Iowa Turfgrass
Research Report

I o w a S ta te U n iv e r s it y
University Extension

Department of Horticulture
Department of Plant Pathology
Department of Entomology
Cooperative Extension
IOWA STATE UNIVERSITY

Ames, Iowa

FG-466/July 1999

In Cooperation with the
Iowa Turfgrass Institute

Field Day Program - July 29,1999
9:00 a.m.

Introductory Remarks - R egistration Tent

9:30 a.m.

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

Tour #1

Lawn Care & Grounds — Kentucky bluegrass traffic studies, prairie plants,
seed establishment, shade study, crabgrass and corn gluten meal
weed control, disease control, mower maintenance.

Tour #2

Golf Course —Bentgrass varieties, crabgrass and com gluten meal weed
control, sloped green study, disease control, plant growth regulators,
seed establishment, mower maintenance.

Tour #3

Sports Turf — SportGrass and Enkamat, tarp color demonstration, Kentucky
bluegrass traffic studies, bermudagrass/ryegrass, crabgrass control,
disease control, mower maintenance, seed establishment.

Tour #4

Landscape —Selection and care of landscape plants for Iowa.

11:30 a.m.

1 :0 0 p .m .

Lunch (Served in Exhibit Area)

Educational Sessions and Demonstrations
♦ Pesticide Recertification Cont. Ed. Course (2 hours) —Main Building
♦ T\irf I.D. and Weed, Disease & Insect Control Tour —
Dr. Dave Minner and Dr. Nick Christians
♦ Vendors and Equipment —Exhibit Area

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Native Grass
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Sports Turf Tour
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Introduction
Nick E. Christians and David D. Minner
The following research report is the 20th 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 third year that the entire report is
available on the Internet. It can be accessed at:
http://www.hort.iastate.edu/hort/pages/faculty/g_frame.html
Several new projects were started in the 1998 season. The fine fescue trial was replaced with a new
trial that includes 79 species and cultivars. The fairway-height and green-height bentgrass studies
were replaced with the newest cultivars from the National Turfgrass Evaluation Program (NTEP) in
September. A new fairway height bluegrass study was also added for the first time. Other new
research sites, including 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 were also completed in 1998.
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; Dr. Young Joo, visiting scientist; Jay Hudson, Deying Li, Mike
Faust, Mark Howieson, Rod St. John, and Melissa McDade, graduate students; and all others employed
at the field research area in the past year for their efforts in building the turf program. Jim Dickson
left the manager position in 1998 and Rod St. John was hired into the position in 1999. We would
like to thank Jim for his years of service to the 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

Table of Contents
Environm ental D ata..........................................................................................................................

1

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

5

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

10

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

13

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

16

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

18

Fairway Height Bentgrass Cultivar Trials...................................................................................

21

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

23

Overseeding of Northern Turfgrass Sports Fields with Bermudagrass.......................................

25

H erbicide and Growth Regulator Studies
Preemergent Annual Grass Control Study..................................................................................

27

Postemergent Annual Weed Control Study................................................................................

32

Postemergent Broadleaf Weed ControlStudy..............................................................................

36

Postemergent Granular & Sprayable Broadleaf Weed Control Study.......................................

40

Postemergence Ground Ivy Weed Control Study at Veenker....................................................

48

LCO Weed Control Study............................................................................................................

50

Poaannua Control Studies - 1998.......................................................................................

55

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

57

Fairway Bentgrass Growth Regulator Study................................

60

Effect of Trinexapac-ethyl on Kentucky Bluegrass Sod Establishment..................................

63

Effects of Trinexapac-ethyl on Poa annua Populations in Green Height
Creeping Bentgrass..............................................................................................................

66

Effects of Trinexapac-ethyl on Poa annua Populations in Fairway Height
Creeping Bentgrass...............................................................................................................

69

Turfgrass Disease Research
Evaluation of Fungicides for Control of Dollar Spot on Creeping Bentgrass.........................

71

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

73

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

74

Fertilizer Trials
Creeping Bentgrass Establishment and Management on Sand Greens.....................................

76

E nvironm ental Research
Corn Gluten Hydrolysate for Weed Control..............................................................................

79

1991 Corn Gluten Meal Crabgrass Control Study - Year 8 .......................................................

80

1995 Corn Gluten Meal Rate Weed Control Study - Year 4 .....................................................

84

v

Turf Management
Select® Liquid Ice Melter Study....................................................................................................

90

Soil Modification and Sand-based Systems
Stabilizing Sand-based Athletic Fields with Enkamat.................................................................

92

Managing Cool-season Grasses as part of a SportGrass® System...............................................

97

Managing Bentgrass Stress on Putting Green Slopes.................................................................. 104
Effects of Inorganic Soil Amendments on Sand-based Media................................................... 106
Modifying Athletic Field Soils with Calcined Clay and Tillage................................................. 109
Athletic Field Turfgrass Response to Calcined Clay Topdressing............................................ 111
The Effect of Tarp Color on Turfgrass Growth........................ ................................................ 112
Calcium Applications to Turf on Sand-based Media.................................................................. 114
Ornamental Studies
Effect of Organic and Mineral Mulches on Soil Properties and Growth of Fairview
Flame® Red Maple Trees...................................................................................................... 115
Prairie Demonstration................................................................................................................. 119
Introducing
The Iowa State University personnel affiliated with the Turfgrass Research Program.......... 120
Companies and Organizations that made donations or supplied products to the Iowa
State University Turfgrass Research Program........................................................ ................... 121

Environmental Data

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Environmental Data

2

Environmental Data

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Environmental Data

4

Species and Cultivar Trials

Results of Regional Kentucky Bluegrass Cultivar Trials
Nick E. Christians, David D. Minner, and James R. Dickson
The United States Department o f Agriculture (USDA) has sponsored several regional Kentucky bluegrass cultivar
trials conducted at most o f the northern agricultural experiment stations. Three trials were underway at Iowa State
University during the 1998 season. The first, a high-maintenance study, was established in 1995, and received 4 lb
N/1000 ft2/yr, and is irrigated as needed. The second trial was established in 1995 and received 4 lb N/1000 ft2/yr,
is irrigated as needed and receives 'traffic’. They are mowed at two inches. The third trial was established in the fall
o f 1995 and was a low-maintenance study that received 1 lb o f N/1000 ft2/yr in September and is non-irrigated. The
objective o f the high-maintenance, irrigated study was to investigate cultivar performance under a cultural regime
similar to that used on irrigated home lawns in Iowa. The objective o f the second study was to observe cultivar
response under conditions similar to those found in irrigated lawns and sports fields that receive substantial traffic
wear. The objective o f the third study was to evaluate cultivars under conditions similar to those maintained in a
park or school ground.
The values listed under each month in Tables 1 and 2 are the averages o f visual quality ratings made on three
replicated plots for the three studies. Visual quality was based on a scale o f 9 to 1: 9 = best quality, 6 = lowest
acceptable quality, and 1 = worst quality. Yearly means o f monthly data were taken and are listed in the last
column. The first cultivar received the highest average rating for the entire 1998 season. The cultivars are listed in
descending order o f average quality.
Data for genetic color (Gcol), spring greenup (Gm), and leaf texture (Leaf) also are included for the high-maintenance,
irrigated and for the low-maintenance trials. Genetic color was rated using a 9 to 1 scale with 9 = dark and 1 = light
green. Spring greenup was estimated using a 9 to 1 scale with 9 = green and 1 = dormant turf. Leaf texture was
assessed with a 9 to 1 scale with 9 = fine and 1 = coarse texture.
Data for the high-maintenance, irrigated traffic study are included in Table 3. The cultivars are listed in descending
order according to wear tolerance ratings for the 1998 season. Tolerance was assessed using a 9 to 1 scale with 9 =
best and 1 = worst tolerance. The first cultivar listed was the most wear tolerant cultivar. D ie percentage o f fall
ground cover (Fcov) data also are included in Table 3.

T able L 1998 visual quality1 and other ratings2 for the high-maintenance, irrigated Kentucky bluegrass trial.
T urfquality....
Sept
June
July
Oct
May
A ug
Cultivar
Gcol
Grn
Leaf
8.0
8.0
7.3
7.7
7.7
7.3
6.7
6.3
5.3
1
Award
8.0
7.3
8.0
7.7
7.7
2
Liberator (ZPS-2572)
6.0
5.0
7.0
6.3
7.7
8.0
6.3
7.3
8.0
7.0
6.0
4.7
3
BAR VB 3115B
7.3
6.7
7.0
7.7
8.0
7.7
4
PST-BO-141
7.7
5.3
6.7
6.3
7.7
6.7
7.3
7.3
7.3
Blacksburg
6.3
5.3
7.7
6.7
5
8.0
6.0
6.7
7.7
7.0
7.7
6.7
6.0
6
Haga
6.3
7.0
7.7
7.0
7.3
7.0
7.3
5.0
6.0
7
7.3
LKB-95
7.7
7.0
6.7
7.3
8.0
8
PST-B2-42
7.3
6.0
7.0
6.7
7.0
8.0
7.3
7.0
7.3
7.0
6.7
6.3
9
Quantum Leap (J-1567)
5.0
7.7
7.0
7.0
7.0
7.7
Absolute (M E D -1497)
7.0
5.0
6.0
6.3
10
6.7
7.7
8.0
6.7
6.3
7.0
6.3
6.0
11
BA 81-058
6.0
7.0
7.3
6.7
7.3
7.7
5.7
6.3
12
7.3
5.3
Coventry
6.7
6.7
6.7
8.0
7.3
7.7
7.0
7.3
7.3
13
H 86-690
6.7
7.3
7.0
7.3
7.7
6.7
5.3
7.0
6.3
14
Impact (J-1576)
7.7
7.0
7.7
7.3
7.3
6.7
5.0
5.7
6.7
15
M idnight
6.7
7.0 ♦ 7.0
7.7
7.7
6.0
6.3
7.0
7.3
16
NJ 1190
7.0
7.7
7.7
6.3
7.3
7.3
5.3
6.7
6.3
17
Total Eclipse (TCR-1738)
7.3
7.7
7.3
6.0
7.7
6.3
6.7
5.3
6.7
18
U nique
6.7
6.7
7.3
7.0
7.3
7.0
6.0
7.0
6.7
19
A bbey
7.7
7.0
7.0
7.0
7.0
7.0
6.0
6.3
6.3
20
BA 73-373
6.7
7.0
7.7
7.3
6.7
6.7
6.7
5.0
6.0
21
BA 81-270
6.7
7.0
7.0
7.3
6.7
7.3
6.7
6.3
6.3
22
Baron
7.0
7.3
7.7
6.7
6.3
7.0
7.0
6.7
6.3
NJ-GD
23
7.0
6.7
6.7
7.7
7.7
24
6.7
5.0
6.0
6.3
Serene (PST-A7-245A)

5

Mean
7.5
7.5
7.4
7.3
7.2
7.2
7.2
7.2
7.2
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.0
7.0
7.0
7.0
7.0
7.0

Species and Cultivar Trials

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
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

Cultivar
Shamrock
ZPS-2183
Bartitia
Caliber
Challenger
Classic
Odyssey (J-1561)
America
Arcadia (J-1936)
Baronie
N uglade
Pick 8
PST-BO-165
Seabring (BA 79-260)
W ildw ood
Allure
A scot
Bluechip (M ED -1991)
Chateau
Explorer (Pick 3561)
Goldrush (BA 87-102)
Jefferson
Marquis
North Star (PST-A7-60)
N ustar
Rambo (J-2579)
Rugby II (M ED-18)
Sodnet
A 88-744
BA 75-490
BA 81-227
Blackstone (PST-638)
Cardiff
J - 1555
L ivingston
M ED-1580
Nimbus
NJ-54
Raven
SR 2000
SR 2109
SRX 2205
BA 76-197
BA 81-113
Conni
Dragon (ZPS-429)
Limousine
SR 2100
ASP200 (HV 130)
BA 70-060
Chicago (J-2582)
Glade
Lipoa
Princeton 105
.
PST-P46
Apollo (PST-B3-180)
BA 81-220
Champagne (LTP-621)
Eclipse
K enblue
Pick-855
Sidekick

Gcol
6.7
6.7
6.7
6.3
6.7
7.0
7.3
7.7
7.3
6.3
7.3
7.0
6.7
7.0
7.0
6.7
6.7
7.3
6.3
6.0
6.7
7.3
7.0
6.3
6.3
6.7
6.7
7.0
7.7
6.7
6.7
8.0
6.7
6.7
6.3
7.0
5.7
6.3
7.3
7.3
6.7
6.7
6.3
7.0
6.0
6.7
6.7
7.7
6.7
6.7
6.3
7.0
7.3
6.7
7.3
6.7
6.3
6.7
6.3
6.3
7.0
7.0

Grn
6.7
6.3
4.3
6.3
5.3
6.3
5.7
5.3
5.0
6.3
4.7
6.0
5.7
5.7
5.3
5.7
6.0
6.0
5.3
5.7
5.3
6.3
5.7
5.0
5.7
5.7
5.0
6.0
7.3
7.3
5.3
7.0
6.0
5.7
6.3
5.7
5.3
5.0
6.0
6.3
5.7
5.3
6.0
6.3
4.3
7.0
5.7
6.0
5.3
5.7
5.7
5.3
4.7
5.0
5.3
5.0
6.0
6.7
6.0
7.3
6.0
6.3

Leaf
6.7
6.7
6.7
6.3
7.0
6.3
6.7
7.3
6.0
6.3
6.7
6.3
5.7
6.7
7.0
5.3
6.0
6.3
5.7
6.7
6.3
7.0
6.0
6.7
7.0
7.7
6.3
6.3
6.0
6.0
5.7
6.0
6.3
6.7
6.7
6.3
7.3
6.3
6.7
6.0
6.3
8.0
7.0
6.7
7.3
6.3
7.0
5.3
6.0
6.0
6.3
6.7
8.0
6.7
7.0
7.0
6.3
6.0
6.3
7.7
6.3
6.0

6

May
6.3
6.7
6.3
7.0
6.3
6.3
6.3
6.7
6.3
6.3
6.3
6.3
6.3
6.3
6.7
6.3
6.7
7.0
6.7
6.0
6.3
6.7
6.7
6.7
7.0
7.0
6.3
6.0
7.0
6.3
6.7
6.3
6.0
6.3
6.3
6.7
6.7
6.3
6.7
6.3
6.3
6.7
6.3
6.3
6.3
6.7
6.3
6.7
6.7
6.0
7.0
6.3
6.7
6.3
6.7
6.0
7.0
6.0
6.0
6.7
6.3
6.3

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

.Thì.ìihìIàìx.

July
6.3
6.3
6.7
6.7
6.7
6.0
7.0
6.3
6.7
6.3
6.7
6.0
6.3
6.7
6.7
. 6.7
6.3
6.7
6.3
6.7
6.7
6.3
6.7
6.7
7.0
7.0
7.0
7.0
6.0
6.7
6.7
6.7
6.7
6.7
6.3
6.3
6.7
. 7.0
6.0
6.7
6.7
6.7
. 6.3
6.7
6.3
6.3
6.0
5.3
6.3
6.0
6.0
6.7
6.0
6.0
6.7
6.0
6.3
6.0
6.0
5.7
6.3
6.0

A ug
8.0
7.7
7.7
6.7
6.7
6.3
6.7
6.3
6.7
5.7
7.3
6.7
6.7
6.7
6.3
7.7
6.7
7.3
6.7
6.3
6.3
6.7
6.7
6.3
6.3
6.7
6.3
6.3
6.7
6.7
7.3
7.3
6.3
6.3
6.7
6.3
6.3
6.7
7.0
7.0
6.7
6.3
6.7
6.7
6.7
7.0
6.0
7.0
5.7
6.7
5.7
6.0
6.0
6.7
6.3
6.3
6.0
6.0
6.3
5.7
6.0
6.3

Sept
6.7
7.0
6.7
6.7
7.3
7.3
7.0
7.3
7.3
7.3
6.7
7.3
6.7
7.0
6.7
6.3
6.7
6.0
7.0
7.0
6.7
6.7
6.3
6.7
6.3
6.3
7.3
7.0
6.7
6.7
6.0
6.0
6.7
7.0
6.3
6.3
6.0
6.0
6.3
6.7
7.0
6.3
6.0
6.0
6.3
6.0
6.3
6.3
6.7
6.7
6.7
6.3
6.3
6.3
6.0
7.0
6.0
6.7
6.7
5.7
6.3
6.7

O ct
8.0
7.3
7.7
7.3
7.7
7.7
7.3
7.3
7.3
7.7
7.7
7.7
7.7
7.7
7.3
6.7
7.0
6.7
7.0
7.7
7.0
7.0
7.3
7.3
6.7
7.3
7.0
7.3
6.7
7.0
7.0
6.7
7.0
7.0
7.3
6.7
6.7
7.0
6.7
7.7
7.3
6.7
7.0
6.3
7.3
6.3
6.7
7.3
6.7
6.7
6.7
6.7
7.0
7.0
7.0
6.7
5.7
7.0
6.7
6.7
6.7
6.7

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

Species and Cultivar Trials

Turf quality
Sept
Oct
Mean
Cultivar
Gcol
Grn
June
July
Leaf
May
A ug
87
VB 16015
8.0
7.3
6.7
5.7
6.0
6.3
6.3
6.3
7.0
6.3
5.7
6.7
5.7
6.7
6.3
6.3
88
6.3
6.3
6.7
6.7
ZPS-309
6.2
6.3
6.7
89
BA 75-163
7.7
6.3
6.0
5.7
6.3
6.3
5.3
6.0
6.0
6.3
6.2
90
BA 75-173
7.0
6.0
6.3
6.3
6.3
6.0
7.0
6.2
5.7
5.7
91
6.3
6.3
6.7
6.7
6.7
BAR VB 5649
5.7
6.0
6.2
6.7
7.0
5.3
6.0
6.3
6.7
6.3
7.7
92
Baruzo
5.7
6.7
7.0
6.2
Misty (BA 76-372)
7.3
5.0
5.3
6.3
6.0
5.3
93
6.7
5.7
6.3
6.3
6.2
6.3
5.0
6.0
94
Pepaya (DP 37-192)
6.3
6.3
6.0
6.0
6.3
7.0
6.1
8.0
5.0
5.7
6.0
5.0
M oonlight (PST-A418)
95
6.0
5.7
6.0
6.0
6.3
6.0
BA 77-702
7.0
5.7
5.7
6.0
96
6.0
5.7
6.3
5.7
5.7
6.0
6.7
6.0
7.0
6.7
97
Fortuna
6.3
6.0
5.7
6.3
7.0
6.3
5.7
6.3
5.7
5.7
98
LTP-620
6.0
5.7
5.7
5.3
6.3
5.9
6.0
5.3
5.7
6.7
99
Compact
6.0
5.3
5.3
5.9
6.7
6.0
6.7
6.7
6.7
5.7
P latini
100
4.7
5.3
5.7
5.7
7.0
5.7
7.3
6.7
6.7
5.3
101
BAR VB 6820
5.0
4.7
5.6
6.0
7.7
4.7
4.7
6.0
7.0
7.0
102
BAR VB 233
5.4
4.7
5.3
5.7
6.7
7.0
7.0
5.7
5.7
5.7
103
HV 242
1.5
1.5
1.0
1.0
1.4
2.0
1.2
1.6
1.7
NS
LSDo os
—IT,-'"""
Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
2Genetic color (Gcol) was rated using a 9 to 1 scale: 9 = dark and 1 = light green. Spring greenup (Grn) was determined
using a 9 to 1 scale: 9 = green and 1 = dormant. Leaf texture (Leaf) was assessed with a 9 to 1 scale: 9 = fine and 1 = coarse
texture.
NS = means are not significantly different at the 0.05 level

Table 2. 1998 visual quality1 and other ratings2 for the 1995 low-maintenance, non-irrigated Kentucky bluegrass trial.
Turf quality
Sept
O ct
Mean
June
July
A ug
Gcol
Grn
Leaf
May
C ultivar
4.7
6.0
6.2
6.3
6.3
7.0
7.0
7.0
6.0
1 BAR VB 3115B
6.3
5.7
6.0
6.3
6.0
6.0
5.7
6.0
5.7
6.0
6.3
2 Caliber
5.3
5.7
5.8
6.3
5.7
6.0
4.7
6.0
6.0
6.0
3 B artitia
6.7
6.7
6.0
4.3
5.8
5.0
6.3
7.3
5.3
5.7
4 E agleton
5.7
4.7
5.3
5.7
5.7
6.0
6.0
6.7
6.3
6.3
5 Canterbury
6.0
6.0
5.7
5.7
6.0
5.7
5.7
7.7
6.0
5.0
6 South Dakota
5.0
6.7
6.0
5.7
5.6
5.7
6.0
6.3
4.7
6.3
7 K enblue
4.3
5.3
4.7
5.0
5.3
6.0
4.7
6.7
5.0
5.7
8 BAR VB 233
4.0
5.3
5.3
5.7
6.0
5.3
5.7
5.3
4.3
6.0
9 BAR VB 5649
5.2
6.0
5.0
3.3
6.3
5.3
6.0
4.0
6.0
5.0
10 Baron
3.7
4.7
5.2
5.0
5.3
6.3
4.7
6.7
6.3
5.3
11 Baronie
5.2
5.7
4.7
4.7
5.7
5.7
4.7
5.3
6.0
6.0
12 BH 95-199
5.0
4.3
5.3
5.1
5.7
5.0
6.0
5.0
5.0
5.3
13 Blue Star
5.7
4.0
5.3
5.1
5.0
5.3
3.7
5.7
6.0
5.0
14 North Star (PST-A7-60)
4.0
4.7
5.0
5.3
5.3
5.3
5.3
3.7
6.3
5.3
15 MTT 683
3.7
4.7
4.8
4.7
5.3
5.3
5.3
5.0
5.3
6.0
16 Baruzo
3.3
6.0
4.8
4.7
4.7
5.3
5.3
5.3
6.0
5.0
17 Dragon (ZPS-429)
4.0
5.3
4.8
4.3
4.7
5.0
7.0
6.0
5.7
5.3
18 VB 16015
3.7
4.7
4.6
4.7
4.0
5.3
5.0
6.0
4.7
5.3
19 PST-B9-196
4.0
5.0
4.7
3.7
4.5
5.7
4.7
5.0
4.3
5.3
20 L ipoa
3.3
4.0
3.9
4.0
4.3
4.3
4.0
3.7
5.7
6.3
21 BAR VB 6820
1.4
1.9
2.8
2.7
1.0
1.1
0.9
1.2
1.0
2.1
LSDo os
ITT“
V
isual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
2Genetic color (Gcol) was rated using a 9 to 1 scale: 9 = dark and 1 = light green.
Spring greenup (Gm) was determined using a 9 to 1 scale: 9 = green and 1 = dormant. Leaf texture (Leaf) was assessed
with a 9 to 1 scale: 9 = fine and 1 = coarse texture.
NS = means are not significantly different at the 0.05 level

7

Species and Cultivar Trials

Table 3. 1998 fall ground cover1 and wear tolerance ratings2 for the 1995 high-maintenance, irrigated traffic regional
Kentucky bluegrass test.
Fall ground cover
Cultivar
Wear tolerance
(%)
18.3
8.3
ZPS-309
1
20.0
7.7
2
Pepaya (DP 37-192)
43.3
6.3
BAR VB 5649
3
38.3
6.3
4
HV 242
40.0
6.3
5
P latini
40.0
6.0
Absolute (M ED-1497)
6
38.3
6.0
7
BAR VB 233
38.3
6.0
Dragon (ZPS-429)
8
50.0
6.0
SR 2100
9
43.3
6.0
ZPS-2183
10
5.7
BA 75-163
45.0
11
56.7
5.7
12
Baruzo
50.0
5.7
H 86-690
13
14
Liberator (ZPS-2572)
61.7
5.7
41.7
5.7
15
L ipoa
SR 2000
48.3
5.7
16
45.0
5.7
SRX 2205
17
45.0
5.3
BA 81-113
18
53.3
BAR VB 6820
5.3
19
56.7
5.3
Bartitia
20
Blacksburg
43.3
21
5.3
51.7
22
Haga
5.3
50.0
Impact (J-1576)
5.3
23
60.0
24
J - 1555
5.3
L ivingston
45.0
5.3
25
56.7
M ED-1580
5.3
26
55.0
A 88-744
27
5.0
56.7
28
Abbey
5.0
55.0
5.0
29
BA 73-373
56.7
BA 76-197
5.0
30
50.0
BA 81-058
5.0
31
56.7
Challenger
5.0
32
56.7
Compact
5.0
33
56.7
34
5.0
Eclipse
58.3
5.0
35
Explorer (Pick-3561)
50.0
36
Jefferson
5.0
61.7
37
Moonlight (PST-A418)
5.0
55.0
NJ-54
38
5.0
50.0
NJ-GD
5.0
39
60.0
40
N uglade
5.0
55.0
41
N ustar
5.0
55.0
42
Pick-855
5.0
51.7
5.0
43
PST-BO-165
51.7
44
5.0
PST-P46
55.0
45
Quantum Leap (J-1567)
5.0
60.0
5.0
46
Sodnet
66.7
47
VB 16015
5.0
65.0
4.7
48
Apollo (PST-B3-180)
60.0
Arcadia (J-1936)
4.7
49
53.3
50
A scot
4.7
56.7
51
ASP200 (HV 130)
4.7
BA 81-220
58.3
52
4.7
53.3
53
Baronie
4.7
54
56.7
Blackstone (PST-638)
4.7
56.7
55
Caliber
4.7
60.0
56
Conni
4.7
57
Fortuna
63.3
4.7
58
Goldrush (BA 87-102)
56.7
4.7
59
Marquis
53.3
4.7
60
Pick 8
60.0
4.7

8

Species and Cultivar Trials

Fall ground cover
(%)
Seabring (BA 79-260)
60.0
61
55.0
Baron
62
M idnight
56.7
63
Misty (BA 76-372)
58.3
64
61.7
North Star (PST-A7-60)
65
58.3
Odyssey (J-1561)
66
70.0
PST-B2-42
67
PST-BO-141
58.3
68
61.7
Shamrock
69
58.3
SR 2109
70
68.3
Total Eclipse (TCR-1738)
71
58.3
W ildw ood
72
58.3
73
A llure
68.3
America
74
66.7
BA 77-702
75
BA 81-227
63.3
76
56.7
77
Cardiff
66.7
Champagne (LTP-621)
78
66.7
Classic
79
66.7
G lade
80
66.7
K enblue
81
68.3
LTP-620
82
70.0
Rambo (J-2579)
83
61.7
Raven
84
58.3
Aw ard
85
68.3
BA 70-060
86
71.7
BA 75-173
87
68.3
BA 75-490
88
70.0
N im bus
89
73.3
NJ 1190
90
68.3
Rugby II (M ED-18)
91
65.0
U nique
92
66.7
Bluechip (M ED -1991)
93
60.0
Chicago (J-2582)
94
66.7
Lim ousine
95
73.3
LKB-95
96
70.0
Princeton 105
97
68.3
Sidekick
98
68.3
BA 81-270
99
76.7
BAR VB 3115B
100
78.3
Chateau
101
75.0
Coventry
102
76.7
Serene (PST-A7-245A)
103
23.1
LSDo os
‘These values represent the percentage of area per plot covered by turf in the fall of 1998.
2Wear tolerance was assessed using a 9 to 1 scale: 9 = best and 1 = worst wear tolerance.
Cultivar

9

Wear tolerance
4.7
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
4.0
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.3
3.3
3.3
3.3
3.3
3.3
3.0
3.0
2.7
2.7
2.3
2.1

Species and Cultivar Trials

Regional Tall Fescue Cultivar Evaluation - Established 1996
Nick. E. Christians and James R. Dickson
This was the second year o f 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 o f the trial is to study
the regional adaptation o f 129 tall fescue cultivars. Cultivars were evaluated for seedling vigor in October. The
study is established in full sun. Three replications o f the 3 x 5 ft (15 ft2) plots were established for each cultivar in
the spring o f 1996. 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.
Cultivars were evaluated for turf quality each month o f the growing season. Visual quality was assessed using a 9 to
1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality. The values listed under each month in Table 1
are the averages o f ratings made on three replicated plots for the three studies. Yearly means o f data from each month
are listed in the last column. The cultivars are listed in descending order o f average quality.
Data for genetic color (Gcol), spring greenup (Gm), and leaf texture (Leaf) also are included. Genetic color was rated
using a 9 to 1 scale with 9 = dark and 1 = light green. Spring greenup was estimated using a 9 to 1 scale with 9 =
green and 1 = dormant turf. Leaf texture was assessed with a 9 to 1 scale with 9 = fine and 1 = coarse texture.

Table 1. 1998 visual quality1 and other ratings2 for the tall fescue regional cultivar trial established in 1996.
Cultivar
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

Renegade
Titan 2
Arid
Plantation (Pennington 1901)
Kentucky-31 w/endo
MB 28
Pixie E+
ISI-TF11
MB 216
Millennium (TMI-RBR)
Regiment
Crossfire II
CU9501T
Duster
Finelawn Petite
Marksman
Shenandoah
Tulsa
WRS2
Aztec II (TMI-AZ)
Bonsai 2000 (Bullet)
Pick FA B-93
Rebel Sentry (AA-A91)
Bandana (PST-R5AE)
J-101
Leprechaun
PST-523
Safari
WX3-275
ZPS-5LZ
Anthem II (TMI-FMN)
BAR FA6 US6F
Coronado

Gcol
7.0
6.3
5.7
7.0
6.0
7.0
7.0
6.3
7.7
6.7
7.0
7.0
7.0
7.0
7.0
6.0
6.3
5.7
7.0
7.0
7.3
7.0
6.0
6.7
7.0
6.3
6.3
6.0
5.7
7.0
6.7
7.0
6.7

Gm
4 .0
4.7
6.0
4 .0
6 .0
4.3
5.3
4.3
4.3
4 .0
5.7
4.7
4.3
4.3
4 .0
4.3
4.3
4 .0
4 .0
4 .0
4.3
4.3
4.3
5 .0
4 .0
4 .0
4.7
5.3
4.7
4 .0
4 .7
4 .0
4 .0

Leaf
6.0
5.3
4.3
5.3
4 .0
6.7
6.0
5.3
5.7
6.7
6.3
5.3
5.7
5.3
5.7
5.0
6.3
6.0
6.0
6.3
5.7
5.7
6.3
6.7
7.0
6.3
6.3
5.7
6.7
6.3
6.7
5.7
7.0

10

May
6.7
5.3
5.7
5.7
5.7
5.7
6 .0
5.3
5.7
5.3
5.7
5.3
6 .0
5.3
5 .0
5.3
5.7
5.3
5 .0
5 .0
5.7
4 .7
5 .0
5.3
5 .0
5.3
5.3
5.7
5.3
5.3
5.0
5 .0
5.3

June
5.0
6.3
5.7
5.3
6 .0
5.3
6.0
5.3
5.3
4.7
5.0
5.0
4.3
5.3
4 .7 .
6 .0
5.3
5 .0
4 .7
4 .7
4.7
4.7
5 .0
5.0
4 .0
5 .0
5.0
4.7
5 .0
5.0
4.3
4.3
4.7

.... Turf .9.v.?.!i.ty.....
July
Aug
Sept
6.7
6.3
6 .0
6.3
6 .0
6.3
6.3
5.7
6.7
5.3
5.7
7.3
6.3
6.3
5.7
6 .0
6.3
6 .0
5 .7
6.3
5.7
5.7
6.3
6.3
6 .0
6.3
5.3
6 .0
6.7
6 .0
5 .7
6.3
6 .0
6.3
5.3
6.3
6.3
5 .0
6 .0
5.3
5.7
6.3
6.3
5 .0
6.3
5.7
5 .7
6 .0
6 .0
5.3
6 .0
5 .0
6.7
5.7
5.3
6.3
6.3
5.7
6 .0
6 .0
4 .7
6 .0
6 .0
5.7
5.3
6.3
5.7
5.3
5.7
5.3
5.7
6 .0
5 .0
5.7
6.3
5 .0
6.3
5.3
5 .0
6 .0
6 .0
5.7
5.3
5.3
5 .0
5.7
6.3
5.3
5.7
5.7
4 .7
6 .0
6 .0
5.3
5.3
5 .7
5.3
5.3
6 .0

Oct
7.3
6.7
6.3
6.7
5.3
6.3
5.7
6 .0
6 .0
6.3
6 .0
5.7
6 .0
5.7
6 .0
5 .0
5.3
6 .0
6 .0
5.7
6 .0
6.3
6.3
5 .0
6.3
5.7
5 .0
5.7
5.3
5.3
5.7
6 .0
5.3

Mean
6.3
6 .2
6.1
6 .0
5.9
5.9
5.9
5.8
5.8
5.8
5.8
5.7
5.6
5 .6
5.6
5.6
5.6
5.6
5.6
5.5
5.5
5.5
5.5
5 .4
5 .4
5 .4
5 .4
5 .4
5 .4
5 .4
5.3
5.3
5.3

Species and Cultivar Trials

Cultivar
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
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89

Coyote
DP 7952
Empress
Genesis
OFI-96-32
PRO 8430
PSII-TF-10
PSII-TF-9
PST-5M5
Rebel 2000 (AA-989)
Rembrandt (LTP-4026 E+)
Wolf pack (PST-R5TK)
WVPB-1D
ZPS-2PTF
Alamo E
ATF-038
Gazelle
JSC-1
MB 213
MB 29
R5AU
Southern Choice
SR 8210
SRX 8084
Tar Heel
Twilight II (TMI-TW)
ATF-253
Bravo (RG-93)
Falcon II
JTTFA-96
JTTFC-96
Kickoff (PST-5E5)
Masterpiece (LTP-SD-TF)
MB 212
MB 215
Mustang II
OFI-931
Shortstop II
WPEZE (WVPB-1C)
Apache II
ATF-022
BAR FA 6D
CU9502T
Jaguar 3
Lion
MB 214
WVPB-1B
ATF-188
ATF-192
ATF-196
AV-1
BAR FA 6LV
BAR FA6 US2U
BAR FA6D USA
Cochise II
DLF-1

Gcol
6.7
6.0
6.3
7.0
6.7
6.3
6.7
6.3
7.0
7.0
7.0
6.7
6.7
7.0
6.7
6.0
6.0
6.7
6.7
6.7
7.0
6.7
6.0
6.3
7.0
7.0
7.0
6.7
6.7
5.7
5.7
6.3
7.0
7.0
7.0
6.0
6.7
6.0
6.7
6.3
6.3
6.3
5.7
6.7
6.7
7.3
6.3
6.3
6.0
6.3
6.3
5.7
6.7
6.7
6.7
6.0

Grn
4 .7
5.7
4 .0
4 .0
4 .0
4.7
6.3
4.7
4.3
4 .0
3.7
5 .0
5.0
4 .0
4 .0
4 .0
4.7
4.3
4 .0
4 .0
4 .0
4 .0
4 .0
4.3
4.3
4 .0
4.3
4 .7
4 .7
6.3
5.3
4 .0
4.3
4.7
4 .0
4.3
4 .0
4 .0
4.3
4 .0
4.7
4.3
4.3
4 .7
4.7
4 .0
4.3
4 .0
4 .0
4.3
4.7
4.3
4.3
4.3
4 .0
5.0

Leaf
6.3
5.0
5.7
6.0
6.3
6.0
6.0
5 .0
5.3
5.3
5.7
5.7
6.0
6.0
6.0
5.3
6.7
6.3
5.0
5.0
6.3
7 .0
6.0
6.0
6.3
6.0
6.7
5.7
5.0
5.7
6.3
6.7
7.7
6.3
6.3
6.3
6.3
7.0
6.7
5.7
5.3
6.7
7 .0
6.7
6.0
6.7
6.3
6 .0
5.0
7.3
5.7
7.3
7.0
6.7
6.0
6 .0

11

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

June
4 .7
4.7
4.3
4.3
5 .0
4.7
4.3
4.7
4.7
4.3
4.3
4 .7
4 .7
4.3
4 .7
4 .0
5 .0
4.3
5.0
5 .0
4.3
4 .7
4.7
4.7
4 .0
4.3
4.3
4.7
4 .0
3.7
5.0
4.7
4.3
4.7
4 .0
4 .7 •
4 .0
4.3
4 .7
4.7
4.3
4.3
4.3
4 .0
4.3
4.3
5.0
3.7
4.3
4.7
4 .0
4.3
3.7
4.3
4 .0
4.7

July
5.3
5.3
5 .0
5 .0
5 .0
5 .0
5.3
5 .0
4.3
5 .0
5.3
5 .0
5.3
5 .0
5 .0
5.3
5 .0
5 .0
5 .0
5.3
5 .0
5 .0
4 .7
5 .0
5.3
5.7
5.3
5 .0
5 .0
4 .7
5 .0
4.3
4 .7
5 .0
4 .7
4 .7
4 .7
5 .0
3.7
5 .0
4.3
5 .0
4.3
4 .7
5.3
5.3
5 .0
4.3
4.3
4.3
4.7
4 .7
4 .7
5 .0
4 .7
4.7

Turf£uali_ty_
Aug
Sept
6.7
5.0
5.7
5.3
6 .0
6 .0
6.3
5.7
5.3
5.3
5.3
5.7
5.7
5.3
5.0
5.7
5.3
6.0
6.0
5.7
5.0
6.3
5.7
5.7
5.7
5.7
5.7
6.0
5.0
6 .0
5.3
5.7
6.0
5.3
6.0
5.3
5.0
5.7
5 .0
5.0
5 .0
6.3
5.0
5.7
5.3
5.7
5.7
5.7
5.7
6.3
5.7
5.7
5.0
5.7
5.0
5.3
5.7
5.3
5.7
5.0
4.7
5.0
5.7
4.7
5.3
5.7
5.0
5.3
5.7
6.3
5.7
5.7
5.3
5.3
5.3
5.3
5.7
6.0
5.3
4.7
5.3
5.3
5 .0
5.3
5.7
5.3
5.3
6 .0
5.7
5 .0
5 .0
5.0
5.0
5 .0
5.7
5.3
4.7
6 .0
5.0
5.3
5.7
5.7
5.0
5.0
6.0
5.3
5.3
5.3
5.7
5.3
5.3
5.3

Oct
5.7
5.7
5.7
5.7
5.7
6.0
5.7
6.3
6.3
5.3
5.7
5.7
5.7
5.7
5.3
6.0
5.3
5.7
5.7
5.3
5.7
5.7
5.7
5.3
5.7
5.0
5.7
5.3
6.0
6 .0
5.3
5.7
6 .0
5.7
5.3
5.0
6.0
5.3
5.3
5.7
5.7
5.3
6.0
5 .0
5 .0
5.3
5 .0
5.7
6 .0
5.7
5.3
5.7
5.3
5 .0
5 .0
4.7

Mean
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5 .2
5 .2
5 .2
5.2
5.2
5 .2
5.2
5 .2
5 .2
5 .2
5.2
5 .2
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5.1
5 .0
5 .0
5 .0
5 .0
5 .0
5 .0
5 .0
5 .0
4 .9
4 .9
4 .9
4 .9
4 .9
4 .9
4 .9
4 .9
4 .9

Species and Cultivar Trials

Turf quality
Grn
June
July
Aug
Sept
Mean
Gcol
Leaf
May
Oct
4 .7
5.3
5 .0
90
EA 41
6.7
4 .0
7 .0
4 .7
4.3
5.7
4 .9
4 .0
4.3
5 .0
5.3
91
OF1-96-31
5.3
6.0
4.7
5.3
5 .0
4 .9
5.7
OFT-FWY
4 .0
4 .7
4.3
4 .7
4 .7
4 .9
92
6.3
5.7
5 .7
93
PC-AO
7.0
4.7
6.0
4 .7
4 .7
4 .7
5 .0
5 .0
5.3
4 .9
4 .0
5 .0
4 .7
94
6.7
4 .0
4.7
5 .0
4.3
6 .0
4 .8
ATF-257
5 .0
4 .0
4.3
4 .7
5 .0
5.7
6.0
4.3
5.3
4 .8
95
BAR FA6 US3
5.0
4.3
4 .3
5 .0
5 .0
5.3
4 .8
Coronado Gold (PST-5RT)
6.3
3.7
6.0
96
4.3
5.7
5 .0
5 .0
4 .0
4.3
5.3
4 .8
6.0
6.7
97
ISI-TF9
4.3
4 .7
5 .0
5.3
4 .0
4.3
5 .0
4 .8
6.0
98
Kitty Hawk S.S.T. (SS45DW)
5.3
4 .7
5.3
6.0
3.7
6.7
4.3
4 .0
5 .0
5.3
4 .8
99
MB 26
3.7
5.7
5.7
4 .8
4.3
4.3
4 .3
5.3
5.3
100
Pick FA XK-95
7.0
4 .7
5 .0
5 .0
4 .8
7.0
4 .0
5.7
5.3
4 .3
4 .7
101
SRX 8500
4.3
4.3
5 .0
5.7
6.7
4.7
5.3
5.0
4 .7
4 .8
102
TA-7
4 .0
5 .0
4 .7
4 .7
5 .0
4 .7
6.0
4 .0
5.7
4.7
103
Arid 3 (J-98)
6.0
4 .7
5.3
4.3
4 .0
5.3
4 .3
5 .0
4 .7
5.3
104
Bonsai
5 .0
4 .7
6.0
4.3
4.3
5 .0
Good-en (KOOS 96-14)
4.3
5.7
4.7
4 .7
105
4 .0
4 .7
4.3
5.0
4 .7
4 .7
4 .7
'6 .3
6.3
5 .0
106
MB 210
3.7
5 .0
4.3
4.3
4 .7
5 .0
6.3
6.3
5.3
4 .7
107
OFI-951
3.7
4.3
5 .0
5 .0
6.7
4.3
4.3
4 .7
6.3
5.7
108
Pick FA 15-92
6.0
4 .0
5 .0
3.3
3.7
5.7
5.3
4 .7
5.3
109
Pick RT-95
6.7
3.7
4 .7
4 .7
4.3
7.0
4.3
5 .0
5 .0
4 .6
5.7
110
Arabia (J-5)
5.7
4 .0
4 .0
4 .0
4 .7
4 .7
5 .0
5.3
5.3
4 .6
111
ATF-020
5 .0
5 .0
6.3
4.7
6.0
3.7
4 .3
4.3
4 .6
5 .0
112
Comstock (SSDE31)
4 .0
3.7
4 .0
5.7
5.3
6.7
4 .0
5 .0
4 .6
6.0
113
PICK FA 20-92
4 .0
4 .0
4 .0
5 .0
5.3
4 .6
6.3
4.3
6.0
5 .0
114
Sunpro
4.3
5 .0
4 .6
4.7
4.3
4 .0
5 .0
6.3
4.3
6.0
115
Tomahawk-E
4 .7
4 .7
4.7
4 .0
4 .3
4 .7
4 .5
5.7
4 .0
5.3
116
EC-101
4.7
3.3
4.3
4 .7
5 .0
5 .0
4 .5
7.0
4 .7
5.7
117
ISI-TF10
4 .7
4 .5
5 .0
4 .7
4.3
4 .0
4.3
6.0
4 .7
6.7
Reserve (ATF-182)
118
4 .4
4 .0
5 .0
3.7
5 .0
4 .0
4.7
4 .3
6.3
6.3
119
BAR FA6 US1
4 .4
4.3
4 .7
4.3
4.3
4.3
4 .7
4 .0
5.0
5.3
Pick FA 6-91
120
4 .7
4.3
4.3
3.7
4.3
4 .7
5.7
4.3
6.7
4.3
121
Arid 2 (J-3)
4.3
5 .0
4 .0
3.7
5 .0
4 .3
4 .0
5.0
4 .7
6.0
122
DP 50-9011
4 .0
4.3
4 .3
4.3
5 .0
4 .3
4.3
4 .0
6.0
Equinox (TMI-N91)
5.7
123
4 .7
4 .0
4 .7
4 .7
4.3
4.3
3.3
4.3
6.0
6.3
124
MB 211
4 .0
4 .0
5 .0
4 .3
4 .0
4.3
4 .7
4.3
6.0
6.7
125
Pick GA-96
4 .3
4 .2
3.3
4 .0
4 .7
5 .0
5 .0
4 .0
6.0
4.3
126
Pick FA N-93
4 .0
4 .2
4 .0
4.3
4.3
4 .3
5.7
4.3
7.3
4 .0
127
Pick FA UT-93
4 .7
4 .2
3.3
4.3
4.3
5 .0
3.7
6.7
4 .0
6.0
PST-5TO
128
3.7
3.7
4 .0
3.3
4.3
4 .7
3 .9
4 .7
6.7
6.3
129
AA-983
2
.2
2.3
2
.4
2.0
1.9
NS
1.5
1.7
1.1
2.6
.....................
U.W.1--------------------------------.................................. ...I
I .1 ■ .1.
.....
.................
........................
LSDft.ft5
"TwV
Visual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
2Genetic color (Gcol) was rated using a 9 to 1 scale: 9 = dark and 1 = light green. Spring greenup (Gm) was determined
using a 9 to 1 scale: 9 = green and 1 = dormant. Leaf texture (Leaf) was assessed with a 9 to 1 scale: 9 = fine and 1 = coarse
texture.
NS = means are not significantly different at the 0.05 level
Cultivar

