos, CA 92069
Iowa Golf Course
Superintendents Association
Iowa Professional Lawn Care
Association
Iowa Sports Turf Managers
Association
Iowa Turfgrass Institute
LESCO Incorporated
PO Box 10915
Rocky River, OH 44116-0915

Gardens Alive
5100 Schenley Place
Lawrenceburg, IN 47025

162

Pepsi-Cola General Bottlers,
Inc.
3825 106th St.
Des Moines, IA 50322
Pickseed West Incorporated
PO Box 888
Tangent, OR 97389
Pursell
201 W. Fourth St.
PO Box 450
Sylacauga, AL 35150
Rainbird Irrigation Company
Reams Sprinkler Supply
13410 C Street
Omaha, NE 68144

Renaissance Fertlizer Co.
5275 Edina Industrial Blvd.
Edina, MN 55435

Turf-Seed, Inc.
PO Box 250
Hubbard, OR 97032

Rhone-Poulenc Chemical
Company
Black Horse Lane
PO Box 125
Monmouth Junction, NJ 08852

United Horticultural Supply
14075 NE Arndt Road
Aurora, OR 97002

Ringer Corporation
Eden Prairie, MN 55344
Rohm and Haas Co.
7808 Highland Farms Road
Houston, TX 77095
The Scotts Company
14111 Scottslawn Road
Marysville, Ohio 43041

Viridian Inc.
(Formerly Sherritt Inc.)
3500 Manulife Place
10181 101st Street
Edmonton, Alberta
Canada TJ5 354
Weathermatic Corporation
Telsco Industries
PO Box 180205
Dallas, TX 75218-2005

SportGrass, Inc.
6849 Old Dominion Drive,
Suite 219
McLean, VA 22101

Williams Lawn Seed
Company
224 South Hills Drive
PO Box 112
Maryville, MO 64468

Spraying Systems Company
N Avenue at Schmale Road
Wheaton, IL 60187

Zeneca Professional Products
4300 Comhusker Hwy #B6
Lincoln, NE 68504

Standard Golf Company
PO Box 68
Cedar Falls, IA 50613
SubAir
PO Box 910
Vernon, NY 13476
TeeJet Spray Products
2400 NW 86th St.
Urbandale, IA 50322
Terra Chemical Corporation
Box 218
Quimby, IA 51049
The Toro Company
Minneapolis, MN
Tri State Turf & Irrigation
Co.
6125 Valley Drive
Bettendorf, IA 52722
True Pitch, Inc.
803 8th Street SW
Altoona, IA 50009

163

V.

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/

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... and justice for all
The Iowa Cooperative Extension Service’s programs and policies are consistent with pertinent federal
and state laws and regulations on nondiscrimination. Many materials can be made available in
alternative formats for ADA clients.
'
V
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( .

.

Issued in furtherance of Cooperative Extension work, Acts of May 8 and June 30, 1914, in cooperation
with the U.S. Department of Agriculture. Stanley R. Johnson, director, Cooperative Extension Service,
Iowa State University of Science and Technology, Ames, Iowa.
>

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