1993
Iowa
Turfgrass
Research
Report

Io w a St a t e U n i v e r s i t y
University Extension
FG-461 IJuly 1993

Am es, Iow a

Introduction
N. E. Christians and M. L. Agnew

The following research report is the 13th 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.
The 1991 season was an establishment year for several new trials that were established in 1990. The
1992 season was the first full season of data collection for many of these new studies. Among the
new trials established in the fall of 1990 were a low-maintenance Kentucky bluegrass trial, a highmaintenance Kentucky bluegrass trial, a perennial ryegrass trial, a green-height creeping bentgrass trial,
and a creeping bentgrass green for fungicide trials.
For the third year, this research report contains a section titled "Environmental Research." This
section is included to inform the public of our many research projects that are aimed at the many
environmental issues that face the turf industry. In the past three years this has become a major thrust
of the research program and many of our more extensive, in-depth projects are now aimed at
environmental issues.
We would like to acknowledge Richard Moore, manager of the turfgrass research area; Mark Stoskopf,
superintendent of the ISU Horticulture Research Station; Sue (Kassmeyer) Berkenbosch, technical
assistant; Doug Campbell, technical assistant, and all others employed at the field research area in the
past year for their efforts in building the turf program.
Special thanks to Lori Westrum for her work in typing and helping to edit this publication.
Edited by Nick Christians, professor, Horticulture; and Michael Agnew, associate professor,
Horticulture.

Table of Contents
Turfgrass Research Area Maps

1

Environmental Data

4

Species and Cultivar Trials
Results of Kentucky Bluegrass Regional Cultivar Trials - 1992

6

The Recovery of Kentucky Bluegrass Cultivars Following
Summer Dormancy

12

National Perennial Ryegrass Study - 1992

14

Regional Fine Fescue Cultivar Evaluation - 1992

17

Shade Adaptation Study - 1992

20

USGA Buffalograss Trial - 1992

22

Alkaligrass Evaluations - 1992

23

Green Height Bentgrass Cultivar Trial (Native Soil) - 1992

24

Fairway Height Bentgrass Study - 1992

25

Herbicide and Growth Regulator Studies
1992 Preemergence Annual Weed Control Study

26

1992 Postemergence Annual Grass Control Study

29

1992 Broadleaf Weed Control Study

32

Effects of Dithiopyr (Dimension) on the Rooting of Creeping Bentgrass

36

1992 Sod Rooting Trial - 1

38

1992 Sod Rooting Trial - II

43

Ethofumesate (Prograss) Demonstration on a Green, Tee, and Fairway
at Veenker Golf Course in Ames, Iowa

45

The Efficacy of Ignite as a Non-selective Herbicide, 1992

47

The Effects of Quinclorac on the Establishment of Three Grass Species

48

1992 Growth Regulator Study

52

Turfgrass Disease and Insect Research
Evaluation of Fungicides for Control of Snow Molds on Creeping
Bentgrass, 1992-1993
Evaluation of Fungicides for Control of Brown Patch in Creeping
Bentgrass

55

57

Evaluation of Fungicides for Control of Dollar Spot in ’Penncross’
Bentgrass - 1992

60

Pythium and Root Disease of Creeping Bentgrass

62

Comparative Effectiveness of Insecticides Against Annual White Grubs, 1992

65

Fertilizer Trials
The Effects of Granular Nitrogen Fertilizer Sources on the Growth
and Quality of ’Vantage’ Kentucky Bluegrass

68

Perennial Ryegrass Fertilizer Study

79

Scott’s Poly-S Study

84

Plant and Soil Response to Nitrogen Fertilizer Sources

86

1992 Soil Activator Study

91

The Effects of Application Rate of Sprint 330 on the Quality of
’Penncross’ Creeping Bentgrass

93

Soil Relation Studies
The Effects of Soil Compaction on Soil Physical Properties and
Plant Growth of Five Cultivars of Tall Fescue

94

Modification of Disturbed Soils

96

The Effects of Compost Topdressing on Compacted Soils

102

The Effects of Compost Topdressing on Existing Thatch

105

The Effects of Topdress Sand Source and Potassium Level on the
Growth and Development of Creeping Bentgrass Greens

108

Environmental Research
Pesticide and Fertilizer Fate in Turfgrasses Managed under
Golf Course Conditions

109

Isolation and Identification of Root-Inhibiting Compounds
from Com Gluten Meal

112

The Use of a Natural Product for the Preemergence Control of
Annual Weeds

113

Drift of Postemergence Herbicide Spray during a Turfgrass Application

116

Ground Ivy Control with Borax

119

National Crabapple Evaluation Program

121

Introducing
The Iowa State University Personnel affiliated with the Turfgrass
Research Program

Companies and Organizations that made donations or supplied products
to the Iowa State University Turfgrass Research Program

125

127

Turfgrass Research
Area Maps

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Species and Cultivar
Trials

Results of Kentucky
Bluegrass Regional Cultivar Trials -1992
N. E. Christians and R. W. Moore

The United States Department of Agriculture (USDA) has sponsored several regional Kentucky
bluegrass cultivar trials conducted at most of the northern agricultural experiment stations. The current
test consists of 62, 80, or 128 cultivars; the number depending on the year of establishment and the
type of trial, with each cultivar replicated three times.
Three trials were underway at Iowa State University during the 1992 season. A high-maintenance
study was established in 1990 that receives 4 lb N/1000 ft2/yr and is irrigated as needed. The second
trial was established in 1985 and receives 4 lb N/1000 ft2/yr, but is not irrigated. The third trial was
established in the fall of 1991 and is a low-maintenance study that receives 1 lb of N/1000 ft2/yr in
September and is non-irrigated. The objective of the high-maintenance study is to investigate cultivar
performance cultivars under a cultural regime similar to that used on irrigated home lawns in Iowa.
The objective of the second study is to observe the cultivar response under conditions similar to those
found in non-irrigated lawns that receive a standard lawn care program. The objective of the third
study is to evaluate cultivars under conditions similar to those maintained in a park or school ground.
The values listed under each month in Tables 1, 2 and 3 are the averages of visual quality ratings
made on three replicated plots for the three studies. Visual quality was based on a scale of 1 to 9: 9
= best quality, 6 = acceptable quality, and 1 = poorest quality. Yearly means of data from each month
were taken and are listed in the last column. The first cultivar received the highest average rating for
the entire 1992 season. The cultivars are listed in descending order of average quality.
Table 1. The 1992 quality ratings for the high-maintenance, irrigated Kentucky bluegrass trial.

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

Cultivar
PST-A7-1877
PST-B8-106
798
BA 70-131
Cardiff
PR-1
Cheri
BA 77-292
Challenger
Connie
Limousine
PST-C-76 (Unique)
Trenton
602 (Preakness)
BA 69-82
Crest
Classic
Fylking
Nassau
PST-C-224
RAM-1
BA 73-540
Coventry

May
8.0
8.0
8.0
7.7
7.0
7.7
8.0
7.0
7.3
7.3
8.0
7.3
8.0
7.3
7.7
7.3
7.7
7.3
6.7
7.3
7.7
7.7
7.7

June
7.7
7.7
7.3
7.7
7.3
7.3
7.7
7.3
6.7
7.7
7.7
7.0
7.0
7.7
7.3
7.7
7.0
6.3
7.7
7.0
7.3
7.3
7.0
6

July
6.7
7.3
6.7
6.3
7.0
6.0
6.3
6.7
6.3
7.0
6.7
6.3
6.3
5.7
6.0
6.7
6.0
6.7
6.3
6.0
5.7
6.0
6.0

August
8.3
8.0
7.7
7.7
8.0
8.3
7.3
8.0
8.0
7.0
7.7
7.3
7.3
7.3
7.7
7.3
7.0
7.7
7.3
7.7
7.0
7.0
7.3

Sept
8.7
8.7
7.7
8.0
8.0
8.0
7.7
7.7
8.0
7.3
6.7
8.3
7.7
8.0
7.3
7.0
8.0
7.3
7.7
7.3
8.0
7.0
7.0

Mean
7.9
7.9
7.5
7.5
7.5
7.5
7.4
7.3
7.3
7.3
7.3
7.3
7.3
7.2
7.2
7.2
7.1
7.1
7.1
7.1
7.1
7.0
7.0

24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77

Cultivar
Estate
Freedom
J-229 (Nublue)
Ampellia
Cobalt
Eagleton
EVB 13.863
J13-152
J34-99
Julia
Kelly
NE 80-47
PST-A84-405
Silvia
WW AG 505
A-34
Baron
Dawn
Glade
Jll-94
Livingston
Miracle
Miranda
PST-A84-928
PST-RE-88 (4 ACES)
PSU-151
Washington
Able I
Aspen
BA 77-279
Georgetown
H86-712 (Shamrock)
Minstrel
Nustar
PST-B8-13
SR 2000
BA 76-305
BAR VB 1184
Blacksburg
Summit (Apex)
Banff
BAR VB 1169
BAR VB 7037
BAR VB 895
Barmax
Cynthia
Eclipse
Fortuna
Gnome
J-335
J-386
Midnight
PST-0514
R751A

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

June
7.0
6.7
6.7
7.0
6.3
6.3
7.3
7.0
6.7
6.7
7.3
7.3
7.0
7.3
6.7
6.7
7.0
6.3
7.0
7.0
7.0
7.0
7.3
7.0
7.3
6.3
6.3
6.3
6.7
6.7
7.0
6.7
6.7
6.7
6.3
7.3
6.7
6.0
6.3
6.3
6.3
6.3
6.3
6.3
6.7
6.3
6.3
7.0
7.0
6.3
6.3
6.3
5.3
6.3
7

July
5.7
6.0
5.7
5.7
6.3
6.0
6.3
6.0
5.7
5.3
6.7
5.7
6.0
5.7
5.3
5.7
6.7
5.7
5.7
5.3
6.0
5.7
6.0
6.3
6.3
5.7
6.0
6.3
5.7
5.7
5.7
5.3
6.3
6.0
7.0
5.3
6.3
5.7
5.7
5.7
5.3
4.3
5.0
5.0
5.0
5.7
6.0
6.0
5.7
5.3
6.0
5.7
5.7
6.0

August
7.0
7.0
7.3
6.7
7.3
8.0
7.0
7.0
7.7
7.0
6.3
6.7
7.0
7.0
8.0
7.3
7.3
6.7
6.7
7.0
7.0
6.3
7.0
6.7
6.7
7.3
7.0
7.3
6.7
7.3
6.3
6.7
7.0
6.7
7.3
6.3
7.0
7.7
6.7
7.0
7.0
7.0
6.3
6.3
6.0
7.0
7.0
6.3
6.7
7.0
7.0
6.3
7.3
6.3

Sept
7.3
7.7
8.0
7.0
7.7
8.0
6.7
7.0
7.0
7.7
6.7
7.3
7.3
7.3
7.3
7.0
6.3
7.7
7.7
7.0
7.3
7.7
6.3
7.0
6.7
7.3
7.3
7.7
7.3
8.0
7.0
7.0
6.7
6.7
6.3
7.0
6.3
7.7
7.0
7.7
7.0
7.3
7.0
7.0
7.0
7.7
6.3
6.7
6.7
7.0
6.3
7.3
8.0
7.0

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

78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128

Cultivar
Barzan
Haga
Indigo
KWS PP 13-2
Liberty
PST-UD-12
WW AG 508
BA 73-366
BA 73-382
Barsweet
Bartitia
Chelsea
EVB 13.703
Marquis
PST-A7-341
PST-R-740
Touchdown
Barblue
Merion
SR 2100
1757
Abbey
BA 74-114
BA 77-700
BA 78-258
Destiny
HV 125
Merit Cert.
Monopoly
Opal
Platini
PST-1DW
PST-A84-803
Ronde
Suffolk
BA 73-381
Noblesse
PST-UD-10
Gemor
J-333
Princeton 104
PST-HV-116
Alpine
Greenley
Melba
Donna
Ginger
South Dakota Cert.
Trampas
Broadway
Kenblue
l s d (0.05)

May
6.3
7.0
7.3
6.7
6.3
7.3
6.0
7.0
6.7
7.3
6.7
5.3
7.0
7.0
7.0
6.3
7.0
7.0
5.7
6.7
7.0
6.3
6.3
6.0
6.3
6.0
6.7
6.7
6.0
6.3
7.0
6.7
6.3
6.0
6.7
6.0
6.7
6.3
6.7
6.3
6.3
6.0
5.7
5.7
5.7
6.0
4.7
4.7
5.3
5.7
5.0
1.3