12

Species and Cultivar Trials

Regional Fine Fescue Cultivar Evaluation - 1993
Nick. E. Christians and James R. Dickson
This was the final year o f data from the '93 fine fescue trial. This was a National Turfgrass Evaluation Program
(NTEP) trial. It was conducted at many locations around the U.S. The purpose o f the trial was to study the
regional adaptation o f 59 fmeleaf fescue cultivars. Cultivars were evaluated for quality each month of the growing
season through August. The study was conducted in full sun. Three replications o f the 3 x 5 ft (15 ft2) plots were
established for each cultivar in September o f 1993. The trial was maintained at a 2-inch mowing height, fertilized
with 3.5 lbs N/1000 ft2 during the growing season, and irrigated when needed to prevent drought. Preemergence
herbicide was applied once in the spring.
Visual quality was evaluated monthly in 1998 from May through August. Quality was assessed using a 9 to 1 with
9 = b e s t, 6 = lowest acceptable, and 1 = worst quality. Genetic color was rated in August using a 9 to 1 scale with
9 = darkest and 1 = lightest green.
A new fine fescue trial was initiated in September 1998. Seventy-nine fmeleaf fescue cultivars were established for
evaluation. The study was arranged in full sun with three replications and individual plot size of 5 x 5 ft.
Percentage fall living ground cover data were taken in October.
T able 1. The 1998 genetic color and visual quality ratings1 for cultivars in the 1993 Fineleaf Fescue Cultivar Trial.
A ugust
Mean
June
July
Species
Color
May
Cultivar
5.3
6.8
7.7
7.0
7.0
STC
6.7
1 Rondo
5.3
6.3
6.7
7.0
6.3
STC
4.3
2 Jasper (E)
4.7
6.3
6.7
6.7
7.0
STC
4.3
3 PST-4VB Endo
5.7
6.3
7.0
6.3
6.3
CF
5.7
4 Shadow II (PST-44D)
6.0
6.3
6.7
6.7
6.0
CF
5.3
5 Jamestown II
6.2
5.0
6.7
6.7
6.3
CF
5.0
6 Tiffany
5.0
6.1
6.0
6.3
7.0
STC
4.7
7 Shademaster II
6.0
6.1
5.7
6.3
6.3
CF
4.7
8 Banner II
5.7
6.1
6.0
6.3
6.3
CF
4.7
9 Banner III (MB 61-93)
5.3
6.1
6.0
6.7
CF
6.3
4.0
10 Culumbra (MB 64-93)
4.3
6.0
6.7
6.0
7.0
4.7
STC
11 PST-4ST
5.9
4.3
7.3
5.7
6.3
CF
3.3
12 Victory (E)
4.7
5.9
5.7
6.7
6.7
CF
4.0
13 Treazure (ZPS-MG)
3.3
5.8
6.0
7.0
6.7
STC
3.0
14 BAR UR 204
5.0
5.8
5.3
6.3
6.3
CF
4.3
15 Victory II (Pick 4-91W)
5.8
5.3
6.0
6.0
6.0
CF
4.7
16 K-2 (MB 65-93)
5.0
5.8
6.0
5.7
4.7
6.3
CF
17 SR 5100
5.3
5.8
6.0
6.0
6.0
CF
4.7
18 Sandpiper (PRO 92/20)
4.3
5.8
6.3
6.3
6.0
STC
4.3
19 Flyer II (ZPS-4BN)
5.7
5.3
6.3
5.3
5.7
CF
4.3
20 NJ F-93
4.0
5.7
6.7
5.7
6.3
CF
3.3
21
M edina
4.0
5.6
6.3
5.3
6.7
CF
3.0
22 Bridgeport
4.0
5.6
5.7
6.3
6.3
STC
4.3
23 PST-4DT
4.7
5.6
5.7
6.0
6.0
CF
5.0
Shadow (E)
24
4.3
5.6
6.0
6.7
STC
4.7
5.3
25 CAS-FR13
4.0
5.5
6.7
5.7
5.7
STC
2.7
26 A ruba
4.0
5.5
5.7
6.0
6.3
CF
3.3
27 Eco (MB 63-93)
3.7
5.4
6.0
5.7
6.3
3.7
SLC
28 D aw son
5.4
5.0
6.0
5.0
5.7
CF
4.0
29 Darw in
5.4
4.3
6.0
5.7
5.7
STC
4.3
30 WX3-FFG6
4.0
5.4
6.0
5.7
6.0
CF
3.3
31
WX3-FF54
4.0
5.4
6.0
5.3
6.3
CF
3.7
32 Brittany

13

Species and Cultivar Trials

Cultivar
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

ISI-FC-62
Flyer
Jamestown
Common creeping
Discovery
M olinda
Seabreeze
MB 66-93
MB 82-93
Osprey (PRO 92/24)
Cascade
BAR Frr 4ZBD
TMI-3CE
Quatro (FO 143)
Aurora w/endo.
Ecostar
N ordic
Spartan
Reliant II
Scaldis
Pamela
Silverlawn (WVPB-STCR-101)
Defiant (MB 81-93)
Vernon (MB 83-93)
Brigade
67135
SR 3100

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

Color

May

June

July

A ugust

Mean

4.7
5.4
5.7
6.0
5.3
6.3
5.3
3.7
5.2
5.3
3.7
5.7
6.0
5.3
5.2
6.0
5.3
6.0
3.3
5.2
3.7
2.7
7.7
6.3
5.1
6.0
5.0
3.3
5.3
4.9
3.3
5.3
5.3
5.7
4.9
4.7
4.3
5.0
4.8
5.3
3.0
6.0
3.7
6.3
4.8
2.7
3.0
6.7
6.7
4.8
5.0
3.7
5.7
5.0
4.8
5.3
4.7
3.7
4.7
5.0
4.0
5.3
4.3
4.6
4.7
3.0
5.3
5.3
3.7
4.3
5.0
4.0
3.0
4.3
5.0
2.7
2.3
6.0
5.3
4.1
3.7
3.0
4.7
4.0
4.7
2.7
5.0
3.3
5.0
4.0
3.0
2.7
4.7
5.3
3.9
4.7
3.0
2.7
5.0
3.8
5.0
3.3
2.3
4.7
3.8
3.3
2.0
5.3
4.3
3.8
3.0
2.0
5.3
5.0
3.8
3.7
2.0
4.3
4.7
3.7
4.3
3.0
2.0
4.7
3.5
3.7
3.7
2.3
3.5
4.3
2.7
2.7
4.0
4.0
3.3
1.4
1.5
2.1
1.2
1.6
and visual quality is assessed using a 9 to 1 scale with 9 = best,

3.7
3.0
3.3
3.0
3.0
3.0
4.0
3.3
3.0
3.0
4.0
4.7
4.3
3.3
3.3
2.0
2.7
3.0
3.0
2.7
3.3
4.7
2.3
2.0
2.7
3.3
3.0
2.1
L S D ( o.o5)
'Genetic Color (Color): 9 = dark green and 1 = light green
6 = lowest acceptable, and 1 = worst quality.
Species: CF = Chewings Fescue, HF = Hard Fescue, SF = Sheep Fescue, SLC = Slender Creeping Fescue,
STC = Strong Creeping Fescue

T able 2. Percentage fall living ground cover1 for cultivars established in the 1998 Fineleaf
Fescue Cultivar Trial.
Percentage fall cover (%)
Species
#
Name
90.0
CF
1
Sandpiper
89.7
STF
2
Salsa
86.7
Pathfinder
3
86.7
CF
4
Jamestown II
83.3
STF
5
Boreal
80.0
STF
6
SRX 52LAV
78.3
SLF
7
Seabreeze
76.7
STF
8
DGSC 94
76.7
CF
9
Brittany
76.7
STF
10
Jasper II
76.7
CF
Culombra
11
76.7
STF
12
SRX 52961
73.3
STF
PST-EFL
13
73.3
STF
Common creeping red
14
71.7
CF
15
ACF 092
71.7
STF
16
Shademark
71.7
STF
17
ISI Frr 5
71.7
CF
18
ABT-CHW-3
70.0
SLF
19
ASR 049
70.0
SLF
20
Dawson E+

14

Species and Cultivar Trials

#
Name
Percentage fall cover (%)
Species
21
70.0
Defiant
HF
70.0
22
Pick FF A-97
HF
Bridgeport
CF
70.0
23
70.0
24
Longfellow II
CF
70.0
25
ABT-CR-3
STF
68.3
HF
ABT-HF1
26
CF
68.3
27
SR 5100
68.3
HF
28
ABT-HF-3
66.7
CF
Intrigue
29
66.7
30
Oxford
66.7
CF
31
Magic
66.7
CF
Pick Frc 4-92
32
66.7
CF
Treazure (E)
33
66.7
CF
34
Shadow II
66.7
STF
35
ISI Frr 7
66.7
ABT-CHW-2
CF
36
TH
66.7
37
SR 6000
66.7
ABT-CR-2
STF
38
65.0
HF
39
4001
65.0
STF
40
Florentine
65.0
CF
41
Tiffany
65.0
HF
42
SRX 3961
65.0
HF
43
Heron
63.3
STF
44
ASC 082
CF
63.3
BAR CHF 8 FUS2
45
63.3
CF
Pick Frc A-93
46
Shademaster II
STF
63.3
47
63.3
CF
48
MB-63
63.3
HF
49
ISI FI 12
HF
63.3
ABT-HF-4
50
CF
63.3
ABT-CHW-1
51
63.3
HF
52
ABT-HF-2
63.3
Banner III
CF
53
61.7
HF
54
BAR HF 8 FUS
60.0
HF
55
Rescue 911
60.0
STF
PST-4FR
56
60.0
HF
D iscovery
57
60.0
SF
Quatro
58
58.3
HF
AHF 008
59
56.7
STF
60
ASC 087
56.7
HF
AHF 009
61
56.7
62
Ambassador
56.7
STF
BAR CF 8FUS1
63
56.7
HF
Reliant II
64
55.0
HF x BF
M inotaur
65
55.0
STF
66
PST-47TCR
SLF
53.3
BAR SCF 8 FUS3
67
53.3
BF
68
SR 3200
53.3
HF
Nordic (E)
69
51.7
HF
70
Scaldis
51.7
HF
Bighorn
71
51.7
HF
72
ISI FI 11
HF
50.0
73
Attila E
50.0
CF
74
PST-4HM
50.0
HF
75
Osprey
BHF
48.3
76
PST-4MB
40.0
STF
77
ASC 172
36.7
HF
MB-82
78
15.9
79
LSD 0.05
‘These figures represent the percentage area covered by fine fescue.
BF = blue fescue, BHF = blue hard fescue, CF = creeping fescue, HF = hard fescue, SF = sheep
fescue, SLF = slender creeping fescue, STF = strong fescue, TH = tufted hairgrass.

15

Species and Cultivar Trials

Perennial Ryegrass Study - Established 1994
James R. Dickson and Nick E. Christians
This trial began in the fall o f 1994 with the establishment o f 96 cultivars o f perennial ryegrass at the Iowa State
University Horticulture Research Station. The study was established on an irrigated area that was maintained at a 2inch 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 o f 1994.
Cultivars were evaluated for turf quality each month o f the growing season. Visual quality was assessed using a 9 to
1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality. The values listed under each month in Table 1
are the averages o f ratings made on three replicated plots for the three studies. Yearly means o f data from each month
are listed in the last column. The cultivars are listed in descending order o f average quality.
Data for genetic color (Gcol), spring greenup (Gm), and leaf texture (Leaf) are also included. Genetic color was rated
using a 9 to 1 scale with 9 = dark and 1 = light green. Spring greenup was estimated using a 9 to 1 scale with 9 =
green and 1 = dormant turf. Leaf texture was assessed with a 9 to 1 scale with 9 = fine and 1 = coarse texture.
T able L 1998 visual quality1 and other ratings2 for the national perennial ryegrass study.___________________________

Turf quality
C ultivar
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

D ivine
Secretriat (RPBD)
SR 4010 (SRX 4010)
Line Drive (MB 47)
Monterey (J-1706)
SR 4400 (SRX 4400)
Achiever
Blackhawk (TMI-EXFLP94)
Edge
Excel (MB 1-5)
Express
Manhattan 3
Premier II (BAR USA 94-11)
Spell Bound (WVPB-93-KFK)
Wizard (MB 41)
WX3-93
Accent
A ssure
Brightstar
Buccaneer II (WVPB 92-4)
Caddieshack (MED 5071)
CAS-LP23
ISI-MHB
Mardigras (ZPS-2NV)
Mb 45
N obility
Omega3 (ZPS-2DR-94)
PST-2CB
Saturn II (ZPS-2ST)
Sonata (PST-2R3)
Stallion Select
Vivid
Wind Star (PST-28M)
ASP400 (APR 106)
Blazer III (Pick 928)
Catalina (PST-GH-94)
Chaparral (PST-2DLM)
Cutter
Dancer
Imagine

Gcol
7.0
6.7
6.0
7.7
7.0
7.0
6.3
7.0
6.3
7.3
6.7
6.3
7.3
6.3
7.0
7.0
6.7
6.7
7.3
6.7
6.3
7.0
7.0
6.3
7.7
7.3
7.0
7.3
7.3
7.0
7.0
7.0
6.7
6.3
6.7
7.7
7.3
6.3
7.3
7.3

Gm
5.7
6.3
6.3
6.3
5.7
5.3
6.0
6.0
6.3
6.0
6.0
5.3
6.3
5.3
6.3
5.7
5.3
6.3
5.7
5.7
5.7
6.0
5.7
6.0
5.0
5.0
5.7
6.0
5.3
5.7
6.0
5.3
6.0
5.0
6.0
5.3
6.0
5.3
5.7
5.3

Leaf
6.0
5.7
5.3
5.3
5.7
6.0
5.7
5.0
5.3
5.3
6.0
5.7
5.3
5.7
6.0
5.3
5.0
5.3
5.3
5.3
5.7
6.0
6.0
5.7
5.7
5.0
6.0
5.7
5.7
5.0
5.7
5.7
5.3
5.0
6.0
6.3
6.3
6.0
5.3
6.3

16

May
5.0
5.3
6.0
5.3
6.0
5.7
5.3
5.3
5.7
6.0
5.7
5.0
5.3
5.7
5.7
4.7
4.7
5.0
5.0
5.7
5.3
5.3
5.0
5.7
4.7
5.3
5.7
5.0
5.7
5.3
5.0
5.0
5.3
5.3
5.0
4.7
4.7
5.7
5.3
4.3

June
7.7
7.0
7.0
6.3
7.7
7.0
7.0
7.3
6.7
7.7
6.7
7.0
7.3
6.7
6.3
7.0
7.0
6.7
7.0
7.3
6.7
6.7
6.3
6.3
7.7
7.7
7.3
6.7
6.3
7.3
6.7
8.0
7.7
6.3
7.0
7.3
6.3
6.3
7.0
6.3

July
5.7
6.3
6.7
6.0
5.7
6.7
6.0
6.3
6.3
6.0
6.0
5.7
6.0
6.0
5.7
6.3
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.3
6.0
6.0
6.0
6.0
5.7
5.7
6.7
6.0
6.0
6.0
6.0
5.7
6.0
5.7
6.0
6.3

A ug
6.0
6.7
6.7
6.7
6.3
6.0
5.7
6.0
6.3
5.3
6.0
6.3
6.0
6.0
6.0
6.3
6.3
6.0
5.7
5.3
6.0
6.0
6.3
6.3
6.0
5.3
6.0
6.0
6.0
6.3
5.7
5.7
6.0
6.0
5.7
5.7
5.3
6.0
5.7
6.0

Sept
7.3
7.3
6.7
7.3
6.7
7.0
7.0
7.0
6.7
7.0
7.3
7.3
6.7
7.0
7.3
7.3
7.0
7.0
7.0
7.0
7.0
7.0
7.0
6.7
7.0
6.7
6.7
7.0
7.0
7.0
7.0
7.0
6.7
6.7
7.0
7.0
7.3
7.0
7.0
7.0

O ct
7.7
7.0
6.7
7.3
6.7
6.7
7.3
6.7
6.7
6.3
7.0
7.0
7.0
7.0
7.3
7.0
6.7
7.0
7.0
6.7
7.0
6.7
7.0
6.3
6.7
6.7
6.3
7.0
7.3
6.3
6.7
6.3
6.3
7.0
6.7
7.0
7.7
6.3
6.3
7.0

Mean
6.6
6.6
6.6
6.5
6.5
6.5
6.4
6.4
6.4
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
6.3
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

Species and Cultivar Trials

Turf quality
O ct
Mean
Gcol
Grn
A ug
Sept
Leaf May June July
6.3
6.3
6.2
41
6.7
7.0
6.0
6.0
5.0
5.7
5.3
KOOS 93-6
6.7
6.7
6.2
7.0
5.7
6.0
42 Laredo
6.3
5.3
5.3
6.3
6.7
7.0
7.0
6.2
7.7
6.0
4.7
6.3
5.7
43 LRF-94-CB
6.3
7.0
7.0
6.2
6.0
5.7
44 Night Hawk
7.3
6.0
5.7
5.3
6.3
5.7
7.0
6.3
6.2
6.3
4.7
7.0
6.3
45 Omni
5.3
6.0
6.7
6.3
6.2
6.7
5.0
7.0
6.0
6.0
5.7
46 Panther (ZPS-PR1)
5.3
7.0
6.7
6.2
5.7
5.7
47 Pennant II (MB 42)
8.0
5.7
5.7
5.0
7.3
7.0
6.3
6.2
6.3
6.0
6.0
6.7
5.7
48 Protocol (KOOS 93-3)
5.3
5.3
7.0
6.7
6.2
6.7
5.7
6.0
6.7
5.0
5.7
5.7
49 PS-D-9
7.0
7.0
6.2
6.7
5.7
5.3
4.3
7.0
6.3
5.7
50 Q uickstart
7.0
6.3
6.2
5.7
6.3
6.0
6.7
5.7
5.7
5.7
51 R2 (ISI-R2)
6.0
7.0
6.3
6.2
7.0
5.7
6.7
5.0
52 Roadrunner (PST-2ET)
6.3
5.7
7.0
6.7
6.2
5.3
6.0
4.7
7.0
6.3
53 Stardance (PST-2FE)
7.0
6.0
7.0
6.7
6.2
6.0
7.7
6.0
6.0
4.7
7.3
5.7
54 Sunshine(Pick LP 102-92)
6.3
6.3
6.1
6.0
7.0
5.7
6.3
5.7
5.0
5.3
55 Academy (PC-93-1)
7.0
5.7
6.3
6.1
6.3
6.3
5.7
56 APR 124
5.3
5.3
5.3
6.3
5.7
6.1
6.0
5.7
6.0
6.0
5.7
5.3
7.3
57 Elf
6.7
6.7
5.3
6.1
7.3
5.7
58 E squire
5.0
7.0
6.0
5.3
6.3
6.0
6.0
6.1
7.0
6.7
59 Majesty (MB 43)
6.0
5.7
5.0
6.3
6.0
5.7
6.1
6.7
7.7
5.7
6.0
60 MB 44
5.7
6.7
5.3
Palmer III (LRF-94-MPRH)
7.0
6.7
6.0
6.3
6.3
5.7
6.1
61
5.3
6.0
5.3
7.0
6.0
6.3
6.1
62 Riviera II
7.0
4.7
6.7
6.0
5.7
5.3
6.0
5.7
6.0
6.7
6.7
6.0
6.3
6.0
5.7
5.0
63 APR 066
6.7
6.7
7.0
5.7
6.0
6.0
64 APR 131
6.0
5.7
5.0
6.0
6.0
5.7
6.7
7.0
5.7
6.0
6.0
6.0
5.7
65 BAR ER 5813
5.3
7.0
6.7
5.7
7.0
6.3
5.7
6.0
66 Passport (PST-2FF)
5.7
5.7
4.7
5.0
7.3
6.7
6.0
6.7
6.3
5.7
67 P egasus
6.3
5.7
5.0
6.7
6.3
5.7
5.7
6.0
68 Precision
6.3
6.0
5.7
5.3
6.3
5.7
7.0
6.3
6.0
4.7
69 Prizm
6.3
6.3
6.3 • 6.0
5.3
6.3
6.3
6.0
5.7
6.0
7.0
5.7
6.3
70 SR 4200
6.3
5.3
6.0
6.0
6.3
6.3
6.0
6.0
71
Stallion Supreme (PSI-E-1)
6.3
5.3
5.7
5.3
6.7
6.7
5.7
6.0
6.7
6.3
72 Top Hat
7.3
6.0
4.0
6.3
6.3
5.7
6.0
6.0
WVPB-PR-C-2
7.0
6.3
6.3
5.7
5.3
5.3
73
6.7
6.0
5.9
74 A dvantage
5.7
5.0
6.3
5.7
5.7
7.3
5.0
6.7
6.7
5.7
5.9
6.7
6.3
6.0
6.3
4.3
75 Citation III (PST-2DGR)
5.3
6.7
5.7
60
6.3
5.9
76 DLP 1305
6.3
6.0
5.7
5.3
5.3
5.7
6.3
7.3
6.7
5.9
6.0
5.3
4.7
5.0
77 DSV NA 9401
5.3
6.3
5.7
6.0
6.7
5.9
5.7
5.0
5.7
5.3
78 Legacy II (LESCO-TWF)
7.3
7.0
5.7
6.3
5.3
6.0
5.9
7.0
5.0
5.3
5.3
79 Morning Star
5.7
5.0
6.7
6.0
5.9
7.0
5.7
5.3
7.0
80 MVF-4-1
5.3
6.0
7.0
6.0
5.7
6.3
5.9
7.0
4.7
81 N avajo
6.3
5.3
5.7
7.0
6.0
6.0
5.9
6.0
4.3
6.3
82 Top Gun (J-17030
6.3
6.7
6.7
6.0
5.9
6.0
5.7
4.3
6.3
6.0
6.0
83 WX3-91
5.3
6.7
6.3
5.8
84 Brightstar II (PST-2M3)
7.7
6.3
6.3
6.0
5.7
7.0
3.3
6.0
6.0
6.0
5.8
85 Calypso II
6.7
6.0
5.7
4.7
6.3
6.0
6.3
6.0
5.7
5.8
86 Head Start (Pick PR 84-91)
5.0
6.3
5.7
7.3
5.7
6.0
7.0
6.3
5.8
4.3
5.3
5.3
87 N IN E-O -O N E
7.3
5.0
5.3
6.3
6.0
5.7
6.0
6.7
6.7
5.8
88 Repell III (LRF-94-C7)
7.7
6.0
6.3
4.0
7.0
6.0
5.0
6.3
6.7
5.7
5.8
89 Saturn
6.0
5.3
4.7
6.0
6.7
6.0
5.3
5.7
5.8
6.0
90 W illiam sburg
5.7
5.3
5.3
5.3
5.0
7.3
7.7
5.8
91
Wind Dance (MB 46)
7.7
5.3
6.0
4.0
5.3
6.7
6.0
5.7
5.7
5.7
5.3
6.7
5.0
92 Figaro
5.7
6.0
5.7
6.3
5.7
5.7
5.0
5.6
6.3
5.3
5.3
93 DSV NA 9402
5.3
5.7
5.3
6.7
6.0
5.6
7.7
6.7
4.0
6.0
94 Prelude III (LRF-94-B6)
5.3
6.7
5.7
4.3
6.3
5.5
7.0
5.3
7.3
4.7
95 Pennfine
5.3
6.0
5.7
4.0
4.0
4.3
5.7
7.7
3.0
3.3
5.0
96 L inn
1.4
NS
1.9
0.7
1.9
1.4
1.2
1.3
NS
1.7
LSDo os
HT“
V isual quality was assessed using a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
2Genetic color (Gcol) was rated using a 9 to 1 scale: 9 = dark and 1 = light green. Spring greenup (Grn) was determined
using a 9 to 1 scale: 9 = green and 1 = dormant. Leaf texture (Leaf) was assessed with a 9 to 1 scale: 9 = fine and 1 = coarse
texture.
NS = means are not significantly different at the 0.05 level.
C ultivar

17

Species and Cultivar Trials

Shade Adaptation Study - 1998
Nick E. Christians, Barbara R. Bingaman, Lois A. Benning, and Gary M. Peterson
The first shade adaptation study was established in the fall o f 1987 to evaluate the performance o f 35 species and
cultivars o f grasses. 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 trivialis).
A new shade trial was added in the fall of 1994 to evaluate the performance o f cultivars o f 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 trivialis), and Poa supina. Both areas are located under a canopy o f a mature Siberian elm trees (Ulmus
pumila) at the Iowa State University Horticulture Research Station north o f 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. The grass is irrigated
during extended drought periods but is otherwise not irrigated.
Monthly quality data are collected from May through October (Table 1 and 2). Visual quality was based on a scale
o f 9 to 1: 9 = best quality, 6 = lowest acceptable quality, and 1 = worst quality.
Table 3 contains a cumulative list o f yearly averages from the original trial for years 1991 through 1998. Note that
the final averages include data from 1988 to 1998, although only data from 1991 on are listed in the table to save
space. The species and varieties are ranked from best to worst over the 11-year period.

Table 1. 1998 Visual quality1 data for turfgrass culitvars in the Shade Trial established in 1987.
May
Cultivar
Victor (C.F.)
7.3
6.7
Waldina (H.F.)
7.0
Shadow (C.F.)
6.0
Jamestown (C.F.)
Waldorf (C.F.)
7.3
6.7
Agram (C.F.)
6.0
Atlanta (C.F.)
7.0
Pennlawn (C.R.F.)
5.7
Mary (C.F.)
4.0
Bar Fo 81-225 (H.F.)
5.7
Banner (C.F.)
6.0
Koket (C.F.)
5.0
Sabre (Poa trivialis)
5.0
Rebel II (T.F.)
5.7
Reliant (H.F.)
5.7
Wintergreen (C.F.)
5.7
Rebel (T.F.)
Highlight (C.F.)
6.7
Ensylva (C.R.F.)
6.0
Estica (C.R.F.)
5.3
St-2 (SR3000) (H.F.)
5.3
Midnight (K.B.)
4.3
3.7
Spartan (H.F.)
3.3
Biljart (H.F.)
5.3
Apache (T.F.)
5.0
Bonanza (T.F.)
4.7
Falcon (T.F.)
4.7
Arid (T.F.)
3.0
Scaldis (H.F.)
3.3
Coventry (K.B.)
4.3
Ram I (K.B.)
Bristol (K.B.)
5.0
3.3
Glade (K.B.)
4.0
Nassau (K.B.)
1.7
Chateau (K.B.)
2.6
LSDo 05
U
7!_ quality was assessed using a scale of 9 to
‘Visual
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

A ugust
September
June
O ctober
July
Mean
7.7
6.0
7.0
7.0
7.0
7.0
6.7
6.7
6.3
6.3
6.4
6.0
7.0
5.3
6.0
6.3
6.3
6.3
7.0
5.3
6.0
6.0
6.3
6.1
5.0
5.7
6.7
5.7
6.0
6.1
5.0
6.0
6.3
6.3
5.7
6.0
6.3
5.3
5.7
6.3
5.7
5.9
7.3
4.3
5.7
5.3
5.8
5.3
4.7
6.7
6.0
6.0
6.0
5.8
6.0
6.0
6.3
6.3
6.0
5.8
5.7
7.0
4.7
5.7
5.7
5.7
4.7
6.0
5.7
5.3
5.7
5.6
4.3
4.0
5.4
6.3
6.7
6.3
5.7
5.7
5.7
5.7
5.0
5.4
4.7
5.7
5.7
5.0
5.7
5.4
5.0
6.3
4.7
4.7
5.3
5.3
5.0
5.7
5.0
4.7
6.0
5.3
4.0
5.3
4.3
5.2
5.7
5.3
4.3
5.3
5.3
5.2
5.0
5.0
4.7
5.0
6.0
5.7
4.3
5.2
4.7
4.0
5.7
4.7
6.0
5.1
5.3
4.0
4.0
4.7
5.0
4.6
4.3
5.0
5.3
4.3
4.7
4.6
5.0
4.0
5.0
5.0
4.0
4.4
4.7
3.3
3.7
5.0
3.3
4.2
4.0
4.0
3.0
5.3
3.7
4.2
4.7
4.3
4.0
3.0
4.2
4.3
4.0
4.3
3.0
3.7
4.3
4.0
4.7
3.7
3.7
3.4
3.7
3.7
3.3
3.0
4.7
4.0
2.3
3.4
3.7
3.0
2.7
3.0
2.3
3.2
2.7
3.3
3.0
2.3
2.0
3.1
3.0
2.3
2.7
1.7
3.0
2.7
2.0
2.3
2.0
2.0
2.0
2.4
2.3
2.3
2.3
1.7
2.1
2.3
2.2
1.9
2.0
1.9
1.4
1.5
1 with 9 = best, 6 = lowest acceptable, and 1 = worst turf quality.

18

Species and Cultivar Trials

Table 2. 1998 Visual quality1 data for turfgrass culitvars in the Shade Trial established in 1994.
Cultivar
May
September
October
June
July
August
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

Cypress {Poa trivialis)
Sabre {Poa trivialis)

5.0
5.0
4.0
4.3
5.3
4.3
5.3
5.7
3.7
4.3
SR5100 (C.F.)
3.7
5.0
4.7
4.7
4.3
Southport (C.F.)
4.7
4.7
3.3
4.0
4.0
Shadow (C.F.)
5.0
5.3
2.3
3.3
4.3
Bonanza II (T.F.)
3.0
3.7
4.3
4.3
4.7
Midnight (K.B.)
3.7
4.0
4.3
3.7
4.3
4.3
Bridgeport (C.F.)
5.0
5.0
3.0
3.0
Molinda (C.F.)
2.3
3.3
4.7
5.3
4.3
3.0
Banner (C.F.)
4.3
4.0
4.3
3.3
3.3
4.0
Bonanza (T.F.)
3.7
4.7
4.0
Polder (Poa trivialis)
4.0
3.0
3.3
3.3
4.3
3.3
4.3
Silvana (H.F.)
3.7
4.0
2.7
3.0
3.0
Waldina (H.F.)
4.0
4.3
3.3
2.3
3.3
Victory (C.F.)
3.7
4.3
4.0
4.0
2.7
Shenandoah (T.F.)
3.3
3.7
3.7
2.7
3.7
Banner II (C.F.)
4.0
5.0
2.7
3.0
Arid (T.F.)
3.7
4.0
4.0
2.7
Rebel II (T.F.)
3.7
4.0
3.7
3.3
3.0
3.0
Ascot (K.B.)
3.0
3.3
2.7
3.3
Flyer (C.R.F.)
2.3
3.0
3.0
3.0
3.3
Glade (K.B.)
3.0
2.7
2.7
3.7
3.7
Adobe (T.F.)
2.7
3.0
2.3
2.3
3.0
2.7
3.0
Bristol (K.B.)
2.3
2.3
2.7
2.7
2.3
Coventry (K.B.)
2.3
2.7
2.3
1.7
2.3
Buckingham (K.B.)
3.0
2.7
2.3
2.7
2.3
Nordic (H.F.)
2.3
2.0
2.0
2.7
2.7
2.0
Aztec (T.F.)
2.3
2.0
2.3
2.0
Mirage (T.F.)
2.3
2.3
2.3
2.3
2.3
Spartan (H.F.)
2.3
2.3
2.3
2.0
2.0
Bonsai (T.F.)
3.0
2.3
2.3
2.0
2.0
Rebel (T.F.)
2.3
2.3
2.0
1.7
1.7
Falcon II (T.F.)
1.3
2.3
1.7
1.7
1.0
Supranova (Poa supina)
1.7
1.7
2.0
1.3
1.0
Brigade (H.F.)
1.0
2.0
1.3
2.4
NS
NS
2.2
2.1
l s d (M
)5
-lx,-:
Visual quality was assessed using a scale of 9 to 1 with 9 = best, 6 = lowest acceptable, and 1 = worst

19

5.0
5.0
5.0
4.7
4.3
4.0
3.7
3.3
3.3
4.0
3.3
4.0
4.0
3.7
4.0
4.0
2.7
3.3
2.7
3.3
3.7
2.3
2.3
2.0
2.3
2.0
2.3
2.0
2.7
1.7
1.7
2.0
2.0
1.7
1.3
2.0
turf quality.

Mean
4.8
4.7
4.6
4.2
4.1
4.0
3.9
3.9
3.9
3.8
3.8
3.7
3.7
3.6
3.6
3.6
3.4
3.4
3.4
3.1
3.1
3.0
2.6
2.5
2.4
2.3
2.3
2.3
2.3
2.2
2.2
2.1
1.8
1.6
1.3
1.8

Species and Cultivar Trials

Table 3. The average quality ratings for grasses in the Shade Trial: 1991 - 1998.
1991

1992

1993

1994

1995

1996

1997

1998

Ave.*

1 Victor (C.F.)

4.3

5.9

7.2

7.1

6.6

6.6

7.1

7.0

6.50

2

Waldorf (C.F.)

5.5

7.3

5.9

6.2

5.8

6.1

6.6

6.1

6.18

3

ST-2 (SR 3000) (H.F.)

5.1

6.3

5.7

6.1

6.1

5.5

5.8

5.1

6.15

Cultivar

4

Mary (C.F.)

3.9

6.4

6.7

6.6

6.7

6.3

6.2

5.8

6.13

5

BAR FO 81-225 (H.F.)

4.9

6.5

5.5

6.1

6.5

5.7

5.9

5.8

6.05

6

Jamestown (C.F.)

4.2

6.0

6.5

6.6

6.2

5.9

6.1

6.1

6.03

7

Shadow (C.F.)

4.7

6.0

6.6

6.6

5.9

5.9

6.6

6.3

6.02

8

Atlanta (C.F.)

4.9

6.1

5.8

5.7

5.5

6.7

6.6

5.9

5.93

Waldina (H.F.)

4.1

5.5

5.5

5.8

5.8

5.1

5.9

6.4

5.89

10

Pennlawn (C.R.F.)

4.7

6.2

6.3

5.5

5.5

5.9

6.2

5.8

5.84

11

Rebel (T.F.)

5.3

6.0

6.9

5.9

5.7

4.6

4.5

5.3

5.83

12

Sabre (Poa trivialis)

6.9

6.4

7.4

6.2

4.8

4.9

5.0

5.4

5.80

9

13

Estica (C.R.F.)

4.1

5.6

6.6

6.1

5.6

4.3

4.3

5.2

5.77

14

Banner (C.F.)

4.5

5.0

6.0

5.6

5.3

6.2

6.3

5.7

5.74

15

Bonanza (T.F.)

6.5

6.9

6.3

6.2

5.2

4.2

4.1

4.2

5.65

16

Biljart (H.F.)

5.1

6.1

5.0

5.1

5.1

4.8

5.1

4.4

5.63

17

Rebel II (T.F.)

5.3

5.6

6.1

6.2

5.1

4.3

4.1

5.4

5.59

18

Falcon (T.F.)

5.3

6.0

6.5

6.3

5.2

4.2

4.2

4.2

5.56

19

Agram (C.F.)

3.9

5.9

5.4

5.3

5.1

5.5

5.6

6.0

5.48

20

Apache (T.F.)

6.0

6.0

6.3

5.4

5.3

3.7

3.2

4.2

5.47

21

Wintergreen (C.F.)

4.6

5.9

5.0

5.0

5.0

6.0

5.9

5.3

5.45

22

Spartan (H.F.)

3.5

4.2

4.7

5.1

4.9

5.0

4.8

4.6

5.32

23

Arid (T.F.)

6.0

7.1

6.7

5.6

4.7

2.9

2.7

4.0

5.28

24

Ensylva (C.R.F.)

4.0

5.1

5.9

5.4

4.4

5.3

4.9

5.2

5.26

25

Koket (C.F.)

4.2

5.2

5.2

5.7

4.6

4.6

5.4

5.6

5.19

26

Scaldis (H.F.)

3.7

5.2

4.6

4.4

4.8

4.1

4.6

3.7

4.90

27

Highlight (C.F.)

3.5

4.6

5.0

4.8

4.7

4.9

5.1

5.2

4.78

28

Coventry (K.B.)

5.7

5.4

6.0

4.7

3.8

3.9

3.5

3.4

4.72

29

Midnight (K.B.)

5.9

5.5

6.4

4.6

4.4

4.0

3.9

4.6

4.56

30

RAM I (K.B.)

5.0

5.0

5.9

4.3

3.3

2.8

2.7

3.2

4.52

31

Reliant (H.F.)

3.1

3.5

4.2

4.9

4.8

4.9

5.0

5.4

4.43

32

Chateau (K.B.)

6.2

5.5

5.2

4.1

3.0

2.2

1.9

2.1

4.26

33

Glade (K.B.)

5.5

4.8

5.3

3.3

2.8

2.8

2.3

2.7

4.12

34

Bristol (K.B.)

3.9

3.9

5.0

4.1

3.6

2.8

2.4

3.1

3.87

35

Nassau (K.B.)

3.4

3.8

4.3

3.3

2.4

2.1

2.0

2.4

3.25

Quality Based on a 9 to 1 scale: 9 = best quality, 6 = lowest acceptable quality, and 1 = poorest quality.
*Average includes 1988, 1989, and 1990 data (not listed).
Compiled by Gary Peterson, ISU Extension Commercial Horticulture Field Specialist

20

Species and Cultivar Trials

Fairway Height Bentgrass Cultivar Trials - Established 1993
Nick E. Christians and James R. Dickson
This is the final year o f data from the Fairway Height Bentgrass Cultivar trial established in the fall o f 1993. Data
collection began after the cultivars were fully established in July, 1994. The area was maintained at a 0.5-inch
mowing height. This was a National Turfgrass Evaluation (NTEP) trial and was conducted at several research
stations in the U.S. It contained 21 o f the newest seeded cultivars and a number o f experimentáis. The cultivars
were maintained with 4 lbs o f N/1000 ft2/growing season. Fungicides are used as needed in a preventative program.
Herbicides and insecticides were applied as needed.
Visual quality ratings were taken from May through August 1998 (Table 1). Visual quality was assessed using a 9
to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality. Genetic color (Color), spring greenup
(Green), and leaf texture (Leaf) were evaluated in August 1998. Genetic color was based on a 9 to 1 scale with 9 =
dark green and 1 = light green. Spring greenup was evaluated using a 9 to 1 scale with 9 = best and 1 = worst
greenup. Leaf texture was estimated using a 9 to 1 scale with 9 = fine and 1 ===coarse texture.
A new Fairway Height Bentgrass Cultivar trial was established in September 1998. It contains 26 cultivars and the
study will be maintained under the same guidelines as the 1993 study. The only data taken for this study in 1998
were for fall percentage living cover (Table 2).

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

Trueline
BAR Ws 42102
Southshore
18th Green
Penn G-6
Penn G-2
Lopez
Crenshaw
Seaside II (DF-1)
Providence
Seaside
Cato
PRO/CUP
Penncross
Penneagle
BAR As 492
ISI-At-90162*
Pebble*
Exeter
Tendenz*
SR 7100*
L S D ( o.o5)

Color

Green

Leaf

May

June

July

Aug

Mean

7.7
6.0
6.0
6.3
5.7
6.0
5.7
6.0
5.7
5.7
7.7
5.3
7.0
7.0
6.3
6.0
6.0
7.0

5.7
5.3
6.3
6.0
5.7
5.7
5.7
6.3
5.7
6.3
4.7
6.7
6.0
5.3
6.3
5.3
5.7
5.0
5.3
5.0
5.3
P>F=0.07
1.1

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

7.0
7.7
7.7
6.7
6.7
7.3
6.7
7.0
6.7
6.3
6.0
6.7
6.0
6.0
6.3
6.0
6.3
5.7
5.3
5.3
5.3
NS

7.0
7.0
7.3
6.7
7.7
6.7
6.7
6.0
6.0
7.0
6.0
6.3
6.3
6.0
6.3
6.0
6.0
5.3
5.3
4.7
5.0
1.3

7.0
7.0
6.7
7.0
7.0
7.0
6.3
6.7
7.0
6.0
6.0
6.3
5.7
5.7
6.0
5.7
5.3
5.7
5.3
5.3
4.7
P>F=0.07
1.6

7.3
6.0
6.0
7.0
6.0
5.7
6.3
6.0
5.7
5.3
6.3
5.0
6.3
6.7
5.7
6.0
5.3
6.0
6.0
5.7
5.3
NS

7.1
6.9
6.9
6.8
6.8
6.7
6.5
6.4
6.3
6.2
6.1
6.1
6.1
6.1
6.1
5.9
5.8
5.7
5.5
5.3
5.1
NS

6 .0

6.3
6 .0

1.3

* Colonial Bentgrass
Color (Genetic color): 9 = dark green and 1 = light green. Green (Greenup): 9 = best and 1 = worst greenup. Leaf (Leaf
texture): 9 = fine and 1 = coarse.
Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
NS = means are not significantly different at the 0.05 level.

21

Species and Cultivar Trials

Table 2. Percentage fall living cover data1for cultivars in the 1998 Fairway
Height Bentgrass Trial.
Cultivar
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

Percentage fall cover (%)

Backspin
Century
Penneagle
SR 1119
Trueline
Providence
Penn G-6
Imperial
Grand Prix
Seaside II
PST-9HG*
Penncross
Princevill
Tiger
PST-OVN
SRX IBP A A
L-93
Seaside
SRX 1120
GolfStar**
ABT-Col-2*
SRX 7MOBB*
PST-9PM*
ISI At-5*
SR 7100*
SRC 7MODD*

78.3
78.3
76.7
73.3
71.7
70.0
70.0
68.3
66.7
66.7
65.0
65.0
63.3
63.3
63.3
61.7
58.3
58.3
58.3
58.3
56.7
55.0
53.3
50.0
50.0
45.0
17.0
LSD(005)
T T 71These figures represent the percentage area per plot covered by bentgrass.
* Colonial Bentgrass
** Idaho Bentgrass

22

Species and Cultivar Trials

Green Height Bentgrass Cultivar Trial - Established 1993
Nick E. Christians and James R. Dickson
This is the final year o f data from the Green Height Bentgrass Cultivar trial established in the fall o f 1993. The area
was maintained at a 3/16-inch mowing height. This was a National Turfgrass Evaluation Program (NTEP) trial and
was conducted at several research stations in the U.S. It contained 28 seeded cultivars, including a number o f
experimentáis.
The cultivars were maintained with a fertilizer program o f 1/4 lb N applied at 14-day intervals with a total of 4 lbs o f
N/1000 ft2/growing season. Fungicides were used as needed in a preventive program. Herbicides and insecticides
were applied as needed.
A new Green Height Bentgrass Cultivar trial was begun in September 1998. Twenty-six cultivars including
numerous experimentáis are being screened. The only data collected from this study in 1998 were estimates o f the
percentage o f green ground cover taken in the fall.

Table 1. 1998 visual quality and other physical ratings for cultivars in the 1993 Green Height Bentgrass Trial.
Quality
Cultivar
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

Penn G-2 (G-2)
Crenshaw
Imperial (Syn 92-5)
Penn A -l (A -l)
Penn G-6 (G-6)
Penn A-4 (A-4)
BAR Ws 42102
Century (Syn 92-1)
Backspin (Syn 92-2)
Regent
Cato
Southshore
Providence
SR 1020
Loft's L-93 (L-93)
PRO/CUP
Pennlinks
18th Green
ISI-Ap-89150
BAR As 492
Trueline
Penncross
DG-P
MSUEB
Lopez
Mariner (Syn-1-88)
Tendenz*
Seaside
L S D ( o.o5>

Color

Green

Leaf

May

June

July

Aug

Mean

6.3
7.0
6.0
6.7
6.3
5.7
6.0
5.3
5.7
6.0
5.3
5.7
6.7
4.7
6.0
5.7
6.0
6.0
6.0
6.0
5.0
5.7
6.0
5.7
5.7
6.3
6.0
5.3
NS

6.0
6.7
6.0
6.3
6.0
5.7
5.0
5.7
6.0
5.0
6.0
5.3
5.3
5.7
5.3
5.0
5.0
6.0
5.7
5.7
4.3
5.3
5.0
5.0
4.3
5.0
5.3
4.7
1.1

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

7.3
7.0
7.0
6.3
7.0
6.7
6.7
6.7
6.7
6.3
6.0
6.3
5.7
6.3
6.0
6.0
6.0
5.7
5.3
5.7
5.7
5.7
6.0
5.7
5.7
5.3
5.3
5.0
NS

8.0
6.7
7.7
7.0
7.0
7.0
7.0
6.7
7.0
6.0
6.3
6.0
5.3
6.3
6.3
6.0
6.0
6.0
5.7
5.3

7.7
7.3
7.3
7.3
7.7
6.7
6.7
6.7
6.3
7.0
7.0
6.7
7.0
6.7
6.3
6.0
5.7
6.0
6.0
6.0
5.7
5.3
6.0
6.0
5.7
6.3
5.0
4.7
1.1

7.0
7.0
6.0
7.3
6.0
6.0
5.7
6.0
5.7
6.0
5.7
6.3
7.0
6.0
6.3
6.0
6.3
6.0
6.7
6.3
5.7
6.0
5.7
5.7
5.7
5.7
5.3
5.0
NS

7.5
7.0
7.0
7.0
6.9
6.6
6.5
6.5
6.4
6.3
6.3
6.3
6.3
6.3
6.3
6.0
6.0
5.9
5.9
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.1
4.9

1.0

6.0
6.0
5.3
6.0
6.0
5.7
4.7
5.0
1.4

1.0

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

23

Species and Cultivar Trials

Table 2. Percentage fall living cover data1 for cultivars in the 1998 Green Height
Bentgrass Trial.
Cultivar
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

Backspin
Penn A-4
Imperial
Providence
ISI Ap-5
Pennlinks
Penncross
Penn A-2
L-93
Syn 96-2
SR 1119
ABT-CRB-1
BAR AS 8FUS2
SR 7200*
Penn G-l
Penn A-l
Bavaria*
Pick CB 13-94
SRX 1BPAA
Century
BAR CB 8US3
Pick MVB*
Syn 96-1
SRX 1120
SRX 1NJH
Crenshaw
PST-A2E
Penn G-6
Syn 96-3
LSD/o.05)

Percentage fall cover (%)
81.7
78.3
76.7
76.7
75.0
75.0
75.0
75.0
73.3
73.3
73.3
71.7
71.7
71.7
71.7
71.7
70.0
70.0
70.0
68.3
68.3
68.3
68.3
68.3
68.3
66.7
66.7
66.7
65.0
NS

‘These figures represent the percentage area per plot covered by bentgrass.
*Velvet Bentgrass

24

Species and Cultivar Trials

Overseeding of Northern Turfgrass Sports Fields with Bermudagrass
David D. Minner, Roch Gaussoin, and Steve Keeley
Objective:
To determine if seeded bermudagrass can be established in the summer and then used for intensely trafficked sport
fields in late summer/early fall.