June
5.3
6.3
6.7
6.0
5.7
6.7
6.0
6.7
7.0
6.7
6.0
6.0
6.3
6.7
6.0
6.7
5.7
5.7
5.7
6.7
5.7
6.3
6.3
7.0
6.0
6.3
5.3
6.3
6.3
5.7
6.3
6.0
5.7
6.0
5.7
6.3
6.0
6.0
5.7
6.0
5.3
6.0
5.0
5.7
5.3
5.7
5.0
6.0
5.3
5.7
4.7
2.5

July
6.0
5.0
5.7
6.3
5.0
5.0
5.7
5.0
6.0
5.0
5.0
6.3
5.3
5.7
5.3
6.0
5.0
5.3
6.3
5.0
5.3
5.3
5.7
5.7
5.3
5.0
4.7
5.3
5.3
5.3
4.3
5.0
5.0
6.0
4.7
5.3
4.7
4.7
5.3
4.3
4.7
4.7
4.3
5.7
5.0
5.0
6.0
5.7
4.7
4.0
5.0
NS

August
7.3
6.7
6.0
6.7
7.3
6.0
6.7
6.3
5.7
6.0
7.0
7.0
6.0
6.0
6.3
6.3
7.3
6.7
6.7
6.3
6.3
6.3
6.0
5.7
6.3
6.3
6.7
6.0
6.3
6.7
6.3
6.0
6.3
6.3
6.7
6.0
6.0
6.0
6.0
6.0
6.3
5.7
6.7
6.0
6.0
6.0
5.7
5.7
5.7
5.0
5.7
2.4

Quality based on a scale of 1 to 9: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality.
8

Sept
7.0
7.0
6.3
6.3
7.7
7.0
7.7
6.7
6.3
6.3
7.0
7.0
7.0
6.0
7.0
6.3
6.7
6.3
6.7
6.3
6.3
6.0
6.0
6.0
6.3
7.0
7.3
6.0
6.7
6.3
6.7
7.0
7.3
6.0
7.0
6.3
6.7
7.0
6.0
7.0
7.0
6.7
7.0
5.3
6.7
5.0
6.0
5.3
6.7
6.0
6.3
1.5

Mean
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
6.2
6.2
6.2
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.0
6.0
6.0
5.9
5.9
5.9
5.8
5.7
5.7
5.7
5.5
5.5
5.5
5.5
5.3
5.3
1.5

Table 2.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52

The 1992 quality ratings for the high-maintenance, non-irrigated regional Kentucky bluegrass test.

Cultivar
Wabash
Mystic
Monopoly
Able I
Aquila
A-34
Kenblue
Joy
Destiny
Conni
F-1872 Freedom
Blacksburg
Sydsport
Somerset
NE 80-88
HV 97
Huntsville
NE 80-14
NE 80-50
NE 80-30
RAM-I
Compact
America
Asset
Amazon
WW AG 495
Park
Lofts 1757
Eclipse
Liberty
Julia
Kl-152
Harmony
Rugby
PST-CB1
WW AG 491
BA 73-626
BAR VB 534
Cynthia
Glade
Trenton
NE 80-47
NE 80-55
Classic
Parade
Ikone
South Dakota Cert.
NE 80-110
Tendos
Georgetown
Merit
BA 70-139

April
7.3
6.0
6.3
5.5
5.3
6.0
7.0
7.0
6.0
5.7
5.7
6.0
5.0
5.7
6.0
6.0
5.3
6.0
6.0
5.7
5.7
5.7
4.7
5.7
5.3
4.7
6.0
5.0
5.0
5.7
5.7
5.3
5.7
5.7
5.0
5.0
4.7
5.3
5.3
5.7
5.3
5.7
5.0
3.7
5.0
5.7
6.3
4.3
5.3
5.3
5.3
4.3

May
7.7
6.7
7.3
6.0
6.3
6.7
6.0
6.0
6.0
6.0
5.7
5.7
6.3
5.7
6.0
6.0
5.7
6.0
6.3
5.7
5.7
5.7
5.3
6.0
5.7
6.3
6.0
5.3
5.3
5.0
5.7
5.7
5.7
5.3
6.0
6.7
5.3
5.7
6.0
5.3
5.3
5.7
5.0
5.0
5.0
5.7
5.7
5.3
5.7
5.3
5.3
5.7
9

July
7.0
8.3
7.0
7.5
7.3
7.7
7.0
8.3
6.7
7.3
7.0
6.3
5.3
5.3
6.7
6.3
7.0
6.7
5.7
6.7
6.3
6.0
5.0
6.7
6.3
6.7
7.3
7.0
6.0
7.0
6.0
6.7
7.3
6.3
6.7
6.7
6.7
7.3
6.7
6.0
6.0
6.0
6.0
6.3
6.3
5.7
6.3
7.0
5.7
6.3
6.7
5.3

Aug
8.0
9.0
7.7
8.0
8.0
7.7
8.3
7.3
8.0
7.7
7.0
7.7
7.0
7.0
7.3
7.3
7.7
7.0
6.7
6.7
7.0
7.3
7.7
6.3
6.7
7.3
8.0
7.0
7.3
7.0
7.0
6.3
7.0
7.3
7.3
6.3
7.3
6.7
7.0
6.7
7.0
7.0
7.3
7.0
7.3
7.0
7.3
7.3
6.3
6.3
6.3
6.7

Sept
7.7
6.3
6.7
8.5
7.7
7.0
7.3
6.3
7.0
7.0
7.3
7.3
8.0
8.3
7.0
7.0
7.7
7.3
7.3
8.0
8.0
7.3
7.7
7.7
8.0
7.3
5.7
6.7
7.3
7.3
6.7
7.3
6.0
6.7
6.3
6.3
6.3
6.0
6.3
7.7
6.7
6.7
7.0
7.7
6.7
6.7
5.7
6.3
6.7
6.3
6.7
7.3

Oct
6.3
6.7
6.3
6.0
6.7
5.3
4.7
4.3
5.7
5.3
6.3
6.0
6.7
6.7
5.3
6.0
5.3
5.7
6.7
6.0
5.3
6.0
7.3
5.7
5.7
5.7
5.0
6.0
6.0
5.3
6.0
5.7
5.7
6.0
6.0
6.0
6.3
5.7
5.0
5.3
6.3
5.7
6.0
6.3
5.7
5.3
4.7
5.7
6.0
6.0
5.3
6.3

Mean
7.3
7.2
6.9
6.9
6.9
6.7
6.7
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
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.1
6.1
6.1
6.1
6.1
6.1
6.1
6.0
6.0
6.0
6.0
6.0
5.9
5.9
5.9
5.9

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

Cultivar
BA 70-242
BA 72-441
BA 72-500
Nassau
Midnight
NE 80-48
Haga
Annika
Vieta
Meri on
WW AG 496
P-104
BAR VB 577
BA 73-540
WW AG 468
Barzan
BA 69-82
Cheri
239
Challenger
Gnome
Aspen
K3-178
Dawn
Bristol
BA 72-492
Welcome
Baron
LSD(0.05)

April
5.0
5.3
4.3
6.0
4.7
5.7
4.3
4.3
4.3
4.7
5.3
5.0
5.5
4.3
4.3
4.7
4.7
4.0
5.0
4.7
4.3
4.3
3.7
4.3
4.3
4.3
4.0
4.3
NS

May
5.3
5.3
6.7
5.7
4.3
5.7
5.0
4.7
5.0
5.3
5.7
5.0
5.5
4.7
4.7
5.0
4.0
5.3
4.7
5.0
4.7
5.0
4.7
4.3
4.3
4.3
4.7
4.3
NS

July
6.3
6.7
5.3
5.7
6.7
5.7
6.0
6.3
6.3
6.0
5.7
6.3
6.0
5.7
6.0
6.0
5.7
5.7
6.0
6.3
6.7
5.3
5.7
5.3
5.3
5.0
5.7
5.0
1.5

Aug
6.7
7.3
6.3
6.7
7.0
6.3
7.7
6.7
6.7
7.0
6.7
7.0
6.5
6.3
7.3
6.7
6.7
6.3
6.7
6.0
6.3
6.3
6.3
6.7
6.0
6.3
6.3
6.0
NS

Sept
6.7
6.0
7.3
5.7
7.3
6.3
6.7
7.0
7.0
7.0
6.0
6.0
5.5
7.0
6.7
5.7
6.7
6.7
6.3
6.3
6.0
6.3
6.7
6.3
6.7
6.3
5.3
5.7
1.6

Mean
5.9
5.9
5.9
5.9
5.9
5.9
5.8
5.8
5.8
5.8
5.8
5.7
5.7
5.7
5.7
5.6
5.6
5.6
5.6
5.6
5.5
5.5
5.5
5.4
5.3
5.3
5.3
5.1
1.0

Oct
5.3
4.7
5.7
6.0
5.3
5.7
5.3
6.0
5.3
5.0
5.7
5.0
5.3
6.0
5.3
5.3
5.7
5.7
5.0
5.3
5.0
5.7
6.0
5.7
5.3
5.7
5.7
5.0
1.3

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality.
Table 3.

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

The 1992 quality ratings for the low-maintenance, non-irrigated Kentucky bluegrass trial.

Cultivar
MN 2405
Alene
Kenblue
Park
South Dakota Cert.
Barsweet
PST-A7-111
BA 78-376
BAR VB 1169
Voyager
BAR VB 7037
Barmax
Bronco
ISI-21
EVB 13.863
Haga
Sophia
ZPS-84-749

April
6.0
6.0
5.3
5.7
6.0
4.3
5.7
5.0
5.0
5.7
5.0
5.7
4.0
6.0
4.0
5.0
4.0
4.7

May
6.7
6.3
6.7
6.3
6.0
5.3
6.7
6.0
6.3
7.3
6.0
7.3
6.3
6.3
6.0
7.0
6.7
6.0

June
5.7
5.7
5.3
6.3
5.7
5.3
5.3
5.7
6.0
5.0
6.3
5.0
5.0
4.3
4.0
4.7
5.7
4.7

10

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

Aug
7.3
6.7
6.3
6.7
6.7
7.0
6.3
6.7
6.3
5.7
6.0
5.0
6.7
6.3
5.7
5.7
5.7
7.0

Sept
6.3
6.7
6.3
5.7
6.7
7.0
6.0
5.0
6.0
5.7
5.7
5.7
7.0
5.7
6.3
6.0
6.0
6.3

Oct
6.0
6.3
6.3
6.0
5.7
6.7
6.0
6.3
6.0
6.0
5.7
6.0
6.0
7.0
6.3
5.7
5.7
5.0

Mean
6.4
6.3
6.1
6.1
6.1
6.0
6.0
5.9
5.9
5.8
5.7
5.7
5.7
5.7
5.6
5.6
5.6
5.6

19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62

Cultivar
Chelsea
Cynthia
Opal
PST-YQ
RAM-1
Washington
GEN-RSP
Monopoly
BAR VB 1184
Baron
Barzan
J-229 (Nublue)
Merit
Nustar
Suffolk
Amazon
BA 74-017
Freedom
H76-1034
KWS PP 13-2
BAR VB 895
J-386
Fortuna
J-335
Liberty
Livingston
Midnight
Miracle
PST-C-391
798
Destiny
NJIC
PST-C-303
Gnome
PST-C-76 (Unique)
Unknown
Crest
Cobalt
NE 80-47
Bartitia
EVB 13.703
Kyosti
Merion
SR 2000
LSD(ao5)

April
4.3
4.7
4.7
5.3
4.3
4.0
5.7
3.7
4.0
3.7
3.7
4.0
4.3
4.7
4.7
5.0
4.0
4.7
5.7
4.3
4.0
4.0
4.7
3.7
4.3
4.7
3.0
3.7
4.7
4.0
4.0
4.0
4.7
3.7
3.7
3.7
3.0
4.0
4.0
3.3
4.0
2.3
2.7
3.7
1.6

May
5.7
5.3
6.0
6.3
6.3
5.3
6.0
6.3
4.7
5.0
5.0
6.0
5.3
4.7
6.0
5.7
5.3
6.0
5.3
5.7
5.7
5.0
5.0
5.0
4.3
6.0
5.0
5.7
4.7
5.3
5.0
5.3
5.3
4.7
4.37
4.3
4.3
4.0
4.7
4.3
4.0
4.3
4.0
3.7
1.6

June
4.7
4.7
5.0
5.0
5.0
4.7
4.7
5.3
4.3
3.7
4.0
4.0
3.3
3.7
4.3
5.0
3.7
4.3
4.3
5.0
4.0
4.7
3.7
4.0
3.0
4.0
3.7
4.7
3.3
3.7
3.7
4.0
3.3
3.7
3.7
3.0
3.0
3.3
3.7
3.0
3.3
3.3
2.7
3.0
1.4

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

Aug
6.3
6.7
5.3
4.7
5.7
7.3
5.3
5.3
7.0
5.3
6.3
6.0
6.3
6.7
5.7
5.0
6.0
5.0
5.7
5.7
6.0
6.0
5.3
6.0
5.7
4.7
6.0
5.3
5.7
5.3
5.3
4.7
5.3
5.3
5.3
5.7
5.7
5.0
4.7
4.3
5.0
5.7
4.7
3.7
1.9

Sept
5.0
6.0
6.3
6.3
5.7
6.3
5.7
5.7
6.0
7.7
6.0
6.7
6.0
6.7
6.0
5.7
6.0
5.3
5.3
5.0
5.7
5.7
5.3
5.3
6.3
5.3
6.3
5.7
5.7
5.7
5.3
5.0
5.0
5.0
5.7
5.3
5.3
5.0
4.7
5.3
4.7
4.0
4.3
4.3
2.0

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality.

11

Oct
6.0
5.7
5.3
6.0
5.7
6.0
6.3
6.0
5.7
6.3
6.0
5.0
6.0
6.0
6.0
5.3
6.0
6.0
5.3
5.3
6.0
5.7
5.3
5.7
6.0
5.7
5.3
5.7
6.0
5.3
5.0
5.3
5.3
5.7
5.7
5.0
5.7
4.7
5.0
5.3
5.0
4.0
4.7
4.7
2.1

Mean
5.5
5.5
5.5
5.5
5.5
5.5
5.4
5.4
5.3
5.3
5.3
5.3
5.3
5.3
5.3
5.2
5.2
5.2
5.2
5.2
5.1
5.1
5.0
5.0
5.0
5.0
5.0
5.0
5.0
4.9
4.8
4.8
4.8
4.7
4.7
4.6
4.5
4.4
4.4
4.3
4.3
4.0
3.9
3.9
1.0

The Recovery of Kentucky Bluegrass Cultivars
Following Summer Dormancy
N. E. Christians
In earlier work at Iowa State University (Grounds Maintenance 24(8):49-50) it was shown that Kentucky
bluegrass cultivars vary greatly in their recovery from summer dormancy. Common, or public varieties,
generally recover much more rapidly from drought-induced dormancy than do the newer improved
cultivars. The objectives of this study were to further evaluate 4 cultivars that were previously shown to
recover rapidly from dormancy and 4 cultivars that were slower to recover when maintained under low
and high fertility regimes: 1 lb N/1000 ft2 in September and 4 lb N/1000 ft2 applied in 1 lb applications
in April, May, August, and September.
South Dakota Common, S-21, Kenblue, and Argyle (cultivars observed to recover rapidly in earlier
studies) and Midnight, Nassau, Glade, and Ram I (cultivars observed to recover more slowly). Kentucky
bluegrass was established in 21 ft2 plots on September 26, 1989 on a non-irrigated site at the turfgrass
research area of the Iowa State University Horticulture Research Station north of Ames, Iowa. The soil
on the site is a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with a pH of 6.8 and 2.3% organic
matter, a P content of 20 lbs/A, and a K content of 216 lbs/A. The study was replicated three times.
Each plot was split in half. The two fertility treatments were randomly applied to the two halves of the
plots.
The 1990 season was very wet and at no time did the grasses on the study area go into summer dormancy.
The spring of 1991 was also very wet and the late summer and fall were dry. The 1992 season was the
opposite of the 1991 season. The spring and summer were very dry up to the 4th of July. The remainder
of the summer and fall were very wet. The low-maintenance grasses (S.D. Common, S-21, Kenblue, and
Argyle) maintained the best quality at the 1 lb N rate through the season (Table 4). At the higher N rate,
the low-maintenance varieties maintained the best quality during the early dry period, but the highmaintenance varieties (Midnight, Nassau, Glade, and Ram-I) caught up late in the season during the wetter
conditions.
The low-maintenance varieties are the best choice under non-irrigated conditions, particularly under low
N regimes. The high-maintenance varieties are much better adapted to higher N regimes under irrigated
conditions or during wet years.
This study will be continued for at least the next 2 years.

12

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National Perennial Ryegrass Study - 1992
S. M. Berkenbosch and N. E. Christians

This trial began in the fall of 1990 with the establishment of 125 cultivars of perennial ryegrass at the
Iowa State University Horticulture Research Station. The study was established on an irrigated area
and maintained at a 2-in mowing height, fertilized with 3 to 4 lb N/1000 ft2/yr. The area receives
preemergence herbicide in the spring and broadleaf herbicide in September.
Cultivars were evaluated for turf quality each month of the growing season. Visual quality was based
on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality. The values
listed under each month in Table 5 are the averages of ratings made on three replicated plots for the
three studies. Yearly means of data from each month are listed in the last column. Brightstar, Palmer
II, Pick 89-4, and Pick DKM were the top four performers in 1992. The cultivars are listed in
descending order of average quality.

Table 5. The 1992 quality ratings for the national perennial ryegrass study.
Cultivar
1 \ l Brightstar (PST-GH-89)
2
Palmer II (P89)
3
Pick 89-4
4
Pick DKM
5
Prelude II (2P2-90)
6 ^ Quickstart (PST-2FQR)
7
Assure
8
N-33
9
ZPS-2EZ
10
APM
KOOS 90-1
11
12
Legacy
13
MVF 89-88
14
Pick 1800
15
Prizm (ZPS-28D)
16
PST-290
17
Entry 124
18
PR 9118
19
Rodeo II
SYN-P
20
21 \ Charger
22
Cowboy II (WM-II)
23
Danaro
24
Dimension (2H7)
25
KOOS 90-2
26
MOM LP 3147
27
Navajo (PST-2DPR)
28
PR 9108
29
PST-28M
30
PST-2B3
31
PST-20G
Sherwood
32

April
6.7
6.7
7.0
7.0
6.3
6.7
6.0
6.7
6.7
6.7
6.7
5.0
6.3
6.0
6.0
5.3
6.0
5.3
5.7
5.7
5.7
4.7
6.7
5.3
5.7
5.7
5.7
6.3
7.0
6.0
6.7
5.7
14

May
8.7
7.7
8.0
7.7
7.7
7.7
8.0
7.7
7.0
7.3
7.3
7.7
7.7
7.0
7.0
7.7
7.0
8.3
7.3
7.7
8.0
7.3
7.7
8.0
7.3
7.0
8.0
7.7
7.0
7.3
7.0
6.7

June
7.0
7.0
6.3
6.7
6.7
6.7
6.3
7.0
6.7
6.3
6.7
7.0
6.7
6.3
6.7
7.0
6.7
6.7
6.7
6.7
6.7
6.7
6.7
7.0
6.7
6.7
6.7
6.3
6.7
6.0
6.7
6.3

July
8.0
8.3
7.7
7.7
7.7
7.7
7.7
7.3
7.7
7.3
7.3
7.3
7.0
7.7
7.3
7.7
7.3
7.0
7.3
7.3
7.0
7.7
6.7
7.3
7.0
7.3
7.0
7.0
7.0
7.3
7.3
7.3

Aug
7.7
8.0
7.7
7.7
8.0
7.3
7.7
7.3
7.7
7.3
7.3
7.7
7.3
8.0
8.0
7.7
7.7
7.3
7.3
7.3
7.0
7.7
7.0
7.0
7.3
7.3
7.0
7.0
7.0
7.3
7.3
7.7

Sept
7.3
7.3
7.7
7.7
7.3
7.7
7.7
7.3
7.7
7.3
7.3
7.7
7.3
7.7
7.3
7.0
7.3
7.3
7.7
7.3
7.0
7.3
6.7
7.0
7.7
7.3
7.0
7.3
7.0
7.3
6.7
7.7

Mean
7.6
7.5
7.4
7.4
7.3
7.3
7.2
7.2
7.2
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.0
7.0
7.0
7.0
6.9
6.9
6.9
6.9
6.9
6.9
6.9
6.9
6.9
6.9
6.9
6.9

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

Cultivar
SR 4200
4DD-Delaware Dwarf
89-666
Allegro
Duet
Entry 125
Envy
Equal
Express
Gettysburg
Night Hawk (WVPB-89-PR-A-3)
Nomad
OFI-F7
Pebble Beach
Pinnacle
Pleasure
Regal
Repel 1 II (LDRD)
Topeka (WVPB-88-PR-D-10)
WVPB-88-PR-C-23
WVPB-89-87A
ZW 42-176
Accolade
Advent
Affinity (GEN-90)
BAR LP 086FL
BAR LP 852
Competitor
Cutless
Dandy
Derby Supreme
Entrar
Essence (PR 8820)
Fiesta II
Goalie
Patriot II
Pennant
Pick 89LLG
Pick 9100
Pick EEC
Poly-SH
PR 9119
PST-2FF
PST-2ROR
Repell
Seville
Stallion Select (PS-105)
Yorktown III (LDRF)
856
C-21
Calypso
CLP 39

•

April
5.0
6.3
5.3
6.0
6.0
5.7
5.3
5.7
5.7
5.3
5.3
5.0
6.0
6.3
6.0
6.0
6.7
5.0
5.7
5.3
5.3
5.7
6.0
5.3
5.7
4.7
5.3
6.0
4.7
5.3
5.3
5.7
4.7
4.7
6.3
6.0
5.7
5.0
5.3
5.3
6.0
5.7
5.7
5.0
5.0
5.0
5.0
5.3
5.3
5.0
6.0
4.7

15

May
7.7
7.0
6.7
7.0
6.7
7.0
7.3
7.3
7.7
6.7
8.0
7.7
7.0
7.3
7.3
7.0
6.7
7.7
7.3
7.3
7.3
7.7
7.3
7.0
7.3
7.7
6.3
7.0
7.3
7.0
7.3
8.0
7.0
8.0
7.3
7.0
6.7
8.0
7.0
7.3
7.3
7.0
7.0
7.7
7.0
7.3
7.3
7.7
7.7
7.3
7.0
7.7

June
7.0
6.7
6.7
7.0
6.3
6.7
7.0
6.7
6.3
7.0
7.0
7.0
6.7
6.3
6.7
6.7
6.3
6.7
6.7
6.7
7.0
6.7
6.0
6.7
6.7
7.0
6.3
6.3
6.3
6.7
6.3
6.7
6.7
7.0
6.3
6.7
6.7
7.0
6.0
6.3
6.3
6.7
6.3
7.0
6.7
6.7
6.7
6.3
6.7
6.7
6.3
6.7

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

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

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

Mean
6.9
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
6.8
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
6.7
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

85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125

Cultivar
EEG 358
HE 311
Manhattan II (E)
MVF 89-90
OFI-D4
PR 9109
PST-23C
Saturn
Unknown
Barrage
Commander
Surprise
WVPB 89-92
Danilo
Lindsay
MOM LP 3111
PR 9121
Riviera
Stallion
Statesman (WVPB-88PRD12)
Target
Taya
Gator
Mulligan (NK 89001)
Pennfine
Premier
Cartel
Citation II
MOM LP 3182
Ovation
Barrage ++
Caliente
CLP 144
MOM LP 3184
Loretta
Troubadour
Meteor
MOM LP*3185
MOM LP 3179
Toronto
Linn
LSD(0.o5)

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

16

May
7.0
6.3
6.7
7.0
7.7
7.0
7.7
7.0
7.7
7.0
7.0
7.0
6.7
7.0
7.3
6.7
6.7
7.0
6.7
7.0
7.3
7.0
7.0
6.0
6.0
5.7
6.7
6.3
6.7
6.3
6.3
6.7
7.0
6.3
7.3
7.3
6.3
7.0
6.7
6.0
5.3
1.1

June
6.7
6.3
7.0
6.3
7.0
6.7
6.3
6.7
6.0
6.7
6.0
6.3
6.7
6.3
6.0
6.3
6.3
6.0
6.3
6.3
6.0
6.7
6.0
6.3
6.0
6.3
6.7
6.0
7.0
6.3
6.0
6.3
6.7
6.3
6.0
6.3
6.7
6.3
5.7
6.0
6.0
NS

July
6.7
7.0
6.7
7.0
6.3
6.7
7.0
7.0
6.7
6.0
6.3
6.3
7.0
6.3
6.3
6.3
7.0
6.7
7.0
6.7
6.7
6.0
6.3
6.0
6.0
6.3
6.0
6.3
6.0
6.0
5.7
6.0
6.0
6.0
5.3
5.7
5.7
5.7
5.0
5.7
5.0
0.7