Procedure:
This is a cooperative research project with Dr. Roch Gaussoin, University o f Nebraska, and Dr. Steve Keeley,
Kansas State University. Field plots were also established in Kansas and Nebraska, but only the Iowa data is
reported at this time. This field research project was established at the Iowa State University Horticulture Research
Station, Ames, IA. On 19 June 1998 the study area was prepared by treating the existing stand o f grass and weeds
with glyphosate. Eleven days later all o f the vegetation was dead and approximately 50 percent o f the area was
showing exposed soil. On 2 July 1998 the test area was verticut in two directions to a depth o f 0.5 inches. The area
was immediately fertilized, seeded, and watered. One pound o f N, P205, and K20 was applied per 1000 sq. ft. Six
bermudagrass varieties (3 lbs. seed /1000 sq. ft.) and Bright Star perennial ryegrass (15 lbs. Seed/1000 sq. ft.) were
established in 8 foot by 15 foot whole-plots. Grass was watered and mowed to a two-inch cutting height. Plots were
rated on 24 August and then half o f each bermudagrass whole-plot was slit seeded with Bright Star perennial
ryegrass (10 lbs/1000 sq. ft.) to provide a 4-foot by 15-foot split-plot. The experimental design was a randomized
complete block with seven whole-plot treatments (bermudagrasses: Sultan, Numex Sahara, SWI-10, Blend C,
Mirage, and Pyramid), two split-plot treatments (with or without perennial ryegrass), and three replications.
Traffic was applied with a Brouwer roller that was modified with football cleats to supply differential-slip-type
traffic. Fifteen passes over the test area were made with the traffic simulator between 27 August and 15 September
1998.

Table 1. Percent turf cover for six bermudagrass selections and one perennial
Grass
Sultan
NuMex Sahara
Mohawk
Blend Cz
Mirage
Pyramid
Bright Star
z Blend C contains Princes 50%, SWI-10 25%, and Sultan 25%.

Avg94.6
94.6
97.6
93.3
95.0
96.3
23.3

Table 2. Turfgrass color, quality, and cover average ratings of 16 Oct 1998.
Grass
Sultan
Sultan +P R
NuMex Sahara
NuMex Sahara + PR
Mohawk
Mohawk + PR
Blend C
Blend C + PR
Mirage
Mirage + PR
Pyramid
Pyramid + PR
Bright Star PR

Color
3
4
3
4
3
4
3
4
3
4
3
4
8

Quality
6
6
6
6
6
6
6
6
6
6
6
6
5

25

Cover
75
73
73
72
75
73
73
73
72
73
72
75
52

Species and Cultivar Trials

Results:
Table 1 shows the advantage o f establishing a warm season grass like bermudagrass during the summer compared
with perennial ryegrass. On 24 August all o f the bermudagrass selections had greater than 90% turf cover, while
perennial ryegrass had only 23% turf cover. This resulted in a substantial advantage that would coincide with the
beginning o f a normal fall football season. Even with an additional perennial ryegrass seeding on 24 August, the
bermudagrasses provided more turf cover than perennial ryegrass at the end o f the football season. Bermudagrass
cover was approximately 75% compared with 52% for perennial ryegrass (Table 2).
All o f the bermudagrass cultivars retained 100% o f their green color on 15 September. By 1 October the
bermudagrasses were showing signs o f winter dormancy and green color retention was approximately 60 percent.
By 16 October 1998 bermudagrass leaves were mostly brown with only about 30% green tissue present. Table 2
shows that there was a slight improvement in turf color on 16 October when bermudagrass was overseeded with
perennial ryegrass. By 16 October the perennial ryegrass only treatment had much better color than the
bermudagrass or the bermudagrass/overseeded with rye treatments.

26

Herbicide and Growth Regulator Studies

Preemergent Annual Grass Control Study
Barbara R. Bingaman, Melissa C. McDade, Michael B. Faust, and Nick E. Christians
In this study various preemergent herbicide and herbicide plus fertilizer formulations were screened for efficacy in
controlling annual grass weed species in turfgrass. The study was conducted at the Iowa State University
Horticulture Research Station near Ames, IA in established 'Nassau' Kentucky bluegrass that had a heavy crabgrass
infestation in 1997. The soil was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with an organic matter
content o f 3.35%, a pH o f 6.85, 5 ppm P, and 93 ppm K.
The study was arranged as a randomized complete block. Individual plot size was 5 x 5 ft with three replications.
Thirty-three treatments were included in single and split applications with a fertilized control and an untreated
control (Table 1).
Preemergent applications were made on April 29, 1998 before crabgrass germination. It was 54° F with overcast
skies and a northeast wind at 10 mph. Crabgrass was detected in the untreated controls on June 10. Sequential
(POST) applications o f treatments 2 - 9 were made on June 16 (6 to 8 weeks after initial applications).
Temperatures were in the mid 70's and it was mostly sunny with a light NW wind. The crabgrass plants in the
untreated controls were in the 1- to 2-leaf stage. On July 1, sequential applications o f treatments 10-15 and 21-25
were made. It was 80° F and mostly sunny with northwest winds at 5-10 mph. Crabgrass in the untreated controls
was in the 1- to 4-leaf stage.
Liquid formulations were applied at 30 psi with a carbon dioxide backpack sprayer equipped with TeeJet® #8006
flat fan nozzles. Liquids were diluted into 287 ml o f water which translates to an application rate o f three gal/1000
ft2. Granular materials were applied using ‘shaker dispensers’.
Visual turf quality data were taken weekly from May 5 through September 2 (Tables 2 and 3). Quality was assessed
using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality. The plot was checked for
phytotoxicity on each o f these dates and none was detected.
Annual grass populations were estimated as percentage crabgrass cover per plot. These data were taken weekly from
July 7 through September 2 (Table 4). Annual grass control was determined by calculating percentage reductions in
crabgrass cover as compared with the untreated controls (Table 5). Broadleaf population data for oxalis, clover,
dandelion, and black medic were taken on September 2 (Table 6).
All data were analyzed using the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Fisher's Least Significant Difference (LSD) tests were used to compare means separation.
The quality o f turf treated with herbicide plus fertilizer formulations was better than the untreated controls on May 5
(Table 2). By June 4, most o f the fertilizer effects on quality were gone. Improved quality also was detected in turf
receiving sequential applications o f herbicide plus fertilizer formulations on either June 16 or July 1. Nineteen o f the
materials produced significantly better mean quality than the untreated controls (Table 3).
There were significant differences in percentage crabgrass cover on all data collection dates (Table 4). Seventeen of
the materials maintained percentage crabgrass cover < 5.3% for the duration o f the study and twenty materials
suppressed cover to < 10% for this period. Twenty-four herbicide formulations produced mean percentage cover <
8.7%.
Crabgrass cover reductions were significantly different on all collection dates (Table 5). Twenty herbicides reduced
crabgrass cover by > 95% as compared with the untreated controls on July 7 and 10 herbicides provided 100%
control on that date. By July 29, the level o f control had decreased for some o f the formulations but 21 herbicides
were still providing > 90% control. By September 2, 16 herbicides were still reducing crabgrass cover > 90% as
compared with the untreated controls. Thirteen herbicides provided > 90.0% crabgrass control for the duration o f the
study (Table 5).
Dandelion was the only broadleaf weed species that was distributed among all o f the plots (Table 6). There were
significantly fewer dandelions in turf treated with eight o f the herbicides as compared with the untreated controls.
Some o f the largest dandelion populations were found in turf treated with herbicides that provided excellent control

27

Herbicide and Growth Regulator Studies

o f crabgrass. In these areas, dandelions could more easily establish because o f less competition from crabgrass and
other weed species.
Oxalis, black medic, and clover distributions were sporadic. The efficacy o f the tested herbicides in controlling
these species, therefore, could not be determined from these data.

Table 1. Materials and rates for the 1998 Pre- & Postemergent Annual Weed Control Study.
Material
1.
2.
3.
4.
5.
6.
7.
8.
9.

10.
11.
12.
13.
14.
15.

Untreated control
S-80961
S-80961
S-80971
S-80971
S-81621
S-81621
S-81611
S -81611

Team Pro NAF-324 0.86GR2
Team Pro NAF-324 0.86GR2
Pendimethalin 0.86GR2
Pendimethalin 0.86GR2
Dimension 0.10 GR2
Barricade 0.22 GR2

(PRE) Rate
(g product/ft2)
N /A
2.06
2.06
2.06
2.06
1.56
1.56
1.53
1.53
(PRE) Rate
lb a.i./A
1.5
2.0
1.5
2.0
0.38
0.5
Rate
lb a.i./A

(POST) Rate
(g product/ft2)
N /A
none
2.06
none
2.06
none
1.56
none
1.53
(POST) Rate
lb a.i./A
1.5
none
1.5
none
none
none
Timing of application

PRE
0.75
BAS051434H Drive 75DF3
PRE
0.50
BAS051434H Drive 75DF3
PRE
0.75
BAS 514 0.57GR3
PRE
0.50
BAS 514 0.57GR3
PRE
3.00
Pendimethalin 60WDG3*
POST
0.75
BAS051434H Drive 75DF
1.0%
+ M S03
POST
0.50
BAS051434H Drive 75DF
22.
1.0%
+ M S03
POST
0.75
BAS 514 0.57GR3
23.
POST
0.50
24.
BAS 514 0.57GR3
POST
0.50
Dimension 1EC
25.
0.50%
+ NIS3
PRE
0.25
26.
Dimension 1EC4
PRE
0.25
Dimension 0.164FG AND4454
27.
PRE
0.25
28.
Dithiopyr 1.06XF 98-0254
PRE
0.25
29.
Dithiopyr 0.89XF 98-0264
PRE
0.25
30.
Dithiopyr 2.20XF 98-0294
PRE
0.25
Dimension 40WP4
31.
PRE
N /A
32.
Fertilized control4
‘These materials are being screened for The Scotts Company.
2These materials are being screened for Dow AgriSciences.
3These materials are being screened for BASF.
4These materials are being screened for Rohm and Haas and were applied with methylene urea (39-0-0) at 4 lb/1000 ft2.
Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at 6 to 8 WAT on June 16, Dow
(trt 10-15) sequential applications at 8 to 10 WAT on July 1, and BASF (trt 21-25) POST applications on July 1.
16.
17.
18.
19.
20.
21.

28

Herbicide and Growth Regulator Studies

Material
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.
----ITT----

Untreated control
S-8096
S-8096
S-8097
S-8097
S-8162
S-8162
S-8161
S-8161
Team Pro NAF-324 0.86GR
Team Pro NAF-324 0.86GR
Pendimethalin 0.86GR
Pendimethalin 0.86GR
Dimension 0.10 GR
Barricade 0.22 GR
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Pendimethalin 60WDG
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Dimension 1EC + NIS
Dimension 1EC
Dimension 0.164FG AND445
Dithiopyr 1.06XF 98-025
Dithiopyr 0.89XF 98-026
Dithiopyr 2.20XF 98-029
Dimension 40WP
Fertilized control

May 5
7.0
8.7
8.7
8.3
8.3
7.3
8.0
7.0
8.7
7.3
9.0
8.7
8.0
8.3
9.0
7.3
7.7
8.0
8.0
8.0
7.7
7.3
8.0
7.3
7.0
8.3
7.7
8.7
8.0
7.7
7.3
8.0
1.0

L S D oo5

May 13
7.0
7.0
7.0
7.3
7.7
6.7
6.7
7.0
7.7
7.7
7.0
6.7
6.7
7.0
7.0
6.0
6.3
7.0
6.7
6.7
7.0
6.7
6.7
7.0
7.0
7.7
7.3
7.0
7.0
7.3
7.7
7.0
NS

May 19
6.3
7.7
7.3
8.0
8.0
6.3
6.3
7.3
7.0
7.7
7.7
7.7
8.0
8.0
7.0
5.7
5.7
6.0
6.0
6.0
6.3
6.3
6.3
6.0
6.0
7.3
7.3
7.0
7.0
7.7
7.3
7.0
1.1

May 27
6.0
7.7
7.7
7.7
9.0
7.0
6.7
8.0
7.0
7.7
7.7
8.3
8.7
8.3
7.0
5.3
5.7
5.7
6.0
6.7
6.7
6.0
6.0
6.3
6.0
9.0
8.3
8.7
8.0
8.3
8.3
8.3
1.0

June 4
6.0
6.3
6.0
6.7
6.7
6.3
6.0
6.7
6.3
6.7
6.0
6.7
6.0
6.7
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.3
6.3
6.0
6.0
6.3
7.0
6.3
6.0
6.3
7.0
6.7
0.6

June 10
5.3
6.7
6.7
7.0
7.0
5.7
5.7
6.0
6.3
6.0
6.0
6.7
7.06.7
6.3
5.0
5.0
5.0
5.3
5.3
5.3
5.3
5.0
5.0
5.3
7.7
7.3
7.3
7.0
7.7
7.3
8.3
1.1

June 16
5.7
7.3
7.7
7.3
7.3
6.7
7.3
6.3
6.3
7.3
7.0
7.3
7.7
7.7
7.3
5.0
5.7
5.7
6.3
6.3
6.3
6.3
5.7
5.0
5.7
9.0
8.3
7.7
8.7
8.3
8.0
8.3
1.4

June 24
6.0
6.0
8.0
6.0
8.0
6.0
8.0
6.0
8.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
-

June 30
6.0
6.7
9.0
6.3
8.7
6.0
8.0
6.3
8.0
6.3
6.3
6.3
7.0
6.7
6.3
5.7
6.3
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
7.3
7.3
7.7
8.0
7.7
7.0
7.3
0.9

July 7
6.0
6.3
8.7
7.3
8.0
6.0
6.7
6.7
7.0
8.7
6.3
8.3
6.3
6.3
6.0
6.3
6.0
6.0
6.0
6.0
6.3
6.0
6.3
6.0
6.0
6.7
7.3
7.0
7.0
7.0
7.7
6.3
1.1

Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at 6 to 8 WAT on June 16, Dow (trt 10-15) sequential applications at 8 to 10 WAT on
July 1, and BASF (trt 21-25) POST applications on July 1.
NS = means are not significant at the 0.05 level.
-- = means comparisons tests are not valid for these data.

Material

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.
— ITT----

Untreated control
S-8096
S-8096
S-8097
S-8097
S-8162
S-8162
S-8161
S-8161
Team Pro NAF-324 0.86GR
Team Pro NAF-324 0.86GR
Pendimethalin 0.86GR
Pendimethalin 0.86GR
Dimension 0.10 GR
Barricade 0.22 GR
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Pendimethalin 60WDG
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Dimension 1EC + NIS
Dimension 1EC
Dimension 0.164FG AND445
Dithiopyr 1.06XF 98-025
Dithiopyr 0.89XF 98-026
Dithiopyr 2.20XF 98-029
Dimension 40WP
Fertilized control
L S D o.<)5

July 14
6.0
6.0
7.0
6.3
6.7
6.3
6.3
6.3
6.7
7.0
6.3
7.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.3
6.3
6.0
6.0
6.0
6.0
6.7
6.3
6.7
7.0
6.7
6.7
6.7
0.7

July 29
7.0
7.3
7.3
7.0
7.3
7.0
7.0
7.0
7.0
7.7
7.0
7.3
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.3
7.3
7.0
NS

Aug 4
7.0
7.0
7.3
7.0
7.3
7.0
7.0
7.0
7.3
8.0
7.0
7.7
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.7
7.3
7.3
0.5

Aug 11
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
-

Aug 18
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
-

Aug 27
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
-

Sept 2
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
-

2k

Mean
6.4
6.9
7.4
7.0
7.5
6.5
6.9
6.7
7.1
7.1
6.8
7.2
7.0
7.0
6.8
6.2
6.3
6.4
6.4
6.5
6.5
6.4
6.4
6.3
6.4
7.2
7.1
7.1
7.1
7.2
7.2
7.1
0.3

Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at 6 to 8 WAT on June 16, Dow (trt 10-15) sequential applications at 8 to 10 WAT on
July 1, and BASF (trt 21-25) POST applications on July 1.
NS = means are not significant at the 0.05 level.
-- = means comparisons tests are not valid for these data.

29

Herbicide and Growth Regulator Studies

T a b le 4. Percentage crabgrass cover1 in Kentucky bluegrass treated for the 1998 Pre- & Postem ergent Annual W eed Control Study.
A u gl 1
Aug 18
Aug 27
Material
July 7
July 14
July 24
July 29
Aug 4

Sept2

Mean

38.3
2.3
0.3
3.3

53.3
3.7
0.3
3.7

29.5
1.7

1.0

1.0

0.4
2.2
0.4
0.4
0.9
0.7
1.3
5.6
4.3
0.8
1.7
20.6
23.3
12.7
28.3
1.7
0.9
1.7
3.9
14.3
2.9
4.5
1.2
11.7
7.1
8.7
4.0
17.6
9.0

%
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.

Untreated control
S-8096
S-8096
S-8097
S-8097
S-8162
S-8162
S-8161
S-8161
Team Pro NAF-324 0.86GR
Team Pro NAF-324 0.86GR
Pendimethalin 0.86GR
Pendimethalin 0.86GR
Dimension 0.10 GR
Barricade 0.22 GR
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Pendimethalin 60WDG
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Dimension 1EC + NIS
Dimension 1EC
Dimension 0.164FG AND445
Dithiopyr 1.06XF 98-025
Dithiopyr 0.89XF 98-026
Dithiopyr 2.20XF 98-029
Dimension 40WP
Fertilized control
L S D

().o 5

13.3
0.7

14.0
0.7

26.7
1 .0

26.7
0.3

33.3
2.0

25.0
2.7

35.0
2.3
0.3

0.0

0.0

0 .0

0 .0

0 .0

0 .0

0.0

0.0

0.7

0.3

0.3

0.0

0 .0

0.0

1.7
0.3

0.7
0.3
0.3

0.3
3.7

5.0

0.0

0.7
0.7
2.0
0.3

0 .0

1.0

0.0

0 .0

0.3

0 .0

0.0

0 .0

0 .0

0.0

0 .0

0 .0

0 .0

0 .0

0.7

0.7
2.0

0.7
0.3

1.0

0.3

0.7
0.3

0 .0

0 .0

1.0

1.0

1.0

1.7
0.3
0.3
0.3
9.0
11.7
2.0
11.7

2.0
1.3

0.3
8.3
2.7

6.7
1.3

5.0
5.3

3.3
4.3

0 .0

0 .0

0 .0

0 .0

1.0

2.7
25.7
21.7
10.3
25.0
1.7
0.7
0.3
3.3
10.0
3.0
4.3

1.3
18.3
18.3
10.7
28.3
1.3

1.0

0 .0

0.7
4.0
13.3
7.0
9.3
0.3

0 .0

0 .0

0 .0

0 .0

0.3
3.0
2.3
0.7
0.3
6.7
2.0

0.7
6.3
2.3

1.0

0.7
5.3
5.8

1 .0
0 .0

6.7
3.7
1.3
1.7
6.0
6.9

1.7

0 .0

1.0

7.0
7.7
8.7
3.7
20.0
10.1

0.3

1.0

16.7
23.3
13.7
28.3
3.3

21.7
20.0
9.3
23.3
0.7

1 .0

0 .0

0 .0

0 .0

2.0
3.7
11.7
3.7
2.3
1.7
12.0
8.7
12.0
4.0
16.7
11.8

3.0
9.3
2.0
2.3
0.7
12.0
4.3
6.7
'2.3
13.3
8.7

0.7
8.3
1 .0

1.7
0.7
16.7
7.3
5.7
3.7
16.7
9.3

1.0

0 .0

0.7
1.7
0.7
2.7
6.7
6.7
1.7
2.0
20.0
25.0
13.3
30.0
2.0
1.3
4.3
6.7
18.3
5.3
6.3
2.0
10.3
6.3
11.7
5.3
18.3
9.8

1 .0

0.7
0.7
2.3
5.0
8.3
2.0
2.3
33.3
35.0
21.7
41.7
2.0
2.3
4.0
7.0
26.7
2.3
10.0
0.7
13.7
10.3
13.3
6.7
30.0
14.1

5.3
1.7
2.0
1.7
1.7
3.7
12.0
8.3
2.0
3.7
36.7
41.7
26.7
56.7
3.7
2.3
4.0
10.0
35.0
3.7
12.0
3.7
20.0
13.3
18.3
8.3
31.7
16.0

0 .1
1.0

'These figures represent the area per plot covered by crabgrass.
Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at 6 to 8 W AT on June 16, Dow (trt 10-15) sequential applications at
8 to 10 W AT on July 1, and BASF (trt 21-25) POST applications on July 1.
Table 5. Percentage crabgrass cover reductions' in Kentucky bluegrass treated for the 1998 Pre- & Postemergent Annual Weed Control Study.
Aug 11
Aug 18
Aug 27
Aug 4
Sept 2
July 14
July 24
July 29
Material
July 7

1.

Untreated control
S-8096
S-8096
S-8097
S-8097
S-8162
S-8162
S-8161
S-8161
Team Pro NAF-324 0.86GR
Team Pro NAF-324 0.86GR
Pendimethalin 0.86GR
Pendimethalin 0.86GR
Dimension 0.10 GR
Barricade 0.22 GR
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Pendimethalin 60WDG
BAS051434H Drive 75DF
BAS051434H Drive 75DF
BAS 514 0.57GR
BAS 514 0.57GR
Dimension 1EC + NIS
Dimension 1EC
Dimension 0.164FG AND445
Dithiopyr 1.06XF 98-025
Dithiopyr 0.89XF 98-026
Dithiopyr 2.20XF 98-029
Dimension 40WP
Fertilized control

0 .0

0 .0

0 .0

0 .0

95.0
95.2
96.3
98.8
100.0
100.0
100.0
100.0
100.0
98.8
100.0
97.5
100.0
100.0
100.0
97.5
97.6
93.8
93.8
100.0
100.0
100.0
100.0
98.8
100.0
100.0
100.0
100.0
97.5
100.0
95.2
97.5
97.6
97.5
100.0
92.5
100.0
100.0
98.8
96.3
85.7
68.8
75.0
87.5
90.5
90.0
95.0
97.5
100.0
100.0
100.0
97.5
95.2
90.0
95.0
97.5
71.4
3.9
31.3
32.3
4.8
12.3
18.9
31.3
50.0
60.0
85.0
61.3
0 .0
33.3
6.4
12.3
100.0
97.6
95.0
93.8
100.0
100.0
97.5
96.3
100.0
100.0
98.8
100.0
95.2
97.5
97.5
87.5
54.8
62.5
68.8
77.4
83.3
82.5
88.8
96.3
95.0
92.9
83.8
93.8
100.0
97.5
97.5
96.3
52.4
37.6
50.0
73.8
85.0
73.8
71.3
72.5
92.5
90.5
67.5
78.8
88.1
86.3
95.0
86.3
57.1
37.6
59.9
25.1
49.1
43.5
37.8
35.0
L S D
5
‘These values represent reductions in percentage crabgrass cover per plot as compared with
Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at
8 to 10 W AT on July 1, and BASF (trt 21-25) POST applications on July 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.

o o

30

0 .0

94.0
100.0
98.0
98.0
94.0
99.0
100.0
98.0
99.0
97.0
85.0
84.0
100.0
97.0
50.0
30.0
59.0
14.9
90.0
100.0
94.0
89.0
65.0
89.0
93.0
95.0
64.0
74.0
64.0
88.0
50.0
35.5

0.0

89.3
100.0
97.3
98.7
98.7
100.0
100.0
96.0
98.7
96.0
86.7
82.7
96.0
96.0
13.3
20.0
62.7
6.7
97.3
100.0
96.0
88.0
62.7
92.0
90.7
97.3
52.0
82.7
.73.3
90.7
46.7
34.6

0.0

93.3
99.0
100.0
99.0
89.5
97.1
98.1
95.2
98.1
92.4
81.0
81.0
95.2
94.3
42.9
28.6
61.9
14.3
94.3
96.2
87.6
81.0
47.6
84.8
81.9
94.3
70.5
81.9
66.7
84.8
47.6
28.0

0 .0

93.9
99.1
91.3
97.4
86.9
100.0
97.4
98.3
98.3
93.9
86.9
78.2
94.8
93.9
13.0
8.6
43.4

Mean

0 .0

0 .0

93.1
99.4
93.1
98.1
90.0
96.9
96.2
96.9
96.9
93.1
77.5
84.4
96.2
93.1
31.2
21.8
50.0

94.3
99.7
97.3
98.7
93.8
99.1
99.1
97.2
97.6
96.4
81.6
87.0
97.8
94.7
32.1
19.6
59.2
7.4
95.1
97.7
95.4
88.7
55.9
89.3
86.9
96.6
58.5
76.6
73.8
87.3
42.9
31.8

0 .0

0 .0

94.8
93.9
89.6
81.7
30.4
93.9
73.9
98.3
64.3
73.0
65.2
82.6
21.7
36.7

93.1
95.6
92.5
81.2
34.3
93.1
77.5
93.1
62.5
75.0
65.6
84.4
40.6
30.0

the untreated controls.
6 to 8 W AT on June 16, Dow (trt 10-15) sequential applications at

Herbicide and Growth Regulator Studies

Table 6. The number of dandelions, oxalis, black medic, and percentage clover cover1 in Kentucky bluegrass treated for the
________ 1998 Pre- & Postemergent Annual Weed Control Study (data taken September 2).___________________________
Percentage
Counts
cover
M aterial
Clover
D andelion
Oxalis
Black Medic
1. Untreated control
25.3
0.7
0.0
6.7
2. S-8096
19.7
0.3
0.3
1.7
0.0
0.7
3. S-8096
6.3
8.3
4. S-8097
26.3
0.0
6.3
1.7
5. S-8097
6.0
0.7
1.7
0.0
6. S-8162
15.7
0.0
1.7
1.7
7. S-8162
0.0
12.3
0.0
1.7
8. S-8161
20.0
0.7
1.7
5.0
9. S-8161
14.0
0.3
1.0
1.7
10. Team Pro NAF-324 0.86GR
21.0
0.0
0.0
0.3
11. Team Pro NAF-324 0.86GR
0.0
0.0
15.3
3.3
12. Pendimethalin 0.86GR
14.0
0.0
1.0
8.7
13. Pendimethalin 0.86GR
0.0
0.0
15.3
6.7
14. Dimension 0.10 GR
12.7
0.0
1.0
0.0
15. Barricade 0.22 GR
16.7
0.0
0.0
0.0
16. BAS051434H Drive 75DF
15.0
2.3
0.0
0.3
17. BAS051434H Drive 75DF
0.7
21.3
0.0
0.3
18. BAS 514 0.57GR
16.7
0.7
0.0
0.0
19. BAS 514 0.57GR
19.7
0.7
2.7
0.0
20. Pendimethalin 60WDG
13.3
0.3
0.3
5.0
21. BAS051434H Drive 75DF + MSO
1.7
1.0
0.0
0.0
22. BAS051434H Drive 75DF + MSO
3.0
2.0
0.0
0.3
23. BAS 514 0.57GR
1.7
0.7
1.0
0.0
24. BAS 514 0.57GR
0.3
8.3
0.3
0.3
25. Dimension 1EC + NIS
14.3
0.3
0.7
16.7
26. Dimension 1EC
17.3
0.0
0.0
5.0
27. Dimension 0.164FG AND445
24.7
0.3
2.0
0.0
28. Dithiopyr 1.06XF 98-025
12.7
0.0
0.3
0.3
29. Dithiopyr 0.89XF 98-026
14.0
0.0
0.0
10.0
30. Dithiopyr 2.20XF 98-029
18.0
0.0
0.3
13.3
31. Dimension 40WP
17.7
0.3
0.3
0.0
32. Fertilized control
12.0
0.0
0.0
10.3
12.6
NS
2.6
NS
L S D o os
^ h e s e values represent the number of dandelion, black medic, and oxalis plants per plot. Percentage clover cover data
represent the area covered by clover per plot.
Initial applications (PRE) were made on April 29, Scott's (trt 2-9) sequential applications at 6 to 8 WAT on June 16, Dow
(trt 10-15) sequential applications at 8 to 10 WAT on July 1, and BASF (trt 21-25) POST applications on July 1.
NS = means are not significantly different at the 0.05 level.

31

Herbicide and Growth Regulator Studies

Postemergent Annual Weed Control Study
B arbara R. Bingaman, M elissa C. M cDade, an d N ick E. Christians
The efficacy o f experimental postemergence herbicides for the control o f annual grass and broadleaf weed species in
turf was evaluated in this study. It was conducted at the Iowa State University Horticulture Research Station north
o f Ames, IA in an area of'common' Kentucky bluegrass. The soil was a Nicollet (fine-loamy, mixed, mesic Aquic
Hapludoll) with 3.4% organic matter, 38 ppm P, 145 ppm K, and a pH o f 7.0. Turf mowing height was consistent
with a high (home lawn) mowing regime o f 2 to 3” for Kentucky bluegrass.
The experiment was arranged in a randomized complete block design. Individual plots were 5 x 5 ft with 3
replications. There were fourteen treatments including an untreated control (Table 1). Treatments were applied
early postemergence (EARLY POST) when crabgrass was in the 1- to 4-leaf stage and mid-postemergence (MID
POST) when crabgrass had 1 to 3 tillers. EARLY POST treatments included Dimension 1EC at 1.5 oz/1000 ft2,
Acclaim Extra 0.57EW at 0.06 lb a.i./lOOO ft2 and Preclaim 3.09EC at 1.5 and 2.0 lb a.i./lOOO ft2 Preclaim 3.09EC
also was applied MID POST at 2.0 and 3.0 lb a.i./lOOO ft2. Bas514 50WP was applied MID POST at 0.55
oz/1000 ft. Experimental formulations L-0051, L-0260, L-0289, L-0259, an L-0261 were applied MID POST at
3.0 lb a.i./lOOO ft2. In addition, L-0051 was applied MID POST at 4.0 lb a.i./1000 ft2.
Early postemergence applications were made on July 1, 1998 and the MID POST on July 14. Liquids were applied
using a carbon dioxide backpack sprayer equipped with Teejet® #8006 flat fan nozzles at 30 psi. The herbicides
were diluted into 283 ml o f water that translates to an application volume o f 3 gal/1000 ft2.
Kentucky bluegrass phytotoxicity was evaluated weekly beginning July 9. Phytotoxicity was rated using a 9 to 1
scale with 9 = no damage, 6 = some symptoms and 1 = dead turf. Turf quality was determined weekly beginning
July 9. Quality was rated visually using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
Crabgrass damage was assessed on July 29, August 4, and August 11 by estimating the percentage living crabgrass
per plot (Table 2). Damage was determined by estimating the amount o f damage to the crabgrass plants within each
plot using a 0 to 100% scale with 0 = no damage and 100% = dead plants. To assess crabgrass mortality, the
percentage o f area per plot covered by crabgrass was estimated on July 9, August 18, August 26, September 4,
September 9, September 16, and September 21 using a 0 to 100% scale (Table 3). Percentage reductions in cover
were calculated by comparing the cover in treated turf to the untreated controls (Table 4).
Broadleaf weed control was determined through population counts on July 21. The number o f oxalis, spurge, and
dandelion plants per plot was counted. Clover populations were determined by estimating the percentage o f area per
plot covered by clover (Table 5). In addition, because o f the large numbers o f small plants in some plots,
percentage cover data also were taken for dandelion.
All data were analyzed using the Statistical Analysis System (SAS, version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Differences among the means were examined with Fisher's Least Significant Difference (LSD)
means separation test.
There was no bluegrass phytotoxicity detected following either the EARLY POST or MID POST applications.
There was a slight yellow tint observed on bluegrass following treatment with Preclaim 3.09EC but this
discoloration disappeared after 24 hours. There were no visual quality differences among the treated and untreated
plots throughout the season.
On July 9, virtually all o f the crabgrass was dead in turf treated with the EARLY POST materials (Table 3 and 4).
The MID POST treatments began to cause damage on July 17, three days after application. Symptoms included
curling o f leaves, collapsed plants, and leaf discoloration. Two weeks after the MID POST applications, crabgrass
plants were exhibiting a wide range o f damage from slightly damaged to moderately damaged (Table 2). Damage
was severe in most treated plots by August 11.

32

Herbicide and Growth Regulator Studies

There were significant differences in percentage crabgrass cover for August 18 through September 21 (Table 3). All
materials significantly reduced crabgrass cover as compared with the controls on August 18, September 4, and
September 9 (Table 4). On August 18, there was at least 55% crabgrass cover reduction in turf treated with the MID
POST materials as compared with the untreated controls. Turf treated with the EARLY POST materials had > 93%
reductions in crabgrass cover as compared with the controls on August 18. After September 9, some o f the materials
were no longer providing significant reductions in crabgrass cover as compared with the untreated controls. The
EARLY POST materials (treatments 9-11 and 14), however, provided > 81% reductions in crabgrass for the
duration o f the study.
The mean crabgrass reduction data show that all materials significantly reduced crabgrass cover as compared with the
untreated controls. Mean reductions were > 50% for all materials. Two EARLY POST materials, Dimension 1EC
at 1.5 oz/1000 ft2 and Preclaim 3.09EC at 2,0 lb a.i./A, provided reductions in crabgrass cover > 96%. The other
EARLY POST materials (Preclaim 3.09EC at 1.5 lb a.i./A and Acclaim Extra 0.57EW at 0.06 lb a.i./A) and
Preclaim 3.09EC at 2.0 and 3.0 lb a.i./A MID POST produced mean reductions > 86%.
This study did not produce any hard evidence concerning the efficacy o f these materials for controlling broadleaf
weeds. There were numerical differences in oxalis and spurge populations found in the treated and untreated turf but
the differences were not statistically different (Table 5). Most treated turf contained more oxalis plants that the
untreated controls. Clover was found only in turf treated with either the EARLY POST materials or Preclaim MID
POST. These results can probably be attributed to the decrease in competition in turf where the crabgrass was
killed.
Dandelion counts were significantly different but no product significantly reduced dandelion populations as compared
with the untreated control (Table 5). The largest dandelion populations were found in treated turf where the removal
o f crabgrass had reduced competition as compared to the untreated turf.

Table 1. Materials used in the 1998 Postemergence Annual Weed Study.
Rate
lb/1000 ft2
N/A
3.00
4.00
3.00
3.00
3.00
3.00
0.55 oz
1.50 oz
Rate
lb a.i./A
1.50
2.00
2.00
3.00
0.06

Materials
1
2
3
4
5
6
7
8
9

Untreated control
L-00511
L-00511
L-02601
L-02891
L-02591
L-02611
BAS514 50W P1
Dimension 1EC1

Timing o f
applications
N/A
MID POST
MID POST
MID POST
MID POST
MID POST
MID POST
MID POST
EARLY POST

10 Preclaim 3.09 EC2
EARLY POST
EARLY POST
11 Preclaim 3.09 EC2
12 Preclaim 3.09 EC2
MID POST
13 Preclaim 3.09 EC2
MID POST
14 Acclaim Extra 0.57EW 1&2
EARLY POST
These materials are being screened for LESCO1 and AgrEvo2.
Early post applications were made on July 1 when the crabgrass was in the 1 to 4 leaf stage
and mid post applications on July 14 when the crabgrass had 1 to 3 tillers.

33

Herbicide and Growth Regulator Studies

Table 2. Percentage living crabgrass per plot1 in Kentucky bluegrass treated for the 1998 Postemergence Annual
_________ Weed Study.___________________________________________________________________________

Materials

___

July
29

August
4

August
11

Mean

%

Untreated control
100.0
45.0
L-0051
L-0051
63.3
76.7
L-0260
L-0289
66.7
L-0259
85.0
53.3
L-0261
BAS514 50WP
53.3
Dimension 1EC
0.0
Preclaim 3.09 EC
0.0
0.0
Preclaim 3.09 EC
Preclaim 3.09 EC
16.7
Preclaim 3.09 EC
36.7
Acclaim Extra 0.57EW
0.0
42.2
LSDo os
'These figures represent the percentage of crabgrass per plot that was
1
2
3
4
5
6
7
8
9
10
11
12
13
14

80.0
38.3
25.0
41.7
58.3
11.7
58.3
18.3
10.0
68.3
68.3
16.7
60.0
13.7
61.7
3.7
30.0
0.0
66.7
6.7
0.0
0.0
8.3
2.0
8.3
1.7
0.0
1.0
48.0
17.3
green and healthy.

72.8
37.2
44.4
51.1
48.3
56.7
42.3
40.0
10.0
24.4
0.0
9.0
15.6
0.3
28.2

Table 3. Percentage crabgrass cover1 in Kentucky bluegrass treated for the 1998 Postemergence Annual Weed
Study.

Materials

July
9

August
18

August
26

Sept
4

Sept
9

Sept
16

Sept
21

58.3
23.3
16.7
12.0
23.3
25.0
13.7
23.7
0.3
8.3
0.3
6.7
5.3
8.3
27.0

70.0
35.0
43.3
43.3
33.3
35.0
28.3
25.0
5.0
13.3
3.3
1.7
10.0
13.3
32.4

76.7
41.7
61.7
43.3
53.3
55.0
53.3
26.7
5.0
2.0
3.7
16.7
5.0
20.0
43.1

Mean
cover

0/n
1
2
3
4
5
6
7
8
9
10
11
12
13
14

9.3
71.7
58.3
Untreated control
12.0
32.0
L-0051
33.7
25.0
26.7
25.0
L-0051
13.7
31.7
31.7
L-0260
7.7
16.7
25.0
L-0289
11.7
16.7
18.3
L-0259
20.0
L-0261
19.3
21.7
25.0
BAS514 50WP
18.3
23.3
0.0
2.0
Dimension 1EC
1.7
0.0
5.0
Preclaim 3.09 EC
8.3
Preclaim 3.09 EC
0.0
0.7
2.0
Preclaim 3.09 EC
17.3
3.7
8.3
Preclaim 3.09 EC
32.3
3.3
3.7
2.0
Acclaim Extra 0.57EW
0.3
5.3
NS
27.2
27.9
LSD 0 0 5
'These figures represent the area per plot covered by crabgrass.
EARLY POST applications were made on July 1 and MID POST

34

66.7
32.0
18.3
7.0
20.0
25.3
23.7
28.3
0.7
6.7
0.3
8.7
3.7
5.0
29.8

applications on July 14.

58.7
30.0
31.0
26.1
25.6
26.7
25.7
24.3
2.1
6.2
1.5
9.0
9.0
7.8
26.8

Herbicide and Growth Regulator Studies

Table 4. Percentage crabgrass cover reductions1 in Kentucky bluegrass treated for the 1998 Postemergence Annual
Weed Study.

Materials

July
9

August
18

August
26

Sept
4

Sept
9

Sept
16

Sept
21

Mean
reduction2

%
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
55.4
52.0
60.0
42.3
50.0
45.7
50.8
0.0
62.8
71.4
57.1
72.5
38.1
19.6
52.3
0.0
55.8
45.7
89.5
79.4
38.1
43.5
57.9
17.9
76.7
70.0
60.0
52.4
30.4
57.1
57.2
0.0
76.7
68.6
62.0
57.1
50.0
28.3
56.3
0.0
72.1
62.9
64.5
76.6
59.5
30.4
60.0
0.0
67.4
59.4
57.1
57.5
65.2
62.1
64.3
100.0
97.2
97.1
99.0
99.4
92.9
93.5
96.4
100.0
93.0
85.7
90.0
85.7
97.4
81.0
89.4
100.0
99.1
99.4
96.6
99.5
95.2
95.2
97.5
0.0
94.9
85.7
87.0
88.6
97.6
78.3
88.6
0.0
95.3
93.7
94.5
90.9
85.7
93.5
92.3
96.4
97.2
85.7
90.9
92.5
81.0
73.9
86.8
NS
37.9
46.2
47.9
44.6
46.3
56.2
42.7
L S D o os
‘These figures represent reductions in crabgrass cover in treated turf as compared with the untreated control.
2Mean reductions include data from August 18 through September 21. Mean reductions for the EARLY POST
treatments (trts 9-11 and 14) include values from July 9 through September 21.
EARLY POST applications were made on July 1 and MID POST applications on July 14.
NS = means are not significantly different at the 0.05 level.
1
2
3
4
5
6
7
8
9
10
11
12
13
14

Untreated control
L-0051
L-0051
L-0260
L-0289
L-0259
L-0261
BAS514 50WP
Dimension 1EC
Preclaim 3.09 EC
Preclaim 3.09 EC
Preclaim 3.09 EC
Preclaim 3.09 EC
Acclaim Extra 0.57EW

Table 5. Broadleaf weed species populations1 on September 21 in Kentucky bluegrass treated for the 1998
Postemergence Annual Weed Study.
Oxalis

Spurge

Dandelion
Clover
Percentage
Percentage
Materials
cover (%)
Counts
Counts
Counts
cover (%)
1
Untreated control
1.7
16.0
6.7
2.3
0.0
2
L-0051
7.3
3.7
13.3
5.0
0.0
3
L-0051
13.3
7.0
0.0
3.7
0.0
4
L-0260
3.3
13.3
0.3
8.3
0.0
5
L-0289
12.3
15.7
0.7
8.3
0.0
6
L-0259
4.7
1.0
7.0
3.7
0.0
7
7.0
L-0261
1.0
10.0
3.7
0.0
8
BAS514 50WP
2.7
13.7
0.3
6.7
0.0
9
Dimension 1EC
7.3
2.0
31.3
20.0
1.7
10 Preclaim 3.09 EC
1.0
0.3
32.3
18.3
8.3
11 Preclaim 3.09 EC
3.0
2.0
19.3
11.7
5.0
12 Preclaim 3.09 EC
2.3
1.3
12.3
7.0
0.3
13 Preclaim 3.09 EC
1.7
28.7
20.0
0.7
5.0
14 Acclaim Extra 0.57EW
7.3
5.7
31.3
21.7
10.0
P > F = 0.08
14.2
NS
16.0
NS
NS
LSD 0 0 5
‘Count data represent the number o f Oxalis, Spurge, and Dandelion per plot. Percentage cover data represent the
area per plot covered by Dandelion and Clover.
Early post applications were made on July 1 when the crabgrass was in the 1-to 4-leaf stage
and mid post applications on July 14 when the crabgrass had 1 to 3 tillers.
NS = means are not significantly different at the 0.05 level.

35

Herbicide and Growth Regulator Studies

Postemergent Broadleaf Weed Control Study
Barbara R. Bingaman, Melissa C. McDade, Michael B. Faust, and Nick E. Christians
The efficacy o f Drive 75DF applied alone postemergently (POST) and in combination with other postemergence
broadleaf herbicides was evaluated. This study was conducted at the Iowa State University Horticulture Research
Station north o f Ames, IA in 'common' Kentucky bluegrass with a dense population o f red clover, white clover,
dandelions, plantain, and other assorted broadleaf weed species. The soil in this plot was a Nicollet (fine-loamy,
mixed, mesic Aquic Hapludoll) with 4.45% organic matter, 26 ppm P, 257 ppm K, and a pH o f 6.65. The
experimental design was a randomized complete block. The individual plots were 5 x 10 ft with 3 replications.
There were eight treatments including an untreated control. Drive 75DF was applied at 0.25, 0.50, and 0.75 lb a.i./A
(Table 1). Drive 75DF also was applied at these same rates as a tank mix with 2, 4-D Amine 4.1SL at 0.75 lb a.i./A.
Trimec Classic 3.32EC at 1.5 lb a.i./A and an untreated control were included for comparisons. Methylated soy soil
(MSO) was added to all treatments as a carrier at 1.0% V/V.
All materials were applied POST on June 5, 1998 after the broadleaf weeds were well established. Application was
made at 30 psi with a carbon dioxide backpack sprayer equipped with Teejet® #8006 flat fan nozzles. The materials
were diluted into 567 ml o f water that translates to an application rate o f 3 gal/1000 ft2.
The study was checked for phytotoxicity and visual quality differences weekly beginning June 10 (Table 1). Visual
quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality. Phytotoxicity
was quantified using a 9 to 1 scale with 9 = no damage, 6 = moderate damage, and 1 = dead turf.
Weed control was evaluated for all broadleaf and grass species found. Dandelion and clover damage ratings were
taken on June 10, 24, and 30 (Table 2). Damage was assessed using a 9 to 1 scale with 9 = no damage, 5 = plants
50% dead, 1 = dead plants. Dandelion counts were taken on July 8 and July 30 and these figures represent the
number o f dandelions per plot (Table 3). Because of the large numbers o f small dandelion plants, percentage
dandelion cover data were taken on July 15 and July 30 (Table 4). In plots with large numbers o f dandelions, the
number in a portion o f the plot was counted and this number was then adjusted to represent the entire plot.
Percentage clover cover data were taken on July 8, July 15, and July 30 (Table 5). Percentage cover data represent
the area per plot covered by clover. Population assessments were made o f all weed species in each plot on July 30
(Table 6). The number o f crabgrass, spurge, plantain, purslane, and oxalis was counted per plot.
All data were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Treatment effects were compared with Fisher's Least Significant Difference (LSD) test.
No phytotoxic symptoms were found on any treated turf as compared with the untreated controls. None o f the
materials reduced the quality o f the treated turf as compared with the untreated controls (Table 1).
Some materials were causing damage to dandelion and clover as early as 5 days after treatment on June 10 (Table
2). By June 24, all treated dandelion and clover were damaged and by June 30, dead clover was found in turf treated
with Drive 75DF at 0.25, 0.50, and 0.75 lb a.i./A (treatments 5-7).
All materials significantly reduced dandelion counts (Table 3). Drive 75DF at 0.25, 0.50, and 0.75 lb a.i./A in tank
mix with 2,4-D Amine 4.1SL and Drive 75DF at 0.75 lb a.i./A alone reduced dandelion populations > 92.5% on July
8 and > 86.2% on July 30 as compared with the untreated controls.
Percentage dandelion cover was significantly lower in all treated turf as compared with the untreated controls (Table
4). On July 15 and July 30, Drive 75DF plus 2,4-D Amine 4.1SL tank mixes and Drive 75DF alone at 0.50 and 0.75
lb a.i./A reduced dandelion cover by > 90.0% as compared with the untreated controls.
All treatments significantly reduced percentage clover cover as compared with the untreated controls (Table 5).
Cover was reduced at least 95.9% in all treated turf for July 8, July 15, and July 30 as compared with the untreated
controls.

36

Herbicide and Growth Regulator Studies

The distribution o f spurge, plantain, purslane and oxalis were quite sporadic. Populations of these broadleaves were
not significantly different in the treated and untreated controls (Table 6).
The distribution o f crabgrass was more uniform and there was more crabgrass in all treated turf than in the untreated
controls (Table 6). There were significantly more crabgrass plants in turf treated with Drive 75DF at 0.25 lb a.i./A
plus 2,4-D Amine 4.1SL and Trimec Classic 3.32EC at 1.5 lb a.i./A than in the untreated controls. The small
crabgrass numbers in the untreated turf can be explained by the competition from the large populations o f clover and
dandelion. In the treated turf, crabgrass moved into bare areas created where dandelion and clover were killed.

Table 1. Visual turf quality1 o f turf in the 1998 Postemergence Broadleaf Weed Control Study.
Material2
1.
2.
3.
4.
5.
6.
7.
8.

Untreated control
Drive 75DF
Drive 75DF
Drive 75DF
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1 SL
Trimec Classic 3.32EC

Rate
(lb a.i./A)
N/A
0.25
0.50
0.75
0.25
0.75
0.50
0.75
0.75
0.75
1.50

June
10
9
9
9
9
9

June
24
7
7
7
7
7

June
30
7
7
7
7
7

July
8
7
7
7
7
7

July
15
7
7
7
7
7

July
24
7
7
7
7
7

July
30
7
7
7
7
7

9

7

7

7

7

7

7

9

7

7

7

7

7

7

9

7

7

7

7

7

7

--

-

~
LSDoos
T
TTT
1Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable & 1 = worst quality.
2MSO was added to all treatments at 1.0% V/V. POST applications were made on June 5, 1998.
—= means comparisons tests are not valid for these data.

Table 2. Dandelion and clover damage1 following treatment for the 1998 Postemergence Broadleaf Weed Control
_________ Study.______________________________________________________________________________________
Dandelion damage______
_______ Clover damage
Material2
June
June
June
Rate
June
June
June
24
30
24
10
(lb a.i./A)
10
30
1. Untreated control
9.0
9.0
N/A
9.0
9.0
9.0
9.0
2.
Drive 75DF
8.7
0.25
8.7
7.3
7.3
4.3
2.3
3.
5.0
Drive 75DF
0.50
9.0
8.0
4.7
8.3
2.0
4.
Drive 75DF
7.0
0.75
8.7
7.0
5.0
8.0
2.0
5. Drive 75DF
0.25
9.0
7.0
8.3
7.0
1.0
3.3
+ 2,4-D Amine 4.1SL
0.75
6.
2.7
4.0
Drive 75DF
0.50
8.3
6.3
7.7
1.0
+ 2,4-D Amine 4.1SL
0.75
7.
7.0
Drive 75DF
2.0
8.0
0.75
8.7
7.0
1.0
+ 2,4-D Amine 4.1SL
0.75
8.
Trimec Classic 3.32EC
1.50
7.0
3.3
7.3
7.3
1.7
7.3
LSD 0 0 5

1.0

1.5

2.1

NS

’Damage was assessed using a 9 to 1 scale with 9 = no damage, 5 = plants 50% dead, 1 = dead plants.
2MSO was added to all treatments at 1.0% V/V.
NS = means are not significantly different at the 0.05 level.

37

2.5

1.7

Herbicide and Growth Regulator Studies

Table 3. Dandelion counts1 and reductions in dandelion counts2 following treatment for the 1998 Postemergence
Broadleaf Weed Control Study.

Material3
1.
2.
3.
4.
5.
6.
7.
8.

Untreated control
Drive 75DF
Drive 75DF
Drive 75DF
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Trimec Classic 3.32EC

Dandelion counts
Mean
July
30

July
8

210.0
95.0
65.0
29.0
8.3

343.3
109.2
69.7
32.5
7.3

0.0
74.1
84.4
92.5
98.7

0.0
54.8
69.0
86.2
96.0

90.5
97.9

3.0

3.0

3.0

99.4

98.6

99.1

1.7

1.0

1.3

99.7

99.5

99.6

107.0

71.7

89.3

77.6

65.9

74.0

79.7

67.7

56.5

16.7

32.3

16.5

Rate

July

(lb a.i./A)

8

N/A
0.25
0.50
0.75
0.25
0.75
0.50
0.75
0.75
0.75
1.50

476.7
123.3
74.3
36.0
6.3

LSD 0 0 5

Count reductions
July
30
Mean
0 .0
6 8 .2

7 9 .7

'These figures represent the number of dandelions per plot. In plots with large populations, dandelion counts were estimated by
counting the number of dandelions in a portion of the plot. Smaller counts in the untreated controls were recorded on July 30
than on July 15. This could be explained by the large increase in the percentage clover cover and the difficulty in finding
dandelions in a dense clover cover.
deductions in dandelion counts are expressed as percentages of the untreated controls.
3MSO was added to all treatments at 1.0% V/V.
POST applications were made on June 5, 1998.

Table 4. Percentage dandelion cover1 and reductions in cover2 following treatment for the BASF Postemergence
_________ Broadleaf Study.____________________________________________________________________________

Rate
Material3

(lba.i./A)

Percentage dandelion cover
July
July
15
30
Mean

________ Cover reductions_____
July
July
15
30
Mean
%

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

Untreated control
Drive 75DF
Drive 75DF
Drive 75DF
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Trimec Classic 3.32EC
LSD 0 0 5

N/A
0.25
0.50
0.75
0.25
0.75
0.50
0.75
0.75
0.75
1.50

23.3
6.7
2.3
0.7
0.3

25.0
6.7
2.3
2.3
1.0

24.2
6.7
2.3
1.5
0.7

71.4
90.0
97.1
98.6

0.0
73.3
90.7
90.7
96.0

0.0
72.5
90.4
93.8
97.2

0.3

0.7

0.5

98.6

97.3

97.9

0.0

0.7

0.3

1 0 0 .0

97.3

98.6

5.3

4.0

4.7

77.1

84.0

80.7

4.0

4.5

4.0

17.1

17.9

16.4

0.0

'Percentage dandelion cover was determined by estimating the area per plot covered by dandelions. These estimations were
made to more accurately depict the dandelion populations in treated plots,
deductions in dandelion cover are expressed as percentages of the untreated controls.
3MSO was added to all treatments at 1.0% V/V.
POST applications were made on June 5, 1998.

38

Herbicide and Growth Regulator Studies

Table 5. Percentage clover cover 1 and reductions in clover cover2 following treatment for the BASF Postemergence
_________ Broadleaf Study._______________________________________________________________________________

Material3

Rate
(lba.i./A)

Untreated control
Drive 75DF
Drive 75DF
Drive 75DF
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Trimec Classic 3.32EC

N/A
0.25
0.50
0.75
0.25
0.75
0.50
0.75
0.75
0.75
1.50

Percentage clover cover
July
July
July
8
15
30
Mean

________ Cover reductions_______
July
July
July
8
15
30
Mean
%

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

LSD 0.05

56.7
2.3
0.0
0.7
1.3

56.7
2.0
0.7
0.0
0.3

73.3
2.3
0.7
0.3
2.3

62.2
2.2
0.4
0.3
1.3 .

0.0
95.9
100.0
98.8
97.6

0.0
96.5
98.8
100.0
99.4

0.0
96.8
99.1
99.5
96.8

0.0
96.4
99.3
99.5
97.9

0.3

0.0

0.3

0.2

99.4

100.0

99.5

99.6

0.0

0.0

0.0

0.0

100.0

100.0

100.0

100.0

1.7

2.0

0.7

1.4

97.1

96.5

99.1

97.7

6.9

12.5

7.1

8.0

12.2

22.1

9.7

12.9

1Percentage clover cover was determined by estimating the area per plot covered by clover,
deductions in clover cover are expressed as percentages of the untreated controls.
3MSO was added to all treatments at 1.0% V/V.
POST applications were made on June 5, 1998.

Table 6. Crabgrass, spurge, plantain, purslane, and oxalis counts1 following treatment for the BASF Postemergence
_________ Broadleaf Study._______________________________________________________________________________
Material2

Rate

Crabgrass

Spurge

Plantain

2.0

0 .0

4.3
4.7
3.3
13.7

1 .3

0 .7

0 .3

0 .0

0 .3

2 .3

1.7
0.3
0.3
0.3
0.0

0 .0

0 .3

7.3

2 .3

0.0

0 .3

0 .3

4.7

2 .3

0.0

1 .3

0 .3

12.3

0 .7

0.0

0 .3

0 .0

7.4

NS

NS

NS

NS

Purslane

Oxalis

(lb a.i./A)

1.
2.

3.
4.
5.
6.

7.
8.

Untreated control
Drive 75DF
Drive 75DF
Drive 75DF
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Drive 75DF
+ 2,4-D Amine 4.1SL
Trimec Classic 3.32EC

N/A
0.25
0.50
0.75
0.25
0.75
0.50
0.75
0.75
0.75
1.50

LSD 0.05
1T
M figures represent the number of plants per plot.
These

3 .7
2 .7

2MSO was added to all treatments at 1.0% V/V.
NS = means are not significantly different at the 0.05 level.

39

0 .0

0 .0

0 .0

0 .0

Herbicide and Growth Regulator Studies

Postemergent Granular & Sprayable Broadleaf Weed Control Study
Barbara R. Bingaman, Melissa C. McDade, Michael B. Faust, and Nick E. Christians
A field study was initiated to compare the efficacy of several new granular broadleaf weed and feed products to the
standard herbicides in applications made to both damp and dry foliage. Sprayable formulations also were screened to:
1) determine the efficacy o f Millenium Ultra, Horsepower, DTD A, XRM-5202, and other research numbered
compounds to traditional 3-way herbicides; 2) determine the efficacy differential between the optical and racemic
isomers o f 2, 4-DP and MCPP; 3) determine the efficacy of Confront as compared to traditional 3-way herbicides.
This study was conducted at the Iowa State University Horticulture Research Station north o f Ames, IA in an area of
common bluegrass with a heavy infestation of red clover, white clover, dandelions, and assorted broadleaf weed
species. The soil in this area was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with an organic matter content
of 4.45%, a pH o f 6.65, 26 ppm P, and 257 ppm K. The experimental plots were 5 x 10 ft with three replications and
two rows per replication.
The study was comprised o f 34 treatments including eight granular materials applied to both wet and dry foliage (Table
1). Those plots receiving the granular materials were split into two 2 1/2 x 10 ft plots. The northern one was wet with
water just prior to application and the southern was kept dry. Half o f the total material for these plots was applied to the
wet foliage and half to the dry.
The sprayable materials included Millenium Ultra, Horsepower, DTD A, XRM 5202, Confront, RDL202, RDL211, and
RDL414. Super Trimec and Trimec Classic were included as industry standards and Triplet as a 3-way herbicide
standard. The racemic (R) and optical (O) formulations o f Dissolve, MCPP, and 2,4-DP also were screened. An
untreated control was included.
Granular materials were applied using cardboard containers as 'shaker dispensers'. Sprayables were applied at 30-35 psi
using a carbon dioxide backpack sprayer equipped with TeeJet® #8006 flat fan nozzles. The liquids were diluted into
567 ml o f water. This translates to an application rate o f 3 gal/1000 ft2. All products were applied postemergently after
dandelions, clover, and other broadleaf species were well established. Applications were made on June 5, 1998. The
plot was neither irrigated nor mowed for 24 hours following application.
Turf quality and phytotoxicity data were taken from June 10 through July 30 (Table 2). Visual quality was assessed
using a scale from 9 to 1 with 9 = best, 6 = lowest acceptable, and 1 = worst quality. Phytotoxicity was recorded as
present or absent.
Broadleaf and grass weed species were monitored. Weed damage data were taken on June 10 (Table 3). Damage to
dandelions and clover was assessed using a 9 to 1 scale with 9 = no damage, 5 = 50% o f plants showing damage, and 1
= 100% o f plants exhibiting damage. The symptoms o f damage included foliage discoloration, wilting, and curling.
Percentage dandelion and clover mortality data were taken on June 24 and June 30 (Table 4). Mortality was assessed
by estimating the number o f living plants per plot and comparing to the untreated controls. Dandelion counts (Table 5)
and percentage clover cover (Table 7) data were collected on July 7, July 14, July 24, and July 30 . For these data, the
number o f dandelions was counted and the percentage clover cover was estimated for each plot. Reductions were
calculated as percentages o f the untreated controls on each collection date for dandelion (Table 6) and clover (Table 8).
Percentage crabgrass cover data were taken on July 7, July 14, July 24, and July 30 (Table 9). Reductions were not
calculated since there was more crabgrass in many of the treated plots than in the untreated controls. The only other
weed species with a widespread distribution was spurge. The number o f spurge per plot was counted (Table 10).
Reductions in numbers were not calculated because there were no spurge plants in the untreated controls.
All data were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis of Variance
(ANOVA) procedure. Fisher's Least Significant Difference (LSD) test was utilized for means comparisons.

40

Herbicide and Growth Regulator Studies

No phytotoxicity was found during this study. Visual quality of turf treated with the herbicide plus fertilizer
formulations was better than the untreated and unfertilized turf (Table 2). The numerical differences were not
statistically significant. The turf treated with the herbicide plus fertilizer materials had consistently improved quality
over the entire duration o f the study as compared with the untreated and unfertilized turf.
Many o f the sprayable materials were causing significant levels of damage to dandelion and clover as compared with
the untreated control on June 10 (Table 3). Dandelion and clover treated with the granular formulations were not
exhibiting significant damage on this date.
By June 30, six o f the sprayable materials had caused dandelion mortality > 90% as compared with the untreated
control (Table 4). On this date, 11 of the sprayable formulations and two granulars (applied to wet foliage) had killed
all o f the clover.
Sixteen o f the sprayable materials significantly decreased dandelion counts on July 7 and all sprayables significantly
suppressed dandelions July 14 through July 30 as compared to the untreated controls (Table 5). Treatment with the
granular formulations applied to either wet or dry foliage resulted in significantly fewer dandelions from July 7 through
July 30 as compared to the untreated controls.
On July 7, 12 sprayable herbicides reduced dandelion populations > 94% as compared with the untreated control (Table
6). By July 30, only eight sprayables were providing this level of reduction. The mean level of control was > 91.4%
for 10 sprayable materials as compared with the untreated control.
One granular formulation reduced dandelion populations > 90% and two granulars produced reductions > 83.4% as
compared with the untreated controls on July 7 (Table 6). Three granulars provided dandelion control that was > 80.5%
on July 30. For some o f the granular materials, significantly better control was achieved when the material was applied
to wet foliage than to dry (Table 11). Mean dandelion control was significantly better for five of the granular materials
when applied to wet foliage than to dry.
All sprayable and granular herbicides significantly suppressed clover cover July 7 through July 30 as compared with the
untreated controls (Table 7). Twenty-three materials kept clover cover below 5.0% on July 7 as compared to the
untreated control. The mean clover cover was < 5.0% for 20 of the materials and 12 of these kept clover cover <1.0%
for the entire duration o f the study.
Twenty-three materials reduced clover cover > 92% on July 7 as compared with the untreated control and 11 o f these
killed all clover (Table 8). Mean clover cover reductions were > 94% for 20 of the herbicide formulations.
Clover control was similar for most granular materials applied on wet and on dry foliage (Table 12). There were
numerical differences in reduction of clover cover between the dry and wet applications but they were not statistically
significant.
Percentage crabgrass cover was significantly higher in turf treated with nine of the sprayable materials than in the
untreated controls on July 14 (Table 9). By July 30, crabgrass cover was > 20% in turf treated with 13 o f the herbicides
and was < 1% in the untreated control. The crabgrass populations in the treated turf can be explained by the reduced
competition from dandelion and clover as compared with competition in the untreated turf.
Spurge numbers were significantly higher in some treated turf as compared with the untreated control (Table 10).
These populations also can be explained by the reduced competition in the treated turf as compared with the untreated
turf.

41

Herbicide and Growth Regulator Studies

Table 1.

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
'The 5 x

Herbicides applied on June 5 for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
Formulation
Rate oz/1000 ft2
Material
Untreated control
Millenium Ultra 47.10%
Horsepower 50.40%
DTDA 47.30%
XRM 5202 55.80%
Confront 45.10%
Triplet (std) 49.67%
RDL202 89.76%DF
RDL211 55.98%
RDL414 55.48%
MCPP (R) 51.90%
MCPP (O) 25.96%
2,4-DP (R) 50.00%
2,4-DP (O) 25.00%
Dissolve (R) 57.70%
Dissolve (O) 43.31%
Super Trimec
Trimec Classic 3.4SL

N/A
0.92
0.92
0.92
1.29
0.74
1.20
0.61
1.10
1.10
1.10
1.10
1.10
1.10
1.50
1.50
1.10
1.50

N/A
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable
sprayable

Dry or wet foliage
N/A
diy
dry
dry
dry
diy
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry

Rate lb/1000 ft2
granular
wet
Millenium U ltra W & F -1 8 '
3.60
granular
wet
Trupower W & F - 18l
3.60
granular
wet
3.60
Dissolve W & F - 181
wet
granular
3.60
Dissolve Ultra W & F - 18'
3.60
granular
wet
Horsepower W & F - 181
granular
wet
XRM 5202 W & F - 1 8 1
3.60
granular
wet
2.94
Turf Builder + 21
wet
granular
3.60
Fertilized control1
dry
granular
3.60
Millenium Ultra W & F - 1 8 1
dry
3.60
granular
Trupower W & F - 181
dry
granular
3.60
Dissolve W & F - 18'
dry
granular
3.60
Dissolve Ultra W & F - 18*
dry
3.60
granular
Horsepower W & F - 181
dry
granular
3.60
XRM 5202 W & F - 1 8 1
dry
granular
2.94
Turf Builder + 21
dry
granular
3.60
Fertilized control1
10 ft plots for these treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.

Table 2.

Visual quality1of turf treated on June 5 for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
July 7
July 14
July 24
July 30
June 10
June 30
June 24
Material
6
6
6
6
7
7
7
1
Untreated control
6
7
7
6
6
6
7
Millenium Ultra 47.10%
2
6
6
7
7
6
6
7
3
Horsepower 50.40%
6
6
6
6
7
7
7
4
DTDA 47.30%
6
6
6
7
7
6
7
5
XRM 5202 55.80%
6
7
6
6
6
7
7
6
Confront 45.10%
6
6
6
7
7
6
7
7
Triplet (std) 49.67%
6
7
6
6
6
7
7
8
RDL202 89.76%DF
6
6
7
7
6
6
7
9
RDL211 55.98%
6
7
6
6
7
7
6
10
RDL414 55.48%
6
6
6
7
7
6
MCPP (R) 51.90%
7
11
6
6
6
6
7
7
7
MCPP (O) 25.96%
12
6
6
6
7
7
6
7
2,4-DP (R) 50.00%
13
6
6
6
6
7
7
7
14
2,4-DP (O) 25.00%
6
6
6
6
7
7
7
15
Dissolve (R) 57.70%
6
6
7
7
6
6
7
16
Dissolve (O) 43.31%
6
6
7
6
6
7
7
17
Super Trimec
6
6
6
6
7
7
7
18
Trimec Classic 3.4SL
7
7 •
7
7
8
8
8
Millenium Ultra W & F -182
19
7
7
7
7
8
Trupower W & F - 182
8
8
20
7
7
7
7
8
8
8
Dissolve W & F - 182
21
7
7
7
7
8
8
8
Dissolve Ultra W & F - 1 8 2
22
7
7
7
7
8
8
8
Horsepower W & F - 182
23
7
7
7
7
8
8
8
XRM 5202 W & F - 182
24
7
7
7
8
8
7
8
Turf Builder+ 22
25
7
7
7
7
8
8
8
26
Fertilized control2
7
7
7
7
8
8
8
Millenium Ultra W & F -182
27
7
7
7
7
8
8
8
Trupower W & F - 182
28
7
7
7
7
8
8
8
Dissolve W & F - 1 8 2
29
7
7
7
7
8
8
8
Dissolve Ultra W & F - 1 8 2
30
7
7
7
7
8
8
8
Horsepower W & F - 182
31
7
7
7
7
8
8
8
XRM 5202 W & F - 1 8 2
32
7
7
7
7
8
8
8
Turf Builder + 22
33
7
7
7
7
8
8
8
34
Fertilized control2
'U r .‘Visual1 quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
2The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.
LSD's were not included because means comparisons were not appropriate for these data.

42

Herbicide and Growth Regulator Studies

Table 3.

Dandelion and clover damage1 on June 10 in turf treated on June 5 for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
Material__________________________________________________________________ Dandelion______________________________ Clover
9.0
1
9.0
Untreated control
7.0
2
Millenium Ultra 47.10%
5.7
6.7
5.7
3
Horsepower 50.40%
5.7
4
DTDA 47.30%
5.7
7.0
5
7.0
XRM 5202 55.80%
7.7
6
5.0
Confront 45.10%
6.3
7
Triplet (std) 49.67%
6.0
6.0
8
5.3
RDL202 89.76%DF
5.7
9
5.7
RDL211 55.98%
4.3
10
RDL414 55.48%
5.3
8.7
8.0
11
MCPP (R) 51.90%
7.0
7.3
12
MCPP (0)25.96%
8.7
13
8.3
2,4-DP (R) 50.00%
7.3
14
2,4-DP (O) 25.00%
8.0
7.3
15
7.0
Dissolve (R) 57.70%
7.0
16
6.7
Dissolve (0)43.31%
6.3
5.0
17
Super Trimec
8.0
18
Trimec Classic 3.4SL
7.0
8.3
19
8.7
Millenium Ultra W & F -182
8.0
20
Trupower W & F - 182
8.7
8.3
21
Dissolve W & F - 182
8.3
7.7
22
Dissolve Ultra W & F - 1 8 2
8.0
8.7
23
Horsepower W & F - 182
8.7
24
8.0
XRM 5202 W & F - 182
8.3
25
8.3
8.0
Turf Builder + 22
26
9.0
Fertilized control2
9.0
27
Millenium Ultra W & F -182
8.3
8.3
28
8.0
Trupower W & F - 182
8.7
29
8.3
Dissolve W & F - 182
8.3
30
Dissolve Ultra W & F - 1 8 2
7.7
8.0
31
Horsepower W & F - 182
8.7
8.7
32
8.0
XRM 5202 W & F - 182
8.3
33
8.3
Turf Builder + 22
8.0
34
Fertilized control2
9.0
9.0
1.8
1.7
LSD 005
'Damage was assessed using a 9 to 1 scale with 9 = no damage, 5 = 50% of plants showing damage, and 1 = 100% of plants exhibiting damage. Symptoms of damage
included foliage discoloration, wilting, and curling.
The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.
Table 4.

Percentage dandelion and clover cover1reductions in turf treated on June 5 for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
Clover cover
Dandelion cover
June 30
Mean
June 24
Mean
Material
June 24
June 30

%
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

Untreated control
Millenium Ultra 47.10%
Horsepower 50.40%
DTDA 47.30%
XRM 5202 55.80%
Confront 45.10%
Triplet (std) 49.67%
RDL202 89.76%DF
RDL211 55.98%
RDL414 55.48%
MCPP (R) 51.90%
MCPP (O) 25.96%
2,4-DP (R) 50.00%
2,4-DP (O) 25.00%
Dissolve (R) 57.70%
Dissolve (O) 43.31%
Super Trimec
Trimec Classic 3.4SL
Millenium Ultra W & F -182
Trupower W & F - 182
Dissolve W & F - 1 8 2
Dissolve Ultra W & F - 1 8 2
Horsepower W & F - 182
XRM 5202 W & F - 1 8 2
Turf Builder + 22
Fertilized control2
Millenium Ultra W & F - 1 8 2
Trupower W & F - 182
Dissolve W & F - 1 8 2
Dissolve Ultra W & F - 1 8 2
Horsepower W & F - 182
XRM 5202 W & F - 1 8 2
Turf Builder + 22
Fertilized control2

0.0

0.0

0.0

0.0

0.0

0.0

56.7
70.0
53.3
36.7
73.3
46.7
40.0
53.3
73.3
46.7
26.7
40.0
56.7
63.3
73.3
73.3
70.0
43.3
43.3
30.0
33.3
33.3
36.7
53.3

86.7
73.3
86.7
83.3
100.0
80.0
100.0
100.0
90.0
36.7
43.3
30.0
36.7
80.0
76.7
100.0
93.3
56.7
63.3
20.0
23.3
10.0
60.0
43.3

71.7
71.7
70.0
60.0
86.7
63.3
70.0
76.7
81.7
41.7
35.0
35.0
46.7
71.7
75.0
86.7
81.7
50.0
53.3
25.0
28.3
21.7
48.3
48.3

63.3
46.7
33.3
36.7
66.7
43.3
40.0
46.7
70.0
23.3
20.0
30.0
26.7
43.3
53.3
63.3
76.7
36.7
60.0
20.0
33.3
33.3
40.0
26.7

100.0
100.0
60.0
100.0
100.0
100.0
100.0
100.0
100.0
50.0
10.0
56.7
40.0
83.3
100.0
100.0
100.0
100.0
100.0
33.3

81.7
73.3
46.7
68.3
83.3
71.7
70.0
73.3
85.0
36.7
15.0
43.3
33.3
63.3
76.7
81.7
88.3
68.3
80.0
26.7
16.7
16.7
53.3
21.7

0.0

0.0

0.0

30.0
30.0
6.7
23.3
33.3
36.7
40.0

46.7
33.3

26.7
30.0

38.3
31.7
3.3
20.0
16.7
31.7
35.0

0.0

0.0

0.0

0.0
16.7

0.0

•

0.0
0.0
66.7
16.7

0.0

0.0

0.0

30.0
53.3
13.3
23.3
30.0
40.0
26.7

76.7
76.7
33.3

20.0
16.7

53.3
65.0
23.3
11.7
15.0
30.0
21.7

0.0

0.0

0.0

0.0
0.0

6.8
33.4
41.5
25.6
28.0
28.7
‘These figures represent percentage reductions in percentage dandelion and clover cover per plot as compared with the untreated controls.
The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.

LSDoos

43

Herbicide and Growth Regulator Studies

Table 5.

Dandelion counts1 in turf treated for the 1998 Postemergence Granular and Spray able Broadleaf Weed Control Study.
July 7
July 24
July 30
Mean count
Material
July 14
342.8
316.7
366.7
390.0
1
Untreated control
298.0
1.7
1.9
1.3
Millenium Ultra 47.10%
2.3
2
2.3
77.7
9.7
35.0
66.7
47.3
3
Horsepower 50.40%
29.6
36.7
41.7
4
DTDA 47.30%
16.7
23.3
26.7
25.7
17.3
5
XRM 5202 55.80%
2.0
15.0
5.7
5.7
3.5
6
Confront 45.10%
0.3
2.3
44.7
37.6
10.7
21.7
73.3
7
Triplet (std) 49.67%
15.0
10.6
RDL202 89.76%DF
10.0
15.0
8
2.3
18.3
12.3
4.0
11.7
15.0
9
RDL211 55.98%
13.7
9.7
13.3
8.3
10
RDL414 55.48%
3.3
151.7
132.6
141.7
112.0
125.0
MCPP (R) 51.90%
11
183.3
191.3
183.3
185.0
173.3
MCPP (O) 25.96%
12
216.7
209.7
216.7
200.0
205.3
13
2,4-DP (R) 50.00%
210.0
200.0
212.3
216.7
222.7
14
2,4-DP (O) 25.00%
20.3
14.8
18.3
7.0
13.3
15
Dissolve (R) 57.70%
125.0
123.0
104.5
80.0
90.0
Dissolve (0)43.31%
16
13.0
10.1
9.0
8.7
9.7
17
Super Trimec
20.0
16.7
13.3
4.3
12.0
18
Trimec Classic 3.4SL
44.7
34.7
46.7
10.7
36.7
19
Millenium Ultra W & F - 1 8 2
106.7
111.3
82.7
63.3
20
Trupower W & F - 182
49.3
186.7
180.0
166.7
200.0
166.7
Dissolve W & F - 1 8 2
21
100.0
110.0
103.3
Dissolve Ultra W & F - 1 8 2
103.3
100.0
22
73.3
76.0
73.2
Horsepower W & F - 182
70.0
73.3
23
91.3
72.7
66.7
63.3
69.3
XRM 5202 W & F - 182
24
58.7
90.0
41.3
40.0
63.3
25
Turf Builder + 22
360.0
366.7
314.7
266.7
265.3
26
Fertilized control2
76.7
143.3
133.3
111.7
Millenium Ultra W & F - 1 8 2
93.3
27
253.3
164.7
250.0
217.0
200.0
28
Trupower W & F - 182
286.7
244.1
Dissolve W & F - 1 8 2
179.7
226.7
283.3
29
230.0
225.5
223.3
233.3
30
Dissolve Ultra W & F - 1 8 2
215.3
260.0
290.0
249.2
216.7
230.0
Horsepower W & F - 182
31
226.7
216.7
190.3
XRM 5202 W & F - 182
138.0
180.0
32
108.7
115.0
104.7
133.3
113.3
33
Turf Builder + 22
366.7
324.5
281.3
316.7
333.3
34
Fertilized control2
76.4
77.2
70.7
78.8
85.7
LSDoos
'These figures represent the number of dandelions per plot.
The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.

Table 6.

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

Percentage reductions in dandelion counts' in treated turf as compared with the untreated controls of the 1998 Postemergence Granular and Sprayable Broadleaf
Weed Control Study
Mean reduction
July 24
July 30
July 7
July 14
Material
n/
%
0.0
0.0
0.0
0.0
0.0
Untreated control
99.7
99.4
99.5
Millenium Ultra 47.10%
99.2
99.3
81.8
80.1
86.2
88.9
96.8
Horsepower 50.40%
91.4
89.3
90.0
94.4
92.6
DTDA 47.30%
94.9
93.4
92.7
99.3
95.3
XRM 5202 55.80%
98.5
99.0
98.5
99.9
99.3
Confront 45.10%
88.5
89.0
80.0
96.4
93.2
Triplet (std) 49.67%
96.2
96.9
95.9
99.2
96.8
RDL202 89.76%DF
96.4
95.3
95.9
98.7
96.3
RDL211 55.98%
96.5
97.2
96.4
97.4
98.9
RDL414 55.48%
61.1
61.4
61.3
60.5
62.4
MCPP (R) 51.90%
50.9
46.5
50.0
37.9
45.3
MCPP (O) 25.96%
44.4
38.8
31.6
45.5
31.1
2,4-DP (R) 50.00%
46.2
38.1
45.5
31.6
25.3
2,4-DP (O) 25.00%
94.8
95.7
95.0
97.7
95.8
Dissolve (R) 57.70%
68.5
69.5
65.9
71.6
73.2
Dissolve (0)43.31%
96.7
97.1
97.4
97.0
97.3
Super Trimec
94.9
96.1
95.5
98.5
96.2
Trimec Classic 3.4SL
88.5
89.9
87.3
96.4
88.4
Millenium Ultra W & F - 1 8 2
71.5
75.9
70.9
80.0
83.4
Trupower W & F - 182
52.1
47.5
54.5
36.8
44.1
Dissolve W & F - 1 8 2
72.7
71.8
69.9
68.4
65.3
Dissolve Ultra W & F - 182
80.5
78.7
80.0
76.8
76.5
Horsepower W & F - 182
76.6
78.8
82.7
78.9
76.7
XRM 5202 W & F - 1 8 2
89.4
82.9
80.0
75.5
86.6
Turf Builder + 22
7.7
8.2
0.0
15.8
11.0
Fertilized control2
65.8
67.4
60.9
70.5
74.3
Millenium Ultra W & F -182
35.0
36.7
31.8
36.8
44.7
Trupower W & F - 182
28.8
26.5
22.7
39.7
28.4
Dissolve W & F - 182
41.0
36.4
34.2
27.7
29.5
Dissolve Ultra W & F - 182
33.3
27.3
20.9
27.4
27.3
Horsepower W & F - 182
41.9
44.5
40.9
53.7
43.2
XRM 5202 W & F - 1 8 2
72.1
66.5
69.1
64.9
57.9
Turf Builder + 22
6.0
5.3
9.1
0.0
5.6
Fertilized control2
19.8
20.6
20.8
26.5
27.1
LSDoos

'These figures represent percentage reductions in dandelion numbers per plot as compared with the untreated controls.
2The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.

44

Herbicide and Growth Regulator Studies

Table 7.

Percentage clover cover1in turf treated for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
July 30
July 24
Material
July 7
July 14

!

Untreated control
50.0
Millenium Ultra 47.10%
0.3
Horsepower 50.40%
0.0
DTDA 47.30%
1.7
XRM 5202 55.80%
0.0
Confront 45.10%
0.0
Triplet (std) 49.67%
0.0
RDL202 89.76%DF
0.0
0.0
RDL211 55.98%
RDL414 55.48%
0.0
MCPP (R) 51.90%
5.3
MCPP (O) 25.96%
13.3
2,4-DP (R) 50.00%
3.7
2,4-DP (O) 25.00%
17.3
Dissolve (R) 57.70%
0.7
0.3
Dissolve (O) 43.31%
Super Trimec
0.0
Trimec Classic 3.4SL
0.0
0.0
Millenium Ultra W & F -1 8 2
Trupower W & F - 182
0.7
Dissolve W & F - 182
18.7
Dissolve Ultra W & F - 182
8.3
Horsepower W & F - 182
2.3
2.0
XRM 5202 W & F - 182
4.0
Turf Builder + 22
26.7
Fertilized control2
0.0
Millenium Ultra W & F -1 82
0.7
Trupower W & F - 182
Dissolve W & F - 182
27.0
Dissolve Ultra W & F - 182
13.3
4.3
Horsepower W & F - 182
1.7
XRM 5202 W & F - 182
10.0
Turf Builder + 22
26.7
Fertilized control2
16.3
LSD o.05
'These figures the area per plot covered by clover.
The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots.
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

Table 8.

61.7
0.0
0.0
0.7
0.0
0.3
0.3
0.0
0.3
0.3
12.0
18.7
8.7
25.3
0.7
0.7
0.0
0.3
0.0
0.7
12.0
13.3
2.3
2.3
5.7
23.3
0.0
0.3
28.7
13.3
7.0
1.0
11.7
20.3
19.7

%
65.0
0.0
0.0
3.3
0.7
0.3
2.0
8.3
0.3
0.0
18.3
28.7
15.3
27.0
0.7
1.0
0.3
0.3
6.7
0.7
13.7
20.0
4.3'
5.3
13.3
38.3
0.0
0.3
33.7
26.7
14.0
3.7
21.7
53.3
21.2

78.3
0.0
0.0
3.3
0.7
0.3
2.0
0.0
0.3
0.0
21.7
33.7
13.7
31.7
2.0
1.0
0.3
0.7
0.0
0.7
17.0
20.0
4.3
5.3
15.0
41.7
0.0
0.3
35.3
35.0
15.7
3.7
28.3
56.7
24.1

Mean cover
63.8
0.1
0.0
2.3
0.3
0.3
1.1
2.1
0.3
0.1
14.3
23.6
10.3
25.3
1.0
0.8
0.2
0.3
1.7
0.7
15.3
15.4
3.3
3.8
9.5
32.5
0.0
0.4
31.2
22.1
10.3
2.5
17.9
39.3
19.1

One-half of each material was applied to a dry and a wet subplot.

Percentage clover cover reductions1in treated turf as compared with the untreated controls of the 1998 Postemergence Granular and Sprayable Broadleaf Weed
Control Study.
July 30
Mean
July 7
July 14
July 24
Material

/o
0.0
0.0
0.0
0.0
0.0
Untreated control
100.0
100.0
99.9
100.0
Millenium Ultra 47.10%
99.3
100.0
100.0
100.0
100.0
100.0
3
Horsepower 50.40%
95.7
96.5
98.9
94.9
4
DTDA 47.30%
96.7
99.1
99.5
99.0
100.0
100.0
5
XRM 5202 55.80%
99.6
99.5
99.6
6
100.0
99.5
Confront 45.10%
96.9
97.4
98.3
7
100.0
99.5
Triplet (std) 49.67%
100.0
96.7
8
100.0
87.2
100.0
RDL202 89.76%DF
99.6
99.6
9
99.5
100.0
RDL211 55.98%
99.5
100.0
100.0
99.9
10
100.0
99.5
RDL414 55.48%
71.8
72.3
80.6
77.5
MCPP (R) 51.90%
11
89.3
57.0
63.0
12
69.7
55.9
MCPP (O) 25.96%
73.3
82.5
83.8
86.0
76.4
13
2,4-DP (R) 50.00%
92.7
14
58.9
58.5
59.6
60.3
2,4-DP (O) 25.00%
65.3
99.0
97.4
98.4
15
98.7
98.9
Dissolve (R) 57.70%
98.5
98.7
98.8
16
98.9
Dissolve (O) 43.31%
99.3
99.6
99.7
17
100.0
100.0
99.5
Super Trimec
99.5
99.1
18
100.0
99.5
99.5
Trimec Classic 3.4SL
100.0
100.0
89.7
97.4
19
Millenium Ultra W & F -182
100.0
99.0
99.1
99.4
20
Trupower W & F - 182
98.7
98.9
79.0
78.3
75.9
21
Dissolve W & F - 1 8 2
62.7
80.6
74.5
75.8
78.4
69.2
22
Dissolve Ultra W & F - 182
83.3
94.5
93.3
94.8
23
95.3
96.2
Horsepower W & F - 182
93.2
91.8
94.1
24
XRM 5202 W & F - 182
96.0
96.2
80.8
85.1
79.5
25
92.0
90.8
Turf Builder + 22
46.8
49.0
41.0
26
46.7
62.2
Fertilized control2
100.0
100.0
100.0
27
100.0
Millenium Ultra W & F -182
100.0
99.6
99.5
99.3
28
98.7
99.5
Trupower W & F - 182
54.9
48.2
51.1
29
53.5
Dissolve W & F - 182
46.0
30
78.4
59.0
55.3
65.4
Dissolve Ultra W & F - 182
73.3
80.0
83.9
31
Horsepower W & F - 182
91.3
88.7
78.5
94.4
95.3
98.4
96.1
96.7
32
XRM 5202 W & F - 182
66.7
63.8
71.9
33
Turf Builder + 22
80.0
81.1
18.0
27.6
34
67.0
38.4
Fertilized control2
46.7
30.7
32.6
29.9
31.9— —— — — ——
LSD0.05
'■ ' —
— — — ——
.......... I I ■ — II I I.
I — — I I 32.5
—
—— — ——
—
These figures represent percentage reductions in clover cover per plot as compared with the untreated controls.
2The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.
1

r

45

Herbicide and Growth Regulator Studies

Table 9.

Percentage crabgrass cover1 in treated turf for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
July 30
Material
July 7
July 24
July 14

Mean

•

%
5.7
30.0
26.7
21.7
16.7
15.0
15.0
16.7
25.0
23.3
15.0
18.3
11.7
18.3
7.3
31.7
23.3
10.0
23.3
28.3
28.3
28.3
6.7
13.3
13.3
10.0
15.3
23.3
5.0
16.7
6.7
8.3
8.3
4.0
NS

1

0.7
1.8
0.7
Untreated control
0.3
38.3
29.3
Millenium Ultra 47.10%
18.7
30.0
30.0
18.8
Horsepower 50.40%
5.3
13.3
25.0
0.7
15.2
DTDA 47.30%
13.3
11.7
28.3
15.1
XRM 5202 55.80%
3.7
12.0
9.0
Confront 45.10%
3.7
5.3
0.7
15.0
9.1
5.7
Triplet (std) 49.67%
18.3
12.7
RDL202 89.76%DF
5.3
10.3
30.0
21.4
RDL211 55.98%
10.7
20.0
23.3
17.6
10.3
13.3
RDL414 55.48%
11.7
8.1
MCPP(R) 51.90%
0.3
5.3
18.3
10.7
1.0
5.0
MCPP (0)25.96%
8.7
6.6
0.7
5.3
2,4-DP (R) 50.00%
20.0
1.7
8.3
12.1
2,4-DP (O) 25.00%
12.7
7.3
Dissolve (R) 57.70%
2.0
7.0
31.7
21.8
10.3
13.3
Dissolve (O) 43.31%
4.0
26.7
16.7
17.7
Super Trimec
3.7
Trimec Classic 3.4SL
5.3
2.3
5.3
5.0
7.0
Millenium Ultra W & F -182
28.3
15.9
3.7
27.0
17.0
Trupower W & F - 182
9.0
6.7
18.7
Dissolve W & F - 182
10.0
15.9
Dissolve Ultra W & F - 1 8 2
7.0
30.0
11.7
19.3
Horsepower W & F - 182
1.0
5.7
0.3
3.4
XRM 5202 W & F - 1 8 2
0.7
8.7
21.7
11.1
6.7
Turf Builder + 22
2.0
2.0
6.0
Fertilized control2
0.0
10.3
3.7
6.0
Millenium Ultra W & F - 1 8 2
0.3
4.0
15.3
8.8
Trupower W & F - 182
3.7
5.3
13.3
11.4
3.7
Dissolve W & F - 1 8 2
6.7
6.7
5.5
Dissolve Ultra W & F - 1 8 2
6.7
17.0
2.3
10.7
Horsepower W & F - 182
0.0
0.7
10.0
4.3
XRM 5202 W & F - 182
3.7
12.0
0.3
6.1
6.7
0.7
4.8
Turf Builder + 22
3.7
Fertilized control2
0.0
2.0
4.3
2.6
10.6
8.8
NS
14.2
LSDo.os
— i^i___
‘These figures represent the area per plot covered by crabgrass.
2The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.
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

Table 10. Spurge counts1in turf treated on June 5 for the 1998 Postemergence Granular and Sprayable Broadleaf Weed Control Study.
Material
Spurge counts
1
0.0
Untreated control
4.0
2
Millenium Ultra 47.10%
3
Horsepower 50.40%
8.3
6.0
4
DTDA 47.30%
7.0
5
XRM 5202 55.80%
6
Confront 45.10%
4.3
3.7
7
Triplet (std) 49.67%
8
1.0
RDL202 89.76%DF
0.0
9
RDL211 55.98%
10
0.7
RDL414 55.48%
MCPP (R) 51.90%
1.3
11
12
0.0
MCPP (O ) 25.96%
13
1.7
2,4-DP (R) 50.00%
14
2,4-DP (O) 25.00%
0.3
15
Dissolve (R) 57.70%
1.3
16
Dissolve (O) 43.31%
1.3
17
4.0
Super Trimec
3.0
18
Trimec Classic 3.4SL
1.0
19
Millenium Ultra W & F -182
4.7
Trupower W & F - 182
20
0.0
Dissolve W & F - 1 8 2
21
0.7
Dissolve Ultra W & F - 1 8 2
22
0.7
Horsepower W & F - 182
23
0.0
24
XRM 5202 W & F - 182
0.0
25
Turf Builder + 22
0.0
26
Fertilized control2
1.3
27
Millenium Ultra W & F -182
4.7
Trupower W & F - 182
28
0.0
29
Dissolve W & F - 1 8 2
0.0
Dissolve Ultra W & F - 1 8 2
30
0.0
Horsepower W & F - 182
31
1.3
XRM 5202 W & F - 182
32
0.0
Turf Builder + 22
33
0.0
34
Fertilized control2
4.4
LSDo.05
'These figures represent the number of spurge per plot.
2The 5 x 10 ft plots for these granular treatments were split into two 2 1/2 x 10 ft subplots. One-half of each material was applied to a dry and a wet subplot.

46

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M

LSD qq5____________________________________ 315 ___________________ 310 ___________________ 316_____________________307 ___________________ 29.9
’These figures represent reductions in clover cover per plot as compared with the untreated controls.

Table 11. Percentage reductions in dandelion counts1 in turf treated with granular herbicides applied on wet vs. dry foliage for the 1998 Postemergence Granular and sprayable
__________Broadleaf Herbicide Study.___________________________________________________________________________________________________________________

Herbicide and Growth Regulator Studies

Herbicide and Growth Regulator Studies

Postemergence Ground Ivy Weed Control Study at Veenker
B arbara R. Bingaman, M elissa C. M cDade, M ichael B. Faust , an d N ick E. C hristians
The efficacy o f Trimec experimental formulations in the control o f ground ivy (creeping charlie) was examined in
this study. It was conducted at Veenker Memorial G olf Course, Ames LA, in a common bluegrass and perennial
ryegrass area heavily infested with ground ivy. The soil in this area was a Nicollet (fine-loamy, mixed, mesic Aquic
Hapludoll) with 7.0% organic matter, 56 ppm P, 368 ppm K, and a pH o f 7.2.
The study was designed as a randomized complete block. Individual plot size was 5 x 5 ft with three replications.
A pretreatment survey o f the area showed the presence of ground ivy in each o f the individual plots. There were
seven Trimec experimental treatments plus an untreated control. Trimec Classic was applied at 1.5 fl oz/1000 ft2
and NB20680 (substituted for EH1349), NB 30137, NB30138, NB30139, NB30140, and NB30141 were applied at
3.0 fl oz/1000 ft2 (Table 2).
Applications were made postemergently on July 14, 1998 after ground ivy was established. A carbon dioxide
backpack sprayer equipped with Teejet® #8006 flat fan nozzles at 30 psi was used. The materials were diluted into
90 ml o f water. This translates to a rate o f 1 gallon/1000 ft2.
Ground ivy control evaluations were made on July 21, July 30, August 6, and August 12. Control was assessed as
the percentage o f living ground ivy per individual plot.
All data were analyzed with the Statistical Analysis System (SAS Version 6.12) using the Analysis o f Variance
procedure (ANOVA). Fisher's Least Significant Difference means separation test (LSD) was used to compare means.
No phytotoxicity was observed in any treated turf. On July 21, treated ground ivy exhibited different degrees o f
damage and symptoms (Table 1).
All materials significantly reduced ground ivy populations (Table 2). Some o f the materials worked faster than
others. On July 21, virtually all o f the ground ivy was dead in turf treated with NB30141 and slightly less
mortality was observed in turf treated with NB20680, NB30139, and NB30140. By August 6, all o f experimental
materials had killed at least 95% o f the ground ivy (Table 3).

Table 1. Ground ivy damage and phytotoxic symptoms observed on July 21.__________________________________
REP 1

48

Herbicide and Growth Regulator Studies

Table 2. Percentage living ground ivy cover in turf plots o f the 1998 PBI Gordon Ground Ivy Study.
Rate
August
[fl oz]
July
July
August
6
12
product
Materials
21
30
/1000 ft2
0/
/u

Mean

NA

63.3

60.0

65.0

66.7

63.8

N B20680 ***

3.0

5.7

2.3

1.7

0.3

2.5

3.

NB30137

3.0

11.0

3.0

■2.1

5.7

5.6

4.

NB30138

3.0

11.3

3.3

0.7

1.7

4.3

5.