Aug
7.0
7.0
7.0
7.0
6.7
6.7
7.0
7.0
7.0
6.7
7.0
7.0
7.0
7.0
7.0
7.0
7.0
6.7
7.0
6.7
6.7
6.7
7.0
6.7
6.7
6.7
6.7
6.7
6.0
6.3
6.7
6.3
6.3
6.3
6.3
6.0
6.0
5.7
5.3
6.0
5.0
0.8

Sept
7.0
7.0
7.0
7.0
6.3
6.7
7.0
7.0
7.0
7.0
7.0
7.0
7.0
6.3
7.0
6.7
6.7
7.0
7.0
6.7
6.7
7.0
7.0
7.3
6.7
6.7
6.7
6.3
6.3
7.0
6.3
6.3
6.0
6.7
6.0
6.0
6.3
5.7
6.0
6.0
6.0
0.9

Mean
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
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.4
6.3
6.3
6.3
6.3
6.2
6.2
6.2
6.2
6.1
6.1
6.1
6.1
6.0
5.9
5.8
5.8
5.7
5.7
5.4
0.5

Regional Fine Fescue Cultivar Evaluation

-

1992

R. W. Moore and N. E. Christians

This was the second year of data on this trial. It was established in the spring of 1990. The study
was conducted in conjunction with several identical trials across the country, coordinated by the
USDA. The purpose of the trial is to identify regional adaptation of 95 fine fescue cultivars.
Cultivars were evaluated for quality each month of the growing season through October. Visual
quality was based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest
quality.
Three replications of the 95, 3 ft x 5 ft (15 ft2) plots were established in a 5 ft by 19 ft grid. The
average seeding rates were approximately 55 g per plot or about 8 lb/1000 ft2.
The trial was maintained at a 2-in mowing height, 3 to 4 lb N/1000 ft2 were applied during the
growing season, and irrigated when needed to prevent drought. Preemergence herbicide was applied
once in the spring and broadleaf herbicide was applied once in September to control weeds.
’Barcrown’ preformed best in 1992 (Table 6). ’SR 3100’, ’Napoli’, ’Attila’, ’Barlotte’, ’Barskol’,
’Biljart’, ’Epsom’, ’Fernando’, and ’FRT-30149’ were the top 10 cultivars in 1992.

Table 6. The 1992 quality ratings for the fine fescue regional cultivar trial.

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

Cultivar
Barcrown
SR 3100 (SRX 89-31)
Napoli (LD 3488)
Attila
Barlotte
Barskol (BAR FR 9P)
Biljart
Epsom
Fernando (HF 112)
FRT-30149
PST-43F
PST-4HD
Smirna (ZW 42-160)
89.LKR
Aurora W/Endo (PST-AUE)
Bargreen
Bridgeport (N-105)
Brigade (Melody)
Cindy
Reliant W/Endophyte
Trophy (Estoril)
Warwick
Atlanta
BAR Fr 9F
Comfort (HF 102)
Enjoy
Jasper

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

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

17

July
8.0
7.7
7.7
7.0
7.3
7.3
6.7
7.0
7.3
7.0
7.3
7.3
7.3
6.7
7.3
7.0
7.0
7.0
6.7
6.7
7.0
7.0
6.7
7.0
7.0
7.3
7.0

Aug
8.0
8.0
7.7
6.7
7.7
7.3
7.7
7.7
7.7
7.0
7.7
7.3
7.3
7.7
7.3
7.3
7.7
7.3
7.7
7.7
7.7
6.7
7.3
7.3
8.0
7.7
7.3

Sept
7.7
8.0
7.0
7.7
6.7
6.7
7.7
7.0
7.7
7.0
7.3
7.7
6.3
7.7
7.3
7.7
7.3
7.3
7.3
7.7
7.3
8.0
7.3
7.3
6.7
7.0
7.0

Mean
7.7
7.7
7.5
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.2
7.1
7.1
7.1
7.1
7.1

28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81

Cultivar
PST-4AG
PST-4C8
PST-4R3
Scarlet
Silvania
Simone (LD 3485)
SR 3000
Eureka
Rainbow
BAR FO 9A2
Dawson
HF 138
PST-4CD
PST-4NI
Shadow W/Endo (PST-SHE)
SR 5000
Vista
Waldorf
Aurora
Camaro
Crystal
ERG 1143
Herald
Jamestown II
Marker
Molinda
Reliant W/O Endophyte
Shademaster
Flyer
Longfellow
Mary
OFI 89-200
PST-4FE
Salem
Serra
Southport
Talus (LD 3438)
Capitol
Dover (NK 82492)
Puma
WW RS 130
Belvedere
Boreal
Collo (LD 3414)
Franklin
Koket
Raymond
Revere (NK 88001)
WW RS 138
WW RS 143
Barnica
Proformer (JMB-89)
Sunset (ZW 42-148)
Bargena

May
6.3
6.3
6.0
7.3
6.7
7.3
7.3
6.3
7.0
7.0
6.7
6.3
7.0
7.3
6.7
7.3
7.0
6.7
7.0
5.7
6.3
6.3
5.7
7.0
5.7
6.3
6.0
6.8
6.3
7.0
7.3
7.3
6.3
7.0
6.7
7.3
6.0
6.3
6.3
6.7
6.3
6.7
6.0
5.7
6.7
5.7
6.7
5.7
6.7
6.0
6.0
7.0
5.7
5.7

June
7.0
7.3
7.3
6.7
6.7
6.7
7.3
6.7
7.0
7.0
7.3
6.7
6.0
7.0
6.7
6.0
7.0
7.0
7.0
6.0
6.0
7.0
6.7
6.3
7.3
6.7
6.7
6.8
7.0
6.0
6.0
5.7
6.0
6.3
6.3
5.7
7.0
6.3
6.7
6.3
6.7
6.7
7.0
6.3
6.7
6.0
6.3
6.7
7.3
7.3
6.0
5.3
6.3
5.7
18

July
7.3
7.3
7.0
6.7
7.0
6.7
6.7
7.0
6.7
7.0
7.3
7.3
6.7
6.0
6.3
6.3
6.7
6.7
6.3
7.3
6.7
6.7
6.7
6.3
8.0
6.7
7.0
6.8
7.0
7.0
6.0
6.3
6.7
6.3
6.7
6.0
6.7
6.0
7.0
6.3
6.3
6.7
6.0
6.7
6.0
6.3
6.0
6.7
6.3
6.3
6.0
6.0
6.0
6.3

Aug
7.0
7.7
8.0
7.3
7.7
7.7
7.0
7.7
7.0
6.5
7.3
7.3
7.7
7.3
7.7
7.7
7.0
7.0
6.7
7.7
7.3
7.0
8.0
7.3
6.3
7.0
7.0
7.3
7.0
7.0
7.3
7.3
7.7
7.3
7.0
7.3
7.0
7.0
6.3
7.0
7.3
6.3
7.0
7.0
6.3
7.3
7.0
7.0
6.3
6.7
7.0
7.0
7.3
7.0

Sept
8.0
6.7
7.0
7.7
7.3
7.0
7.0
7.3
7.3
7.0
6.0
6.7
7.3
7.0
7.0
7.3
6.7
7.0
7.0
7.3
7.7
7.0
7.0
7.0
6.7
7.3
7.3
6.5
6.3
6.7
7.0
7.0
6.7
6.7
7.0
7.0
6.7
7.3
6.7
6.7
6.3
6.3
6.3
7.0
7.0
7.3
6.7
6.3
6.0
6.3
7.0
6.7
6.7
7.0

Mean
7.1
7.1
7.1
7.1
7.1
7.1
7.1
7.0
7.0
6.9
6.9
6.9
6.9
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
6.8
6.8
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
6.5
6.5
6.5
6.5
6.5
6.5
6.5
6.5
6.5
6.4
6.4
6.4
6.3

82
83
84
85
86
87
88
89
90
91
92
93
94
95

Cultivar
Bighorn
Ensylva
Scaldis
Shadow
Valda
Wilma
Banner
Barim (BAR FR8RC3)
Claudia
Jamestown
Elanor
Sylvester
MX 86
Barreppo
LSD(ao5)

May
5.7
5.3
5.7
6.0
5.7
6.3
6.3
6.0
5.3
6.3
5.3
5.0
5.0
4.3
1.4

June
6.0
5.7
6.3
6.3
6.3
5.7
5.3
5.7
6.0
6.0
5.7
5.7
5.3
5.3
1.0

July
6.3
6.0
6.7
6.0
6.7
6.3
6.0
6.3
5.7
5.7
5.3
6.0
6.3
6.3
1.0

Aug
6.7
7.7
6.3
6.7
6.3
6.7
6.7
6.7
7.0
6.0
7.0
6.3
6.0
5.7
1.7

Sept
6.7
7.0
6.7
6.3
6.7
6.3
6.7
6.3
7.0
7.0
6.7
6.3
6.3
6.7
1.9

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality.

19

Mean
6.3
6.3
6.3
6.3
6.3
6.3
6.2
6.2
6.2
6.2
6.0
5.9
5.8
5.7
0.6

Shade Adaptation Study - 1992
'ir/

N. E. Christians

The shade adaptation study was established in the fall of 1987 to evaluate the performance of 35 species
and cultivars of grasses. The species include creeping red fescue (C.R.F.), hard fescue (H.F.), tall fescue
(T.F.), Kentucky bluegrass (K.B.), and rough bluegrass ( P o a t r i v i a l i s ) .
The area is located under the canopies of a mature stand of Siberian elm trees (
p u m i l a ) at the
Iowa State University Horticulture Research Station. The grasses were mowed at a 2-in height and
received 2 lb N/1000 ft2/year. No weed control has been required on the area. The area was irrigated
during extended droughts.
Monthly quality data were collected from May through September (Table 7). Visual quality was based
on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality. Waldorf
Chewings fescue and Arid Tall Fescue were the two highest rated grasses in 1992. The very dry
conditions of early summer and the very wet conditions of late summer resulted in some unusual results
for the 1992 season. The dry conditions in spring tend to greatly lower the quality ratings of the
creeping red fescues and the Chewings fescues. In dry seasons, tall fescue is one of the better choices
for shaded conditions in Iowa. In more normal seasons, the fine fescues tend to perform better. Sabre
( P o a t r i v i a l i s ) performed very poorly in the earlier, drier years part of the season, but in the wet
conditions of late 1992 it performed much better. None of the Kentucky bluegrasses maintained
satisfactory quality through the entire season.

Table 7. The 1992 quality ratings for grasses in the shade trial.

1
2
3
4
5
6
7
8

Cultivar

April

May

June

July

Aug

Sept

Oct

Mean

Waldorf (C.F.)
Arid (T.F.)
Bonanza (T.F.)
BAR FO 81-225 (H.F.)
Mary (C.F.)
Sabre (Poa trivialis)

5.0
6.0

6.7
7.0

8.0
7.0
7.7
8.0
8.0

7.3
7.0
6.7

7.3
7.1

7.3
7.0

4.3
5.3
5.3

8.0
7.3
7.3
7.0
6.7
5.7
7.0
6.7

9.0
8.0

5.3
4.7
4.7
5.3
4.0
4.7

7.3
7.3
6.7
5.3
5.3
7.7
5.8
5.3

7.7
7.5
7.7

7.0
7.3
6.7

6.3
6.2

4.3
4.3
4.0
4.7

5.0

6.0

7.0

7.3

7.0

5.7
5.7
5.3

5.3
5.7
5.0

6.3
6.7
7.0
6.0

7.3
6.7
6.7
6.7

7.3
7.0
7.0

6.3
6.7
6.7
6.7
6.7

6.1
6.1
6.0
6.0
6.0

6.7

6.3

6.0

6.3
6.0

7.0
6.7
6.7

7.0
6.3
5.3
7.0
6.3
6.0

5.0
6.3
6.0
6.0
5.7
6.7

6.0
6.0
7.0
7.0

6.0
5.9
5.9
5.6

7.3
6.0
6.0
6.7

5.6
5.5
5.5
5.5
5.4

ST-2 (SR 3000) (H.F.)
Pennlawn (C.R.F.)

7.3
6.0
6.3

7.0
7.0
7.0
7.0
7.5
7.3

9
10
11
12
13
14

Biljart (H.F.)
Atlanta (C.F.)
Jamestown (C.F.)
Shadow (C.F.)
Rebel (T.F.)
Apache (T.F.)

4.3
4.0

5.0
5.0

6.0
6.0

15
16
17

Falcon (T.F.)
Wintergreen (C.F.)

4.0
4.7

6.0
5.7

Victor (C.F.)
Estica (C.R.F.)
Rebel II (T.F.)
Waldina (H.F.)
Chateau (K.B.)
Midnight (K.B.)
Coventry (K.B.)

5.0
4.3
3.7
4.0
3.3
2.7
4.0
4.0

4.5
3.3
5.0
4.3
5.3
4.3
5.3
5.3

6.3
5.3
6.0
5.0
5.0
5.3
5.7
6.0
4.7
4.7

5.3
6.0

6.7
5.7

Ensylva (C.R.F.)
Banner (C.F.)
RAM I (K.B.)

3.3
4.3
3.7
3.0

4.0
4.3
4.7
4.3

4.7
4.3
4.7
5.0

5.7
5.3
5.0
5.7

6.0
6.0
5.3
6.0

Agram (C.F.)
Glade (K.B.)

3.0
2.7

4.3
4.3

4.0
5.0

5.7
5.0

Highlight (C.F.)
Spartan (H.F.)
Bristol (K.B.)
Nassau (K.B.)

3.3
2.3

3.3
3.0
3.7
3.0

3.3
3.3

2.7
3.0

18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35

Koket (C.F.)
Scaldis (H.F.)

Reliant (H.F.)
I .SI) (o(i5)

2.0
2.3
2.0
1.7

7.0
7.0
7.0
6.7
7.0
7.0
7.0
6.0
6.3
6.3
6.3

5.3
5.7

6.9
6.5
6.4
6.4

6.0
5.7

5.3
6.7
6.0
6.3
5.3
5.7
5.3

6.0
5.7
5.7
5.3
5.7
5.7

5.3
4.7

5.3
4.7

6.0
5.3

5.3
6.0

3.3
3.3

4.0
4.0

5.0
5.0

4.7
4.7

3.0
2.1

4.0
2.2

4.3
4.0
3.7
2.6

4.2
3.9
3.8

4.3
3.0

4.7
3.0

3.5
3.0

Quality based on a scale o f 9 to 1: 9 = best quality, 6 = acceptable quality, and
1 = poorest quality

21

5.2
5.2
5.1
5.0
5.0
4.9
4.8
4.6

USGA Buffalograss Trial 1992
N. E. Christians and R. W. Moore

The USGA buffalograss trial consists of 5 buffalograss ( B u c h l o e d a c t y l o i d e s ) varieties developed as
part of the USGA turfgrass breeding program that are being compared to a standard buffalograss
variety ’Texoka’.
The trial was established in August, 1988 and suffered considerable winter kill because of the late
planting date. Only variety 84-315 survived the first winter in a satisfactory condition. In November
1989, plugs of all varieties were established in the greenhouse and maintained during the winter of
1989-1990. All six field plots were reestablished in the last week of May, 1990. The summer of
1990 was very wet. These plugs became well established during the growing season and all reached
100% cover by dormancy in September, 1990.
The first quality ratings were taken in 1991 and the data included in this report is from the second full
season of data collection (Table 8). Visual quality was based on a scale of 9 to 1: 9 = best quality, 6
= acceptable quality, and 1 = poorest quality. The 84-315 variety received the highest rating during
the 1992 season. This was due in part to its early spring greenup and its high density and uniformity.
The 84-609, 84-304, and 84-409 varieties do not appear to be well adapted to Iowa conditions. Data
collection will continue for several more seasons on these grasses.

Table 8. The 1992 quality ratings for the USGA buffalograss study.
Cultivar

May

June

July

Aug

Sept

Mean

1

84-315

8.7

7.3

8.3

8.7

8.7

8.3

2

Texoka

5.7

5.7

6.7

7.7

7.3

6.6

3

85-378

5.3

5.7

6.3

6.7

7.3

6.3

4

84-609

3.3

4.3

5.3

5.7

6.0

4.9

5

84-304

2.0

2.7

3.7

3.7

4.0

3.2

6

84-409

2.3

2.7

3.7

4.0

4.0

3.3

LSD(0.Q5)

1.0

0.9

1.9

1.0

2.2

1.0

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and
1 = poorest quality

22

Alkaligrass Evaluations - 1992
N. E. Christians

Alkaligrass (
.
elaspp.) is a grass that is well adapted to soils that are high in sodium (Na+). There
cin
u
P
are many regions in the country, particularly in the west where levels of Na+ are so high that Kentucky
bluegrass, ryegrass, and other cool season grasses cannot survive. In these regions, alkaligrass is a
reasonable substitute. In Iowa, there are few areas where Na+ levels are naturally high, but Na+ can readily
be elevated to toxic levels along city streets and other road areas where salt is applied for ice melting
purposes in the winter and alkaligrass is used in the state in those areas.
The United States Golf Association has been supporting research at Colorado State University for several
years on the selection and development of alkaligrass for use on golf courses. Four of these varieties are
presently being compared to an industry standard (Fultz weeping Alkaligrass) at the Iowa State University
Turfgrass research area since 1991. The results of the 1992 test are in Table 9.
It has been very difficult to get the alkaligrasses established at the ISU location. It was not until late in
1992 that they began to fill in satisfactorily. There were no significant differences among any of the
varieties in 1992 and all of them generally maintained an unacceptable quality rating through the season.
The varieties are showing some improvement in the spring of 1993 and they will be evaluated through
the 1993 season.

Table 9. The 1992 quality ratings for the alkaligrass, non-irrigated study.
Cultivar

May

June

July

Aug

Sept

Oct

Mean

1

Fultz

3.7

2.7

3.0

3.3

3.3

3.0

3.2

2

#2

3.0

2.7

2.7

3.0

3.0

3.7

3.0

3

#14

3.7

2.7

2.7

2.7

3.7

3.7

3.2

4

#18

3.7

3.0

3.0

3.3

3.3

4.0

3.4

5

#57

3.3

3.0

3.0

3.3

4.3

3.7

3.4

LSD(0.05)

NS

NS

NS

NS

NS

NS

NS

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and
1 = poorest quality

23

Green Height Bentgrass Cultivar Trial - 1992
(Native Soil)
N. E. Christians and R. W. Moore

This is the second year of data for the 20 cultivars that were established in the fall of 1989 at the Iowa
State University Horticulture Research Station. The study was reseeded in the spring of 1990 because
of poor winter survival.
The cultivars are maintained with a fertilizer program of 1/4 lb N applied at 14-day intervals with an
approximate total of 6 lbs of N/1000 ftVgrowing season. A 3/16-in mowing height was used.
Fungicides were used as needed in a preventative program. Herbicides and insecticides were applied
only in a curative program.
Table 10 contains the averages of monthly visual quality ratings. Visual quality was based on a scale
of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality. Penncross (Table 10) had
the best quality of any cultivar in 1991, but dropped to number 12 in 1992. Forbes had the best
quality rating in 1992 followed, closely by SR 1020, 88.CLB, Pennlinks, and Putter. Fifteen cultivars
maintained a mean of 6 (acceptable) or better. Egmont, BR1518, and Allure had the lowest quality
ratings of the 20 cultivars.

Table 10. The 1992 ratings for the green height bentgrass trial.

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

Cultivar
Forbes 89-12 (PRO/CUP)
SR 1020
88.CBL
Pennlinks
Putter
WVPB 89-D-15 (Lopez)
88.CBE
Carmen
Southshore
Normarc 101 (Regent)
Providence
Penncross
Cobra
National
Emerald
Bardot
Tracenta1
Egmont2
Allure1
BR 15183
LSD(0.05)

Apr
5.7
4.3
5.3
5.3
4.0
6.3
5.3
5.0
6.0
5.7
3.3
6.3
5.3
6.0
5.7
5.0
4.3
3.7
3.7
3.7
1.6

1Tracenla and Allure are colonia bentgrasses, A g r o s tis
2Egmont is a browntop bentgrass, A g r o s tis c a p illa r is.
3BR 1518 is a dryland bentgrass, A g r o s tis c a sto lla n a .

May
7.3
6.7
6.0
6.7
6.7
7.3
6.0
6.3
6.3
6.0
6.0
6.3
5.3
4.7
5.3
7.0
4.7
4.3
3.7
3.3
1.2

June
7.7
7.7
8.0
7.0
7.3
6.7
7.7
7.0
5.7
7.3
6.3
6.0
6.7
5.7
5.7
5.7
5.7
4.0
3.7
3.3
1.0

July
8.0
8.0
8.0
7.7
7.7
7.0
7.3
7.7
7.7
7.0
7.0
6.3
6.3
6.7
6.0
5.7
5.3
5.0
3.7
4.0
1.0

Aug
7.7
8.0
7.7
8.0
8.0
6.3
7.3
7.3
7.3
7.0
7.7
6.7
6.0
6.0
5.7
6.0
5.0
4.7
4.3
4.0
1.0

ten u is.

Quality based on a scale of 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest quality.

24

Sept
9.0
9.0
9.0
8.3
8.7
8.7
7.7
8.3
8.0
7.7
9.0
7.3
7.7
8.0
7.3
6.7
5.3
4.7
4.0
4.0
1.1

Oct
7.3
8.0
7.3
7.7
7.7
7.7
7.3
7.7
7.3
6.7
7.7
7.0
6.7
5.7
6.0
5.0
4.3
4.7
4.0
3.0
1.5

Mean
7.5
7.4
7.3
7.2
7.1
7.1
7.0
7.0
6.9
6.8
6.7
6.6
6.3
6.1
6.0
5.9
5.0
4.4
3.9
3.6
0.7

Fairway Height Bentgrass Study - 1992
N. E. Christians and R. W. Moore

The fairway height bentgrass study was established in the fall of 1988 to compare the response of several
new cultivars of seeded bentgrasses with the older types. The grass was kept at a 0.5-in mowing height,
the standard mowing height for creeping bentgrass fairways. The area received liquid applications of urea
as needed during the season (0.2 lb N/1000 inapplication in 3 gal water/1000 ft2). The total N application
rate was approximately 3 lb/season. Fungicides and insecticides were used as needed. The area was
irrigated as needed.
Table 11 contains monthly visual quality ratings. Visual quality is based on a scale of 9 to 1: 9 = best
quality, 6 = acceptable quality, and 1 = poorest quality. The 1992 season was very dry early and very
wet late in the season. J.H. Bent had the highest numerical ratings over the entire season, although there
were no statistically significant differences among the yearly mean ratings for the varieties.

Table 11. The 1992 quality ratings for the fairway height bentgrass study.
Cultivar

April

May

June

July

Aug

Sept

Oct

Mean

1

J.H. Bent

6.3

7.3

8.0

8.0

7.7

6.7

7.3

7.3

2

Emerald

5.7

6.3

7.7

7.3

8.3

7.7

7.7

7.2

3

Southshore

5.3

7.3

6.3

7.3

8.0

8.0

7.0

7.0

4

Penncross

5.7

6.7

7.7

7.3

7.3

7.0

7.0

7.0

5

Pennlinks

5.3

7.0

8.0

8.0

6.7

7.3

6.3

7.0

6

Putter

5.0

7.0

7.7

7.7

7.7

7.3

6.3

7.0

7

ISI 123

5.0

6.7

6.7

7.3

7.0

8.0

7.7

6.9

8

Providence (SR 1019)

4.7

7.0

7.7

8.0

7.3

7.0

6.3

6.9

9

ISI 124

4.3

7.7

7.3

7.3

7.0

7.7

6.3

6.8

10

Penneagle

4.7

6.0

7.0

7.7

7.7

8.0

6.7

6.8

11

SR 1020

3.7

5.7

6.7

7.7

7.0

8.7

8.3

6.8

12

Cobra

5.0

6.7

7.3

6.7

6.7

6.7

6.7

6.5

13

National

5.7

5.7

6.3

7.0

6.3

6.3

6.7

6.3

14

Prominent

5.7

5.3

5.7

7.0

6.7

6.0

6.3

6.1

15

Carmen

4.7

6.0

6.7

6.3

6.0

7.3

5.3

6.0

16

Exeter (Colonial Bent)

4.7

5.3

5.7

6.0

6.3

6.0

5.7

5.7

LSD(o.o5)

NS

1.4

NS

NS

NS

1.6

NS

NS

♦Quality based on a scale o f 9 to 1: 9 = best quality, 6 = acceptable quality, and 1 = poorest
quality.