NB30139

3.0

5.7

2.3

1.0

1.0

2.5

6.

NB30140

3.0

5.7

6.0

1.0

1.0

3.4

7.

NB30141

3.0

1.0

1.7

2.0

0.7

1.3

8.

Trimec Classic

1.5

58.3

18.3

20.0

8.0

26.2

19.9

9.7

17.8

11.4

12.8

1.

Untreated control

2.

LSD oos

**NB20680 used instead o f EH 1349.

Table 3. Percentage reduction in living ground ivy cover1 in turf plots o f the 1998 PBI Gordon Ground Ivy Study.
July
July
August
August
Materials
21
30
6___________
12___________ Mean
0.0

0.0

--------- % --------0.0

0.0

0.0

NB20680 ***

91.0

96.1

97.4

99.5

96.1

3.

NB30137

82.6

95.0

95.9

91.5

91.2

4.

NB30138

82.1

94.4

99.0

97.5

93.3

5.

NB30139

91.0

96.1

98.5

98.5

96.1

6.

NB30140

91.0

90.0

98.5

98.5

94.6

7.

NB30141

98.4

97.2

96.9

99.0

97.9

8.

Trimec Classic

7.8

69.4

69.2

88.0

59.0

31.5

16.2

27.4

17.1

20.0

1.

Untreated control

2.

LSD oos

‘These values represent reductions in living ground ivy cover as compared with the untreated controls.

49

Herbicide and Growth Regulator Studies

LCO Weed Control Study
Barbara R. Bingaman, Melissa C. McDade, and Nick E. Christians
This study was designed to evaluate full season weed control with Drive 75DF delayed lawn care (LCO) programs
compared to standard LCO programs. It was conducted at the Iowa State University Horticulture Research Station
at Ames, IA in an established area of'Park' Kentucky bluegrass. The soil in this area was a Nicollet (fme-loamy,
mixed, mesic Aquic Hapludoll) with 3.9% organic matter, 3.5 ppm P, 116 ppm K, and a pH o f 7.3.
The study was arranged as a randomized complete block with three replications. Individual plot size was 10 x 5 ft
with treatments randomly assigned within replications. There were four treatments with combinations o f pre(PRE), early post (EPOST), post (POST), late postemergent (LPOST) applications, and an untreated control (Table
1). One treatment combination included Pendimethalin 60WDG applied at the label rate PRE and Trimec Classic
3.32EC at 1.5 lb a.i./A applied POST and LPOST. Drive 75DF at 0.75 lb a.i./A was applied EPOST in a tank
mix with Pendimethalin 60WDG at 2/3 label rate and was applied LPOST with 2,4-D Amine 4.1SL at 0.75 lb
a.i./A. The fourth treatment was a tank mix o f Drive 75DF at 0.75 lb a.i./A plus 2, 4-D Amine 4.1SL at 0.75 lb
a.i./A applied EPOST and LPOST. Methylated soy soil (MSO) was added to all treatments as a carrier at 1.0%
V/V.
Preemergent applications were made May 6, 1998 before crabgrass germination. Early post applications were made
as delayed LCO pre- postemergent treatments on June 16. Postemergence applications were made following
standard POST broadleaf timing schedules on July 14. Late postemergence treatments were applied as standard
LPOST broadleaf materials on September 1, 1998.
The products were applied at 30 psi using a carbon dioxide backpack sprayer equipped with Teejet® #8006 flat fan
nozzles. The materials were mixed into 567 ml water that translates to an application volume o f 3 gal/1000 ft2.
Turf quality and phytotoxicity were assessed from May 13 through October 1 (Tables 2 - 4). Turf quality was
estimated by making visual rankings using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst
quality. Phytotoxicity was quantified using a 9 to 1 scale with 9 = no injury, 6 = moderate damage, and 1 = dead
turf. Dandelion and clover damage were determined on June 30, July 7, and July 23 following the EPOST and
POST applications (Table 5). Damage was estimated using a 9 to 1 scale with 9 = no damage, 6 = 50% dead, 1 =
100% dead. Damage symptoms included collapsed, discolored, and curled leaves. Percentage cover data were taken
for dandelion (Tables 6 - 7), clover (Tables 8 - 9), and crabgrass (Tables 1 0 -1 1 ) from July 15 through October 1.
These data represent the percentage o f area per plot covered by each weed species.
All data were analyzed using the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
Procedure (ANOVA). Differences among means were compared with Fisher’s Least Significant Difference (LSD)
Test.
The only significant differences in turf quality were observed on July 15, one day after the POST applications
(Tables 2 - 4). There were numerical differences in quality on June 24 (8 days after the EPOST applications), on
August 18, on September 16(15 days after the LPOST applications), and on September 23. N o phytotoxicity was
detected.
On June 30 (15 days after the EPOST materials were applied), Drive 75DF plus either Pendimethalin 60WDG or
2,4-D Amine 4.1SL was causing severe levels o f damage to dandelion and clover (Table 5). By July 15, the Drive
75DF tank mixes had reduced the percentage dandelion cover to < 1.0% and the clover cover to < 0.3% as compared
to 16.7% dandelion cover and 6.7% clover cover in the untreated controls (Tables 6 - 8). On July 23, seven days
after the POST treatments, the pendimethalin 60WDG tank mix was causing severe damage to the dandelion and
clover and by July 29, the percentage cover for both species was significantly reduced as compared with the untreated
controls. After July 29, all o f the herbicides provided significant reductions in dandelion and clover populations as
compared with the untreated controls (Tables 6 - 9).
Crabgrass was first detected in the untreated turf on July 15 and in the treated turf on July 23 (Tables 10 - 11).
Crabgrass populations in the treated turf were reduced as compared with the untreated controls for the duration o f the
trial. The reductions were not statistically significant for all o f the collection dates.

50

Herbicide and Growth Regulator Studies

Table 1. Materials and application information for the 1998 LCO Weed Control Study.
Rate
lb a.i./A
Timing o f application
Material
N/A
1.
Untreated control
N/A
PRE
1.50
2.
Pendimethalin 60WDG*

3.

4.

Trimec Classic 3.32EC

1.50

POST

Trimec Classic 3.32EC

1.50

LATE POST

Drive 75DF
+ Pendimethalin 60WDG*
+ MSO

0.75
1.00
1.00%

EARLY POST
EARLY POST
EARLY POST

Drive 75DF
+ 2, 4-D Amine 4.1SL
+ MSO

0.75
0.75
1.00%

LATE POST
LATE POST
LATE POST

Drive 75DF
+ 2, 4-D Amine 4.1SL
+ MSO

0.75
0.75
1.00%

EARLY POST
EARLY POST
EARLY POST

Drive 75DF
+ 2, 4-D Amine 4.1SL
+ MSO

0.75
0.75
1.00%

LATE POST
LATE POST
LATE POST

PRE applied on May 6, EARLY POST on June 16, POST on July 14, and LATE POST on September 1, 1998
♦Pendimethalin (Pre-M 60WDG) was substituted for Pendulum 3.3EC per Dave Eastman.

Table 2. Visual turf quality1 in turf treated for the 1998 LCO Weed Control Study (May 13 - July 7).
Material
May 13 May 18 May 27 June 16 June 24 June 30
1.
Untreated control
9.0
9.0
9.0
9.0
7.0
7.0
2.
Pendimethalin 60WDG
& Trimec Classic 3.32EC
9.0
9.0
9.0
9.0
6.3
7.0
& Trimec Classic 3.32EC
3.
Drive 75DF
+ Pendimethalin 60WDG + MSO
9.0
& Drive 75DF
9.0
9.0
9.0
5.7
7.0
+ 2, 4-D Amine 4.1SL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
9.0
9.0
9.0
9.0
5.0
7.0
+ 2, 4-D Amine 4.1SL + MSO
NS
LSDo.os
lx
r:
‘Visual quality was assessed with a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = best quality.
— = means separation tests are not appropriate for these data.
NS = means are not significantly different at the 0.05 level.

51

July 7
7.0
7.0

7.0

7.0
-

Herbicide and Growth Regulator Studies

Table 3. Visual turf quality1 in turf treated for the 1998 LCO Weed Control Study (July 15 - August 26).
Aug 11 Aug 18
Aug 5
Material
July 29
July 15 July 23
7.0
7.0
7.0
8.0
Untreated control
8.0
7.0
Pendimethalin 60WDG
7.0
7.0
7.0
7.0
& Trimec Classic 3.32EC
7.0
6.3
& Trimec Classic 3.32EC
Drive 75DF
3.
+ Pendimethalin 60WDG + MSO
7.0
7.0
7.0
& Drive 75DF
7.0
7.0
7.0
+ 2, 4-D Amine 4.ISL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
7.0
7.0
7.0
7.0
& Drive 75DF
7.0
7.0
+ 2, 4-D Amine 4.1SL + MSO
1.2
LSD 0.05
Visual quality was assessed with a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = best quality.
1.
2.

Aug 26
7.0
7.0

7.0

7.0
-

-- = means separation tests are not appropriate for these data.

Table 4. Visual turf quality1 in turf treated for the 1998 LCO Weed Control Study (Sept. 4 - Oct. 1).
Material
Sept 4
Sept 9
Sept 23
Sept 16
Oct 1
1. Untreated control
7.0
6.0
6.7
8.0
6.0
2.
Pendimethalin 60WDG
& Trimec Classic 3.32EC
7.0
6.0
6.3
7.0
6.0
& Trimec Classic 3.32EC
3.
Drive 75DF
+ Pendimethalin 60WDG + MSO
& Drive 75DF
7.0
6.0
6.0
7.0
6.0
+ 2, 4-D Amine 4.1SL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
7.0
6.0
6.0
7.0
6.0
+ 2, 4-D Amine 4.1SL + MSO
NS
NS
LSDo.os

Mean
7.5
7.2

7.2

7.2
0.1

~~T777

1Visual quality was assessed with a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = best quality.
— = means separation tests are not appropriate for these data.
NS = means are not significantly different at the 0.05 level.

Table 5. Dandelion and clover damage1 following treatment for the 1998 LCO Weed Control Study.
Clover
Dandelion
Material
June 30
June 30
July 23
July 7
July 7
1. Untreated control
9.0
9.0
9.0
9.0
9.0
2.
Pendimethalin 60WDG
9.0
& Trimec Classic 3.32EC
8.3
8.3
2.7
9.0
& Trimec Classic 3.32EC
3.
Drive 75DF
+ Pendimethalin 60WDG + MSO
9.0
& Drive 75DF
3.3
3.7
2.3
1.7
+ 2, 4-D Amine 4.1SL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
9.0
2.7
1.0
& Drive 75DF
3.0
2.0
+ 2, 4-D Amine 4.1SL + MSO
1.6
1.2
2.7
1.2
1.8
LSDoos
1Damage was estimated using a 9 to 1 scale with 9 = no damage, 6 = 50% dead, 1 = 100% dead.
— = means separation tests are not appropriate for these data.

52

July 23
9.0
9.0

9.0

9.0
—

Herbicide and Growth Regulator Studies

Table 6. Percentage dandelion cover1 in tu rf treated for the 1998 LCO W eed Control Study (July 15 - Aug. 26).
1.
2.

3.

4.

Material
Untreated control
Pendimethalin 60WDG
& Trimec Classic 3.32EC
& Trimec Classic 3.32EC
Drive 75DF
+ Pendimethalin 60WDG + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
LSD oos

July 15
16.7

July 23
23.3

July 29
21.7

Aug 5
30.0

Aug 11
25.0

Aug 18
21.7

Aug 26
23.3

18.3

18.3

4.7

1.0

0.3

0.7

1.0

1.0

0.7

1.0

2.3

3.7

6.7

8.3

0.0

0.0

0.3

0.7

0.3

2.0

2.3

12.5

8.5

6.0

9.5

2.2

7.6

7.3

‘These figures represent the area per plot covered by dandelion.

Table 7. Percentage dandelion cover1 in turf treated for the 1998 LCO Weed Control Study (Sept. 4 - Oct. 1).
Sept 16
Sept 23
Material
Sept 4
Sept 9
Mean cover
Oct 1
1.
16.7
25.0
30.0
Untreated control
10.0
20.0
21.9
2.
Pendimethalin 60WDG
& Trimec Classic 3.32EC
2.3
2.0
2.3
2.3
2.3
4.6
& Trimec Classic 3.32EC
3.
Drive 75DF
+ Pendimethalin 60WDG + MSO
0.3
0.0
3.4
& Drive 75DF
6.7
8.3
2.3
+ 2, 4-D Amine 4.1SL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
2.3
2.0
1.7
0.0
1.2
2.3
+ 2, 4-D Amine 4.1SL + MSO
3.9
7.4
3.7
4.3
7.7
2.3
L S D o os
‘These figures represent the area per plot covered by dandelion.
PRE applied on May 6, EARLY POST on June 16, POST on July 14, and LATE POST on September 1, 1998

Table 8. Percentage clover cover1 in turf treated for the 1998 LCO Weed Control Study (July 15 - Aug. 26).
Material
Aug 5
Aug 11
Aug 18 Aug 26
July 15 July 23
July 29
1.
16.7
18.3
8.3
26.7
Untreated control
6.7
18.3
23.3
2.
Pendimethalin 60WDG
20.0
2.0
2.0
0.3
0.0
& Trimec Classic 3.32EC
20.0
2.3
& Trimec Classic 3.32EC
3.
Drive 75DF
+ Pendimethalin 60WDG + MSO
0.0
0.3
0.7
& Drive 75DF
0.3
0.0
0.3
0.3
+ 2, 4-D Amine 4.1SL + MSO
4.
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
0.0
0.0
0.0
0.0
0.0
0.0
& Drive 75DF
0.0
+ 2, 4-D Amine 4.1SL + MSO
3.0
7.1
2.5
2.7
3.2
7.5
3.0
LSD o.05
“T7T
1These figures represent the area per plot covered by clover.

53

Herbicide and Growth Regulator Studies

Table 9. Percentage clover cover1 in turf treated for the 1998 LCO Weed Control Study (Sept. 4 - Oct. 1).
1.
2.

3.

4.

Material
Untreated control
Pendimethalin 60WDG
& Trimec Classic 3.32EC
& Trimec Classic 3.32EC
Drive 75DF
+ Pendimethalin 60WDG + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
L SD oos

Sept 4
56.7

Sept 9
41.7

Sept 16
56.7

Sept 23
56.7

Oct 1
53.3

Mean cover
31.9

2.7

1.0

2.0

0.7

0.0

4.4

0.7

0.3

0.0

0.0

0.0

0.3

0.3

0.3

0.0

0.0

0.0

0.1

6.3

14.3

14.7

11.5

5.8

4.4

1These figures represent the area per plot covered by clover.
PRE applied on May 6, EARLY POST on June 16, POST on July 14, and LATE POST on September 1, 1998

Table 10. Percentage crabgrass cover1 in turf treated for the 1998 LCO Weed Control Study (July 15 - Aug. 26).
1.
2 .

3.

4.

Material
Untreated control
Pendimethalin 60WDG
& Trimec Classic 3.32EC
& Trimec Classic 3.32EC
Drive 75DF
+ Pendimethalin 60WDG + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
L S D o.05

July 15
0.3

July 23
2.3

July 29
4.0

Aug 5
6.7

Aug 11
11.7

Aug 18
16.7

Aug 26
6.9

0.0

0.7

1.7

0.7

5.3

2.3

1.8

0.0

3.7

0.3

0.0

3.3

0.7

1.3

0.0

0.7

0.0

0.3

2.0

0.7

0.6

NS

NS

NS

NS

2.7

P=0.07
7.4

P=0.07
13.3

‘These figures represent the area per plot covered by crabgrass
NS = means are not significantly different at the 0.05 level.

Table 11. Percentage crabgrass cover1 in turf treated for the 1998 LCO Weed Control Study (Sept. 4 - Oct. 1).
1.
2.

3.

4.

Material
Untreated control
Pendimethalin 60WDG
& Trimec Classic 3.32EC
& Trimec Classic 3.32EC
Drive 75DF
+ Pendimethalin 60WDG + MSO
& Drive 75DF
+ 2, 4-D Amine 4.1SL + MSO
Drive 75DF
+ 2, 4-D amine 4.1SL + MSO
& Drive 75DF
+ 2, 4-D amine 4.1SL + MSO
L SD oos

Sept 4
3.7

Sept 9
5.7

Sept 16
13.3

Sept 23
12.0

Oct 1
16.7

Mean cover
8.5

2.3

0.3

5.0

2.0

0.0

1.8

0.0

0.3

0.0

0.0

0.0

0.8

0.7

0.0

0.0

0.3

0.0

0.5

NS

NS

P = 0.06
10.1

NS

NS

NS

"T™1

‘These figures represent the area per plot covered by crabgrass
NS = means are not significantly different at the 0.05 level.

54

Herbicide and Growth Regulator Studies

P oa annua Control Studies - 1998
NickE. Christians
Prograss (ethofumasate) is an herbicide that has been shown to selectively remove Poa annua from perennial
ryegrass on golf course fairways. It is a postemergence material but also has some preemergence effects on
susceptible species. While Prograss has been shown to be safe for use on perennial ryegrass, its usefulness on
Kentucky bluegrass and creeping bentgrass fairways is less certain and there is a risk o f damage to these species at
higher rates o f application.
Primo (trinexapath-ethyl) is a GA (gibberellic acid) inhibiting compound that is used as a growth retardant on golf
course fairways. It has been promoted as both a prestress conditioning product to help Poa annua survive the stress
conditions in summer and as a potential method o f reducing Poa annua population in creeping bentgrass fairways.
The objectives o f the 1998 Poa annua control studies were to observe the effects o f Prograss and Primo on Poa
annua populations in golf course fairways and to observe the effects o f these compounds on a variety o f species
under controlled conditions at the Iowa State University turfgrass research area.
MATERIAL AND METHODS
The treatments listed in Table 1 were applied to the fairway plots monthly from May through November and data on
Poa annua survival were taken in November of 1998. The plots were also observed through the season for any
signs o f damage from the treatments.
The studies were conducted on the following sites:
1. The 16th fairway at Otter Creek Golf Course in Ankeny, Iowa, which is located in the central part o f the state.
Species: Kentucky bluegrass, with 10 to 20% Poa annua.
2. The 13th fairway at Hyperion Country Club in Johnston, Iowa, also in central Iowa. Species: Creeping
bentgrass (Penneagle) fairway with 55 to 70% Poa annua.
3. The 5th fairway (15th fairway for small plots) at Fort Dodge Country Club, Fort Dodge, Iowa, located in the
northern and western part of the state. Perennial ryegrass/Kentucky bluegrass fairway (originally seeded to
Fylking, Park and common) with 45 to 70% Poa annua.
There were two treated areas at each site. Large plots that measured 5 ft. wide and extended the full width o f the
fairway received treatments 1-10 (Table 1) monthly from May through November. The treatments were applied by
course personnel with fairway sprayers that had only one boom section active.
A small plot area was also established on fairways at each course. These plots measured 3 x 5 ft. and all 11
treatments (Table 1) were applied in 3 replications. These treatments were applied monthly with a small plot
sprayer by Steve Krantz o f D&K Turf Products in Des Moines and myself, with help from Steve Davis o f AgrEvo.
Data were collected on percentage Poa annua population at initiation o f treatments in May o f 1998 and at the end of
the season in November. An analysis o f variance was conducted on percentage Poa annua reduction in each plot.
The treated plots were also observed on a regular basis for any signs o f phytotoxicity (damage) from the treatments.
RESULTS
The results o f treatments at each site are listed in Table 1. Notice that on the line marked LSD 0.05, NS means
nonsignificant. Even though there appears to be treatment differences, these differences are due to chance because
o f the high degree o f variability among replications. Where a number occurs in this line, such as the 17 under the
Fort Dodge Fairway column, there are real differences among treatments. In this case, any treatment responses that
are at least 17 units apart are considered to be significantly different. The study was very successful at Fort Dodge

55

Herbicide and Growth Regulator Studies

Country Club and significant reductions o f Poa annua were observed in response to several treatments. Otter Creek
treatments on large plots were also effective in several cases. No treatment effects were observed at the end o f the
season at Hyperion and no data are listed for November, 1998 observations. In the spring o f 1999, however,
significant reductions in annual bluegrass were observed on plots treated with higher rates o f Prograss.
Small plot treatments were also very effective at Fort Dodge Country Club. Because o f mid-season flooding on the
small plots at Otter Creek, there were no significant treatment effects. Small plots at Hyperion actually showed an
increase in Poa annua populations in several treatments. The reason for this response is unknown.
At no times during the season were there any signs of phytotoxicity on any o f the plots at the three golf courses.

Table 1. Percentage reduction in Poa annua in response to Prograss and Primo, 1998.

ON

OO
ON
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OS
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tXQ
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73

£

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Uh

5
g

£

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'3
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£
C/3

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£

Uh

U h

a
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B
8
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0

17

22

14

0

5

39

0

9

2. Prograss EC+Sprint 330+46-0-0

.75 oz + 7.34 oz + .54 lb

19

38

60

14

79

62

3

+39

3. Prograss EC+Sprint 330+46-0-0

1.5 oz + 7.34 oz + .54 lb

53

74

82

0

35

73

18

+64

4. Primo EC+Sprint 330+46-0-0

.25 oz + 7.34 oz + .54 lb

11

22

14

39

24

60

5

0

5. Primo EC+Sprint 330+46-0-0

.5 oz + 7.34 oz + .54 lb

14

24

20

32

60

58

3

+26

6. Prograss EC+Sprint 330+46-0-0

.25 oz + 7.34 oz + .54 lb

13

17

17

6

13

49

5

+42

7. Prograss+Primo Sprint 330+46-0-0

.25 oz +.25 oz + 7.34 oz + .54 lb

15

24

11

7

63

55

10

+14

8. Prograss+Primo Sprint 330+46-0-0

.75 oz +.25 oz + 7.34oz + .54 lb

24

30

58

49

42

54

0

+55

9. Prograss+Primo Sprint 330+46-0-0

1.5 oz +.25 oz + 7.34 oz + .54 lb

60

90

79

54

95

69

38

+116

7.34 oz + .54 lb

19

19

28

19

36

46

3

+11

Q

Treatment
1. Control

10. Sprint 330 + 46-0-0
11. Prograss Alone

Rate/1000 fit2

O
Q

28

1.5 oz
17

LSD 0.05

4

21

There were no reductions in quality o f fairway grasses at any of the sites during the season.

56

S h
>>

X

+12

45
33

47

NS

12

58

Herbicide and Growth Regulator Studies

Effect of Beacon on the Germination of
Kentucky Bluegrass and Creeping Bentgrass - 1998 Report
B arbara R. Bingaman, N ick E. Christians, M ichael B. Faust, and M elissa C. M cD ade
In this study the effect o f CGA #136872 (Beacon) on seed germination and establishment o f Kentucky bluegrass and
creeping bentgrass was evaluated. This study started in 1997 and concluded in 1998 at the Iowa State University
Horticulture Research Station located north o f 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 o f 3.9%, a pH o f 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 carbon dioxide 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 o f water per plot which
translates to an application rate o f 3 gal/1000 ft2.
Treatments were applied in 1997. 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, 1997.
There was a heavy infestation o f weeds in the plots and border rows at the time o f 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
o f 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, 1997. 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 o f area per plot covered by each species.
Percentage cover data were taken in 1997 on October 9, October 14, and November 11 (Table 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.
Additional germination data were taken spring 1998. Percentage creeping bentgrass cover data were taken on April
22 and May 13, 1998 (Table 3). Data for Kentucky bluegrass were taken on May 13.
Data were analyzed with the Statistical Analysis System (SAS, version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference (LSD) test.
There were observable reductions in percentage cover o f creeping bentgrass on October 9 and 14, 1997 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 o f bentgrass when compared
with the untreated control. Although the ‘one day before seeding’ treatment o f 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).
Because o f the weather conditions in October 1997, 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 November 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 2 weeks before seeding at 40 g product/A (Table 2). These were unusual results
for the Kentucky bluegrass and observations will be made Spring 1998 to confirm these results.

57

Herbicide and Growth Regulator Studies

In 1998, there were no significant reductions in either creeping bentgrass or Kentucky bluegrass percentage cover but
there were numerical differences in bentgrass cover on both dates (Table 3). Percentage bentgrass cover was 10.0%
on April 22 and 13.3% on May 13 in plots treated with CGA #136872 1 day before seeding as compared to 40.0
and 43.3% in the untreated plots. Kentucky bluegrass cover was similar in all untreated and treated plots in May
1998.

Table 1. Percentage cover1 o f ‘Penneagle’ creeping bentgrass in the 1997 Carryover Seedling Study.

Material2

Rate
product/A.

Timing o f
application
(before seeding)

NA

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

October
9

October
14

November
11
0

Mean
cover

/

32
35
55
41
2 0 .0 g
40
45
73
53
54
2 0 .0 g
43
43
75
20.0 g
30
32
72
44
20.0 g
22
27
40
29
33
65
44
40.0 g
35
40.0 g
20
20
45
28
40.0 g
20
23
53
32
40.0 g
5
5
12
7
NS
NS
38
NS
L S D o .05
'Percentage cover was estimated as the area per plot covered by creeping bentgrass.
CGA #136872 was applied with SCOIL MSO at 0.25% VA/.
'Eight-weeks before seeding' materials were applied on July 14, '4-weeks' on August 15, '2-weeks' on August 28, and '
day' on September 11, 1997. Seeding took place on September 12, 1997.
NS == means are not significantly different at the 0.05 level.
1
2
3
4
5
6
7
8
9

Untreated Control
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872

Table 2. Percentage cover1o f ‘Award’ Kentucky bluegrass in the 1997 <Carryover Seedling Study.

Material2

Rate
product/A.

Timing of
application
(before seeding)

October
9

October
14

NA
20.0 g
20.0 g
20.0 g
20.0 g
40.0 g
40.0 g
40.0 g
40.0 g

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

November
11
• /o

1
2
3
4
5
6
7
8
9

Untreated Control
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872
CGA #136872

1 -1
53
32
48
25
35
50
40
35
40
(p > 0.06)
18

Mean

% cover

27
20
28
17
19
27
22
21
20

NS
NS
NS
LSD005
'Percentage cover was estimated as the area per plot covered by Kentucky bluegrass.
2CGA #136872 was applied with SCOIL MSO at 0.25% V/V.
'Eight-weeks before seeding' materials were applied on July 14, '4-weeks' on August 15, '2-weeks' on August 28, and Tday' on September 11, 1997. Seeding took place on September 12, 1997.
NS = means are not significantly different at the 0.05 level.

58

Herbicide and Growth Regulator Studies

Table 3. Spring 1998 percentage cover1 o f ‘Penneagle’ creeping bentgrass and ‘Award’ Kentucky bluegrass data for
_________ the 1997 Carryover Seedling Study.______________________________________________________________
Creeping
bentgrass____________

Material2

Rate
product/A.

Timing of
application
(before seeding)

April
22

May
13

Mean
cover

Kentucky
bluegrass
May
13

o/_
NA
40.0
41.7
11.7
NA
Untreated Control
43.3
53.3
11.7
CGA #136872
20.0 g
8 weeks
53.3
53.3
61.7
15.0
4 weeks
60.0
63.3
CGA #136872
20.0 g
20.0 g
2 weeks
60.0
56.7
11.7
CGA #136872
53.3
1 day
40.0
39.2
8.3
CGA #136872
20.0 g
38.3
40.0 g
53.3
53.3
53.3
6.7
8 weeks
CGA #136872
30.8
8.3
4 weeks
CGA #136872
40.0 g
28.3
33.3
CGA #136872
40.0 g
2 weeks
40.0
36.7
38.3
8.3
40.0 g
1 day
10.0
13.3
11.7
11.7
CGA #136872
NS
NS
NS
NS
LSDoos
‘Percentage cover was estimated as the area per plot covered by either creeping bentgrass or Kentucky bluegrass.
2CGA #136872 was applied with SCOIL MSO at 0.25% V/V.
'Eight-weeks before seeding' materials were applied on July 14, '4-weeks' on August 15, '2-weeks' on August 28, and '1day' on September 11, 1997. Seeding took place on September 12, 1997.
NS = means are not significantly different at the 0.05 level.
1
2
3
4
5
6
7
8
9

59

Herbicide and Growth Regulator Studies

Fairway Bentgrass Growth Regulator Study
Barbara R. Bingaman, M elissa C. McDade, and Nick E. Christians
'Penneagle' Creeping bentgrass maintained at fairway height (0.5 inches) was evaluated after treatment with Proxy
2SL (ethephon). This study was conducted at the Iowa State University Horticulture Research Station located north
o f Ames, IA.
The study was arranged as a randomized complete block with 3 replications. Individual plot size was 5 x 5 ft with 3
ft barrier rows between replications. Chipco Proxy was applied at 0 ,4.7, 6.0, and 12.0 fl oz/1000 ft2 (Table 1).
There were four applications at these rates made at four week intervals. The first application was made on June 22,
1998 on Penneagle established on a native (Nicollet) soil. Because o f construction in this area, the July, August, and
September applications were made on a relocated plot of'Penneagle' established on a soil composed o f 1 part peat, 1
part Nicollet soil, and 1 part sand. Subsequent applications on the relocated site were made on July 23, August 20,
and September 23. The Proxy was applied in 283 ml water/plot, which translates to an application rate o f 3 gal/1000
ft2. Applications were made at 30 psi with a carbon dioxide backpack sprayer equipped with Teejet® #8006 flat fan
nozzles.
Turf quality and color data were evaluated on a weekly basis following all applications and for six weeks following
the last application. Turf quality was based on color, uniformity, and turf density and was based on a 9 to 1 scale
with 9 = best, 6 = lowest acceptable, and 1 = worst quality. Visual observations o f phytotoxicity were made weekly
following all applications and for 6 weeks following the last application. Phytotoxicity was recorded as either
present or absent. Fresh clipping weights were taken on a weekly basis when there was sufficient growth. Mowing
height for collecting clippings was 0.5 in.
The data from the original and relocated plots were analyzed separately and are presented in discrete tables. All data
were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance (ANOVA)
procedure. Treatment effects were examined with Fisher's Least Significant Difference means separation test
(LSD).
Original Study
Turf quality data were taken from the original plot on June 30, July 7, July 15, July 23, and July 30 (Table 1).
Clippings were gathered on June 30, July 7, and July 30 (Table 2).
On July 7, the bentgrass surfaces in the original plot were examined using a Clegg Impact Soil Tester that measured
surface hardness. Readings of'hardness' were taken at 3 and 6 inch drop heights. Six readings per plot were taken
and the highest and lowest readings were deleted. The remaining 4 values were averaged for each plot and each
height. The means for each plot were analyzed (Table 3).
The only significant differences in turf quality were recorded on July 15 (Table 1). All treated bentgrass had poorer
quality than the untreated controls on July 15 but the quality was still above the lowest acceptable rating o f 6.0.
There were no statistical differences in clipping weights on any o f the collection dates (Table 2). On July 7, the
numerical differences between the treated and untreated bentgrass were quite large. The clipping weight o f turf
treated with Proxy 2SL at 12.0 fl oz/1000 ft2 was almost twice that o f the untreated controls and Proxy at the lower
rates produced at least a 150% increase in clippings as compared with untreated turf.
Measurements with the Clegg Impact Soil Tester showed very little difference in hardness o f the bentgrass surface
among the treatments (Table 3). Hardness was similar for treated and untreated turf at the 3 and 6 inch heights.
Relocated Study
Quality ratings were made for the relocated plot on August 5, August 12, August 20, August 27, September 4,
September 11, September 17, September 23, October 2, October 9, October 15, October 22, and October 30 (Table
4-5). Clippings were taken from the relocated plot on August 12, September 4, September 11, September 23, and
October 9 (Table 6).

60

Herbicide and Growth Regulator Studies

There were no differences in visual quality between treated and untreated bentgrass until October 9 (Table 4-5).
Significant reductions in quality were found in all treated bentgrass from October 9 through October 30. The quality
o f the treated turf during this period did not drop below the lowest acceptable rating o f 6.0.
Clipping weights were not significantly reduced by the treatments as compared with the untreated controls at any of
the test dates (Table 6).

Table 1. Visual quality1 of'Penneagle' creeping bentgrass treated in the 1998 Fairway Bentgrass Growth Regulator
Study for June 30 through July 30 (on original site).
Rate
June
July
Material
(fl oz/1000 ft2)
30
7
1
2
3
4

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

9.0
7.0
7.0
7.0

8.0
8.0
8.0
8.0

July
15

July
23

July
30

Mean

9.0
7.7
8.0
8.0

8.0
8.0
8.0
8.0

8.0
8.0
8.0
8.0

8.4
7.7
7.8
7.8

_
_
_
0.6
L S D o.o5
1Visual quality assessments were made using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
-- = Fisher's Least Significant Difference means separation test is not valid for these data.

0.1

Table 2. Fresh clipping weights1 o f ’Penneagle’ creeping bentgrass treated in the 1998 Fairway Bentgrass Growth
Regulator Study (on original site).
July
30

Mean
weight

22.0
34.1
33.2
42.7

23.4
23.6
24.2
23.9

19.2
23.6
25.7
27.5

NS
NS
LSD 0 0 5
‘Fresh clipping weights represent grams fresh tissue.
Applications were made on June 22.
-- = Fisher's Least Significant Difference means separation test is not valid for these data.

NS

NS

Material

Rate
(fl oz/1000 ft2)

June
30

July
7

rr

5

1
2
3
4

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

12.1
13.0
19.7
15.8

Table 3. Hardness of'Penneagle' creeping bentgrass surfaces as measured with the Clegg Impact Soil Tester in the
1998 Fairway Bentgrass Growth Regulator Study (on original site).
3 inch
Rate
height
Material
(fl oz/1000 ft2)
1
2
3
4

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

LSD 0 0 5
NS = means are not significantly different at the 0.05 level.

61

6 inch
height

28.8
26.8
28.8
27.9

42.5
50.3
44.1
46.0

NS

NS

Herbicide and Growth Regulator Studies

Table 4. Visual quality1 of'Penneagle' creeping bentgrass treated in the 1998 Fairway Bentgrass Growth Regulator

1
2
3
4

Study for August 5 - September 17 (on relocated site).
Aug
Aug
Rate
Material
(fl oz/1000 ft2)
5
12

Aug
20

Aug
27

Sept
4

Sept
11

Sept
17

9.0
9.0
9.0
9.0

6.0
6.0
6.0
6.0

7.0
7.0
7.0
7.0

8.0
8.0
8.0
8.0

6.0
6.0
6.0
6.0

7.0
7.0
7.0
7.0

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

9.0
9.0
9.0
9.0

~
-~
L S D o.05
17777
Visual
quality assessments were made using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
-- = Fisher's Least Significant Difference means separation test is not valid for these data.

-

Table 5. Visual quality1 of'Penneagle' creeping bentgrass treated in the 1998 Fairway Bentgrass Growth Regulator
Study for September 23 - October 30 (on relocated site).
Sept
Oct
Rate
(fl oz/1000 ft2)
23
2
Material
1
2
3
4

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

9.0
9.0
9.0
9.0

8.0
8.0
8.0
8.0

Oct
9

Oct
15

Oct
22

Oct
30

Mean

9.0
7.3
7.0
6.3

9.0
7.0
7.3
7.0

8.0
6.0
6.0
6.0

8.0
6.7
6.3
7.0

8.4
7.7
7.8
7.8

___
___
0.7
1.7
0.6
1.0
LSDo.05
Visual quality assessments were made using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
—= Fisher's Least Significant Difference means separation test is not valid for these data.

0.1

Table 6. Fresh clipping weights1 of'Penneagle' creeping bentgrass treated in the 1998 Fairway Bentgrass Growth
Regulator Study (on relocated site).
Rate
(fl oz/1000 ft2)
Material
1
2
3
4

Untreated control
Chipco Proxy 2SL
Chipco Proxy 2SL
Chipco Proxy 2SL

N/A
4.7
6.0
12.0

Aug
12

Sept
4

Sept
11

Sept
23

Oct
9

Oct
30

Mean

1.0
1.4
1.4
1.6

63.7
62.3
76.7
98.3

25.3
30.0
26.0
42.0

rr
fe
17.5
13.8
16.8
12.9

22.8
23.5
24.6
21.9

20.0
15.7
13.5
16.5

25.0
24.4
26.5
32.2

NS

NS

NS

NS

NS

NS
NS
LSDo.05
^resh clipping weights represent grams fresh tissue.
Applications were made on July 23, August 20, and September 23.

62

Herbicide and Growth Regulator Studies

Effect of Trinexapac-ethyl on Kentucky Bluegrass Sod Establishment
Barbara R. Bingaman, Melissa C. McDade, Michael B. Faust, and NickE. Christians
The growth regulator, Trinexapac-ethyl (Primo), was screened for effects on the establishment o f ‘Majestic’
Kentucky bluegrass sod. This study was conducted at the Iowa State University Horticulture Research Station north
o f Ames, Iowa in a ‘Majestic’ Kentucky bluegrass area where a similar sod study was conducted in 1996. The sod
was cut in the opposite direction as the previous study to offset any possible carryover effects. The soil in this area
was a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with 4.5% organic matter, a pH o f 7.12, 4 ppm P, and 93
ppm K.
Rainfall was sporadic throughout the duration o f this study. Supplemental irrigation was used to maintain the
bluegrass in good growing condition and to facilitate sod root development.
Individual plots were 5 x 5 ft and four replications were conducted. There were six Primo treatment regimes and an
untreated control. All Primo applications were made at the label rate for Kentucky bluegrass (0.75 fl oz/1000 ft2).
The timing o f applications was in reference to sod cutting and establishment. The treatments included an
application o f Primo six and two weeks before sod establishment, two and six weeks after, two weeks before, two
weeks after, six and two weeks before plus two and six weeks after, and two weeks before plus two weeks after
(Table 1).
Primo 1EC was applied at 30 psi with a carbon dioxide powered backpack sprayer equipped with Teejet® #8006 flat
fan nozzles. The Primo was mixed in 283 ml o f water which translates to an application rate o f 3 gal/1000 ft2.
The six weeks before sod establishment treatments were applied on June 10, 1998 and the two weeks before were
made on July 9. The two weeks after treatments were applied on August 5 and the six weeks after sod establishment
treatments were made on September 2.
The bluegrass on the entire experimental plot was cut on July 23 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 that were constructed with
bottoms o f 18 mesh screen. The pieces were trimmed and transplanted into the frames and 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 o f four quadrants. The study was watered thoroughly upon completion and was watered on a regular
basis to prevent the sod from drying.
Root development was measured using a hydraulic sod pulling apparatus equipped with steel cables that could be
attached to screw hooks on the corners o f wooden frames (Figure 1). The tensile strength required to ‘pull’ a frame
from the soil was measured in pounds per square inch (psi). One frame per plot was sampled on each o f four
collection dates beginning on August 4, two weeks after sod establishment. The other frames were harvested at twoweek intervals on August 18, September 2, and September 16 (Table 4).
Visual quality data were taken on a weekly basis from June 16 through September 16 (Tables 2 and 3). Visual
quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
Data were analyzed using the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Means were compared with Fisher’s Least Significant Difference (LSD) means separation
test.
On June 24 and July 17, numerical differences in visual quality were found. The Primo treated plots showed a slight
phytotoxicity on June 24, two weeks after treatment. On July 17, the bluegrass that was treated on both June 10 and
July 9 (treatments 2 and 6) had a better color than the other treated and untreated turf. The bluegrass treated on July
9 only (treatments 4 and 7) showed a slight phytotoxicity. The phytotoxicity was not detectable after a few days.
There were no differences in turf quality after July 17 (Table 2).

63

Herbicide and Growth Regulator Studies

There were numerical tensile strength differences in sod harvested on August 4, August 18, and September 2 but the
treatment effects were not statistically different (Table 4). On September 16, the sod treated with Primo 1EC two
weeks before establishment had significantly more root development than sod treated two and six weeks before, two
weeks before and after, sod treated two and six weeks after, and the untreated control. Root development was
similar for sod treated six and two weeks before and two and six weeks after establishment and sod treated two
weeks after establishment. The data from September 16 show that root tensile strength was 30% higher for sod
treated with Primo 1EC two weeks before establishment than for untreated sod.

Table 1. Timing o f Primo applications for the 1998 Sod Establishment Study
Timing o f applications*
6 weeks
2 weeks
2 weeks
6 weeks
Material
Rate /plot
before
before
after
after
1 Untreated control
NA
NA
NA
NA
NA
2
0.75 oz
yes
Primo 1EC
yes
no
no
3
0.75 oz
no
no
Primo 1EC
yes
yes
4
0.75 oz
no
Primo 1EC
yes
no
no
0.75 oz
5
Primo 1EC
no
no
yes
no
6
0.75 oz
Primo 1EC
yes
yes
yes
yes
7
0.75 oz
Primo 1EC
no
yes
yes
no
*Timing is in reference to cutting of sod. Six and two weeks before cutting and two and six weeks after establishment. Sod
Harvested on July 23. Six weeks before harvest applications made June 10, 2 weeks before on July 9, 2 weeks after on August 5,
and 6 weeks after on September 2.
Frames were pulled on August 4, August 18, September 2, and September 16.

Table 2. Visual quality1 o f Kentucky bluegrass in the 1998 Sod Establishment Study (June 16 - August 4).
June
June
July
July
June
July
August
Material
16
24
30
7
17
4
29
1
Untreated control
8.0
8.0
7.0
7.0
6.3
7.0
7.0
2
8.0
7.0
7.5
5.0
7.0
7.0
Primo 1EC
7.0
8.0
8.0
7.0
3
Primo 1EC
7.0
6.3
7.0
7.0
4
8.0
6.0
7.0
6.0
Primo 1EC
7.0
7.0
7.0
5
Primo 1EC
8.0
8.0
7.0
7.0
6.5
7.0
7.0
6
Primo 1EC
8.0
5.0
7.0
7.0
6.8
7.0
7.0
7
Primo 1EC
8.0
8.0
7.0
7.0
6.0
7.0
7.0
NS
NS
~
-~
LSD0.05
11Visual
wquality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
NS = means are not significantly different at the 0.05 level.
—= means comparison tests are not applicable to these data.

Table 3. Visual quality1 o f Kentucky bluegrass in the 1998 Sod Establishment Study (August 11 - September 16).
Sept
Sept
August
August
August
Sept
Mean
11
Material
18
26
2
9
16
quality
1 Untreated control
7.0
8.0
7.0
7.0
8.0
9.0
7.4
2
8.0
8.0
Primo 1EC
7.0
7.0
7.0
9.0
7.3
3
Primo 1EC
7.0
7.0
8.0
8.0
7.0
9.0
7.4
4
Primo 1EC
7.0
7.0
7.0
8.0
8.0
9.0
7.2
5
7.0
8.0
Primo 1EC
7.0
7.0
8.0
9.0
7.4
6
Primo 1EC
7.0
8.0
8.0
7.0
7.0
9.0
7.2
7
Primo 1EC
7.0
7.0
7.0
8.0
8.0
9.0
7.4
0.1
LSD 0.05
I77T
Visual
quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
NS = means are not significantly different at the 0.05 level.
~ = means comparison tests are not applicable to these data.

64

Herbicide and Growth Regulator Studies

Table 4. Root tensile strength and knitting o f Kentucky bluegrass sod growing in frames in the 1998 Sod
_________ Establishment Study as measured by the number of pounds per square inch (psi) to pull 1 ft2 frames.
August
August
September
September
Mean
__________ Material______________ 4______________ 18______________ 2______________ 16___________ strength
1
2
3
4
5
6
7

Untreated control
Primo 1EC
Primo 1EC
Primo 1EC
Primo 1EC
Primo 1EC
Primo 1EC
LSDo.os

57.5
37.5
53.8
18.8
23.8
35.0
33.8
NS

252.5
285.0
270.0
298.8
272.5
315.0
243.8
NS

--------- p si-------385.0
395.0
300.0
346.3
341.3
331.3
346.3
NS

355.0
385.0
382.5
460.0
401.3
415.0
395.0
63.0
P > F = 0.07

NS = means are not significantly different at the 0.05 level.
Frames were pulled on August 4, August 18, September 2, and September 16.

Figure 1. The hydraulic sod pulling device used to measure root tensile strength o f the sod in the 1998 Sod
Establishment Study.

262.5
275.6
251.6
280.9
259.7
274.1
254.7
NS

Herbicide and Growth Regulator Studies

Effects of Trinexapac-ethyl on
an n u a Populations
in Green Height Creeping Bentgrass
B arbara R. Bingaman, M elissa C. M cDade, an d N ick E. C hristians
This study was designed to evaluate the growth regulator, Trinexapac-ethyl (Primo), for Poa annua control in
creeping bentgrass maintained at green height following a fall conversion program. This study was conducted on a
practice green at Veenker Memorial Golf Course in Ames, IA. The turf in this area consisted o f creeping bentgrass
with an infestation o f Poa annua that ranged from 50 to 80% through the 1998 season.
The experimental design was a randomized complete block. Individual plot size was 5 x 5 ft with 3 replications.
Treatments were applied to the same plots as in 1997. Primo 1EC was used at 0.3 fl oz/1000 ft2 monthly from May
through September. Initial application was made on May 14 and subsequent applications were made on June 17,
July 14, August 19, and September 23, 1998. Primo 1EC was mixed with 283 ml o f water (3 gal/1000 ft2) and was
applied at 30 psi with a carbon dioxide 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.
Visual turf quality data were taken from April 22 through October 27, 1998 (Tables 1 and 2). Visual turf quality
was assessed with a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst turf quality. On each o f these
dates, the plots were checked for phytotoxicity. Phytotoxicity was assessed using a 9 to 1 scale with 9 = no
damage, 6 = moderate tip bum (browning) and 4 = severe tip bum.

Poa annua populations were estimated as the percentage o f area per plot covered by Poa annua. Percentage cover
data were taken on May 13, May 28, June 12, July 14, July 30, August 12, August 26, September 10, September
22, October 1, October 14, and October 27 (Table 3 and 4). Poa annua control is represented by calculating
reductions in percentage cover as compared with the untreated control (Tables 5 and 6).
On May 16, 1998, the practice green was core aerified and topdressed. The effects o f Primo on the recovery from
this procedure were examined on May 28 by estimating the percentage bentgrass recovery. Estimations were based
on bentgrass growth into the 'core areas'.
All data were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Treatment effects were compared with Fisher's Least Significant Difference (LSD) test.
In general, quality differences between the treated and untreated bentgrass were found throughout the season
approximately 14 days following Primo applications (Tables 1 and 2). In October, treated bentgrass consistently
was darker green than the untreated bentgrass. No phytotoxicity was found.
Primo treated bentgrass had less Poa annua than the untreated control from May 28 through October 27 (Tables 4
and 5). The differences in percentage cover were significant on all data collection dates except July 30 and August
26. Mean percentage Poa annua cover also was significantly lower in treated bentgrass than untreated. Significant
reductions in Poa annua cover ranged from 22.7 to 63.3% as compared with the untreated controls (Tables 5 and 6).
The mean reduction in Primo treated bentgrass was 47.6%.
Primo treated bentgrass recovered from core aerification significantly slower that untreated bentgrass (P > F =
0.0339). On May 28, recovery in the Primo treated bentgrass was 65% as compared with 88.3% recovery for
untreated bentgrass. By June 12, recovery was 100% for both treated and untreated bentgrass.
Additional percentage cover data will be taken spring 1999 beginning at greenup. Winter damage also will be
assessed spring 1999.

66

Herbicide and Growth Regulator Studies

Table 1. Visual quality1 o f green height creeping bentgrass treated for the 1997-98 Green
Conversion Study (April 22 - August 12, 1998).
Rate
fl otJ
A p r il
May
June
June
Material
May
22
30
1000 ft2
28
12
13
N /A
6.0
7.0
6.7
7.0
1 Untreated control
6.7
8.0
0.3
6.0
7.0
8.0
2 Primo 1EC2
7.0
1.4
NS
NS
L S D o.os

Height Poa annua

July
14
7.0
7.0
-

July
30
7.0
7.0
-

Aug
12
7.0
7.0
-

‘Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
2Primo 1EC applications were made on May 14, June 17, July 14, August 19, and September 23.
NS = Means are not significantly different at the 0.05 level.
— = Means separation tests are not valid for these data.

Table 2. Visual quality1 o f green height creeping bentgrass treated 1998 Green Height Poa annua Conversion

Material
1 Untreated control
2 Primo2
L S D o os

Ur:...., —

Rate
fl oz/
1000 ft2
N/A
0.3

- ________ ^ ..

Aug
26
7.0
8.0
-

Sept
10
7.0
7.0
-

Oct
1
7.0
9.0
-

Sept
22
7.0
7.0
-

Oct
14
7.0
9.0
-

Oct
27
6.3
9.0
1.4

Mean
quality
6.8
7.6
0.5

Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
NS = Means are not significantly different at the 0.05 level.
— = Means separation tests are not valid for these data.

Table 3. Percentage Poa annua cover1 in creeping bentgrass treated for the 1997-98 Green Height Poa annua
Conversion Study (May 13 - August
' — n — ~ 26, 1998).
j
Rate
July
July
August
August
May
June
May
Material
fl oz/
12
14
30
26
12
13
28
1000 ft2
0 /n

1 Untreated control
2 Primo2

N/A
0.3

46.7
53.3
NS

73.3
56.7
7.2
L S D o os
" T t l _______ __________ _____ L~
‘These values represent the area per plot covered by Poa annua.

58.3
21.7
28.7

78.3
43.3
12.4

51.7
18.3
NS

46.7
20.0
28.7

50.0
25.0
NS

2Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
NS = Means are not significantly different at the 0.05 level.

Table 4. Percentage Poa annua cover1 in creeping bentgrass treated for the 1997-98 Green Height Poa annua
_________ Conversion Study (September 10 - October 27, 1998).________________________________________
Rate
Oct
Mean
Oct
Oct
Sept
fl oz/
Sept
Material
Cover
27
14
1
10
1000 ft2
22

OA
N/A
0.3

43.3
23.3
12.4

46.7
21.7
12.4
LSD 005
1^1_____
1__________
_ area per plot covered by Poa annua.
‘These values
represent. the
1 Untreated control
2 Primo2

50.0
18.3
7.2

53.3
21.7
28.7

2Primo applications were made on May 14, June 17, July 14, August 19, and September 23.

67

63.3
23.3
32.9

46.7
20.0
7.2

Herbicide and Growth Regulator Studies

Table 5. Reductions in percentage Poa annua cover1 in creeping bentgrass treated for the 1997-98 Green Height
_________ Poa annua Conversion Study (May 13 - August 26, 1998).______________________________________
Rate
June
July
July
August
Material
fl oz/
May
May
August
1000 ft2
12
14
30
12
13
28
26
%
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
22.7
44.7
62.8
64.5
57.2
50.0
NS
9.8
15.9
17.8
18.5
20.5
24.8
L S D o os
‘These values represent reductions in the area per plot covered by Poa annua ;as compared with the untreated controls.
Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
NS = Means are not significantly different at the 0.05 level.
1 Untreated control
2 Primo2

N/A
0.3

Table 6. Reductions in percentage Poa annua cover1in creeping bentgrass treated for the 1997-98 Green Height
Poa annua Conversion Study (September 10 - October 27, 1998).
Rate
fl oz/
Sept
Material
Oct
Oct
Oct
Sept
Mean
1000 ft2
10
22
1
14
27
Cover
%
0.0
0.0
0.0
0.0
46.1
53.6
63.3
59.3
28.7
14.3
27.0
26.6
LSD o.05
‘These values represent reductions in the area per plot covered by Poa annua as compared with the
2Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
1 Untreated control
2 Primo2

N/A
0.3

68

0.0
0.0
63.1
47.6
30.0
13.2
untreated controls.

Herbicide and Growth Regulator Studies

Effects of Trinexapac-ethyl on
an nu a Populations
in Fairway Height Creeping Bentgrass
Barbara R. Bingaman, Melissa C. McDade, and Nick E. Christians
The growth regulator, Trinexapac-ethyl (Primo), was evaluated for P o a an n u a control in creeping bentgrass
maintained at fairway height following a fall conversion program in this study. It was conducted on a fairway height
area surrounding a practice green at Veenker Memorial Golf Course in Ames, IA. The turf in this area consisted of
perennial ryegrass with an infestation o f P o a annua that ranged from 20 to 0% through the 1998 season. The
experimental design was a randomized complete block. Individual plot size was 5 x 5 ft with 3 replications. The
plot was overseeded with perennial ryegrass in September 1998.
Treatments were applied to the same plots as in 1997. Primo 1EC was used at 0.5 fl oz/1000 ft2 monthly from May
through September. Initial application was made on May 14 and subsequent applications were made on June 17,
July 14, August 19, and September 23, 1998. Primo 1EC was mixed with 283 ml o f water (3 gal/1000 ft2) and was
applied at 30 psi with a C 0 2 backpack sprayer equipped with Teejet® #8006 Teeject 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.
Visual turf quality data were taken from April 22 through October 27 (Tables 1 and 2). Visual turf quality was
assessed with a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst turf quality. On each o f these dates,
the plots were checked for phytotoxicity. Phytotoxicity was assessed using a 9 to 1 scale with 9 = no damage, 6 =
moderate tip bum (browning) and 4 = severe tip bum.
All data were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Treatment effects were examined with Fisher's Least Significant Difference means separation
test (LSD).
P o a an n u a populations were estimated as the percentage o f area per plot covered by P o a annua. Percentage cover

data were taken on May 13, May 28, June 12, June 30, July 14, July 30, August 12, August 26, September 10,
September 22, October 1, October 14, and October 27 (Tables 3 and 4). Additional percentage cover data will be
taken spring 1999 beginning at greenup. Winter damage also will be assessed spring 1999.
Primo treated ryegrass had a darker green color than the untreated ryegrass on May 28 and June 12 approximately 2 4 weeks following the first Primo application (Table 1). No further quality differences were noted through the season
until October 27 (Table 2). No phytotoxicity was found.
Primo treated ryegrass had less P o a annua than the untreated control from May 13 through July 30 (Tables 3 and
4). The reduction in P o a an n u a was significantly different on May 13. The reductions were numerically different
from May 28 through July 30. By August 19, the P o a annua had all died in the experimental plot. Close
examinations o f the plot were made from August 19 through October 27 and no P o a annua was found.

69

Herbicide and Growth Regulator Studies

Table 1. Visual quality1 o f perennial ryegrass treated for the 1997-98 Fairway Height P o a a n n u a Conversion Study
(April 22 - August 12, 1998).
Rate
fl oz/
April
May
May
June
June
July
July
Material
1000 ft2
22
12
30
14
30
13
28
N/A
9.0
7.3
9.0
9.0
9.0
1 Untreated control
9.0
7.3
9.0
0.5
9.0
9.0
8.7
9.0
9.0
8.7
2 Primo 1EC2
1.4
1.4
L SD oos
‘Visual quality was assessed using a 9 to 1 scale with 9 - best, 6 = lowest acceptable, and 1 = worst quality.
2Primo 1EC applications were made on May 14, June 17, July 14, August 19, and September 23.
—= Means separation tests are not valid for these data.

Aug
12
9.0
9.0
-

Table 2. Visual quality1 o f perennial ryegrass treated 1998 Fairway Height P o a an n u a Conversion Study (August
26 - October 27, 1998).
Rate
fl oz/
Aug
Oct
Oct
Material
Sept
Sept
Oct
Mean
1000 ft2
26
14
10
22
1
27
quality
9.0
N/A
9.0
9.0
7.0
9.0
1 Untreated control
9.0
8.6
0.5
9.0
9.0
9.0
9.0
2 Primo2
9.0
9.0
8.9
0.2
LSDoos
" T T T :----------;------------ 7 7 ---------------------------------- ‘Visual quality was assessed using a 9 to 1 scale with 9 - best, 6 = lowest acceptable, and 1 = worst quality.
2Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
— = Means separation tests are not valid for these data.

Table 3. Percentage P o a an n u a cover1 in perennial ryegrass treated for the 1997-98 Fairway Height P o a an n ua
_________ Conversion Study (May 13 - August 26, 1998).__________________________________________________
Rate
Material
fl oz/
May
May
June
June
July
July
Aug
Aug
1000 ft2
13
28
12
30
14
30
19
26
%

63.3
16.0
15.0
33.3
5.0
3.7
24.8
NS
NS
L SD oos
‘These values represent the area per plot covered by P o a annua.
2Primo applications were made on May 14, June 17, July 14, August
NS = Means are not significantly different at the 0.05 level.
—= Means separation tests are not valid for these data.
1 Untreated control
2 Primo2

N/A
0.5

3.7
1.7
NS

0.7
0.3
NS

0.7
0.3
NS

0.0
0.0
-

0.0
0.0
-

19, and September 23.

Table 4. Percentage P o a an n u a cover1 in perennial ryegrass treated for the 1997-98 Fairway Height P o a an n ua
_________ Conversion Study (September 10 - October 27, 1998).___________ ________________________________
Rate
fl oz/
Sept
Sept
Oct
Oct
Oct
Mean
__________ Material__________1000 ft2
10_________ 22_________ 1__________14_________27
Cover

------------------------ % -----------------------1 Untreated control
N/A
0.0
0.0
0.0
0.0
2 Primo2
0.5
0.0
0.0
0.0
0.0
LSD q.05
—
—
‘These values represent the area per plot covered by P o a annua.
2Primo applications were made on May 14, June 17, July 14, August 19, and September 23.
-- = Means separation tests are not valid for these data.

70

0.0
0.0
—

8.3
3.7
NS

Turfgrass Disease Research

Evaluation o f Fungicides for C ontrol o f D ollar Spot
on C reeping Bentgrass - 1998
Mark L. Gleason, Nick E. Christians, and James R. Dickson
Trials were conducted at the Iowa State University Horticulture Research Farm near Gilbert, 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 o f 5 gal/1,000 ft2. The experimental design was a randomized complete block with four
replications. All plots measured 4 ft x 5 ft. Five days after inoculation o f the entire plot with rye grain infested with
the dollar spot pathogen, fungicide applications began on Junel2. Subsequent applications were made on June 19,
June 26 and on July 3, 10, 17, and 24.
Dollar spot symptoms were first observed on June 26. Disease development on untreated check plots was light on
29 Jun and moderately severe on July 10 and 16. Most, but not all, fungicide treatments exhibited significantly
(LSD, P=0.05) less disease than the untreated check. Phytotoxicity (browning o f tips o f grass blades) on plots
treated with AMY 300 became progressively worse during July, and was more severe at the 2 oz than the 1 oz rate.
Table 1. 1998 Dollar Spot Trial at ISU Horticulture Station._______________ ________________________
Interval
Trt Product

(days)

Rate/1,000 ft2

1

Mean % Plot Diseased
June 29

July 10

August 25

--

4.0

17.5

22.5

14

0.0

0.0

0.0

Chipco 26 GT

2 oz

+ Cleary’s 3336 F

2 fl oz

3

Cleary 3336 50 WP

2 oz

14

0.0

0.0

0.0

4

Spectro 90 WDG

4 oz

14

0.0

0.0

0.0

5

Spectro 90 WDG

8 oz

14

1.5

0.0

0.0

6

WAC 75

5 oz

14

0.0

0.0

0.0

7

WAC 76

5.3 oz

14

0.0

0.0

0.0

8

Thalonil 90 DF

3.5 oz

14

2.2

2.8

4.0

9

TRA-0232

3.5 oz

14

2.1

4.8

5.8

10

BAS 505 50 DF

0.11 oz

14

0.2

0.3

0.0

11

BAS 505 50 DF

0.14 oz

14

0.3

0.1

0.3

12

BAS 505 50 DF

0.18 oz

14

0.1

0.0

0.0

13

BAS 505 50 DF

0.18 oz

28

0.0

1.5

1.9

14

BAS 505 50 DF

0.26 oz

28

0.1

1.1

1.2

15

BAS 510 4.17 SC

0.11 fl oz

14

2.8

13.0

14.5

16

BAS 510 4.17 SC

0.14 fl oz

14

2.4

0.4

0.2

17

BAS 510 4.17 SC

0.18 fl oz

14

4.1

3.3

1.8

18

BAS 510 4.17 SC

0.18 fl oz

28

3.6

18.0

20.8

19

BAS 510 4.17 SC

0.26 fl oz

28

1.5

8.0

9.0

20

Banner MAXX 1.24 MC

1.0 fl oz

21

0.0

0.0

0.0

+ Thalonil 90 DF

6 oz

Heritage 50 WP

0.2 oz

14

2.3

3.3

3.7

+ Daconil Ultrex

3.8 oz

2

21

71

Turfgrass Disease Research

Interval
Trt Product

Rate/l ,000 ft2

22

Daconil Ultrex

3.8 oz

14

23

Eagle 50 WP

0.5 oz

14

Daconil Ultrex

3.8 oz

14

24

Eagle 50 WP

1.2 oz

25

ZeroTol

0.5 fl oz/80 fit2

26

Bayleton 50 DF

0.25 oz

+ Daconil Ultrex

1.82 oz

Lynx 45 WP

0.28 oz

+ Daconil Ultrex

1.82 oz

28

Bayleton 50 DF

29

(days)

Mean % Plot Diseased
June 29

July 10

August 25

2.0

3.3

8.3

1.1

0.0

0.0

28

0.5

3.1

2.0

7

4.0

18.3

21.3

14

2.4

0.3

0.3

14

0.9

0.1

0.0

0.25 oz

14

1.3

0.7

0.3

Lynx 45 WP

0.28 oz

14

0.3

0.1

0.0

30

A M V 300

1 oz

14

3.8

12.5

18.8

31

A M V 300

2 oz

14

3.5

17.5

20.5

32

UCC-A1562 20 SC

1 fl oz

21

1.0

0.3

2.3

33

UCC-A1562 20 SC

4 fl oz

21

0.1

0.3

0.0

34

UCC-A1562 20 SC

8 fl oz

21

0.0

0.0

0.0

35

Heritage 50 WG

0.4 oz

21

1.4

0.0

4.1

1.8

8.9

8.4

4th and later sprays:

27

Least Significant Difference3
aP = 0.05. n = 4 replications.

72

Turfgrass Disease Research

Evaluation of Fungicides for Control of Pythium Blight on Perennial Ryegrass - 1998
Mark L. Gleason
Trials were conducted on perennial ryegrass, maintained at fairway height, at the Turfgrass Research Area o f the ISU
Horticulture Research Farm near Gilbert, IA. The entire plot was inoculated on June 23 and August 7 with rye
grain infested with isolates o f Pythium aphanidermatum. NOTE: The grain used for the June 23 inoculation was
infested with two isolates o f P. aphanidermatum, one o f which was resistant to metalaxyl. The grain used for the
August 7 inoculation was infested with four isolates o f P. aphanidermatum, two o f which were resistant to
metalaxyl.
Immediately after the infested grain was applied, the inoculated area was covered by Seedguard geotextile fabric for
several days (June 23-24 and August 7-10). Fungicide treatments were applied after the cover was removed.
Fungicides were applied with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1,000 ft2. Fungicide
applications after the first inoculation were made on June 25, then repeated at specified intervals on July 6, 9, 16,
and 23. A single fungicide application, on August 14, was made after the second inoculation.
Weather conditions were conducive to Pythium blight during several periods after the June inoculation, but disease
pressure was slight during June and July. Pythium blight symptoms appeared two weeks after the second
inoculation. Disease development on August 25 was moderate. Ten treatments had significantly (LSD, P=0.05)
less disease than the untreated check. No phytotoxicity was observed in any o f the plots.

Table 1. 1998 Pythium blight trial on perennial ryegrass (fairway height).
Trt

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

BAS 500 2.09 EC
Subdue MAXX
Subdue MAXX
B and 6 EC
Aliette Signature
Heritage 50 WG
Subdue MAXX
+Banol
Subdue MAXX
+ Aliette Signature
Subdue MAXX
+ Aliette Signature
Heritage 50 WG
Heritage 50 WG
Heritage 50 WG
Banol 6 EC
B and 6 EC
+ Fore FF
B an d 6 EC
+ Heritage 50 WG
Subdue MAXX
+ Fore F
Subdue MAXX
+ Heritage 50 WG
Aliette Signature 80 WP
S-8172
S-8174
+ S-5223
S-7248
S-7248
UCC-A1562 20 SC
UCC-A1562 20 SC
UCC-A1562 20 SC
Least Significant Difference3

Rate/1,000 ft2
—
0.7 fl oz
1 fl oz
0.5 fl oz
1.6 oz
4.0 oz
0.2 oz
0.5 oz
1.6 oz
0.5 oz
4.0 oz
0.5 oz
2.0 oz
0.4 oz
0.4 oz
0.7 oz
2 fl oz
1 fl oz
6.4 fl oz
1 fl oz
0.2 oz
0.5 oz
6.4 fl oz
0.4 fl oz
0.2 fl oz
8 oz
6 fl oz
2 fl oz
4.5 oz (add 1st)
20.5 oz
41 oz
1 fl oz
4 fl oz
8 fl oz

aP = 0.05. n = 4 replications

73

Interval
(days)
—
14
14
14
14
14
14
14

Mean number o f infection centers
June 29
July 10
August 25
0.0
0.0
8.75
0.0
0.0
3.75

0.0
0.0
0.0
0.0
0.0
0.0

0.0

14

0.0

0.25

0.0

14

0.0

0.0

0.0

10
14
14
14
14

0.0
0.0
0.0

2.5
4.5
4.0

0.0

0.0
0.0
0.0
0.0
0.0

14

0.0

0.0

5.0

14

0.0

0.0

2.75

14

0.25

0.0

7.25

14
14
14

0.0
0.0

0.25

0.0

0.0
1.0

0.75

0.25

0.5

14
14
14
14
14

0.0
0.0

0.0
0.0

0.25
0.25

0.25
0.25

0.0

0.0

0.38

0.34

0.5
1.5
0.5
5.25
8.5
7.14

0.25

0.25

0.0
0.0
0.0
0.0

0.0
1.0
1.25

0.0
0.75
2.5

1.0
1.0

Turfgrass Disease Research

Evaluation o f Fungicides for C ontrol o f
Brown Patch in C reeping B entgrass - 1998
MarkL. Gleason
Trials were conducted at Veenker Memorial Golf Course on the campus o f 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 o f 5 gal/1,000 ft2. The experimental design was a randomized complete block with four replications.
All plots measured 4 ft x 5 ft. All plots were bordered on opposite sides by 1-fit-wide strips o f untreated turf in order
to help create uniform disease pressure.
Fungicide applications began on May 22 (Bio-Trek treatments only). The remainder o f the treatments received the
first application on June 10. Subsequent applications were made on June 17, 19, and 24; and July 1, 8, 15, and 22.
Brown patch symptoms were first observed on June 29. 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%) - was light on June 29 and
moderate on July 10 and 22. Most, but not all, fungicide treatments exhibited significantly (LSD, P=0.05) less
disease than the untreated check.
Phytotoxicity (browning o f tips o f grass blades) on plots treated with AMV 300 became progressively worse during
July, and was more severe at the higher rate o f product.

Table 1, 1998 Brown Patch Trial - WOI creeping bentgrass greens, Veenker Memorial Golf Course, ISU.
Interval
Trt
1
2

3

4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

Product
Bio-Trek G
Bio-Trek G
Bio-Trek WP
Heritage
Bio-Trek G
Bio-Trek G
Bio-Trek WP
Heritage
3336 50 WP
Spectro 90 WDG
WAC 75
WAC 76
Thalonil 90 DF
TRA-0232
Thalonil 90 DF
TRA-0232
BAS 500 2.09 EC
BAS 505 DF
CGA 279202 50 WG
CGA 279202 50 WG
CGA 279202 50 WG
+ Banner MAXX
Chipco 26 GT 2 SC
EXP 10830A 4.17 SC*
EXP 10830A 4.17 SC*

Rate/1,000 ft2
1.5 lb
1.5 lb
6 oz
0.2 oz
1.5 lb
1.5 lb
3.0 oz
0.2 oz
4 oz
8 oz
5 oz
5.3 oz
3.5 oz
3.5 oz
3.5 oz
3.5 oz
0.42 fl oz
0.21 oz
0.1 oz
0.15 oz
0.1 oz
1 fl oz
4 fl oz
0.3 fl oz
0.6 fl oz

(days)
—
late May
4 wks later
10 days later
21
late May
4 wks later
10 days later
21 days
14
14
14
14
7
7
14
14
14
14
14
14
14
14
14
14

74

Mean disease rating3
June 29
1.75
1.25

July 10
3.25
0.00

July 22
2.50
0.25

0.25

0.25

0.00

0.25
0.00
0.25
0.00
0.00
0.25
0.00
0.25
0.50
1.00
0.25
0.00
0.50

0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.25
0.25
0.25
0.25
0.00
0.50

0.00
0.00
0.00
0.00
0.00
0.75
0.00
0.25
0.25
0.00
0.50
0.50
0.25

1.00
0.50
0.00

0.00
1.75
0.00

0.25
0.50
0.25

Turfgrass Disease Research

Trt
20
21
22
23
24
25

26
27
28
29
30
31
32
33
34
35
36
37
38
39

Product
EXP 10830A 4.17 SC*
Chipco Triton 1.67 SC (=80318)
Chipco Triton 1.67 SC
Heritage 50 WG
Heritage 50 WG
+Daconil Ultrex
Heritage 50 WG
ALTERNATE WITH
Daconil Ultrex
Eagle 50 WP
+ Fore 75 DG
ZeroTol
ProStar 50 WP
ProStar 70 WP
ProStar 70 WP
+ Heritage 50 WG
S-8172
S-8172
S-8206
S-8206
AMV 300
AMV 300
UCC-A1562 20 SC
UCC-A1562 20 SC
UCC-A1562 20 SC
Least Significant Difference13

Rate/1,000 ft2
1 fl oz
1 fl oz
1 fl oz
0.2 oz
0.2 oz
3.8 oz
0.4 oz
3.8 oz
0.6 oz
6 oz
0.5 fl oz/80 ft2
3 oz
2.25 oz
1.5 oz
0.2 oz
4 fl oz
8 fl oz
3.2 fl oz
6.4 fl oz
1 fl oz
2 fl oz
1 fl oz
4 fl oz
8 fl oz

Interval
(days)
14
14
21
14
14

Mean disease rating3
June 29
July 10
July 22
0.00
0.00
0.00
1.00
0.25
0.25
0.00
0.75
0.75
0.50
0.00
0.00
0.00
0.00
0.00

28

0.25

0.50

1.50

14
14

0.25

0.00

0.00

7
14
14
14

0.50
0.75
0.50
0.25

1.00
1.0
0.00
0.00

3.00
0.50
0.50
0.00

14
14
14
14
14
14
14
14
14

0.00
0.00
0.75
0.00
0.75
0.25
1.50
0.50
0.25
1.02

1.50
0.50
0.50
0.00
0.25
0.00
1.50
1.00
0.25
0.98

1.00
0.00
0.50
0.00
3.25
0.00
0.50
1.50
0.25
0.93

aRating Scale: 0 = no disease; 1 = 1-5%; 2 = 5-10%; 3 = 10-25%; 4 = 25-50%; and 5 = >50% of plot diseased.
bP = 0.05. n = 4 replications.

75

Fertilizer Trials

Creeping Bentgrass Establishment and Management on Sand Greens
Michael B. Faust and Nick E. Christians
INTRODUCTION
This creeping bentgrass establishment trial was initiated on 1 Sept. 1996 at the Iowa State University Horticulture
Research Station. Data from the 1998 growing season are discussed in this report. The study was conducted to
observe the development o f creeping bentgrass from seed grown in a sand-based golf course green and to study the
effects o f liquid and granular fertilizer applications on the quality of mature bentgrass.
The objectives of the study were i) to compare the effects of five different combinations of organic-based fertilizer
products and a control on the establishment of creeping bentgrass (Agrostis palustris Huds. cv. Crenshaw), and ii) to
compare the effects o f two different application frequency schedules on the quality of mature 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 o f 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. The
research, with a 900 ft2 area, was conducted as a split-plot design with six treatments as main plots and two
application frequency schedules as subplots. The study included three replications. Each experimental plot (36
total) had an area of 25 ft2.
The main plots o f the research consisted of five liquid fertilizer products and a granular fertilizer material (Tables 1,
2, and 3). Four of the liquid treatments, excluding the control, were general use organic soil conditioners designed
to stimulate microbial activity and to provide overall improved soil fertility. The organic liquid treatments were
mixed in solution with NH4 NO3 and KN0 3 to supply adequate nitrogen and potassium requirements of the plant.
The control treatment contained only the inorganic nitrogen (NH4 NO3 ) and potassium (KN03) sources. All of the
liquid treatments contained the same rate of nitrogen and potassium, and they were applied to the turf using a C 0 2
tank and hand-held spray boom. Granular treatments were applied with a hand-held shaker to match the N and K
rates of the liquid products.
The first application to experimental plots in the spring of 1998 occurred on 21 May. The application frequency
schedule established in 1997, where half of the experimental plots received one application every two weeks and the
other half of the plots received two applications per week, was continued in 1998. Plots treated once every two
weeks received 0.25 lb N and 0.125 lb K/1000 ft2 /application. Plots treated two times per week received 0.0625 lb
N and 0.0313 lb K/1000 ft2 /application. All plots received 0.5 lb N and 0.25 lb K/1000 ft2/month irregardless of
application frequency schedule or treatment differences.
Clipping tissue samples were collected three times during the 1998 season. Individual collection dates were 17 and
31 August, and 14 September. 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 6 8 °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).
One root sample was taken during the 1998 growing season on 1 October. Five one-inch diameter cores were
removed from random locations on each plot at a depth of 15 cm. The roots were washed from the sand media using
a screening technique. The extracted root material was dried at 6 8 °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.
Visual quality data, rating density and color of each plot was taken four times in 1998. The data was collected 17
and 31 August, and 8 and 14 September. Quality was rated on a 1 to 9 scale; where 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.

76

Fertilizer Trials

Differences in plant shoot tissue concentration due to treatment effects were shown for the elements nitrogen (N),
phosphorus (P), magnesium (Mg), copper (Cu), and molybdenum (Mo) (Tables 1 and 2). Compared to the five
liquid treatments, the granular treatment provided the highest tissue N, P, and Mg concentrations. Plants grown in
control plots had the lowest tissue N levels. Phosphorus shoot tissue concentration of plants grown using the
granular treatment was on average 36% higher than plants supplied with the liquid treatments. Tissue P
concentrations were probably higher because the granular product contained 3% P2 0 5 (12-3-9 formulation).
Phosphorus was not supplied to plots receiving the liquid treatments throughout the 1998 growing season. Plants
fertilized by the liquid treatments had significantly more Cu in the shoot tissue as compared to those plants grown
using the granular material. Plants grown using the control and granular treatments had significantly lower Mo
tissue levels as compared to the other liquid treatments. The high organic matter content of the granular product may
have complexed Cu and Mo reducing the ability of the plant to absorb these elements.
Application frequency of treatments (2 vs. 8 applications/month) caused differences in shoot tissue concentration for
the elements: nitrogen (N), copper (Cu), and molybdenum (Mo) (Tables 1 and 2). Nitrogen shoot tissue
concentration was 3% higher for plants grown in plots receiving 8 applications/month compared to those plants
receiving 2 applications/month. Shoot tissue concentrations were 6 % and 8 % higher for Cu and Mo, respectively, in
plots receiving 8 applications/month compared to the plots which received 2 applications/month. However, plants
grown in plots receiving 2 applications/month had an average 8 % higher shoot tissue Mn concentration compared to
plants grown in plots that received 8 applications/month.
Mean visual quality data taken throughout 1998 showed differences among fertilizer treatments (Table 3). The
granular product (treatment 6 ) had significantly higher visual quality ratings compared to the liquid treatments. The
better visual quality could be explained by the shoot tissue nutrient concentration data which showed the highest N
levels in plants treated with the granular feather meal product. Plots receiving 8 applications per month had a higher
visual quality rating than plots receiving 2 applications/month.
No differences were shown between treatments or application frequency schedules for root development of grass
plants (Table 3). These findings are similar to rooting data taken in 1997.
T a b ic 1.

Mean macronutrient tissue concentration and analysis of variance.____________
M a c r o n u tr ie n ts *

Nitrogen
(N)

Phosphorus

22% humic acid

3.39

0.26

6-0-0 w/ organic acids

3.45

0.26

T r e a tm e n t

(P)

Calcium
(Ca)

Magnesium
(Mg)

Sulfur
(S)

1.83

0.74

0.28

0.25

1.87

0.72

0.27

0.25

Potassium
(K)
/O U1 Uiy llaallC

15% humic acid

3.44

0.26

1.87

0.70

0.26

0.25

5-3-2 w/ molasses

3.36

0.26

1.89

0.70

0.26

0.26

Control

3.23

0.25

1.85

0.74

0.27

0.25

12-3-9 ground feather meal

3.47

0.40

1.87

0.77

0.30

0.25

0.14

0.02

NS

NS

0.02

NS

3.34

0.28

1.85

0.74

0.28

0.25

8 apps/month

3.43

0.28

1.87

0.71

0.27

0.25

L S D io.o5iy

0.08

NS

NS

NS

NS

NS

0.0146

0.0001

0.5884

0.2256

0.0038

0.2515

0.3652

0.1965

0.2247

0.1076

L S D io.o5iy

A p p lic a tio n F r e q u e n c y

2 apps/month

A nova*
P rob > F

Treatment
Application frequency

0.0303

0.1851

0.4941
0.7280
0.3067
0.2056
Trt* Application frequency
0.0053
0.6029
zData shown are the mean of three tissue collection dates during the 1998 growing season. Individual collection dates were 17
and 31 August, and 14 September.
yMean separation within columns by Fisher’s least significant difference test.
Significant differences occur at the P < 0.05 level

77

Fertilizer Trials

T a b le 2 .

Mean micronutrient tissue concentration and analysis of variance.
M ic |r |o n u tr ie n tsz

Boron
(B)

Copper
(Cu)

Iron
(Fe)

Manganese
(Mn)
- mg Kg

Molybdenum
(Mo)

Sodium
(Na)

Zinc
(Zn)

22% humic acid

5.37

8.80

213.17

158.17

2.93

64.08

61.49

6-0-0 w/ organic acids

5.52

9.33

205.44

148.37

2.78

60.56

61.47

60.43

62.70
64.21

T r e a tm e n t

15% humic acid

5.43

8.82

170.28

158.77

2.92

5-3-2 wl molasses

5.44

8.89

171.33

163.56

2.86

59.66

Control

5.57

8.99

214.61

166.41

2.61

62.11

62.08

12-3-9 ground feather meal

5.38

6.98

230.89

158.95

2.39

70.07

64.16

NS

0.87

NS

NS

0.31

NS

NS

2 apps/month

5.47

8.37

206.06

165.32

2.64

62.00

62.94

8 apps/month

5.44

8.90

195.85

152.76

2.86

63.63

62.43

LSD(oo5iy

NS

0.50

NS

11.18

0.18

NS

NS

Treatment

0.8838

0.0002

0.2186

0.5175

0.0082

0.0751

0.7501

Application frequency

0.7977

0.0387

0.5379

0.0294

0.0198

0.4422

0.7220

LSD/0.05/
A p p lic a tio n F r e q u e n c y

A nova*
P rob > F

0.1156
0.6871
0.8790
0.9758
0.8349
0.3775
0.8895
Trt* Application frequency
zData shown are the mean of three tissue collection dates during the 1998 growing season. Individual collection dates were 17
and 31 August, and 14 September.
yMean separation within columns by Fisher’s least significant difference test.
xSignificant differences occur at the P < 0.05 level.

T a b le

3. Visual quality, rooting data, and analysis of variance.__________________________________ __________________

T r e a tm e n t

Aug
17

Aug
31

Visual Quality2
Sept
8

Sept
14

Mean

Root Mass (g)
October
1

22% humic acid

6.5

6.8

6.7

7.5

6.9

0.56

6-0-0 w/ organic acids

7.3

6.5

6.7

6 .8

6 .8

0.56

15% humic acid

6.7

6.8

6.5

7.0

6 .8

0.52

5-3-2 w/ molasses

6.7

7.2

7.2

6 .8

7.1

0.58

Control

7.0

6.5

6.7

7.5

6 .8

0.53

7.7

0.63

7.5

7.7

7.7

7.8

NS

0.8

0.6

0.5

0.4

NS

2 apps/month

6.7

6.6

6.5

7.0

6.7

0.56

8 apps/month

7.2

7.3

7.3

7.5

7.3

0.57
NS

0.1325

12-3-9 ground feather meal
LSD/oo5\y

________

A p p lic a tio n F r e q u e n c y

0.4

0.4

0.3

0.3

0.3

Treatment

0.0955

0.0425

0.0031

0.0029

0.0023

Application frequency

0.0213

0.0031

0.0001

0.0031

0.0001

0.7084

0.1224
0.3320
0.4362
0.0302
0.2090
Trt*Application frequency
zVisual quality (Color and Density) was rated on a 9 to 1 scale: l=poor quality; 9=highest quality.
yMean separation within columns by Fisher’s least significant difference test.
Significance occurs at the P<0.05 level.

0.9255

LSD(o.o5iy
A novax
P rob>F

78

Environmental Research

Corn Gluten Hydrolysate for Weed Control
Melissa C. McDade and Nick E. Christians
Com gluten hydrolysate (CGH) is an effective natural preemergent control in growth chamber and greenhouse
environments. Its performance in the field may be improved by using a carrier. Two carriers for 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). CGH at rates o f 0, 10, 20
and 40 lb/1000 ft2, humic acid at rates o f 0, 1 ,2 and 4 gal/acre and oil at rates o f 0, 0.5, 1 and 2 pts/acre were used,
with each rate o f CGH being applied with each rate o f humic acid and oil for a total o f 32 treatments. The
treatments were randomized in each of three replications. Each individual plot measured 5’x 5’. This study took
place at the ISU Horticulture Research Station north o f Ames, Iowa in an area with a mature stand o f Kentucky
bluegrass. Treatments were sprayed onto the plots on 9 May. The study area was irrigated as needed to provide a
good growing condition for the turf. Weed control was determined by collecting data on percent cover o f crabgrass
during the season. Visual quality was also assessed during the season using a 9 to 1 scale: 9 = best quality, 6 =
lowest acceptable quality, 1 = poorest quality. Analysis o f data used the Statistical Analysis System version 6.12
(SAS Institute, 1989-1996).
There were 72% fewer crabgrass plants at the greatest rate o f CGH (200 gm"2) compared to the control (Table 1).
Increasing CGH rates had a positive effect on turfgrass visual quality (Table 1). Humic acid and soybean oil had no
effect on the number o f crabgrass plants or on turfgrass quality.
CGH applied at a rate o f 200 g m -2 provided 72% reduction o f crabgrass in this study, similar to a 6 6 % reduction
found in the first year o f another CGH field study at the 200 g m"2 rate (Bingaman and Christians, 1996). This
reduction is also similar to that o f com gluten meal, which provided 8 6 % control when applied to turf at the 2 0 0
g m ' 2 rate (Bingaman et al., 1998). Rates o f 50 and 100 g CGH per m 2 did not control crabgrass in this study and
varied in effectiveness in previous studies by Bingaman and Christians (1996, 1997, 1998).
Applying 200 g m "2 CGH provides 20 g N per m2, since CGH is 10% N by weight. The CGH has a fertilizing
effect, improving the visual quality o f the turfgrass at higher rates. Other studies have reported this fertilizing effect
in both CGH (Bingaman and Christians, 1996, 1997, 1998) and com gluten meal (Bingaman et al., 1998;
Christians, 1993).
If soybean oil or humic acid had a positive effect on the herbicidal activity o f the CGH, we would have seen similar
crabgrass counts or quality at different rates o f CGH because o f the addition o f soybean oil or humic acid. Only the
rate o f CGH had an effect on crabgrass counts and quality, so the soybean oil and humic acid treatments had no
effect, neither as interactions nor as single effects.
Table 1. Mean number of crabgrass (Digitaria spp.) plants at the end of the 1998 growing season (16 weeks). Mean
turfgrass quality from the 1998 season, rated visually: 9 = highest quality, 6 = acceptable quality, 1 = lowest
________ quality. Each rate of com gluten hydrolysate was applied to 10 plots in each of three replications._________
Turfgrass
Number of crabgrass plants
Com gluten hydrolysate
visual quality
(per 2.25 n r plot)
(gm '2)
6.0
29
0
17
6.5
50
7.0
26
100
8.0
8
200
0.2
13
L S D o .05

REFERENCES
Bingaman, B.R. and N.E. Christians. 1998. 1995 com gluten hydrolysate weed control study - year 3. Iowa Turfgrass Res.
Rpt., Iowa State Univ. Ext. p. 103-104.
Bingaman, B.R. and N.E. Christians. 1997. 1995 com gluten hydrolysate weed control study - year 2. Iowa Turfgrass Res.
Rpt., Iowa State Univ. Ext. p. 75-76.
Bingaman, B.R. and N.E. Christians. 1996. 1995 corn gluten hydrolysate weed control study. Iowa Turfgrass Res. Rpt.,
Iowa State Univ. Ext. p. 87-88.
Bingaman, B.R., N.E. Christians, and M.B. Faust. 1998. 1991 com gluten meal crabgrass control study - year 7. Iowa
Turfgrass Res. Rpt., Iowa State Univ. Ext. p. 95-98.
Christians, N.E. 1993. The use of corn gluten meal as a natural preemergence weed control in turf, p. 284-290. In: Carrow
R.N., N.E. Christians, R.C. Shearman (eds.). Inti. Turfgrass Soc. Res. J. 7. Intertec Publishing Corp., Overland Park, KS.

79

Environmental Research

1991 Corn Gluten Meal Crabgrass Control Study - Year 8
Barbara R. Bingaman, Melissa C. McDade, and Nick E. Christians
A study screening com gluten meal (CGM) for efficacy as a natural product herbicide and fertilizer in turf has been
continued on the same plot for since 1991. It is being conducted at the Iowa State University Research Station north
o f Ames, IA in an area o f ’Parade' Kentucky bluegrass. The soil in this experimental area is a Nicollet (fine-loamy,
mixed, mesic Aquic Hapludoll) with an organic matter content o f 3.6% a pH o f 7.1, 4.5 ppm P, and 101 ppm K.
Individual experimental plots are 5 x 5 ft and there are 5 treatments with 3 replications. The experimental design is
a randomized complete block. Com gluten meal is applied each year to the same plots at 0, 20, 40, 60, 80, 100, and
120 lbs/1000 ft2 (Table 1). Because com gluten meal is 10% N, these rates are equivalent to 0, 2 ,4 , 6, 8, and 10 lb
N/1000 ft2. In 1998, the CGM was applied in a single early spring preemergence application on April 21 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. Visual turf quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and
1 = worst turf quality. Quality data were taken on April 22, May 13, May 18, May 27, June 10, June 16, July 9, July
15, July 29, August 18, and August 28 (Tables 1 and 2).
Weed control was measured by either counting the number of plants or estimating the percentage cover per
individual plot. Crabgrass in the 1- to 3-leaf stage was found in the untreated turf on June 23. The crabgrass plants
were large enough by July 15 to count the number per plot. Additional crabgrass count data were taken on July 29,
August 18, and August 28 (Table 3). Crabgrass counts were converted to express percentage reductions in numbers
as compared to the untreated controls (Table 4).
Dandelion and clover populations also were surveyed. The number o f dandelions per plot was counted on July 15,
July 29, August 18, and August 28 (Table 5). On these same dates, percentage clover cover data were taken. Clover
cover was determined by estimating the area per plot covered by clover (Table 7). Dandelion count and percentage
clover cover data were modified to express percentage reductions as compared to the untreated controls (Tables 6
and 8).
Data were analyzed with the Statistical Analysis System (SAS , Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Fisher’s Least Significant Difference (LSD) means comparison tests were used to assess
CGM effects on bluegrass quality and weed control.
Spring greenup was obvious by April 22. Bluegrass treated with CGM had better quality than untreated turf from
May 13 through June 16 (Table 1 and 2). After June 16, the season was quite hot and dry and the treated and
untreated bluegrass had similar quality.
Crabgrass populations were low in the untreated controls because the dandelion and clover infestations were large
and well established creating intense competition for the emerging crabgrass. Treatment with CGM at all levels
except 20 lb/1000 ft2 resulted in much lower crabgrass populations (Table 3). Reductions in crabgrass populations
were > 91% at 40 and 60 lb/1000 ft2 (Table 4). There were more crabgrass plants in turf treated with CGM at 20
lb/1000 ft2 than in untreated turf (Table 3). In 1997, there also were more crabgrass plants in turf treated with CGM
at 20 lb/1000 ft2 as compared with the untreated control (Table 9). Reductions in crabgrass counts were similar to
1997 at all CGM levels except 40 lb/1000 ft2. Much better crabgrass control was achieved at 40 lb in 1998 as
compared with 1997.
Com gluten meal at all levels except 20 lb/1000 ft2 significantly reduced dandelion counts as compared with the
untreated control (Table 5). Mean reductions > 72% were achieved with CGM at 40 lb and higher (Table 6).
Dandelion control in 1998 was similar to control in 1997 and previous years except at the 20 lb/1000 ft2 level (Table

11).
On July 29 and August 18, there was significantly less clover cover in turf treated with CGM as compared with the
untreated controls (Table 7). On August 28, all CGM levels except 20 lb/1000 ft2 significantly reduced clover
cover. Mean reductions in clover cover were > 84% as compared with the untreated controls in turf treated with
CGM at all levels except 20 lb (Table 8). Clover control in 1998 was similar to that in previous years except at 20
lb/1000 ft2. At this rate, the level o f clover control was much lower in 1998 as compared to 1994 through 1997
(Table 10).

80

Environmental Research

Table 1 Visual quality1 o f Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control Study.

1
2
3

4
5
6
7

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

lbs CGM/
1000 ft2
0
20
40
60
80
100
120

lbs N /
1000 ft2
0
2

April

May
13
5.0
5.7
7.0
8.7
7.7
8.3
9.0
1.4

22

6.7
6.3
7.3
8.3
8.0
8.3
9.0
1.1

4
6
8

10
12

L S D o os

May
18
5.3
6.3
7.7
8.7
8.0
8.3
8.3
0.8

May
27
5.0
6.3
8.0
8.0
8.3
8.0
7.7
1 .4

June
10
5.7
6.3
7.7
8.7
8.7
9.0
9.0
0.6

June
16
5.0
6.3
7.3
8.3
9.0
8.7
9.0
0.6

'Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = least acceptable, and 1 = worst turf quality.
NS = means are not significantly different at the 0.05 level.

Table 2. Visual quality1 o f Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control Study.

1
2
3

4
5
6
7

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

lbs CGM/
1000 ft2
0
20
40
60
80
100
120

July

L S D 005

9

6.0
6.0
6.0
6.0
6.0
6.0
6.0
-

July
15
6.0
6.0
6.0
6.0
6.0
6.0
6.0

July
29
6.0
6.0
6.0
6.0
6.0
6.0
6.0

August
5
6.0
6.0
6.0
6.0
6.0
6.0
6.0

August
18
6.0
6.0
6.0
6.0
6.0
6.0
6.0

August
28
6.0
6.0
6.0
6.0
6.0
6.0
6.0

—

—

—

—

—

Mean
5.4
6.2
7.5
8.4
8.3
8.7
8.7
0.6

V isual quality was assessed using a 9 to 1 scale with 9 = best, 6 = least acceptable, and 1 = worst turf quality.
—= these data are not appropriate for means comparisons tests.

Table 3. Crabgrass count1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control Study.

1
2
3
4
5
6
7

Material
Untreated Control
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal

lbs CGM/
1000 ft2
0
20
40
60
80
100
120

L SD oos

July
15
6.3
5.3
3.7
0.3
8.7
4.0
1.7
NS

July
29
22.7
38.3
1.0
1.0
9.0
4.3
7.0
NS

August
18
29.7
41.3
0.7
3.7
12.0
3.0
6.0
NS

August
28
21.3
36.7
1.7
1.7
5.7
2.0
4.7
NS

Mean
counts
20.0
30.4
1.8
1.7
8.8
3.3
4.8
NS

1These values represent the number of crabgrass plants per plot.
NS = means are not significantly different at the 0.05 level.