25

Herbicide and
Growth Regulator
Studies

1992 Preemergence Annual Weed Control Study
N. E. Christians, D. L. Struyk and R. G. Roe

The 1992 preemergence annual weed control study was conducted at the turfgrass research area on a
Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) soil with a pH of 6.2, 2.3% organic matter, 19
ppm P, and 93 ppm K. The objectives of the project were to evaluate the efficacy of several labeled
and experimental preemergence herbicides applied to a South Dakota Common Kentucky bluegrass
turf for the control of crabgrass. Plots measured 5 ft by 5 ft. They were arranged in a randomized,
complete-block design with three replications.
The area was seeded in the fall of 1991 with a combination of large hairy and smooth crabgrass that
had been harvested from the research area. Treatments were applied on April 28 and watered in on
April 30. Liquids were applied with a backpack carbon dioxide sprayer equipped with 8006 nozzles in
the equivalent of 3 gal. water/1000 sq. ft. Granular materials were applied with a hand-held shaker.
The months of May, June, and the first week of July were very dry. Mid July to late August was a
very wet period. The area was irrigated with 1 inch of water/wk during the dry period.
The study was observed weekly for signs of phytotoxicity and complete phytotoxicity data were
collected on 5/11, 5/27, 6/11, and 6/22 (Table 12). No damage was observed on any of the treated
plots at any time during the summer of 1992. Estimates of the percentage cover of crabgrass were
made on 7/14, 7/28, 8/28, and 10/1. The lower % cover for 10/1 is due to frost kill of crabgrass.
Most treatments were very effective, even though the late summer was very wet. Team 2 G applied in
split applications (tmt # 14) was very effective, whereas the same material incorporated on a fertilizer
carrier (tmt # 15 was much less effective). The PreM 60 WDG (tmt # 19) was ineffective in this trial.
This is a material that has worked quite well in most years at this location. The reason for the poor
control this year is uncertain. The EXP materials (tmt # 29 to 35) are experimentals from Rhone
Poulenc Inc. These materials were generally quite effective. Treatments 36 to 45 are experimental
fertilizer + Dimension materials from Pursell Inc. Depending on the rate of application, these
materials were very effective.

26

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1992 Postemergence Annual Grass Control Study
N. E. Christians, D. L. Struyk, and R. G. Roe

The objective of this study was to investigate the effectiveness of several postemergence annual grass
herbicides for the control of crabgrass. It was conducted on an area adjacent to the 1992
Preemergence Annual Weed Control Study. The work was conducted on a Nicollet (fine-loamy,
mixed, mesic Aquic Hapludoll) soil with a pH of 6.2, 3.3% organic matter, 19 ppm P, and 93 ppm K.
Individual plots measured 5 ft by 5 ft. The grass on the area was South Dakota Common Kentucky
bluegrass. They were arranged in a randomized, complete-block design with three replications. The
area was irrigated as needed to achieve an irrigation + precipitation rate of 1 inch/wk.
The study area was seeded in the fall of 1991, with a combination of large hairy and smooth crabgrass
that had been harvested at the research area. Treatments 1-15 were applied on 5/27/92 when the
crabgrass was in the 1 to 2 leaf stage. Treatments 16 to 24 were applied on 6/23/92 when the
crabgrass was in the 3 leaf to 1st tiller stage. All treatments were applied with a backpack carbon
dioxide sprayer equipped with 8006 nozzles. The spray pressure was 20 - 25 psi. Treatments were
applied with the equivalent of 3 gal water/1000 ft2.
Ratings of phytotoxicity on the Kentucky bluegrass were made on 6/3, 6/10, and 6/22 on a scale of 9
to 1; 9 = no damage and 1 = dead turf. Ratings of 6 and above were acceptable. Estimates of
percentage crabgrass cover were made on 6/22, 7/28, 8/28, and 10/1 (Table 13). Slight phytotoxicity
was observed from the Dimension + Acclaim treatments (#3 and #15) applied on 5/27. Similar
treatments applied 6/23 showed no damage. No other phytotoxicity was observed.
The crabgrass population was very high in the control plots (Table 13). Control with most materials
was satisfactory. What appears to be a drop in crabgrass populations in most plots between the 8/28
and 10/1 rating dates is due to frost kill of crabgrass and fall growth of the bluegrass in September.

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1992 Broadleaf Weed Control Study
N. E. Christians, D. L. Struyk, and R. G. Roe

The objective of this study was to investigate the efficacy of several herbicides as postemergence
controls of broadleaf weeds in turf areas. The study was conducted at the Iowa State University
Horticulture Research Station north of Ames, Iowa. The soil on the site was a Nicollet with an
organic matter content of 3.0%, a pH of 7.25, 10 ppm P, and 105 ppm K. Individual plots measured 5
ft by 10 ft. They were arranged in a randomized, complete-block design with three replications. The
area was irrigated as needed to prevent dormancy of the Kentucky bluegrass turf. The grass on the
area is a common Kentucky bluegrass established in 1968.
This site had a good population of dandelion (
T a r a x a c u m ), white clover
and several other weeds (Table 14). Treatments were applied on May 10, 1992, at 8:00 a.m.
Conditions were nearly ideal for weed control. No rain occurred until May 18, when 0.25 inch of rain
was recorded. All treatments were applied with a backpack carbon-dioxide sprayer equipped with
8006 nozzles. The spray pressure was 20-25 psi. Treatments were applied with the equivalent of 3
gal water/1000 ft2.
No phytotoxicity on the Kentucky bluegrass was observed. Weed counts and estimations of
percentage weed cover were made on July 7, August 17, and October 1, 1992. Tables 14, 15, and 16
contain data on weed control observed on each of the observation dates. The high counts of dandelion
in October were due to germination of dandelion seed during the fall.

32

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Table 15. Weed count on broadleaf weed control trial — August 17, 1992.

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Effects of Dithiopyr (Dimension) on the
Rooting of Creeping Bentgrass
R. G. Roe and N. E. Christians

Dithiopyr (Dimension) is a new herbicide labeled for use on Kentucky bluegrass and other turf species
in 1991. It functions both as a preemergence and early postemergence control of crabgrass.
The objectives of this study were to observe rooting responses and foliar phytotoxicity to dithiopyr on
creeping bentgrass mowed at 3/16-inch and maintained under putting green conditions. This is the 3rd
year of this study at Iowa State University.
The turf was an 11-year-old stand of ’Penncross’ creeping bentgrass established on a 1:1:1 (sand:soil:peat)
soil mixture with a pH of 7.1. The area received 3 to 4 lb N/1000 ft2 in 0.2 lb increments as needed. No
P or K was applied. Standard fungicide and insecticide treatments were made uniformly on all plots.
Each plot measured 5 ft by 5 ft and the study was replicated three times. Treatments applied on May 8,
1992, with a carbon-dioxide backpack sprayer are listed in Table 17.
The grass on the treated plots showed no visible signs of phy to toxicity during the study. Again this year
there was an initial positive response to the granular formulations of dithiopyr in some replications. This
appeared to be due to a nutritional stimulation of the grass by the carrier. These responses were not
consistent enough to be significant.
Root samples were collected on June 9 and August 7 to a depth of 20 cm (Table 17). The diameter of
the cores was 2.54 cm and six cores were collected per plot. The samples were divided into four
subsamples cut in 5 cm increments: 0-5, 5-10, 10-15, and 15-20 cm. All soil was washed from the root
samples, the samples were dried, weighed, and ashed at 500°C. Root weights were reported as the
difference between ashed and dry weights.
Rooting varied by depth on both June 9 and August 7, but no difference was observed with herbicide
treatment.
Bensulide was used as a standard in this trial as it is labeled for use on bentgrass greens. Root weights
of dithiopyr-treated bentgrass were generally similar to that of Bensulide-treated plots. This information
combined with the lack of phytotoxicity has shown that after three years of repeated treatments, dithiopyr
was generally safe for use on ’Penncross’ creeping bentgrass maintained at green height under the
conditions established in this study.

36

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1992 Sod Rooting Trial - I
R. G. Roe and N. E. Christians

The purpose of this study was to observe the effects of selected pesticides on establishment and
rooting of Kentucky bluegrass (cv. ’Ram I’) sod. This study was the second year of a 2-year study.
Two separate trials were conducted, one irrigated and the other on a non-irrigated area. Treatments
are listed in Table 18. The test was conducted on a Nicollet (fine-loamy, mixed, mesic Aquic
Hapludall) soil with a pH of 7.4, and 3.5% organic matter, 6 ppm P, and 74 ppm K on the irrigated
area, and a pH of 6.9, 3.4% organic matter, 7 ppm P, and 115 ppm K on the non-irrigated area.
Individual treatment cells measured 6 ft x 8 ft and were randomized in a complete block design with
three replications.
The Kentucky bluegrass sod was cut at a 3/4 in depth and laid in the standard fashion on March 19
and 20, 1992. Sod pieces were transplanted into wooden frames, 6 frames per plot. The frames had
18-mesh fiberglass screen bottoms and were constructed of 1 in x 2 in pine boards with inside
dimensions of 12 in x 12 in. Screw hooks were placed at each of the four comers to attach the
hydraulic lift apparatus. Check frames were pulled prior to treatment to ensure rooting. Pulling
pressure exceeded 500 psi and the sod in the area was assumed to be fully rooted at that time. Liquid
treatments were applied to the sod on May 5, 1992, with the use of a backpack carbon-dioxide sprayer
equipped with 8006 nozzles in the equivalent of 3 gal. water/1000 sq. ft. Granular materials were
applied with a hand-held shaker.
Rooting was measured with a technique modified from King (King & Beard, 1969). The frames were
lifted vertically with a hydraulic pump apparatus (Fig. 1). Woven steel cords were attached to each of
the four hook screws on the frame and drawn to an apex over the center of the frame. The force at
the point of root breakage from the soil was measured by the use of a hydraulic pressure gauge.
Rooting measurements were used as an indication of sod establishment. The frames were lifted on
July 7 and 8 (63 days post treatment) and September 11 and 17 (126 days post treatment, pulling the
frames from the non-irrigated area was delayed due to rain). An analysis of variance was performed
on all data.
Because of the longer rooting period in this trial, root development was greater. Sod pulling pressure
was at least 200 psi greater than the same trial in 1991, and nearly 500 psi greater than in previous
sod rooting studies. Pulling pressures were higher in the second year of this study due to modification
of the frames. In nearly every case, pulling pressure exceeded the maximum gauge pressure of 1000
psi. There were no significant differences for irrigated and non-irrigated trials in sod pulling pressure
at either the 63- or the 126-day testing time (Tables 18 and 19). No noticeable differences in turf
quality were visible after treatment.

King, J. W. and J. B. Beard. 1969. Measuring rooting of sodded turf. Agronomy Journal 61:497-498.

38

Table 18.

Treatments included in the 1992 rooting trial.

Rate/plot
6 ft x 8 ft

Treatments
1

Balan 2.5 G: 2.0 lb ai/A

40 G

2

Balan 2.5 G: 2.0 + 2.0 lb ai/A - 63-day split application

40 G + 40 G

3

Team 2G: 1.5 lb ai/A

37.5 G

4

Team 2G: 3.0 lb ai/A

75 G

5

Team 2G: 1.5 + 1.5 lb ai/A - 63-day split application

37.5 G + 37.5 G

6

Pendimethalin 60 DG: 2.0 lb ai/A

1.67 G

7

Pendimethalin 60 DG: 1.5 + 1.5 lb ai/A —
63-day split application

1.25 G + 1.25 G

8

Ronstar 2G: 3.0 lb ai/A

75 G

9

Check 1: Sample at time of first application (3 grids/plot)

—

10

Check 2: Sample at 62 days after first appl. (3 grids/plot)
Sample at 62 days after second appl. (3 grids/plot)

39

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1992 Sod Rooting Trial - II
R. G. Roe and N. E. Christians

The purpose of this study was to observe the effects of selected pesticides on the establishment and
rooting of Kentucky bluegrass (cv ’Majestic’) sod. The test was conducted on a Nicollet (fine-loamy,
mixed, mesic Aquic Hapludoll) soil with a pH of 6.9 and 2.3% organic matter. Individual treatment
cells measured 5 ft x 5 ft and were randomized in a complete block design with three replications.
Water was applied as required.
The Kentucky bluegrass sod was cut at a 3/4 in depth on May 7, 1992, and laid in the standard
fashion. Sod pieces were transplanted into wooden frames, 3 frames per plot. The frames had 18mesh fiberglass screen bottoms and were constructed of 1 in x 2 in pine boards with inside dimensions
of 12 in x 12 in. Screw hooks were placed at each of the four comers to attach the hydraulic lift
apparatus. Liquid treatments were applied to the sod on May 8, 1992, with a backpack carbon-dioxide
sprayer equipped with 8006 nozzles in the equivalent of 3 gal. water/1000 sq. ft. Granular materials
were applied with a hand-held shaker (Table 21).
Rooting was measured with a technique modified from King (King & Beard, 1969). Woven steel
cords were attached to each of the four hook screws on the frame and drawn to an apex over the
center of the frame. The frames were lifted vertically with a hydraulic pump apparatus (Fig. 1). The
force at the point of root breakage from the soil was measured by the use of a hydraulic pressure
gauge. Rooting measurements were used as an indication of sod establishment. The frames were
lifted 2, 4, and 6 weeks following treatment. Visual quality ratings were recorded on June 18.
Quality was rated on a scale of 9 to 1, 9 = best, 5 = acceptable, and 1 = dead turf.
There were significant differences in sod-pulling pressure at all three testing times (Table 21). By the
second week following treatment, Barricade 65DG at the 0.65 lb ai/a single application rate showed
the greatest numerical pulling pressure. As would be expected, Surflan 1G at 2 lb ai/a showed the
greatest reduction in pulling pressure 2 wks after treatment. Surflan is not labeled for use on
Kentucky bluegrass. Six weeks after treatment Banner 1.1E at 2 oz/1000 ft2 and EXP30910A 5G at 6
lb ai/a had numerically greater pulling pressure than the other treatments. Again Surflan 1G at 2 lb
ai/a showed the greatest reduction in rooting, followed by Dimension 0.1G at 1 lb ai/a. These
differences were significant at a 0.05 level.
Noticeable differences in turf quality were not visible during the study with the exception of Surflan
which discolored the Kentucky bluegrass for 6 weeks after application.