Table 4. Percentage crabgrass count reductions1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed
Control Study.
Material

lbs CGM/
1000 ft2

July
15

July
29

August
18

August
28

Mean
reduction

%
0.0
0.0
0.0
0.0
0.0
15.7
0.0
0.0
0.0
0.0
42.1
95.6
97.8
92.2
91.3
94.7
95.6
87.6
92.2
91.7
0.0
59.6
73.4
60.3
55.8
89.9
36.8
80.9
90.6
83.3
73.7
69.1
79.8
78.1
75.8
NS
NS
NS
NS
NS
L S D o 05
“T77
rThese values represent percentage reduction in crabgrass plants per plot as compared with the untreated controls.
NS = means are not significantly different at the 0.05 level.
1
2
3
4
5
6
7

Untreated Control
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal

0
20
40
60
80
100
120

81

Environmental Research

T able 5. Dandelion count1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal W eed Control Study.
lbs CGM/
July
July
August
August
Mean
Material
1000 fit2
15
29
18
28
counts
1. Untreated control
47.7
0
25.0
25.7
48.7
36.8
2.
40.7
49.7
Com gluten meal
20
25.0
24.7
35.0
40
15.3
12.0
Com gluten meal
3.
9.0
4.7
10.3
4. Com gluten meal
60
3.0
8.3
8.7
3.7
5.9
4.7
5. Com gluten meal
80
3.7
1.3
3.3
3.3
5.0
6. Com gluten meal
100
4.0
5.3
1.3
3.9
1.3
2.7
7. Com gluten meal
120
0.3
0.7
1.3
15.2
29.6
13.6
11.0
13.7
L SD oos
‘These counts represent the number o f dandelions per plot.
Table 6. Percentage dandelion count reductions1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed
Control Study.
July
July
August
August
lbs CGM/
Mean
18
28
Material
1000 ft2
15
29
reduction
0.0
0.0
0.0
3.9
64.0
81.8
85.3
88.3
85.3
94.8
84.0
94.8
98.7
97.4
54.5
43.0
L SD oos
'These values represent the percentage reduction in dandelions per plot as

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

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

0
20
40
60
80
100
120

%
0.0
0.0
0.0
14.7
0.0
4.8
67.8
75.3
72.1
82.5
82.2
83.9
93.0
90.4
91.2
89.5
89.0
89.3
97.2
94.5
96.6
31.9
60.8
37.3
compared with the untreated controls.

Table 7. Percentage clover cover1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed Control
Study.
August
August
Mean
July
July
lbs CGM/
18
28
cover
29
Material
1000 ft2
15
43.3
53.3
43.7
1. Untreated control
0
34.7
43.3
30.0
41.7
32.1
20
35.0
21.7
2. Com gluten meal
3.3
5.3
6.9
40
10.7
8.3
3. Com gluten meal
6.7
7.0
5.3
6.4
60
4. Com gluten meal
6.7
3.7
3.7
3.2
5. Com gluten meal
80
3.3
2.0
2.0
5.3
4.5
100
6. Com gluten meal
7.0
3.7
3.7
2.3
6.7
5.3
4.5
120
7. Com gluten meal
14.3
13.1
9.3
NS
15.7
L SD oos
‘Percentage clover cover represents the area per plot covered by clover.
Table 8. Percentage clover cover reductions1 in Kentucky bluegrass treated in the 1991 Com Gluten Meal Weed
Control Study.
August
August
Mean
lbs CGM/
July
July
28
1000 ft2
15
29
18
reduction
Material

%
0.0
0.0
0.0
0.0
30.8
21.9
50.0
26.5
92.3
90.0
80.8
84.2
4.
87.7
87.5
83.8
85.3
5.
95.4
91.5
93.1
92.7
95.4
6.
90.0
91.5
89.7
91.5
95.6
7.
87.7
89.7
30.2
26.9
NS
36.2
21.2
L SD oos
~T=7
^ h ese values represent the percentage reduction in clover cover per plot as compared with the untreated controls.
1.
2.
3.

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

0
20
40
60
80
100
120

0.0
0.0
69.3
80.8
90.4
79.8
70.8

82

Environmental Research

Table 9. Comparisons o f the mean percentage crabgrass count reductions1 in Kentucky bluegrass treated in the
_________ 1991 Com Gluten Meal Weed Control Study for 1991 through 1998.______________________________
lbs
Material
CGM/
1991
1992
1993
1994
1995
1996
1997
1998
1000 fit2

%
1
2
3
4
5
6
7

Untreated control
0
0
0
0
20
58
85
Com gluten meal
91
40
86
Com gluten meal
98
98
60
97
98
Com gluten meal
93
80
87
Com gluten meal
93
93
Com gluten meal
100
79
94
95
120
Com gluten meal
97
100
100
44
26
31
l s d 005
'These values represent the percentage reduction in crabgrass plants
controls.
NS = means are not significantly different at the 0.05 level.

0
70
97
98
87
86
98
39

0
36
88
93
75
75
84
40

0
15
97
85
69
87
97
60

0
0
79
82
54
79
82
NS

0
0
91
92
56
83
76
NS

per plot as compared with the untreated

Table 10. Comparisons o f the mean percentage clover cover reductions in Kentucky bluegrass treated in the 1991
Com Gluten Meal Weed Control Study for 1994 through 1998.
lbs CGM/
1994
1000 ft2
1995
1996
Material

1997

1998

%
0
71
82
93
90
92
93
29

0
0
0
0
81
63
27
56
90
84
64
87
95
98
85
93
100
95
93
76
76
94
84
90
93
90
90
93
26
21
48
NS
L S D 00 5
‘Percentage clover cover represent the area per plot covered by clover.
These values represent the percentage reduction o f clover cover per plot as compared with the untreated controls.
1
2
3
4
5
6
7

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

0
20
40
60
80
100
120

Table 11. Comparisons o f the mean percentage dandelion count reductions1in Kentucky bluegrass treated in the
1991 Com Gluten Meal Weed Control Study for 1994 through 1998.
lbs CGM/
1994
1996
Material
1000 ft2
1995

1997

1998

0/n
/O
0
0
0
0
0
71
33
24
5
49
100
75
76
72
77
84
83
100
89
79
98
95
93
91
96
88
100
98
96
89
100
100
97
97
100
50
60
61
37
65
L S D 00 5
'Dandelion counts represent the number o f dandelions per plot.
2These values represent the percentage reduction o f dandelion count per plot as compared with the untreated
controls.
1
2
3
4
5
6
7

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

0
20
40
60
80
100
120

83

Environmental Research

1995 Corn Gluten Meal Rate Weed Control Study - Year 4
Barbara R. Bingaman, Melissa C. McDade, and Nick E. Christians
Com gluten meal (CGM) is being screened for efficacy as a natural product herbicide in turf in this long-term study
begun in 1995. It is being conducted at the Iowa State University Horticulture Research Station north o f Ames, IA
in established ’Ram 1' Kentucky bluegrass. The soil is a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with
an organic matter content o f 3.8%, a pH o f 7.1, 4 ppm P, and 96.5 ppm K. The initial broadleaf weed population
exceeded 50% cover on most o f the test area.
Individual experimental plots are 10 x 10 ft with 4 treatments and 3 replications. The experimental design is a
randomized complete block. Each year com gluten meal is applied at a yearly rate o f 40 lb. CGM/1000 ft2
(equivalent to 4 lb. N/1000 ft2) using 4 different regimes of single and split applications (Table 1). Four applications
o f 10 lb./lOOO ft2, split applications o f 20 lb./lOOO f t 2, an initial application o f 30 lb. plus a sequential o f 10 lb./lOOO
ft2, and a single application o f 40 lb./lOOO ft2 are included with an untreated control.
Initial applications for 1998 were made on April 21 before crabgrass germination. The second application o f
treatment 2 was made on June 3, the third on July 14, and the final on August 26. Sequential applications o f
treatments 3 and 4 were made on July 14.
The experimental plot was checked for phytotoxicity after each treatment. The study was monitored for visual
quality throughout the season. Visual quality was measured using a 9 to 1 scale with 9 = best, 6 = lowest
acceptable, and 1 = worst quality (Tables 1 and 2). Visual quality data were taken on April 22, May 13, May 18,
May 27, June 10, June 18, June 30, July 9, July 15, July 24, July 29, August 11, August 18, and August 26.
Populations o f annual grass and perennial broadleaf weed species were surveyed. Crabgrass populations were
assessed by counting the number o f plants per individual plot on July 9, July 24, July 29, August 11, August 18, and
August 26 (Table 3). Clover infestations were estimated by determining the percentage o f area in each individual
plot covered by clover. These data were taken on July 29, August 11, August 18, and August 26 (Table 5).
Dandelion populations were measured by counting the number o f plants per plot on July 29, August 11, August 18,
and August 26 (Table 7). Levels o f crabgrass, clover, and dandelion control were expressed by converting the
population data to reductions as compared with the untreated control (Table 4, 6, and 8).
Data were analyzed with the Statistical Analysis System (SAS, Version 6.12) and the Analysis o f Variance
(ANOVA) procedure. Means comparisons were made with Fisher’s Least Significant Difference test (LSD).
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 May 13, May 27, June 10, June 18, June 30, July 9,
August 11, August 18, and August 26 (Table 1 and 2). Mean visual quality for the entire season was better for
bluegrass treated with CGM than the untreated grass.
Crabgrass populations were lower in turf treated with CGM than in untreated turf but the counts were not
statistically different (Table 3). Crabgrass numbers were low in the untreated controls. Broadleaf weed species
were well established when the crabgrass was emerging especially in the untreated controls and the competition
from the broadleaves and the mature turf probably prevented the establishment o f large crabgrass populations within
the untreated plots. Reductions in crabgrass populations were not significant for any o f the CGM treatments on any
o f the collection dates but there were large numerical reductions achieved in treated bluegrass as compared with
untreated turf (Table 4). Bluegrass treated with split applications o f 20 lb. CGM reduced crabgrass counts by > 89%
from July 9 through August 11.
In 1998, crabgrass control was much better overall than in 1995, 1996, and 1997 (Table 9). In contrast to 1996 and
1997, there was more crabgrass in the untreated controls than in treated grass in 1998. Split applications o f 20 lb.
CGM provided 86% crabgrass reductions in 1998 as compared to 45, 33, and 50% in 1995, 1996, and 1997,
respectively.
There was significantly less clover in CGM treated turf than in the untreated controls on all data collection dates
except August 18 (Table 5). All CGM rates significantly decreased clover populations and clover cover was lowest
in turf treated with a single application o f 40 lb. CGM. The mean clover cover in untreated turf was 40.4% as

84

Environmental Research

compared to 10.7, 11.4, 14.7, and 3.0% cover in turf receiving treatments 2, 3 ,4 , and 5, respectively. The single
application o f 40 lb. CGM provided > 89% reductions in clover cover throughout the season as compared to the
untreated control (Table 6).
Clover control was better in 1998 than 1996 and 1997 in turf treated with CGM four times at 10 lb. (Table 10).
Clover control in 1998 with split applications o f 20 lb. was slightly less than in 1997 and similar to 1996. Control
provided by CGM at 30 lb. followed by 10 lb. was much lower in 1998 as compared with 1996 and 1997. A single
application at 40 lb. provided similar clover cover reductions in 1998 as in 1996 and slightly lower than 1997.
Dandelion cover was significantly less in all CGM treated turf as compared to the untreated control on all data
collection days except August 26 (Table 7). Percentage reductions in dandelion cover were similar for all CGM
treatments (Table 8).
In 1998, dandelion control was higher than in 1996 and 1997 when CGM was applied four times at 10 lb. and in a
single application at 40 lb. (Table 11). Dandelion reductions were similar in 1996, 1997, and 1998 for CGM at 20
lb. split applications. Percentage reductions were much higher in 1998 as compared with 1996 and 1997 for CGM
applied at 30 lb. followed by 10 lb.

Table 1. Visual quality1 o f Kentucky bluegrass treated with com gluten meal in the 1995 Com Gluten Meal Rate

Material

1.
2.

Untreated control
Com gluten meal

3.
4.
5.

Com gluten meal
Com gluten meal
Com gluten meal

Rate
(lb. product
/1000 ft2)

April
22

May
13

May
18

May
27

June
10

June
18

June
30

0
10 fb lO.fb
10 fb 10
20 fb 20
30 fb 10
40

6.3
8.7

6.0
8.7

6.3
7.0

5.3
7.0

5.0
6.7

6.0
7.3

6.0
7.0

7.7
8.0
7.0

8.7
9.0
8.7

8.7
7.7
8.7

7.7
8.7
8.3

7.0
8.3
9.0

7.0
8.3
8.7

7.3
8.3
9.0

1.4
0.8
0.6
0.9
0.7
NS
0.8
L SD oos
‘Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst turf quality.
All treatments were at an annual rate of 4 lb.s N/1000 ft2. Initial applications were made on April 21. Second application of trt 2
was made on June 3, the third on July 14, and the final on August 26. Sequential applications of trt 3 & 4 were made on July 14.
NS = means are not significantly different at the 0.05 level

Table 2. Visual quality1 o f Kentucky bluegrass treated with com gluten meal in the 1995 Com Gluten Meal Rate
Weed Control Study (July 9 - August 26).

Material

1.
2.

Untreated control
Com gluten meal

3.
4.
5.

Com gluten meal
Com gluten meal
Com gluten meal

Rate
(lb. product
/1000 ft2)

July
9

July
15

July
24

July
29

Aug
11

Aug
18

Aug
26

Mean

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

6.0
7.0

6.0
8.0

6.0
8.0

6.0
8.0

6.0
7.3

6.7
8.3

6.0
8.0

6.0
7.6

7.3
8.0
8.3

7.3
7.7
8.3

7.3
7.7
8.3

7.7
8.3
7.0

7.0
7.3
7.0

8.3
8.3
8.3

9.0
8.3
7.3

7.7
8.1
8.1

0.6

0.5

0.7
1.2
0.7
1.1
1.6
NS
L S D o os
_________
‘Visual quality
was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst turf quality.
NS = means are not significantly different at the 0.05 level

85

Environmental Research

Table 3. Crabgrass counts per plot1 in Kentucky bluegrass treated with com gluten meal (CGM ) in the 1995 Com
Gluten Meal Rate Weed Control Study.
Material

1.
2.

Untreated control
Com gluten meal

3.
4.
5.

Com gluten meal
Com gluten meal
Com gluten meal

Rate
(lb. product
/1000 ft2)

July
9

July
24

July
29

August
11

August
18

August
26

Mean

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

8.7
3.3

13.3
9.0

16.7
6.7

18.3
11.7

23.3
11.7

31.7
23.3

18.7
10.9

0.3
1.0
5.0

0.7
2.3
8.3

1.7
2.0
6.7

2.0
.7.0
10.0

3.7
5.3
6.7

7.0
7.3
16.7

2.6
4.2
8.9

NS
NS
L SD oos
"ITT
1These values represent the number of crabgrass plants per plot.
NS = means are not significantly different at the 0.05 level.

NS

NS

NS

NS

NS

Table 4. Crabgrass count reductions1 in Kentucky bluegrass treated with com gluten meal (CGM) in the 1995 Com
Gluten Meal Rate Weed Control Study.
Material

Rate
(lb. product
/ 1 000 ft2)

July
9

July
24

July
29

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

0.0
61.7

0.0
32.3

0.0
60.1

96.2
88.5
42.5

95.0
82.5
37.3

90.0
88.0
60.1

August
11

August
18

August
26

Mean

0.0
36.2

0.0
50.0

0.0
26.4

0.0
41.5

89.1
61.7
45.4

84.3
77.1
71.4

77.9
76.9
47.4

86.3
77.7
52.5

0/n
/o
2.

Untreated control
Com gluten meal

3.
4.
5.

Com gluten meal
Com gluten meal
Com gluten meal

1.

NS
NS
NS
NS
NS
NS
NS
L S D o os
‘These values represent the percentage reduction in crabgrass plants per plot as compared with the untreated controls.
All treatments were at an annual rate of 4 lb.s N/1000 fr. Initial applications were made on April 21. Second application of trt 2
was made on June 3, the third on July 14, and the final on August 26. Sequential applications of trt 3 & 4 were made on July 14.
NS = means are not significantly different at the 0.05 level.

Table 5. Percentage clover cover per plot1 in Kentucky bluegrass treated with com gluten meal in the 1995 Com
Gluten Meal Rate Weed Control Study.
Rate
(lb. product/1000 ft2)

July
29

August
11

August
18

August
26

Mean

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

40.0
10.7
10.0
11.7
1.7

41.7
8.3
12.0
16.0
1.7

%
31.7
7.0
6.7
14.3
3.3

48.3
16.7
17.0
16.7
5.3

40.4
10.7
11.4
14.7
3.0

20.5
LSD oos
“TTT
‘These data represent the area per plot covered by clover.
NS = means are not significantly different at the 0.05 level.

16.5

NS

21.4

19.6

Material

1.
2.
3.
4.
5.

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

86

Environmental Research

Table 6. Percentage clover cover reductions1 in Kentucky bluegrass treated with com gluten meal in the 1995 Com
Gluten Meal Rate Weed Control Study.
Material

1.
2.
3.
4.
5.

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

Rate
(lb. product/1000 ft2)

July
29

August
11

August
18

August
26

Mean

NA

0.0
73.3
75.0
70.8
95.8

0.0
80.0
71.2
61.6
96.0

%
0.0
77.9
79.0
54.8
89.5

0.0
65.5
64.8
65.5
89.0

0.0
73.6
71.7
63.7
92.6

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

44.4
51.3
39.6
NS
48.5
L S D o os
_____i__________
r percentage reductions in clover cover per plot as compared with the untreated control.
‘These
values representrrthe
NS = means are not significantly different at the 0.05 level.

Table 7. Percentage dandelion cover1 in Kentucky bluegrass treated with com gluten meal in the 1995 Com Gluten
Meal Rate Weed Control Study.
Material
Rate
______________ (lb. product/1000 ft2)

July
August
August
August
Mean
29_________1J_________ 18_________26_____________

------------------- % ------------------1.
2.
3.
4.
5.

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

L S D 005

25.0
8.3
10.0
6.7
10.0

20.0
5.0
6.7
6.0
6.7

15.0
5.0
6.7
4.3
5.7

28.3
11.7
13.3
10.0
11.7

22.1
7.5
9.2
6.8
8.5

7.1

6.6

4.6

NS

4.7

‘These figures represent the area per plot covered by dandelions.
All treatments were at an annual rate of 4 lb.s N/1000
ft2.Initial applications were made on A
was made on June 3, the third on July 14, and the final on August 26. Sequential applications of trt 3 & 4 were made on July 14.
NS = means are not significantly different at the 0.05 level.

Table 8. Percentage reductions in dandelion cover 1 in Kentucky bluegrass treated with com gluten meal in the

Material

Rate
(lb. product/1000 ft2)

August
11

July
29

August
18

August
26

Mean

%
1.
2.
3.
4.
5.

Untreated control
Com gluten meal
Com gluten meal
Com gluten meal
Com gluten meal
LSD oos

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

0.0
66.7
60.0
73.3
60.0

0.0
75.0
66.7
70.0
66.7

0.0
66.7
55.6
71.1
62.2

0.0
58.8
52.9
64.7
58.8

0.0
66.1
58.5
69.5
61.5

28.3

33.1

31.0

NS

21.2

1HP1-

All treatments were at an annual rate of 4 lb.s N/1000 ft2. Initial applications were made on April 21. Second application of trt 2
was made on June 3, the third on July 14, and the final on August 26. Sequential applications of trt 3 & 4 were made on July 14.
NS = means are not significantly different at the 0.05 level.

87

Environmental Research

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LSD qqs________________________________ NS _____________ NS _____________ 22 ____________ 58________
’These values represent the area per plot covered by clover.
2These values represent the percentage reductions in clover cover per plot as compared with the untreated control.
NS = means are not significantly different at the 0.05 level

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Environmental Research

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89

Turfgrass Management

1999 Select® Liquid Ice Melter Study
D avid D. Minner and Barbara R. Bingaman
Objective
To determine if a liquid ice melt material may be suitable to remove ice from golf course putting greens. Ice
formation on putting greens in Iowa is a common occurrence. Freezing rain and melted snow followed by re­
freezing can lead to an ice layer forming on the green nearly 2 inches thick. Some superintendents have tried to
physically remove the ice layer from the green. Various commercial ice melt materials are available for nonturfgrass use.

Materials and Methods
A commercial liquid ice melting product, Select®, was screened for toxicity on creeping bentgrass during the winter
months o f 1999. Select®, a mixture o f potassium acetate and water, was applied at various rates to creeping
bentgrass plugs.
Plugs were cut from an established 'Crenshaw' creeping bentgrass area at the Iowa State University Horticulture
Research Station north o f Ames, IA in January. They were potted in sand medium and maintained outside from
February until mid-March.
Two separate tests were run. In Test I, Select® was applied at 0, 2, 3, 4, 5, 6, and 7 gal/1000 ft2 on three dates
(Table 1). In Test II, the deicer was applied at 0, 6, 9, 12, 15, 18, and 21 gal/1000 ft2 in one application. The deicer
was diluted in water to a volume o f 20 ml for ease o f application using a hand sprayer. Three replications were
conducted for each test.
Treatments for Test I were applied on February 17, February 22, and March 1. Decier was applied for Test II on
February 22. On March 22, the bentgrass plugs were placed in the greenhouse and evaluated for greenup.
Percent green cover and visual quality data were taken beginning on March 24. Percent green cover was estimated
as the area per pot covered by green bentgrass. Visual quality was assessed using a 9 to 1 scale with 9 = best and 1
= worst quality. Additional data were taken on March 29, April 1, April 4, April 9, and April 12.

Table 1. Application rates and timing for treatments in the 1999 Select® Liquid Ice Melter Study.
Trt
1
2
3
4
5
6
7
8
9
10
11
12
13

Material
Untreated control
Select®
Select®
Select®
Select®
Select®
Select®
Select®
Select®
Select®
Select®
Select®
Select®

Application rate
(gal product/1000 ft2)
0.0
2.0
3.0
4.0
5.0
6.0
7.0
6.0
9.0
12.0
15.0
18.0
21.0

90

Number o f Applications
NA
3
3
3
3
3
3
1
1
1
1
1
1

Turfgrass Management

Table 2. Visual quality o f creeping bentgrass treated in the 1999 Select® Liquid Ice Melter Study.
Application rate
April
April
April
Number of
March
March
Trt
Material
(gal product/
9
24
29
1
5
Applications
1000 ft2)
Untreated
9.0
9.0
NA
8.0
0.0
9.0
9.0
1
control
8.0
8.0
8.0
2
Select®
2.0
7.7
9.0
3
3.0
7.7
7.7
7.7
3
Select®
6.7
8.0
3
4
Select®
4.0
7.3
7.3
7.3
5.7
3
7.3
7.52
5.0
7.52
7.52
5.3
5
Select®
4.7
3
6.3
7.0
6
Select®
6.0
3
5.3
7.52
6.3
5.03
7.03
7.03
7.03
6.03
7
Select®
7.0
3
8.0
8.0
8.0
1
8.0
9.0
8
Select®
6.0
7.7
7.7
9
Select®
9.0
1
7.0
8.3
7.7
7.0
7.0
7.0
12.0
10
Select®
1
5.3
7.3
6.0
6.0
6.0
11
Select®
15.0
1
3.02
6.52
6.52
18.0
6.02
6.52
6.52
12
Select®
1
6.02
21.0
6.03
13
Select®
1
6.03
6.03
6.03
3.52
2.4
2.4
2.2
2.2
2.3
LSD 0 0 5
'Visual quality was assessed using a 9 to 1 scale with 9 = best, 6 = lowest acceptable, and 1 = worst quality.
This value represents only two replications •- there was no bentgrass in the third replication.
3This value represents only one replications •■there was no bentgrass in the other two replications.

April
12

Mean

9.0

8.3

8.0
7.7
7.3
5.3
7.0
7.03
8.0
7.7
7.0
6.0
4.7
3.52
NS

8.6
7.7
7.3
5.9
5.8
2.9
8.7
8.3
7.0
5.4
5.3
2.7
2.8

Table 3. Percentage green cover o f creeping bentgrass treated in the 1999 Select® Liquid Ice Melter Study.
Application rate
April
April
March
April
April
Number o f
March
(gal product/
Trt
Material
12
1
5
9
Applications
24
29
1000 fit2)
Untreated
100.0
100.0
100.0
100.0
100.0
66.7
1
0.0
NA
control
86.7
86.7
80.0
86.7
46.7
78.3
2
Select®
2.0
3
15.0
18.3
23.3
28.3
15.0
3.0
7.0
Select®
3
3
15.0
20.0
11.7
23.3
11.7
2.7
4
4.0
Select®
3
5.7
11.7
12.0
13.7
4.7
5.7
5.0
3
5
Select®
5.3
7.0
6.7
8.3
2.7
5.0
6
Select®
6.0
3
1.7
1.7
1.7
1.7
1.7
0.7
7.0
7
Select®
3
76.7
78.3
83.3
60.0
68.3
28.3
6.0
1
8
Select®
61.7
45.0
56.7
65.0
40.0
9.0
16.7
9
Select®
1
25.0
25.0
20.0
18.3
11.7
18.3
Select®
12.0
1
10
5.3
7.0
4.0
5.7
2.0
15.0
11
Select®
1
1.3
13.3
25.0
10.0
13.3
8.3
4.0
12
Select®
18.0
1
0.0
0.7
0.7
0.0
0.3
13
Select®
21.0
1
0.3
17.6
18.1
18.5
20.2
16.3
11.5
LSD 0 0 5
'These values represent the percentage of area per plot covered by green bentgrass.

Mean
94.4
77.5
17.8
14.1
8.9
5.8
1.5
65.8
47.5
19.7
4.2
12.3
0.3
15.1

Results
These results are preliminary and the products mentioned in this report should not be used at this time for removing
ice from golf course turf.
Phytotoxicity caused by Select® was rate dependent. A single application o f Select® at 6 gal/1000 sq. ft. resulted in
some initial phytotoxicity, but turf recovered to an acceptable level within 1.5 months. At 9 to 12 gal/1000 sq. ft.,
injury was greater and recovery slower. Lower application rates applied more frequently reduced injury compared
to single applications applied at an equal rate. Since golf course putting greens are highly scrutinized, this product
should be investigated at rates lower than 2.0 gal/1000 sq. ft.

91

Soil Modification and Sand-based Systems

Stabilizing Sand-based Athletic Fields With Enkamat
D a v id D. M inner and Jay S. Hudson
Objective: The objectives o f 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 o f 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 o f 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 o f individual discrete units that are mixed into the rootzone layer (Baker, 1997).
Enkamat consists o f a bulky mat made from nylon threads which are fused together where they cross. The thickness
o f this three-dimensional mat ranges from 11/16- to 7/8-inch and has an open construction leaving 90% o f 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 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.
Methods:
A 50 ft. by 50 ft. sand-based pad, six inches deep, was constructed in the fall o f 1997 for evaluation o f Enkamat at
the Horticulture Research Station, Ames, Iowa. The sand-based system was placed over a 4-inch gravel blanket
with a network o f 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 o f 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.

Table 1. Treatments used to compare the reinforcement capability o f Enkamat on sand-based athletic fields.
Depth o f synthetic below sod
Comments
Trt
Synthetic
(sod contains 0.75 inches of soil)
Standard for the industry

-

1

Sand

2

Enkamat

0 (0.75 inches)

3

Enkamat

1 (1.75 inches)

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 o f the plots will allow for study o f 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 o f the sand base or one inch below the surface of the sand base. In treatment #2, the top o f the Enkamat
is even with the top o f the sand surface. When sodded, the top o f the Enkamat is then covered by 0.75 inch o f soil.
In treatment #3, the top o f the Enkamat is placed one inch below the surface o f the sand. When sodded, the top o f
the Enkamat is then covered by 1.75 inches o f soil. The study area was sodded on 7 November 1997 with
‘Midnight’ Kentucky bluegrass containing 0.75 inch o f 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

92

Soil Modification and Sand-based Systems

through an automatic watering system at the first sign of wilt. Approximately 1.5 inches o f water will be applied
each week from M ay through September. Nitrogen will be applied at 1 lb N/1000 sq. ft/grow ing month.
Phosphorous, potassium, calcium, magnesium, and micronutrients will be applied based on soil testing.
The study was evaluated for turf appearance, surface hardness, and traction from July through October. Turf
appearance was evaluated by determining turf quality and percent turf cover. 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
o f 18 inches. Also, surface hardness was measured with a 0.5-kg Clegg impact hammer. 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 o f the torque device and the weight was dropped from a height o f 2
inches. Traction was assessed as the amount o f torque (N m ) required to tear the underlying sod. Traction data
represent the average o f two individual measurements per plot. From mid-August through October, traffic was
applied every Monday, Wednesday, and Friday with a model T224 Brouwer roller that has been converted into a
riding traffic simulator. Both o f 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 o f traffic that
produces a tearing action o f the grass surface. During 1998, all Enkamat treatments received a total o f 133 passes o f
simulated traffic. Soil moisture content was performed by randomly sampling soil cores from the study area on each
o f the four different dates. The soil moisture content was 10.69%, 17.21%, 10.57%, and 17.30% respectively for the
four dates. The entire study area will receive both hollow and solid coring in 1999 to determine if Enkamat disrupts
this routine management practice.
The Statistical Analysis System version 6.06 (SAS Institute, 1989) and Analysis o f 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 1 and 2), traction (Table 3), and turf appearance (Table 4).

1998 Results:
On 9 September 1998 Enkamat placed 1 inch below the sod resulted in a significantly harder surface than Enkamat
placed immediately below the sod or the control without Enkamat when measured with the 0.5kg hammer (Table
1). This effect was observed in both the traffic and no traffic areas. Also, on 9 September 1998 the control treatment
without Enkamat was significantly different between the traffic treated areas and no traffic treated areas when measured
with the 2.25kg hammer (Table 2).
Enkamat treatments had no effect on surface traction, turf quality, and percent turf cover under conditions o f no traffic
or intense traffic. On 29 October 1998 turf injury resulted in a quality o f 3 with 30 percent turf cover for the control
and 35 percent turf cover for the treatments with Enkamat (Table 4). This level o f loss resulted in approximately a
10 N m decline in traction (Table 3). Traction was significantly less for the traffic treated areas compared to the nontrafficked turf.
Enkamat treatments did not affect traction in the traffic treated areas. Even though the turf was significantly worn,
30-35 percent turf cover, the sod layer was not “broken through” and the cleats o f the traction measurement device
did not contact the Enkamat. The traction device impacts a rotational force in a plane horizontal to the surface. It
appears that this device does not simulate the forces necessary to cause breakthrough o f the surface as observed when
a player makes a foot-plant or sharp turn. There is currently no device available that measures field stability or the
ability o f a player to break through the sod surface. A visual but quantitative scale also needs to be developed to
rapidly assess surface stability conditions.
Research will continue before a final report is prepared.

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.
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.

93

Soil Modification and Sand-based Systems

Enkamat Study Plot Plan
<—N

Objective: To determine required depth o f placement for Enkamat.
Treatments:
1. No Enkamat
2. Enkamat 0” below surface o f sand.
3. Enkamat 1” below surface o f sand.

Installation procedure:
1. Treatment 1—No Enkamat installed. Existing surface is considered top o f sand.
2. Treatment 2--Loosen top one-half inch o f surface with stiff rake. Press Enkamat into sand and roll surface so that
top o f Enkamat is even with top o f final sand surface.
3. Treatment 3—Remove the top one inch o f sand. Loosen top one-half inch o f surface with stiff rake. Press
Enkamat into sand and roll surface. Replace one inch o f sand on top o f 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 o f soil attached to the
grass mat.

94

Soil Modification and Sand-based Systems

Table 1. Surface hardness measured with the 0.5kg hammer (gmax)
Treatment

7-24-98

8-25-98

9-29-98

10-29-98

Mean

Control - no Enkamat

80.3

84.0

74.7

59.3

74.6

Enkamat - 0 inch below :

77.3

76.0

73.7

61.7

72.2

Enkamat - 1 inch below

81.0

80.0

86.3

60.7

77.0

Control - no Enkamat

88.0

90.0

87.3

62.3

81.9

Enkamat - 0 inch below

86.0

82.0

83.7

64.7

79.1

Enkamat - 1 inch below

86.7

85.0

98.3

64.7

83.7

ns

ns

NO TRAFFIC

TRAFFIC

L S D ( o .o5) =

8.9

ns

5.3

NS = not significant at P < 0.05.

Table 2. Surface hardness measured with the 2.25kg hammer (gmax)
Treatment

7-24-98

8-25-98

9-29-98

10-29-98

Mean

Control - no Enkamat

53.7

53.0

54.3

51.7

53.2

Enkamat - 0 inch below

55.7

55.7

58.3

52.3

55.5

Enkamat - 1 inch below

53.0

52.3

64.0

54.0

55.8

NO TRAFFIC

TRAFFIC

111W m SÊgggKtÊM

Control - no Enkamat

55.0

57.3

67.0

51.3

57.7

Enkamat - 0 inch below

57.0

57.7

63.7

50.7

57.3

Enkamat - 1 inch below

54.0

53.0

73.0

50.0

57.5

3.8

10.3

ns

ns

L S D ( o .o5)

ns

NS = not significant at P < 0.05.

95

Soil Modification and Sand-based Systems

Table 3. Traction measurements (N-m)
Treatment

7-24-98

8-25-98

9-29-98

10-29-98

Mean

Control - no Enkamat

52.3

46.7

48.6

49.9

49.4

Enkamat - 0 inch below

52.8

48.1

48.3

49.8

49.8

Enkamat - 1 inch below

50.4

46.6

52.5

49.7

49.8

Control - no Enkamat

50.6

49.8

49.4

39.3

47.3

Enkamat - 0 inch below

54.6

50.6

48.2

38.4

47.9

Enkamat - 1 inch below

51.6

48.3

49.7

38.3

47.0

ns

ns

ns

NO TRAFFIC

TRAFFIC

L S D ( o .o5)

2.2

ns

NS = not significant at P < 0.05.

Table 4. Percent turf cover (% cov) and turf quality (Q), 10 = best and 1 = worst.
Treatment

•

% COV

Q

8

100

8

8-25-98

9-29-98

% COV

Q

% COV

9

100

10

100

100

9

100

10

8

100

9

100

8

100

9

8

100

7

10-29-98

Mean

% COV

Q

10

100

9

100

100

10

100

9

100

10

100

10

100

9

100

100

6

55

3

30

7.7

71

9

100

6

50

3

35

7.7

71

100

9

100

6

55

3

35

7.7

72

ns

ns

ns

ns

ns

ns

ns

ns

ns

O

% COV

No Traffic

Control - no Enkamat
Enkamat - 0 inch
below
Enkamat - 1 inch
below

•

7-24-98
0

Traffic

Control - no Enkamat
Enkamat - 0 inch
below
Enkamat - 1 inch
below

ns
LSD(0.05)
NS = not significant at P < 0.05.

96

Soil Modification and Sand-based Systems

Managing Cool-season Grasses as Part of a SportGrass® System
David D. Minner and Jay S. Hudson
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 o f natural grass with some o f the more
durable characteristics o f synthetic turf.
The SportGrass® system is a synthetically reinforced layer of grass that is grown on a sand-based rootzone. The system
consists o f natural grass growing in a synthetic matrix containing fibrillated fibers (polypropylene blades) attached to a
backing. Within the layer o f 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 o f the plant are protected. SportGrass® is horizontally and vertically
stabilized by the combination o f 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 o f the SportGrass®
system maintain a stable playing surface. SportGrass® also aids in a quicker recovery o f 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 o f 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 o f thatch and the process o f topdressing can add as much as 0.5 to 2.0 inches o f 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” o f the stabilizer material reduces their effectiveness. We also want to know if current management
practices can be used to prevent accumulation o f 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
o f 1996 to evaluate mat management above the surface o f the stabilizers and to evaluate field hardness.

Methods:
Study # 1 - Mat Management
The objective was to evaluate conventional methods o f turfgrass management as they apply to SportGrass®. O f
particular interest is how grass management practices influence the accumulation o f 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 o f thatch may
improve surface characteristics by increasing cushion and biomass cover. Eight treatments including two nonSportGrass® controls were used to evaluate mat management in the SportGrass® System (Table la). The six
SportGrass® treatments consisted o f catching clippings, returning clippings, verticutting, solid coring, Primo plant
growth regulator, and verticutting after thatch accumulation. Verticutting was applied on 4 May 1998 and was aerified
on both 4 May and 25 August 1998. Primo treatments were applied on 23 May, 27 June, and 29 July 1998.
Verticutting was applied by making two passes over the plot in opposite directions using a Bluebird vertical mower.
The verticut depth was set so that it just touched the top o f 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

97

Soil Modification and Sand-based Systems

SportGrass®. The GA30 Cushman aerifyer with 5/8-inch hollow tines did not adequately penetrate the synthetic
backing o f 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 o f 36 holes/sq ft. Heavier coring equipment such as the
Cushman GA60 have successfully hollow cored through the SportGrass® backing using 3/4-inch tines.

Study #2 - Grass Species
The objective was to evaluate how grass species, seeding rates, and traffic intensity influence the performance o f 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 o f
perennial ryegrass have been described as being more slippery than other types o f grass. This study evaluates the
performance o f a SportGrass® system with respect to hardness and footing.
Studies were evaluated for turf appearance, surface hardness, and traction measurements from May through October 1998.
Turf appearance was evaluated by determining turf quality, turf color, and percent cover on 4 May and 16 October 1998.
On five different dates, 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 o f 18 inches. Also, surface hardness was measured with a
0.5-kg Clegg impact hammer. 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 o f the torque device and
the weight was dropped from a height o f 2 inches. Traction was assessed as the amount o f torque (N m) required to tear
the underlying sod. Traction data represent the average o f three individual measurements per plot. From mid-August
through October, traffic was applied every Monday, Wednesday, and Friday with a model T224 Brouwer Roller that
has been converted into a riding traffic simulator. Both o f 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 differentialslip-type o f traffic that produces a tearing action o f the grass surface. During 1998, all SportGrass® treatments received a
total o f 133 passes o f simulated traffic. Soil moisture content was performed by randomly sampling soil cores from each
study area on data collection dates.
The Statistical Analysis System version 6.06 (SAS Institute, 1989) and Analysis o f 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).

1997 Results:
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 o f 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 o f SportGrass®, the preliminary results in this study indicate that solid tine coring can
be used to effectively manage surface hardness.
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.

1998 Results:
Study # 1 Mat Management
Solid tine coring produced a reduction in surface hardness in both 1997 and 1998 (Tables 5 and 7). In contrast
verticutting produced an increase in surface hardness in both years (Table 5). Primo had no effect on surface hardness
but did produce turf with better color and quality (Table 10a).

98

Soil Modification and Sand-based Systems

Study # 2 Grass Species
Traffic treatment was more detrimental to perennial ryegrass than Kentucky bluegrass. On 16 October 1998, following
approximately two months o f simulated traffic, perennial ryegrass had 60% turf cover while Kentucky bluegrass had
97% turf cover (Table 10b). The ryegrass was showing severe cleat marks every two inches and exposed soil while the
Kentucky bluegrass had only a few cleat marks and no exposed soil.
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. Additional research will
include soil physical characteristics and root sampling above and below the synthetic layer.

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.
Cultivation

PGR

Other

2.
3.
4.
5.

Catch
Return
Return
Return
Return

none
none
Verticut
Solid core
none

none
none
none
none
Primo

6.

Return

none

none

7.
8.

Return
Return

none
none

none
none

none
none
none
none
none
after thatch accumulates, begin
thatch reduction treatment
Seeded control
Sodded control

Trt

C lippings

1.

Table lb. Plot layout for mat management study.
extra plot
extra plot
3 ■

■

6

4

1

3

8

2
5
3
2
i
5
1
7
1_____ ___ §_________
GRASS SPECIES STUDY AREA
6

with SportGrass®
yes
yes
yes
yes
yes
yes
no
no

4

1
6
4

North «
Rep 2

Table 2a. Species layout for grass species study.
Trt

Grass species
(whole plot trt)

Seeding rate
lb/1000 ft2
2
2
4
4
7
7
14
14
2& 7
2&7

Kentucky bluegrass1
1.
2.
Kentucky bluegrass
3.
Kentucky bluegrass
4.
Kentucky bluegrass
5.
Perennial ryegrass2
6.
Perennial ryegrass
7.
Perennial ryegrass
8.
Perennial ryegrass
9.
KB & PR
10.
KB & PR
11
V
n O
. DD
11.
Is Jd oc rK
12.
KB & PR
1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ Perennial ryegrass

fir

A Oc 11 A
4
4

4 & 14

99

Traffic Intensity
............... (Split p lo t)......................
Low
H igh
yes
yes
yes
yes
yes
yes
yes
ves
yes
yes
yes
yes

W.

Soil Modification and Sand-based Systems

Table 2b. Plot plan of treatment arrangements for the grass species study.
MAT MANAGEMENT STUDY AREA
North «

REP 1

REP 2

1

2

3

4

5

6

7

8

9

1
(la)

3
(2a)

5
(3a)

7

9
(5a)

h

(6a)

1
(la)

7

(4a)

(4a)

9
(5a)

10

11

12

13

14

15

16

17

18

2
(lb)

4
(2b)

6
(3b)

8
(4b)

10
(5b)

12
(6b)

19

20

21

22

23

24

25

26

27

7

5
(3a)

h

(6a)

3
(2a)

1
(la)

9
(5a)

5
(3a)

h

(4a)

(6a)

3
(2a)

28

29

30

31

32

33

34

35

36

12
(6b)

4
(2b)

2
(lb)

10
(5b)

8
2
___ (lb)___ ___ (4b)___

10
(5b)

RE P 3

8

6
(3b)___

___ («■»

6
___ (3b

12
4
}_ ____ &ÌÙ___ ____ £b ] ___

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.
Surface hardness (gmax)
Treatments
2.25-kg hammer
1.
2.
3.
4.
5.
6.
7.
8.

94.4
95.3
94.3
77.6
93.5
97.3
73.3
83.5
10.0

Catch clippings
Return clippings
Verticut (prevent thatch)
Solid tine aerify
PGR (Primo)
Verticut (after thatch accumulates)
Control seeded
Control sodded
L S D ( o.o5)

Traction
(N m )
65.2
68.5
67.3
67.5
67.0
67.0
63.6
63.1
NS

NS = not significant at P < 0.05.

Table 3b. Percent soil moisture and organic matter (by weight).
Treatment
extra plot
8
7
7
7

Rep
3
1
2
3

Sample description
fibers in sample
fibers in sample
seeded KB
seeded KB
seeded KB

% soil moisture
3.4
3.1
3.3
4.4
3.0

100

% organic matter
0.7
0.7
0.5
0.7
0.7

Soil Modification and Sand-based Systems

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.
Surface hardness
Seeding rate
Treatments
lb/1000 sq.ft.
________________________ ( g m a x )_______________________________
1. Kentucky bluegrass1
2
92.8
4
88.2
2. Kentucky bluegrass
81.0
3. Perennial ryegrass2
7
14
4. Perennial ryegrass
76.1
5. KB' + PR2
2+7
78.5
77.4
6. KB + PR
4+14
7. KB Control seeded
4
73.3
—
8. KB Control sodded
83.5
6.1
L S D ( o.o5)
1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ perennial ryegrass
Table 5a. Surface hardness and traction measurements for the mat management study on 4 May 1998. Three traction
measurements were taken within each plot and averaged.
Traction
Surface hardness
Surface hardness
Treatments
(g m a x )
(g m a x )
(N m )
2.25-kg hammer
.5-kg hammer
56.7
1. Catch clippings
75.3
68.0
2. Return clippings
73.0
60.1
66.5
3. Verticut (prevent thatch)
75.7
63.4
71.0
4. Solid tine aerify
69.1
64.3
71.3
70.7
61.2
5. PGR (Primo)
70.5
6. Verticut (after thatch accumulates)
73.9
63.2
69.8
7. Control seeded
64.8
69.7
56.9
8. Control sodded
53.2
55.3
68.0

Table 5b. Surface hardness measurements for the mat management study on 4 May 1998 after specific management practices
were performed.
aredimerne

rI ' r p o f m p n f c

3. Verticut (prevent thatch)
4. Solid tine aerify

Surface hardness (gmax)
2.25-kg hammer
94.3
70.4

Surface hardness (gmax)
.5-kg hammer
108.8
58.1

Table 6. Surface hardness and traction measurements taken on 4 May 1998 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. Traction is the average
of three measurements.
Traction
Surface hardness (gmax)
Surface hardness (gmax)
.5-kg hammer
Treatments
2.25-kg hammer
(N m )
1. Kentucky bluegrass1
49.0
69.2
63.1
2. Kentucky bluegrass
63.6
57.7
65.8
60.4
3. Perennial ryegrass2
66.0
63.6
4. Perennial ryegrass
61.3
66.8
64.2
5. KB1+ PR2
62.7
61.6
66.5
6. KB + PR
65.8
65.7
63.8
"l ‘Limousine’
:v~"' — • , Kentucky
.— ;— n
--------------bluegrass
2 ‘Pinnacle’ perennial ryegrass

NOTE: On 4 May 1998 all plots for mat management and grass species studies were rated for turf quality, color, and
% cover.
Quality
Color
% Cover

All plots = 9 (9 = best quality)
All plots = 9 (9 = best color)
All plots = 99% (99% = best cover)

101

Soil Modification and Sand-based Systems

Table 7a. Surface hardness measurements(gmax) for the mat management study on four different dates in 1998 using a 2.25 kg
hammer.
August 25
September 29
October 29
Treatments
July 24
104.4
109.0
2. Return clippings
98.7
95.0
95.7
101.6
113.1
3. Verticut (prevent thatch)
99.5
89.6
94.8
101.9
4. Solid tine aerify
94.8
99.7
107.8
5. PGR (Primo)
97.7
92.1
90.7
86.7
90.3
7. Control seeded
84.3
78.7
75.6
8. Control sodded
81.2
72.8

Table 7b. Surface hardness measurements for the mat management study on four different dates in 1998 using a .5 kg hammer.
October 29
August 25
September 29
July 24
Treatments
106.2
107.5
98.1
115.3
2. Return clippings
118.2
107.9
98.9
124.9
3. Verticut (prevent thatch)
115.5
100.5
116.1
4. Solid tine aerify
100.7
5. PGR (Primo)
107.8
101.8
97.3
111.9
129.7
102.8
96.1
113.5
7. Control seeded
8. Control sodded
114.7
103.9
94.2
98.5

Table 7c. Traction measurements(Nm) for the mat management study on four different dates in 1998. Three traction
measurements were taken within each plot and averaged
Treatments
July 24
August 25
September 29
October 29
73.0
61.7
2. Return clippings
66.3
59.8
71.7
71.0
63.3
61.8
3. Verticut (prevent thatch)
75.0
61.0
4. Solid tine aerify
68.3
57.2
74.7
70.0
64.0
5. PGR (Primo)
62.3
66.3
7. Control seeded
66.5
69.3
56.2
62.0
8. Control sodded
62.8
67.8
57.0

Table 7d. Surface hardness and traction measurements for the mat management study on 25 August 1998 after specific
management practices were performed.
Traction
Surface hardness (gmax)
Surface hardness ( g max )
Treatments
.5-kg hammer
2.25-kg hammer
(N m )
84.0
65.3
66.2
4. Solid tine aerify

Table 8a. Surface hardness measurements(gmax) for the grass species study on four different dates in 1998 using a 2.25 kg
hammer. The a and b parts of the individual plots were combined as an overall plot and surface hardness was
performed.
September 29
October 29
July 24
Treatments
August 25
97.0
103.8
1. Kentucky bluegrass1
96.6
91.0
96.9
2. Kentucky bluegrass
104.5
99.7
89.3
86.2
81.8
85.5
90.6
3. Perennial ryegrass2
85.0
4. Perennial ryegrass
83.0
78.7
89.1
85.0
5. KB1+ PR2
83.7
77.1
90.8
6. KB + PR
81.7
86.5
81.1
91.1
1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ perennial ryegrass

102

Soil Modification and Sand-based Systems

Table 8b. Surface hardness measurements for the grass species study on four different dates in 1998 using a .5 kg hammer.
_________ The a and b parts of the individual plots were combined as an overall plot and surface hardness was performed.
September 29
October 29
Treatments
July 24
August 25
107.4
92.3
104.9
1. Kentucky bluegrass'
110.5
101.8
82.0
106.7
2. Kentucky bluegrass
109.3
115.7
95.3
3. Perennial ryegrass2
115.1
120.5
112.8
95.4
109.1
4. Perennial ryegrass
116.5
116.7
92.7
112.9
5. KB1+ PR2
112.7
96.3
120.7
114.4
113.8
6. KB + PR
1 i ‘Limousine’
•____• , Kentucky
,
, 1:bluegrass
--------2 ‘Pinnacle’ perennial ryegrass
Table 8c. Traction measurements(Nm) for the grass species study on four different dates in 1998. The a and b parts of the
individual plots were combined as an overall plot and surface hardness was performed. Traction is the average of
three m
e a s u
r e m
e n
t s . ______________________________________
August 25
September 29
October 29
Treatments
July 24
61.0
70.7
68.3
58.5
1. Kentucky bluegrass1
75.7
63.0
60.7
65.5
2. Kentucky bluegrass
56.3
55.8
51.0
3. Perennial ryegrass2
64.7
56.8
52.0
47.2
65.7
4. Perennial ryegrass
5. KB1+ PR2
54.2
52.7
58.8
53.0
51.2
6. KB + PR
60.2
55.3
53.3
‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ perennial ryegrass

Table 9. Percent soil moisture (by weight) taken for mat management and grass species study on four different dates.
Mat Management
Grass Species

7/24/98
4.68
5.91

8/25/98
6.98
7.51

9/29/98
6.47
8.14

10/29/98
8.35
9.81

Table 10a. Ratings of turf quality, color, and % cover for the mat management study on 16 October 1998.
Treatments
1.
2.
3.
4.
5.
6.
7.
8.

Catch clippings
Return clippings
Verticut (prevent thatch)
Solid tine aerify
PGR (Primo)
Verticut (after thatch accumulates)
Control seeded
Control sodded

Turf Quality
(9 = best)
6.3
6.3
6.7
6.3
8.0
6.7
5.3
5.0

Turf Color
(9 = best)
6.3
6.3
7.0
6.7
8.0
6.3
6.0
6.0

% Turf Cover
97.0
97.7
99.0
99.0
99.0
99.0
86.7
82.5

Table 10b. Ratings of turf quality and % cover for the grass species study on 16 October 1998.
Treatments
1. Kentucky bluegrass1
2. Kentucky bluegrass
3. Perennial ryegrass2
4. Perennial ryegrass
5. KB1+ PR2
6. KB + PR
1 ‘Limousine’ Kentucky bluegrass
2 ‘Pinnacle’ perennial ryegrass

Turf Quality
(9 = best)
7.0
7.0
4.0
4.0
4.0
4.0

103

% Turf Cover
97.7
97.7
60.0
61.7
65.0
65.0

Soil Modification and Sand-based Systems

Managing Bentgrass Stress on Putting Green Slopes -1998 Report
David D. Minner, Nick E. Christians, Deying Li, Iowa State University
Iowa Golf Course Superintendents Association, Golf Course Superintendents Association o f America
Turf management practices are usually applied uniformly across a putting green. Research greens are usually
perfectly flat and uniform. However the actual greens are not flat and problem areas are not uniform. A meaningful
interpretation o f research results depends on how close the research situation is to the real world. A sloped research
green (SRG) was constructed at the Horticulture Research Center, Ames, IA, in July 1997 to evaluate bentgrass
management under difficult and variable growing conditions. Construction o f the green was funded by Iowa State
University, the Iowa G olf Course Superintendents Association, and the G olf Course Superintendents Association o f
America. The objective o f this project was to evaluate organic and inorganic amendments applied as topdressing.
The SRG was erected to simulate the undulating topography that occurs on many putting greens - as opposed to a
typical flat research green (Figure 1). A 12-inch sand rootzone containing no amendments, organic or inorganic, was
positioned over a 4-inch gravel blanket with 4-inch drain lines. The subgrade, gravel blanket, and sand rootzone all
follow the same contour. 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 o f 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 o f the green is expected to have excessively
wet conditions. To our knowledge, this type o f sloped green project has never been used for putting green research.
The sand for rootzone construction has a pH o f 8.2 and is calcareous. The green was seeded with Crenshaw creeping
bentgrass in September 1997. The sloped green matured and filled in during the summer o f 1998. By August there
was 100 percent turf cover and approximately 0.5 cm o f thatch. The experimental area measures 100 ft by 40 ft.
The main experiment contains five topdressing treatments in a complete randomized block design. Each treatment
unit (plot) measures 40 ft by 6 ft. The long and narrow plots are situated so that each treatment covers all four
distinct microenvironments on the green. The five topdressing treatments are listed in Table 1. Axis, Profile,
Zeolite, and Zeopro are inorganic amendments that will be compared with the organic amendment Dakota Peat.
Axis is a diatomaceous earth, Profile is a porous ceramic clay, Zeolite is a aluminosilicate mineral, and Zeopro is a
nutrient loaded zeolite. In another experiment, Bio-Flex-A-Clay was used as topdressing at three different rates 5
lb/1000 ft2, 10 lb/1000 ft2, 20 lb/1000 ft2. Bio-Flex-A-Clay is a polymer coated sand with a kelp material
incorporated. All o f the products claim to improve cation exchange, and nutrient and water holding capacity.
On 25 September 1998 the green was severely verticut. A 0.5 cm depth o f topdressing material was immediately
applied for each treatment following verticutting. The green was maintained at a 0.25-inch cutting height and
covered during the winter with a Covermaster cover for winter protection. Moderate-to-severe winter desiccation
damage was observed when the protective cover was removed in April. Most o f the injury occurred on the knoll and
south facing slope near the knoll o f the green. The entire green was reseeded with 2.0 lbs. Of'Crenshaw' creeping
bentgrass in May. There were no apparent differences among treatments based on winter injury. An additional 1.5
cm o f topdressing is targeted for the entire 1999 growing season. Topdressing will be applied in light and frequent
applications (Table 2).
Routine traffic, fertilizer and mowing will be applied. Dry condition will be simulated by restricting irrigation on a
temporary basis from July through August. Turfgrass survival and loss will be related to the treatments and micro
climate areas.

104

Soil Modification and Sand-based Systems

Table 1. Organic and inorganic amendments applied to the sloped putting green as topdressing treatments.
Organic
Inorganic
Topdressing Treatment
Calcareous Sand
Amendment
Amendment
% by volume
10
1
90
sand + Dakota peat (control)
2
sand + Axis
80
20
sand + Profile
80
20
3
20
4
sand + Zeolite
80
80
20
5
sand + Zeopro

Table 2. Amount and date of topdressing application.
Topdressing
Treatment
9-25-98 5-14-99 6-2-99
0.5
0.2
0.2
1 sand + Dakota
peat (control)
0.2
0.2
2 sand + Axis
0.5
0.2
0.5
0.2
3 sand + Profile
0.2
4 sand + Zeolite
0.5
0.2
0.5
0.2
0.2
5 sand + Zeopro

Topdressing depth (cm)
6-11-99

6-25-99

7-9-99

7-23-99

8-6-99

Target topdressing depth of 0.2 cm
for each treatment and date.

Fig 1. Sloped R esearch

105

8-20-99

Soil Modification and Sand-based Systems

Effects of Inorganic Soil Amendments on Sand-based Media
Deying Li, Young K. Joo, Nick E. Christians, and David D. Minner
ABSTRACT
Inorganic soil amendments have been suggested for use in turf to alleviate soil compaction, to increase the water
retention and hydraulic conductivity, and to improve many other soil physical properties. No single soil conditioner
can have all those properties. They, therefore, should be used in a site- and case-specific way. This study was to
determine the effects o f four different inorganic soil amendment materials Bio-ceramic, Profile, Axis, and Bio-FlexA-Clay on the soil hydraulic parameters o f a sand-based media. The inorganic materials were added to a USGA
sand-based green at 15% v/v during construction in 1996. The study was conducted during the 1997 and 1998
seasons. A laboratory study using a peat amendment and a pure sand control was also conducted in the spring o f
1999. Data collected on the field areas included saturated hydraulic conductivity (Ksat), water retention, water
release curves, bulk density, and total porosity on both undisturbed and recompacted samples collected from the
treated plots one and two years after establishment. The Profile treatment had significantly higher cation exchange
capacity (CEC) than the control in both years. Bio-ceramic had a higher CEC and Bio-Flex-A-Clay had lower CEC
than the control in 1997. Profile increased the Ksat significantly in the recompacted and undisturbed samples in
1998. Axis increased water retention in both recompacted and undisturbed samples. Ksat o f all treated plots was
reduced by 75% in November o f 1998. The Ksat values in the spring o f 1999 increased from the low levels o f 1998
by 19.2% (Bio-Flex-A-Clay), 43.5% (control), 58.6% (Bio-ceramic), 72.1% (Profile) and 81.7% (Axis). The
changes o f Ksat over the winter may have been induced by freezing and thawing that occurred over the winter. This
hypothesis was further tested in the laboratory in a freeze-and-thaw study conducted in 1999. The bulk density o f
sand mixed with Bio-Flex-A-Clay, peat, Axis and Profile was decreased by 10.7%, 7.2%, 2.5% and 2.2%
respectively following a freeze-and-thaw cycle. The decrease of bulk density in the control and in sand treated with
Bio-ceramic was negligible.

Table 1. Soil test results for the inorganic soil modification study1 (Sand-based green 1998)
CEC
8.3
8.1
8.9
8.1
7.8

PH
8.3
8.3
8.2
8.3
8.2

0.08
0.08
0.08
0.08
0.11

Na
19.7
18.0
19.7
18.3
17.7

OM
0.5
0.5
0.5
0.4
0.6

NIT
1.3
2.3
1.3
1.3
1.7

P
3.0
4.0
4.3
4.7
3.0

K
25
25
49
25
22

Mg
80
78
114
73
79

Ca
1486
1454
1534
1478
1414

L S D 0.05

0.6

NS

NS

NS

NS

NS

NS

4

12

NS

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

S
1.0
1.0
1.0
1.0
1.7

Zn
0.8
0.9
0.7
0.7
0.9

Mn
2.8
2.8
2.5
2.5

Cu
0.6
0.9
0.6
0.7
0.7

Fe
6.57
6.57
7.87
7.23
6.13

B
0.3
0.3
0.3
0.3
0.3

AK
0.8
0.8
1.4
0.8
0.7

AMg
8.1
8.0
10.8
7.5
8.3

ACa
90.1
90.2
86.9
90.8
90.0

ANa
1.0
1.0
0.9
1.0
1.0

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

ss

2 .9

NS
0.5
0.3
*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=NitriteN (ppm)
LSDo.os

0.2
0.7
NS
NS
NS
AK= Actual Potassium (% base saturation)
AMg= Actual Magnesium (% base saturation)
ACa=Actual Calcium (% base saturation)
ANa= Actual Sodium (% base saturation)

106

0.8

NS

Gravimetrie water content (%)

Soil Modification and Sand-based Systems

Water potential (-mbars)

Figure 1. Water release curve of different soil amendment treatments

Test Stage
Figure 2. Freeze and thaw characteristics of soil conditioners

107

Soil Modification and Sand-based Systems

Bulk density decrease (g/crm)

0

0.01

0 .0 2

0 .0 3

0 .0 4

0 .0 5

0 .0 6

0 .0 7

0 .0 8

0 .0 9

Total porosity increase

Figure 3. Saturated hydraulic conductivity increases vs porosity and bulk density changes

Soil Modification and Sand-based Systems

Modifying Athletic Field Soils with Calcined Clay and Tillage
David D. Minner and Jeffrey J. Salmond
The objective o f 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 calcined clay 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 o f the
yard line and 7.5 ft. was on the other side o f the same yard line. Treatments consisted o f 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 o f 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 was seeded in May 1998 with a bluegrass blend containing ‘Nublue’, ‘Limousine’, and
‘Touchdown’. The field is used primarily for fall football practice (September through November) and spring soccer
(April and May). Football in the fall o f 1998 and soccer in the spring o f 1999 resulted in substantial wear in the
center o f the field. Because o f the two different sports, the wear pattern has not been consistent. Football wear was
concentrated around each 5-yard line where the ball was placed to restart a practice set. Soccer wears out the center
circle and the penalty and goalie areas. In the worn areas, the grass has been completely removed and bare soil is
exposed. A visible response from treatments, based on traffic, was not apparent in the fall o f 1998 or spring o f 1999.
In the summer o f 1998, when the grass was establishing, there was a noticeable difference in the green color o f both
the turfgrass and the crabgrass weeds. The highest rate o f Turface had the lightest green color followed by the low
rate o f Turface. The non-Turface control plot had a normal, dark green appearance. After applying 1.0 lb N/1000
sq. ft. to the entire study area in August, the Turface plots produced an acceptable green color that was similar to the
control plots. There was no difference in turf color among treatments during the spring o f 1999.
The inconsistent wear patterns on the research area made it difficult to determine if there were true treatment
differences, even though there were seven reps and very large plots. The field was cored on 3-inch centers with 0.75inch hollow tines on 9 June 1999. Cores were dragged within each plot and the area was drill seeded in three
directions with a drill seeder.
It is too early in this research project to determine if tilling Turface into a field will help maintain better grass under
intense traffic. However, we have observed that the Turface-treated plots dry quicker and make a better playing
surface when the soil is exposed on worn areas. The Turface-treaded areas also are easier to penetrate when the field
playing conditions are normally hard and dry.

109

Soil Modification and Sand-based Systems

Table 1. Experimental plot layout o f calcined clay tilled renovation. Treatments were applied on November 13,
1997.
[CenterAo f field]
Plot #
1
T
Plot size is
!
1
------------- 3------------50 x 15 ft
Goal Line
1
REP 1
1
!
2
1
1
1
2
'
3
1
1
Plots are centered
1
1
A
1
1
between hash marks
1
1
1
1
•
5
REP 2
3
1
1
2
!
6
1
1
1

J"2

1
1

1

1

7

!

8

Each 5-yard line is the
center o f the plot

/

REP 3

■

1
1

2

i

50-yd Line

9
10

1
1
1

1

J

------------- 2-------------

1
1

3

!

12

1

!
1
1
1
1
1

13

1
1
■
1
1
1
1
•
1
1
■
1
1

2
3

11

14

1
1
«

16

3

!

17

1
1

2

!

18

1

3

1
1

19

2

!

20

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

!

21

1

REP 4

REP 5

15

1

1
1
1
1
1
Goal Line

1
1
1
«
1
1
■
«

REP 6

REP 7

Table 2. Treatment listing and respective rates.
Rate
(tons/1000 ft2)
1
1
Turface
.2
2
Turface
NA
3
Untreated control*
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.
Treatment

110

Soil Modification and Sand-based Systems

Athletic Field Turfgrass Response to Calcined Clay Topdressing
David D. Minner and Jeffrey J. Salmond
Inorganic amendments have been used to amend soils that are compacted by excessive traffic. Our objective was to
evaluate Turface as a topdressing material and its effects on turfgrass growth. The study is being conducted on a
local high school football/soccer practice field. Topdressing with Turface is being compared to a topdressing with a
local mason sand.
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 20-yard lines. Each individual plot measured 15 ft. by 50 ft. for
a total o f 12 plots. Treatments consisted o f two topdressing materials, Turface or sand, with six replications. Six
plots were topdressed with Turface (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 o f three Kentucky bluegrass cultivars and two perennial ryegrass
cultivars, and fertilized (Table 1). The sand was topdressed at the same depths as the Turface. Plots were arranged
every 5 yards. Core plugs were left on the surface and the plugs and topdressing were mixed on the surface by
separately dragging each plot.
The topdressing treatments and renovation schedule are presented in Table 1. To date, the Turface-treated plots
contain a rate o f 2142 lbs/ 1000 sq.ft, or 1606 lbs per plot area. One-quarter inch o f topdressed calcined clay on the
individual plots is equivalent to a rate o f 714 lbs/ 1000 sq.ft. The experimental plot layout is presented in Table 2.
The study area receives fall football and spring soccer. So far there have been no distinct differences in turf quality or
percent turf cover that can be attributed to the treatments. In the worn areas o f the study and where soil is exposed,
the Turface maintains a drier surface and improves playing conditions. The study will be continued through 1999.
Table 1. Renovation schedule for Turface and sand topdressing treatments.
Turface 1/4 in. (714 lbs/1000 sq. ft.)
Sept. 1, 1996
core aerify
Sand 1/4 in.
Turface 1/4 in. (714 lbs/1000 sq. ft.)
core aerify
Nov. 1, 1996
Sand 1/4 in.
Turface 1/8 in. (357 lbs/1000 sq. ft.)
June 1, 1997
core aerify
Sand 1/8 in.
Turface 1/8 in. (357 lbs/1000 sq. ft.)
Sept. 1, 1998
core aerify
Sand 1/8 in.

seed

fertilize

seed

fertilize

seed

fertilize

seed

fertilize

Table 2. Experimental plot layout for topdressed calcined clay and sand between the hash marks and 20-yard lines
on a practice football field.
1
1
1
1
1

1

1

9
<S

1
T3
§
CO

1
1

;

1

1

1

1

4>

Ì
^

1

S

;

1

£

1

1

1
11

*
1

30

CO

1

1

1

i—_

1
1
1

1

40

ü
9

1

1

1

1
1

'

1

1
1

Ì0

1
1

T3
g
CO

1
1

1
1

11
»

1

C e n te r

1

1

0>
9
^

Ì

1
1

1

1
1

1

1

1
1

50
yard line

111

«
CO

1

;

o f fie ld

1
1

1
1

1
1

1

1

1
1

1
■

40

d>
&
<S

1 i

1
T3

§
C/5

1

1
1
1

1
1
1
1

1

1

1

1
1

1
11

1
1

1
1

30

IÌ
<L>

1
T3
§
CO

1
1
I

1
1
■

20

Soil Modification and Sand-based Systems

The Effect of Tarp Color on Turfgrass Growth
David D. Minner, Vince Patterozzi, Jeffrey J. Salmond, Jay S. Hudson, and Paul Stevens
Many o f our research ideas come from inventive grounds managers in the turfgrass industry. This project is a good
example. Vince Patterozzi, Head Grounds Manager Baltimore Ravens, noticed that there was a difference in turf
appearance when he used different color rain tarps. After two years o f hearing this comment, Vince put it to me like
this, “There is something going on with tarp color, you figure it out”. He arranged with M Putterman & Company
Inc. (800-621-0146) to send us several different samples of tarp colors. The study below is what developed from a
very astute observation. Thanks Vince.

Objective: To determine if tarp color has any effect on turf growth and color.
Method:
The Putterman Rain Buster Athletic Field tarps used in this study were designed to keep rain or snow o ff o f the
field. The tarps are made from 6-ounce polyethylene or 10-ounce vinyl. These tarps are generally placed on the
field temporarily and then removed when the rain event ends. Fields are generally covered for only a few hours, but
in some cases a tarp may be left on the field for three days or longer. Three different studies have been conducted
since the spring o f 1998 on a mature stand o f ‘Midnight’ Kentucky bluegrass. Five-foot by five-foot tarps o f each
tarp color were pinned to the ground in a randomized block design with 3 replications. Tarps were placed on April 9
and removed on April 24 in study A. Tarps were placed on 3 November 1998 and removed on 23 March 1999 in
study B. Tarps were placed on 23 March and removed 20 April 1999 in study C. Turf color was rated on a scale o f
1-10, 10 = darkest green and 1 = no green color, white/brown, and 6 = lowest acceptable color. Turf growth was
rated on a scale o f 1-10, 10 = most growth and 1 = no growth.

Results:
The data has not been statistically analyzed but the magnitude o f the differences and consistency among replications
has been compelling. Studies A and C were similar because they were covered just during spring green-up. Study
B was covered during the entire winter and then uncovered just before any green-up or growth occurred. In all
studies, tarp color had a dramatic effect on turf color. Yellow, orange, red, and white tarps produced the best turf
color with ratings ranging between 6.5 and 10. When compared to the control, turf color was generally enhanced by
tarp colors yellow, orange, red, and white. Tarp colors light blue, blue, and purple produced some yellowing that
made them inferior to yellow, orange, red, and white. Tarp colors gray, light-green, dark-green, and black produce
the most decrease in turf color and they were considered unacceptable. A Covermaster grow tarp and Enkamat were
also included in the study even though they are not moisture prevention tarps. Both Covermaster and Enkamat
improved turf color compared to the non-covered control plots.

It is clear that tarp color has an affect on turf performance. More investigation will be needed to evaluate duration
o f tarp cover, season o f tarp cover, heat load under tarps, and potential for diseases, and light penetration.

112

Soil Modification and Sand-based Systems

Table 1. Turf color and growth as affected by tarp color.

Study A

Study B

covered for 16
days in April

Covered for 140 consecutive days
November to March

Study C
Covered for 29
consecutive days in

Turf
color
7:5

Turf
color
9.5

Turf
growth
7.0

Turf
color
9.0

Turf
growth
8.5

Turf
color
8.5

Turf
growth
10.0

Red

6.5

8.3

8.7

9.7

9.0

8.7

8.7

Yellow

8.0

8.7

8.3

9.0

7.7

9.0

9.7

White

9.0

8.0

6.7

6.0

5.0

10

5.7

Light blue

5.0

5.0

5.5

6.0

5.0

6.0

6.0

Blue

5.5

6.5

6.5

7.0

7.5

6.0

7.5

Orange

Purple

5.0

5.7

6.7

5.0

6.7

4.0

8.0

Gray

2.0

4.0

4.5

4.0

5.5

2.5

7.7

Light green

3.0

3.7

6.7

4.0

6.7

3.7

8.0

Dark green

1.0

2.7

6.0

1.0

7.0

1.0

8.7

Black/white

1.0

3.0

8.0

1.0

6.0

1.0

7.0

1.0

6.0

8.0

1.0

White/black
Covermaster

7.0

5.0

5.0

5.0

10.0

3.0

Enkamat

9.7

9.0

5.0

4.0

10.0

5.0

6.0

3.3

1.0

4.0

6.3

1.0

Control no tarp

7.5

113

Soil Modification and Sand-based Systems

Calcium Applications to Turf on Sand-based Media
Rodney A. St. John and Nick E. Christians
Introduction:
There are two common ways to test for soil nutrients, the SLAN Method (Sufficiency Level o f Available Nutrients)
and the BCSR method (Basic Cation Saturation Ratio).
The SLAN method measures the amount o f nutrients in the soil and makes recommendations based on studies done
for that particular soil type and crop. Therefore, using the SLAN method for determining the fertilizer requirements
for turfgrasses can be problematic, since soil testing facilities usually make recommendations based upon
agricultural row crops.
The BCSR method consists o f measuring the relative quantities of cations on the cation exchange sites and
comparing their ratios. It is believed that optimal plant growth can be achieved by having Calcium on 60-65% o f
the cation exchange sites with ratios for the other cations being; Mg+2 10-20%, K+ 5-10%, N H / 5% and H* 5-20%.
When test results for a soil are outside the ranges for a cation, fertilizer treatments are recommended to correct any
deficiencies and to bring the ratios back in line.
The majority o f sand used in construction o f greens and athletic fields is termed calcareous, because o f the high
quantity o f calcium carbonate contained in the sand. Moreover, this sand usually, has a high pH around 8.2-8.3 and
a low cation exchange capacity around 1.2 meq/lOOg. It is not unusual for calcium content to be low on cation
exchange sites, resulting in recommendations for adding calcium. Calcium is recommended to be added even
though the soil media is calcareous and contains a large amount o f calcium in the soil.

Objectives:
To discover if adding calcium to calcareous soils that have a low calcium ratio will increase the amount o f calcium
taken up by the turfgrass plant, and more importantly if this increased calcium is beneficial to the grass plant.

Materials and Methods:
During the fall o f 1998, a preliminary greenhouse study was conducted looking at five different calcium treatments
(no calcium added, gypsum, lime, calcium nitrate, and calcium chelate) applied to Kentucky bluegrass and creeping
bentgrass grown on calcareous sand and silica sand.

Results:
During the 12-week test period some visual response trends among the different treatments were noticed, but the
data is still being analyzed to determine if the treatments were significant or not. Preliminary data are listed in
Tables 1 and 2.

Table 2. Calcium concentration in dry tissue (ppm) for

Table 1. Calcium concentration in dry tissue (ppm) for

the two different soil types.

the two different grasses.

No Calcium
Gypsum
Lime
Calcium Nitrate
Calcium Chelate

Bentgrass

Bluegrass

7522
10257
9882
9478
11309

4282
4951
4680
4745
5788

No Calcium
Gypsum
Lime
Calcium Nitrate
Calcium Chelate

114

Calcareous
Sand

Silica
Sand

7664
8675
7523
7159
8317

4140
6532
7038
7064
8781

Ornamental Studies

Effect of Organic and Mineral Mulches on Soil Properties and
Growth of Fairview Flame® Red Maple Trees
Jeffery K. lies and Michael S. Dosmann
Abstract. Five mineral mulches (crushed red brick, pea gravel, lava rock, carmel rock, and river rock) and three
organic mulches (finely screened pine bark, pine wood chips, and shredded hardwood bark) were evaluated over two
years to determine their influence on soil temperature, moisture, and pH, and to quantify their effect on growth of
Fairview Flame® red maple (Acer rubrum L.). Mulch treatments (2.3-m2 (25-ft2) plots o f eight mulches applied as
separate treatments and a non-mulched control) were randomly applied to trees in five blocks. Organic mulches
were placed directly on bare ground, while mineral mulches were underlaid with a woven polypropylene fabric.
Soil temperatures were highest and soil moisture percentages lowest under the mineral mulches and non-mulched
control. Soil pH readings were highest under shredded bark and wood chips, and lowest in the non-mulched control.
Despite these differences in root zone environments, there were no significant differences in tree height. Trees
growing in river rock, crushed brick, pea gravel, and carmel rock, however, had larger stem calipers than those
growing in shredded-bark plots. Crushed brick, pea gravel, and carmel rock treatments also resulted in greater leaf
dry mass than shredded-bark. Leaf dry mass also was greater for trees in crushed brick and pea gravel than screened
pine. Our results indicate mineral mulches used in this study do not create growth-limiting soil environments.

Benefits o f using wood and bark by-products as horticultural mulch over the root zones o f landscape plants are wellestablished (Gleason and lies 1998; Green and Watson 1989; Greenly and Rakow 1995; Skroch et al. 1992; Watson
1988), however, several actual or perceived problems associated with organic mulches such as, unacceptable
appearance (Rakow 1992), creation o f a temporary soil nitrogen deficiency (Ashworth and Harrison 1983), potential
fire hazard (Hickman and Perry 1996), and rapid decomposition (Rakow 1992) have led to increased usage of
mineral or rock mulches. But concerns that materials like rock, gravel, and crushed brick may promote potentially
injurious high temperatures both above and below the mulch layer, alkalinization of the soil, and mechanical injury
to the stems o f plants, have caused many landscape and tree-care professionals to reexamine their rationale for using
mineral mulches as suitable ground-covering materials around woody and herbaceous plants. This experiment was
designed to evaluate and compare the effects o f five mineral and three organic mulches on 1) several soil properties,
and 2) growth o f Fairview Flame® red maple (Acer rubrum L.).
MATERIALS AND METHODS
Ninety bare-root, 1.6- to 2.0-cm (0.6- to 0.8-in-caliper), 1.2- to 1.5-m (4- to 5-ft-tall), branched Fairview Flame®
red maple trees were planted in a Nicollet fine sandy loam soil at the Iowa State University Horticulture Research
Station, Gilbert, Iowa (USDA hardiness zone 5a; lat. 42°3'N), on April 22, 1996. The experimental design was a
randomized complete block with nine treatments, five blocks (replications), with treatments repeated twice in each
replication. Trees were spaced 2.0 m (6.5 ft) apart in north-south oriented rows with 3.0 m (10 ft) between rows.
Trees were hand watered once on the day o f planting to facilitate establishment. Treatments consisted o f 2.3-m2
(25-ft2) plots o f eight mulches: a 5.0-cm (2-in) layer o f 1.9-cm (0.75-in) diameter crushed red brick, 0.9-cm (0.4in) diameter pea gravel, 1.3-cm (0.5-in) diameter lava rock, and 2.5-cm (1.0-in) diameter carmel rock (chert); a
7.5-cm (3.0-in) layer o f 3.8-cm (1.5-in) diameter river rock; a 10.0-cm (4.0-in) layer o f 4.0- to 6.0-cm (1.6- to 2.4in) long finely screened pine bark, 2.0- to 3.0-cm (0.8- to 1.2-in) diameter pine wood chips, and 4.0- to 5.5-cm
(1.6- to 2.2-in) long shredded hardwood bark (mostly oak); and a non-mulched control maintained as bare ground.
Organic mulches were placed directly on bare ground, while mineral mulches were underlaid with a woven
polypropylene fabric (DeWitt Landscape Pro 5). Weeds and other unwanted vegetation within and between
treatment plots, and along the east and west borders o f the plots (15-cm wide) were controlled with glyphosate (1%
v/v). Plots were not fertilized.
Soil moisture was recorded weekly during the growing season (June-August) in 1996 and 1997 with a Theta Probe
(meter type HH1, sensor type ML1; Delta-T Devices Ltd., Cambridge, United Kingdom) soil moisture sensor at 6
cm (2.4 in) below the soil surface. Soil temperature also was determined weekly using a portable Bamant 115
thermocouple thermometer (model 600 2810; Barrington, 111.) at 10 cm (4.0 in) below the soil surface. Both soil
moisture and soil temperature readings were taken on the south side o f the tree, approximately 0.6 m (2.0 ft) from
the trunk.

115

Ornamental Studies

Stem diameter at 15 cm (6 in) above the soil surface and tree height from soil surface to the highest point in the
crown were measured on September 19 and 20, 1997, respectively. Leaves were harvested from each tree on
October 4 and 5, 1997, dried at 67°C (153°F) for five days, and weighed. Randomly chosen soil samples (one from
each treatment in each replication) taken at the soil surface immediately below the mulch treatment, were retrieved
on December 1, 1997 and again on June 17, 1998 to determine pH. All data were subjected to analysis o f variance
and means separated by least significant difference (P < 0.05).
RESULTS AND DISCUSSION

Effects on soil temperature and moisture. In 1997 (data from 1996 are not presented because unseasonably cool,
wet conditions caused a lack o f statistical significance), highest soil temperatures were recorded in the non-mulched
control plots, followed by pea gravel, crushed brick, and carmel rock treatments (Table 1). Plots covered by organic
mulch treatments had significantly lower soil temperatures (mean = 23.4°C/74.1°F) than plots treated with mineral
mulches (mean = 25.9°C/78.6°F). Loosely packed organic mulches insulate soils by intercepting and absorbing
solar radiation instead o f conducting heat energy downward (Waggoner et al. 1960; Montague et al. 1998).
Soil moisture content was highest under the three organic mulches and pea gravel, however, the shredded-bark and
pea gravel treatments were not different from lava rock or crushed brick (Table 1). Lowest moisture percentages
were recorded in the non-mulched control. Soil moisture under mulch is increased through minimizing soil surface
evaporation (Himelick and Watson 1990). In our study, organic mulches that meshed together, and fine-textured
mineral mulches like pea gravel, presented a greater barrier to evaporation than coarser mulch materials or bare soil.

Effects on soil chemistry. Previous researchers report organic mulches cause no change in soil pH (Greenly and
Rakow 1995; Watson and Kupkowski 1991) or reduce pH of the underlying soil (Billeaud and Zajicek 1989; Hild
and Morgan 1993; Himelick and Watson 1990). Mulch-induced pH reduction results from the addition or retention
o f organic matter, with organic acids produced from decomposition o f plant-derived materials accumulating or
leaching into the soil (Himelick and Watson 1990). At the completion o f our study (1997), soil pH was lowest in the
non-mulched control plots and highest under shredded-bark and wood chip mulches (Table 1). Elevated pH under
these mulches could have resulted from the leaching o f basic cations (N H /) from decomposing organic matter
(Tisdale et al. 1993). If so, we would expect the increase in pH from ammonification to be temporary, however,
because pH will decrease as ammonia is oxidized to nitrate by nitrifying bacteria in the soil. In 1998, soil pH
readings again were highest under wood chip and shredded-bark mulches. Lowest pH measurements were recorded
in the lava rock treatment and in the un-mulched control. While some mineral mulches could contribute to
undesirably high soil pH, mineral mulches used in this study did not.
Effects on tree growth. Temperature, moisture, and chemical differences in root-zone environments brought about
by the various mulch treatments did not translate into differences in tree height, however, trees growing in pea
gravel, crushed brick, carmel, and river rock had larger stem calipers than those growing in shredded-bark plots
(Table 2). Stem calipers o f trees in the three organic mulch treatments, lava rock, and in the non-mulched control
were not different.
Crushed brick, pea gravel, and carmel rock treatments resulted in greater leaf dry mass than shredded-bark plots.
Leaf dry mass also was greater for trees in crushed brick and pea gravel than for trees mulched with screened pine.
Dry mass o f trees in the three organic mulch treatments, river rock, lava rock, and in the control were not different.
Differences in tree growth are most likely linked to temperature differences in the soil environment. Although we
did not measure soil temperatures in April and May, based on summer readings it is logical to assume soil
temperatures under organic mulches would be cooler and possibly more growth limiting (at least for the shreddedbark and screened pine mulches) than warmer, growth-enhancing temperatures under the mineral mulches
(particularly pea gravel, crushed brick, and carmel rock). Holloway (1992) reported similar results in Alaska, where
five woody plant species grew best in stone mulch treatments. Elevated pH also might have contributed to poorer
growth for trees in the shredded-bark treatments.

116

Ornamental Studies

CONCLUSION
Our results indicate mineral mulches used in this study do not create growth-limiting soil environments. In fact, the
capacity o f crushed brick and pea gravel to conduct heat to soils below, particularly in early spring, may be
responsible for the observed advantage in leaf dry mass for trees growing in these materials over those growing in
soils kept relatively cool by insulating organic mulches such as shredded-bark and screened pine. Mineral mulches
used in this study also proved to be relatively inert, causing equal or smaller increases in pH than shredded-bark or
wood chips.
These results, however, should not be interpreted as an indictment o f organic mulches. Because soils at the ISU
Horticulture Research Station are fertile and well-drained, the organic matter and nutrient contributions made by
organic mulches may be o f less consequence than if the study had been conducted on poor soils. Moreover, had
conditions been drier and warmer during the years of the study (1996-97), or if the experiment had been conducted
in a warmer climate, organic mulches may have outperformed many of the mineral mulches. Finally, because stem
caliper and leaf dry mass measurements o f trees growing in wood chips and any o f the mineral mulches were not
statistically different, blanket statements and generalizations regarding the performance of woody plants mulched
with organic or mineral (rock) materials are unwise.
The nursery and landscape industry is fortunate to have a wide variety o f mulch materials to choose from, and each
has its place in the landscape. But in the final analysis, cost and maintenance considerations dictate which mulch
materials will be used.

Acknowledgments. The authors wish to acknowledge and thank the International Society o f Arboriculture
Research Trust and the Iowa Nursery & Landscape Association Research Corporation for funding this research.
LITERATURE CITED
Ashworth, S. and H. Harrison. 1983. Evaluation o f mulches for use in the home garden. HortScience 18(2): 180-182.
Billeaud, L.A. and J.M. Zajicek. 1989. Influence o f mulches on weed control, soil pH, soil nitrogen content, and growth o f
Ligustrum japonicum. J. Environ. Hort. 7(4): 155-157.
Gleason, M.L. and J.K. lies. 1998. Mulch matters. Amer. Nurseryman 187(4):24-31.
Green, T.L. and G. W. Watson. 1989. Effects o f turfgrass and mulch on the establishment and growth o f bare-root sugar maples.
J. Arboric. 15(11):268-272.
Greenly, K.M. and D. A. Rakow. 1995. The effect o f wood mulch type and depth on weed and tree growth and certain soil
parameters. J. Arboric. 21(5):225-232.
Hickman, G.W. and E. Perry. 1996. Using ammonium sulfate fertilizer as an organic mulch fire retardant. J. Arboric.
22(6):279-280.
Hild, A.L. and D.L. Morgan. 1993. Mulch effects on crown growth o f five southwestern shrub species. J. Environ. Hort.
1l(l):41-43.
Himelick, E.B. and G.W. Watson. 1990. Reduction o f oak chlorosis with wood chip mulch treatments. J. Arboric. 16(10):275278.
Holloway, P.S. 1992. Aspen wood chip and stone mulches for landscape plantings in interior Alaska. J. Environ. Hort.
10(l):23-27.
Montague, T., R. Kjelgren, and L. Rupp. 1998. Surface energy balance affects gas exchange o f three shrub species. J. Arboric.
24(5):254-262.
Rakow, D.A. 1992. Mulching: Benefits backed by survey. Arbor Age 12(9):22-29.
Skroch, W.A., M.A. Powell, T.E. Bilderback, and P.H. Henry. 1992. Mulches: Durability, aesthetic value, weed control, and
temperature. J. Environ. Hort. 10(l):43-45.
Tisdale, S.L., W.L. Nelson, J.D. Beaton, and J.L. Havlin. 1993. Soil Fertility and Fertilizers. MacMillan Publishing Co., New
York, NY. 634 pp.
Waggoner, P.E., P.M. Miller, and H.C. DeRoo. 1960. Plastic mulching - principles and benefits. Bull. No. 634, Conn. Agric.
Exp. Stn., New Haven.
Watson, G.W. 1988. Organic mulch and grass competition influence tree root development. J. Arboric. 14(8):200-203.
Watson, G.W. and G. Kupkowski. 1991. Effects o f a deep layer o f mulch on the soil environment and tree root growth. J.
Arboric. 17(9):242-245.

117

Ornamental Studies

Table 1. Effect o f eight mulch treatments and a non-mulched control on soil temperature, percentage (%) soil
moisture, and soil pH.

Temperature2

Moisturey

__________PHX

1997
(°C)
(%)
Control
29.3Wav
19" d
6.03’ d
Pea gravel
27.6 b
31 ab
6.44 b
Crushed brick
26.2 c
30 be
6.29 be
26.2 c
29 c
Carmel
6.29 be
River rock
25.2 d
29 c
6.47 b
Lava rock
24.5 d
30 be
6.21 cd
Shredded-bark
23.6 e
31 ab
6.82 a
Wood chip
23.3 e
32 a
6.81 a
Screened pine
23.2 e
32 a
6.13 cd
zSoil temperature measured at 10 cm (4 in) depth, between 2:00 and 4:00 p.m., CST.
ySoil moisture measured at 6 cm (2.4 in) depth, between 2:00 and 4:00 p.m., CST.
xSoil samples for pH measurements collected at 0- to 10-cm (0- to 4-in) depth.
wData shown are means of 12 dates x 5 replications (n=60) in 1997.
vMean separation within columns by LSD, P < 0.05.
“Data shown are means of 12 dates x 5 replications (n=60) in 1997.
Data shown are means of 5 observations. Soil samples collected on December 1, 1997 for pH determination.
sData shown are means of 5 observations. Soil samples collected on June 17, 1998 for pH determination.
Treatment

1998
5.86s d
6.14 be
6.04 cd
6.06 cd
6.33 b
5.82 d
6.81 a
6.37 b
6.14 be

Table 2. Effect o f eight mulch treatments and a non-mulched control on stem caliper, height, and leaf dry mass o f
Acer rubrum Fairview Flame®.
Height1
Stem caliper3'
Leaf dry mass1
Treatment
(cm)
(cm)
(g)
Lava rock
222w av
4.1u ab
441‘abc
Wood chip
222 a
4.1 ab
423 abc
Pea gravel
220 a
4.2 a
467 a
219 a
Crushed brick
4.2 a
478 a
Control
219a
4.1 ab
419 abc
Carmel
218a
4.2 a
463 ab
River rock
214 a
4.2 a
449 abc
Screened pine
214 a
4.0 ab
398 be
Shredded-bark
210a
3.9 b
383 c
zHeight measured from ground level to highest shoot apex on September 20, 1997.
yStem caliper measured 15 cm (6 in) above ground level on September 19, 1997.
xLeaves harvested October 4 and 5, 1997.
"Data shown are means of 10 observations.
vMean separation within columns by LSD, P < 0.05.
“Data shown are means of 10 observations. Each observation is the average of measurements taken at (1) the widest point on the
stem, and (2) rotated 90° clockwise from the first measurement.
Data shown are means of 10 observations.

118

Ornamental Studies

Prairie Demonstration
David D. Minner and Paul Stevens
Table 1. Prairie plant identification plots.
__________ Individual plots are 10 ft by 2 ft.
Sideoats
Tall
Wild
grama
boneset
bergamont

Iowa has two broad regions for potential natural
vegetation. Bluestem prairies are found in the
north half o f Iowa while oak-hickory forests
dominate the southern- half o f the state.
Throughout the entire state there are pockets o f
land that support a mixture o f both prairie and
forest. The term “bluestem prairie” can be
somewhat misleading since there is a wide variety
o f 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 o f 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.

Sand love
grass

Mountain
mint

Little
bluestem

Purple
prairie
cone flw.
Boneset

Western
wheatgrass
Bottle
brush
Tall
dropseed

Individual species o f 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 o f 1997.

Canada
wild rye
Indian
grass
Big blue
stem
Fowl
mana
grass

North
< -

Blue joint
grass
Prairie
cord grass

119

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

False
dragon
head
Foxglove
bear
tongue

Meadow
blazing
star
Prairie
smoke
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 Dept.

Doug Campbell

Research Associate, Horticulture Department

Nick Christians, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Dept.

Jim Dickson

Former Superintendent, Turfgrass Research Station
Horticulture Dept.

Mike Faust

Graduate Student, M.S. (Christians - Graduated Dec. 1998)

Mark Gleason, Ph.D.

Professor, Extension Plant Pathologist, Plant Pathology Dept.

Mark Helgeson

Field Technician, Horticulture Dept.

Clinton Hodges, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Dept.

Mark Howieson

Graduate Student, M.S. (Christians)

Jay Hudson

Graduate Student, M.S. (Minner)

Jeff lies, Ph.D.

Associate Professor, Extension, Nursery Crops/Omamentals
Horticulture Dept.

Young K. Joo, Ph.D.

Visiting Scientist from Korea

Deying Li

Graduate Student, Ph.D. (Christians and Minner)

Melissa McDade

Graduate Student, M.S. (Christians)

David Minner, Ph.D.

Associate Professor, Turfgrass Science Research and Extension
Horticulture Dept.

Richard Moore

Superintendent, Horticulture Research Station

Josh Olson

Field Technician, Horticulture Dept.

Gary Peterson

Commercial Horticulture Specialist

Rodney St. John

Superintendent, Turfgrass Research Station, Horticulture Dept.

Brad Sanders

Field Technician, Horticulture Dept.

Paul Stevens

Field Technician, Horticulture Dept.

Joe Stoeffler

Field Technician, Horticulture Dept.

120

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. Turfco topdresser, and Ryan GA30 aerifier; to
Tri-State Turf and Irrigation for providing a Greensmaster 3100 Triplex Greensmower and a
Groundsmaster 345 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.
Standard Golf Company
SubAir
TeeJet Spray Products
Terra Chemical Corporation
The Toro Company
Tri State Turf & Irrigation Co.
True Pitch, Inc.
Turf-Seed, Inc.
United Horticultural Supply
United Seeds Inc.
Weathermatic Corporation
Williams Lawn Seed Company
Zeneca Professional Products

Agr-Evo USA Company
Akzo Nobel
Big Bear Turf Equipment Company
Cushman Turf
D & K Turf Products
Dakota Peat
DowElanco
Gardens Alive
Glen Oaks Country Club
Golf Course Superintendents Association of
America
Grain Processing Corporation
Great American Outdoor
Heatway
Hunter Industries, Inc.
Iowa Golf Course Superintendents Association
Iowa Professional Lawn Care Association
Iowa Sports Turf Managers Association
Iowa Turfgrass Institute
Jacklin Seed
LESCO Incorporated
M. Putterman & Company Inc.
Milorganite
Monsanto Company
Novartis
Ossian Inc.
PBI/Gordon Corporation
Pickseed West Incorporated
Profile Products
Rainbird Irrigation Company
Reams Sprinkler Supply
Renaissance Fertlizer Co.
Rhone-Poulenc Chemical Company
Riverdale Chemical Company
Rohm and Haas Co.
The Scotts Company
Seeds West Inc.
SportGrass, Inc.

121

. . . 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.
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.