King, J. W. and J. B. Beard. 1969. Measuring rooting of sodded turf. Agronomy Journal 61:497498.

43

Table 21. Pulling pressures required to pull sod frames from Kentucky bluegrass plots.
Treatment

Rate (lb ai/a)

2 weeks

4 weeks

6 weeks

— PSI Pulling Pressure------1. Control

487

588

660

2. Ronstar 2G

4

502

712

625

3. EXP30910A 5G

6

420

585

737

4. Pendimethalin 2G

3

518

625

618

5. Dimension 0.1G

1

347

545

553

6. Barricade 65DG

0.65

577

563

620

7. Surflan 1G

2

167

227

292

8. Banner 1.1E

2 oz/1000 ft2

537

763

812

118

186

115

LSD(005j

44

Ethofumesate (Prograss) Demonstration on a
Tee, and Fairway
at Veenker Golf Course in Ames, Iowa
N. E. Christians and D. L. Struyk

Ethofumesate (Prograss) is marketed as an annual bluegrass (Poa annua) control for golf course
fairways. It is labeled for use on Kentucky bluegrass, perennial ryegrass, and creeping bentgrass
maintained at fairway mowing heights. It is presently not labeled for low-mowed creeping bentgrass
on greens.
In this demonstration, ethofumesate was applied in 15 ft wide strips on #14 fairway and #14 green,
and on #15 ladies tee at Veenker Golf Course in Ames, Iowa. Treatments included a control, 0.50,
and 0.75 lb ai/A on the fairway and tee. On the green, rates included a control, 0.25, 0.50, and 0.75
lb ai/A. The fairway treatments were replicated 2 times. The treatments on the green and tee were
not replicated.
All areas were treated in September and October 1991 at the listed rates. The standard November
treatment was not possible because of early snow in the Ames area in late October 1991. In May
1991, 5-ft wide sub-plots within the existing treated areas were retreated at the same rates applied to
those plots in the fall.
On July 28, 1992, four 4-inch diameter plugs were taken from each treated area and estimates of the
% Poa annua per plug were made visually. These four values were averaged and the data is reported
in Tables 1 through 3.
Ethofumesate was quite effective in reducing Poa annua on the green (Table 22). Initially in the
spring, treated areas appeared to have a very thin stand of grass because of the loss of Poa annua. The
appearance of the area and putting quality returned to normal by late May to early June. This was a
non-replicated demonstration and no evaluation of statistical significance of Poa annua control is
possible. But it is apparent from the data listed in Table 22, that Poa annua populations were reduced
by the ethofumesate treatments and that the additional spring treatment provided increased control over
the fall-only treatments.
There was no visible reduction of Poa annua on the fairway or the tee and no Poa annua differences
were found at the July 28 evaluation (Tables 23 and 24). This lack of control is surprising.
Treatments were made to all areas at the same time with the same tank of material. The only
difference was the low mowing height on the green. There may have been biotype differences among
Poa annua types on the three areas, although this will take further work to determine.

45

Table 22. T he effect o f ethofum esate (Prograss) on Poa annua populations on a Penncross creeping
bentgrass green.

Treatments

Fall Treatments Only*

Fall Treatments Followed by a
Spring Treatment

-------------% poa annua--------------

— lb ai/A —
Control

90

73

0.25

37

36

0.50

48

12

0.75

43

22

*The treatments were made in September and October 1991 in the "fall only'” treatments and
were made in September, October 1991 and May of 1992 in the fall treatments followed by a
spring treatment.

Table 23. The effect o f ethofum esate (Prograss') on Poa annua populations on a creeping bentgrass +
Kentucky bluegrass + perennial ryegrass tee.

Treatments

Fall Treatments Only*

Fall Treatments Followed by a
Spring Treatment

-------------% poa annua--------------

— lb ai/A —
Control

14

u

0.50

18

13

0.75

34

11

*The treatments were made in September and October 1991 in the fall only treatments and
were made in September, October 1991 and May 1992 in the fall treatments followed by a
spring treatment.

Table 24. The effect o f ethofum esate (Prograss') on Poa annua populations in a Kentucky bluegrass +
perennial ryegrass fairway.

Treatments

Fall Treatments Only*

Fall Treatments Followed by a
Spring Treatment

-------------% poa annua...................

— lb ai/A —
Control

31

16

0.50

30

45

0.75

28

9

*The treatments were made in September and October 1991 in the fall only treatments and
were made in September, October 1991 and May 1992 in the fall treatments followed by a
spring treatment.

46

The Efficacy of Ignite as a Non-selective

1992

T. R. Bormann and N. E. Christians

The objective of this study was to evaluate the initial and residual efficacy of Ignite from American
Hoechst Corporation as a non-selective herbicide for the control of Kentucky bluegrass. The study
was conducted on an established ’Majestic’ Kentucky bluegrass turf. The soil on the site is Nicollet
with 3.3% organic matter, a pH of 6.7, 9 ppm phosphorus, and 90 ppm potassium.
Individual plots measured 3 ft by 5 ft. Each plot was then divided into 18 in by 5 ft plots. One-half
of each plot was treated with one of the three treatments (Table 25), and one-half was used as a
control. Each treatment was replicated three times and data on percent dead tissue was taken weekly
for 7 weeks following treatment.
All treatments were applied June 5, 1992, at a time when the grass was being watered to prevent
drought stress. All treatments were applied at the equivalent of 3 gal water per 1000 ft2.
After the June 5 application, 7 weekly ratings were made on a percent damage scale where 100 =
complete kill and 0 = no damage. The study was concluded on July 17, 1992 (Table 25).
The best control obtained by Ignite at the rate of 2 fl oz/gal was 68% and the Ignite at 4 fl oz/gal
reached 88%. The grass treated with Ignite contact herbicide started to recover from its rhizomes after
two weeks. Glyphosate, which is a systemic herbicide, reached 100% at the third week and
maintained the total kill throughout the 7 weeks of the study.
Ignite can be used as a quick, "knock down" treatment for grasses, but extended control of
rhizomatous grasses requires a systemic control.

Table 25. Percentage kill of ’Majestic’ Kentucky bluegrass by Ignite and glyphosate over a 7 wk
period.

Weeks after Treatment (% Dead Tissue)
Treatment

1

2

3

4

5

6

7

Ignite 2 fl oz/gal

68

67

56

37

15

10

8

Ignite 4 fl oz/gal

88

80

72

80

72

58

42

Glyphosate 2.5 fl oz/gal

52

95

100

100

100

100

100

LSD(0.05)

18

4

10

14

24

25

22

47

The Effects of Quinclorac on the Establishment
of Three Grass Species
D. L. Struyk and N. E. Christians

Quinclorac is an experimental herbicide that is being tested as a selective, postemergence material for
the control of crabgrass, white clover, and other weeds in turf areas. It is a product of the BASF
Company and will be marketed under the name "Drive" when it is registered.
The objectives of this study were to observe the effects of quinclorac on the establishment of ’Ram I’
Kentucky bluegrass, ’Dandy’ perennial ryegrass, and ’SR1020’ creeping bentgrass following both pre
and postemergence application.
The study was conducted on newly tilled soil in a strip split-plot arrangement with 6 quinclorac
treatments as main plots. The treatments included a control and 5 quinclorac treatments applied at
0.75 lb a.i./A at different times before and after seeding; immediately after seeding, 1 week after
seeding, 2 weeks after seeding, 4 weeks after seeding, and 8 weeks after seeding. BAS 0900 2S was
included at 1 qt/A with all treatments applied after emergence (treatments 3-6). The three grass
species were included as strip plots. The grasses were seeded on May 18, 1992. The bluegrass was
seeded at a rate of 1.5 lb/1000 ft2, the ryegrass at 3 lb/1000 ft2, and the creeping bentgrass at 0.75
lb/1000 ft2. The soil on the site is a Nicollet (fine-loamy, mixed, mesic Aquic Hapludoll) with a pH
of 6.7 and 2.9% organic matter. Soil test levels on the site were 32 ppm P and 99 ppm K.
The three species were germinated at different times. The last to emerge was Kentucky bluegrass on
May 30. Data was taken 2, 4, 6, and 12 weeks after planting. Crop injury, stand loss, color, and
quality were taken on all four of these dates. Weed control was recorded 4 and 6 weeks after
planting.
Factors that had some effect on the results include flooding of lower areas in the plot and a heavy
infestation of purslane in the Kentucky bluegrass plots due to its slow establishment. "Drive" had no
effect on the purslane.
All treatments showed some visual injury for several weeks after application (Table 26).
Preemergence applications had no effect on creeping bentgrass. The treatments applied to the
Kentucky bluegrass 2 weeks after seeding resulted in consider stand loss. Kentucky bluegrass
appeared to be more sensitive to the treatments by the high losses shown in week 12. This could have
been due to a large purslane population caused by the slow germination of the bluegrass. Grassy weed
control was satisfactory in the PRE, 1 week, and 2 weeks after seeding treatments. Control was not
adequate 8 weeks after seeding treatments.

48

Table 26. BASF seeding study - 1992.
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tO

1992 Growth Regulator Study
T. R. Bormann and N. E. Christians

Recently many states have banned grass clippings and other yard debris from public landfills. One
solution to this is to reduce the amount of clippings produced by a turfgrass area. One way to do this
is by the use of a growth regulator which reduces the amount of growth of the turf plant. In this trial,
an experimental growth regulator, Primo (WP and EC), was tested against a combination of Limit and
Embark. The soil on the test area was a Nicollet with 3.3% organic matter, a pH of 6.7, 9 ppm
phosphorus, and 86 ppm potassium.
The treatments include an untreated control, Primo 1EC at 0.27 lb ai/A, Primo 1 EC at 0.41 lb ai/A,
Primo 25WP at 0.27 lb ai/A, Primo 25WP at 0.41 lb ai/A, and a combination of Limit at 1 lb ai/A
with Embark at 0.1 lb ai/A. The treatments were applied on May 8, 1992, to 10 ft by 10 ft plots of
’Park’ Kentucky bluegrass. The area was mowed 2 days before treatment. The plots were watered to
prevent stress. Quality ratings based on color, uniformity, and density were made on a scale of 9 to 1,
9 = best, 5 = acceptable, and 1 = worst.
Beginning 7 days after treatment, one-half of each treated plot was mowed and fresh weight of
clippings was determined. Height of growth of the unmowed canopy was measured following each
weekly mowing. Quality rating, height measurement, and clipping weights were taken weekly through
the 10th wk after treatment (DAT).
The height of tissue was reduced by the treatments through the first 8 wks after treatment (Table 29).
The most effective treatment at reducing tissue height was the Limit + Embark material.
The treated plots produced lower clipping yields through the 7th wk after treatment (Table 30), but by
the 8th wk the clipping heights from most of the treated plots exceeded that of the control. This postinhibition growth is often observed on grasses that have been treated with growth regulating
compounds. Total clipping yield over the 10-wk period was significantly reduced by all treatments
except the Primo 25WP at the 0.27 lb ai/A rate. The most effective treatment was the Limit + Embark
treatment that reduced total clippings by 21%.
The treated plots, except for the Limit and Embark combination, were observed to have lower quality
ratings throughout the study except for the 3rd wk (Table 31). The lower ratings for the Primo
treatments were due to a gray-green coloration of tissue through must of the test period.

52

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54

Turfgrass Disease
and Insect Research

Evaluation of Fungicides for Control of
Snow Molds on Creeping Bentgrass, 1992-1993
M. L. Gleason

The trial was conducted on a creeping bentgrass tee (Hole #4) at the Waverly Municipal Golf Course,
Waverly, IA. This tee had a history of outbreaks of gray and pink snow molds in most of the last 10
years. The experimental design was a randomized complete block with 4 replications. All plots
measured 5 ft x 5 ft. Fungicides were applied on November 11, 1992, using a modified bicycle
sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2.
Snow cover persisted on the tee from November 20, 1992 until March 30, 1993. Symptoms were
rated on April 5, 1993.
Snow mold development on untreated check plots was light to moderate (Table 32). Only gray snow
mold symptoms were found in plots this year. All fungicide treatments gave significantly better
control of snow mold than the untreated check; 11 of 29 fungicide treatments were free of snow mold
damage. None of the fungicide treatments were significantly different from the others in disease
suppression.

Table 32. 1992-1993 evaluation of fungicides for control of snow molds on creeping bentgrass at
Waverly Municipal Golf Course, Waverly, IA.
Company

Product

Rate/1000 ft2

Control
ISK Biotech

Grace-Sierra

Disease rating3
1.75a

Daconil Flo

8 oz.

0.00 b

Daconil Flo

8 oz.

0.00 b

+fluazanim flo (ASC66825)

2 oz.

Daconil Flo

8 oz.

+ASC 67103 flo

1.25 oz.

Daconil Flo

8 oz.

+ASC 67106

0.33 oz.

Daconil Flo

8 oz.

+fluazanim flo (ASC66825)

3 oz.

0.00 b

0.25 b

0.25 b

GS/SM 92-01

0.00 b

GS/SM 92-02

0.50 b

GS/SM 92-03

0.25 b

GS/SM 92-04

0.00 b

GS/SM 92-05

0.25 b

GS/SM 92-06

0.00 b

55

Company

Grace-Sierra (cont.)

DowElanco

BASF

Rhone-Poulenc

Terra Int’l

Rate/1000 ft2

Product

Disease rating“

Control

1.75a

GS/SM 92-07

0.50 b

GS/SM 92-08

0.75 b

GS/SM 92-09

0.25 b

GS/SM 92-10

0.75 b

GS/SM 92-11

0.00 b

GS/SM 92-12

0.00 b

Rubigan AS

8 oz.

0.50 b

Rubigan AS

4 oz.

0.50 b

Rubigan AS

2 oz.

0.75 b

Ronilan DF

1 oz. a.i.

0.75 b

Ronilan DF

1 oz. a.i.

+Daconil 75

4 oz. a.i.

0.00 b
*

Silbos 75 DF

5.7 oz. a.i.

0.50 b

Chipco 26019WDG (EXP10370A)

4 oz.

0.25 b

+Daconil 2787 fio

8 oz.

Chipco 26019WDG (EXP10370A)

2 oz.

+Daconil 2787 fio

8 oz.

EXP10364A fio

3 oz.

0.25 b

EXP10364A fio

4 oz.

0.00 b

Chlorothalonil 90DF

4 oz.

0.75 b

+Chipco 26019 fio

8 oz.

Chlorothalonil 90DF

8 oz.

+Chipco 26019 fio

8 oz.

0.00 b

0.25 b

“Means of 4 replications. 0 = no disease; 1 = 1-10% of plot showing symptoms; 2 = 10-25% of plot;
3 = 25-50% of plot; 4 = > 50% of plot. Means followed by the same letter are not significantly
different (DMRT, P=0.05).

56

Evaluation of Fungicides for Control of
Brown Patch in Creeping Bentgrass
M. L. Gleason

Trials were conducted at Veenker Memorial Golf Course on the campus of Iowa State University,
Ames, IA. Fungicides were applied to creeping bentgrass maintained at 5/32-inch cutting height, using
a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The experimental design was
a randomized complete block with three replications. All plots measured 4 ft x 5 ft. All plots were
surrounded by 2-ft-wide strips of untreated turf in order to help create uniform disease pressure.
Fungicide applications began on May 25 and continued at recommended intervals (7, 14, 21, or 28
days) until August 7. Disease development was rated on July 17, August 1, and August 14.
The summer of 1992 was the second coolest in Iowa in 120 years. Low temperatures in June through
August suppressed development of brown patch symptoms, despite above-average rainfall in July.
Despite the light to moderate disease pressure, several materials were not significantly better for
disease control than the untreated check: Ronilan 50 DF at 0.5 and 1 oz a.i. at a 14-day interval;
Chipco Flo at 2 and 4-oz rates at 21 days; and Vorlan Flo at a 2 oz rate at 21-day interval. All other
treatments gave significantly better control than the check on at least 2 of the 3 rating dates.
PCNB 75 W formulations at the 4-oz rate and 7-day intervals caused moderately severe yellowing and
browning of the turf in July and August. Sentinel 40 WG caused a slightly enhanced green color of
the turf by early August.

57

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8 8 8 8 8

8
8888
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58

Table 33. 1992 Fungicide tests for brown patch.

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’Means in the same column followed by the same letter are significantly different (DMRT, P=0.05).

Io

Evaluation of Fungicides for Control of
Dollar Spot in
’Penncross’Bentgrass

--

1992

M. L. Gleason

Trials were conducted at the Turfgrass Research Area of Iowa State University’s Horticulture Research
Station. Fungicides were applied to Penncross creeping bentgrass maintained at 5/32-inch cutting
height, using a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The
experimental design was a randomized complete block with four replications. All plots measured 4 ft
x 5 ft.
Fungicide applications began on June 1 and continued at recommended intervals (7, 15, 21, or 28
days) until July 27. Disease development was rated on June 30, July 15, and August 3.
Disease development was moderate during the test period. Several materials were not significantly
better for disease control than the untreated check on at least two rating dates: Chipco 26019 Flo and
WDG at 2 oz and a 28-day interval; and tank mixes of EXP 10357 A with Chipco at 28 days. Other
treatments varied widely in efficacy.
PCNB 75 W at the 10 oz rate and a 7-day interval caused moderately severe yellowing and browning
of the turf in July and August. Hexaconazole at the 6 g a.i. rate and 21-day interval caused a slight
browning of turf on June 30, but not on later rating dates.

60

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Table 34. 1992 Fungicide tests for Dollar spot.

(3

ON N S

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ri o o o Cun
m o un
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JMeans in the same column followed by the same letter are not significantly different (DMRT, P=0.05).

3
00

Pythium and Root Disease of Creeping Bentgrass
C. F. Hodges and D. A. Campbell

The ability of P y t h i u m species to cause root diseases in grasses adapted to turf culture is well
recognized (Smiley et al. 1992; Smith et al. 1989), but the number of critical studies of P y t h i u m
species as root pathogens of A g r o s t i s p a l u s t r i s (creeping bentgrass) is relatively limited. Recognition
of P y t h i u m species as root pathogens of A . p a l u s t r i s seems based on seedling inoculations (seminal
roots) (Endo 1961, Kraft and Endo 1966, Kraft et al. 1967, Nelson and Craft 1991), inoculations of
adventitious roots (Hodges 1992, Hodges and Coleman 1985, Nelson and Craft 1991), and to some
extent an inference of pathogenicity on the basis of isolations from soils and roots supporting this turf
species. The general recognition of P y t h i u m species as root pathogens of A . p a l u s t r i s makes little
distinction between the response of seminal and adventitious root infection; i.e., a kind of unstated
acceptance that the response of one root system is typical of the other. In this respect, seminal root
infection may be more representative of postemergence damping-off diseases and may have little or no
relevance to more complex P y t h i u m interactions with the adventitious root systems of mature stands of
A . p a lu s tr is .
Research in our laboratory has concentrated on the infection of adventitious roots of A . p a l u s t r i s with
numerous species and isolates of P y t h i u m (Table 35). Most P y t h i u m species isolated from adventitious
roots of diseased A . p a l u s t r i s will infect adventitious roots of healthy plants in controlled studies. The
ability to infect is isolate specific and temperature dependent (Table 36) in many species; i.e., isolates
of the same species show different levels of pathogenicity and may be indifferent to temperature, or
may require high or low temperatures to damage plants. Damage under controlled studies, however, is
limited to reduced growth and infection of the roots is confined to root tips, root hairs, and epidermal
and cortical tissues without causing rot. These infection characteristics place P y t h i u m species within
the broad class of minor root pathogens (Salt 1979). The term ’’minor" does not mean that these
pathogens are unimportant; the term refers to pathogens found primarily in juvenile tissues that
generally do not kill the host plant unless it is under stress and/or occurs in combination with other
minor pathogens.
Research conducted in our laboratory over the last eight years suggests that the damage to A . p a l u s t r i s
by P y t h i u m species falls into two broad categories, both of which typify the behavior of minor root
pathogens. The first category is represented by the disease termed P y t h i u m root dysfunction (Hodges
and Coleman 1985) and other disorders that occur in stands of A. p a l u s t r i s turf one-year old or
younger (Nelson and Craft 1991). These diseases of youthful stands of turf can cause extreme damage
on newly established greens within the first year of establishment, but it rarely occurs after the first
year. This type of disease development reflects the ability of P y t h i u m to severely infect young
maturing tissues as plants establish and to kill those plants when they are subjected to heat stress. The
second category is represented by P y t h i u m damage to mature stands of A . p a l u s t r i s turf five or more
years of age. Under these circumstances, turf is lost in a rather nondescript fashion (chlorosis, wilting,
thinning). Typically the adventitious roots yield P y t h i u m , but they also yield other potential root
pathogens. Most common among the other organisms isolated are M i c r o d o c h i u m b o l l e y i and
A c r e m o n i u m ( C e p h a l o s p o r i u m ) ; to a lesser extent, B i p o l a r i s s o r o k i n i a n a , C u r v u l a r i a g e n i c u l a t a , C.
l u n a t a , and species of F u s a r i u m are isolated. It is also common to isolate P y t h i u m from A . p a l u s t r i s
roots with prominent populations of ectotrophic hyphae. Diseased adventitious roots that yield
P y t h i u m and a host of other potential root pathogens are typical of minor root pathogen interactions
and the resulting disease cannot be attributed entirely to P y t h i u m species. P . t o r u l o s u m is a common
isolate from A . p a l u s t r i s roots and interacts with D e s u l f o v i b r i o d e s u l f u r i c a n s in black-layered sand to
decrease shoot and adventitious root growth more than that caused by either organism alone (Hodges
1992).
62

Table 35.

P y th iu m

species and isolates evaluated for pathogenicity to adventitious roots of A g r o s t i s

p a lu s tr is .1

1. P ythium gram inicola/arrhenom anes isolates
PGA-1
PGA-2
PGA-3
PGA-4
PGA-5
PGA-6
PGA-7

P . g r a m in ic o la
P . g r a m in ic o la
P . g r a m in ic o la

Intermediate between P .
Intermediate between P .
Intermediate between P .
Characteristics closer to

g ra m in ic o la
g ra m in ic o la
g ra m in ic o la

and
and
and

P . arrh en o m a n es

P. a rrh en o m a n es
P. a rrh en o m a n es
P . a rrh en o m a n es

than P.

g r a m in ic o la

2. P ythium rostratum isolates
PR-1 P.

r o s tr a tu m

3. P ythium torulosum isolates
PT-1
PT-2
PT-3
PT-4
PT-5

P. t o r u l o s u m
P. t o r u l o s u m
P. t o r u l o s u m
Characteristics closer to P.
Characteristics closer to P.

to r u lo s u m
to r u lo s u m

than P.
than P.

v a n te r p o o li
v a n te r p o o li

4. P ythium vanterpooli isolates
PV-1 P.
PV-2 P.

v a n te r p o o li
v a n te r p o o li

5. Unclassified P ythium isolates
UP-1 Unclassified

‘Classification of the P y t h i u m species in this table was provided by Dr. W. A. M. de Cock,
Centraalbureau voor Schimmelcultures, Julianalaan 67a, 2628 BC DELFT (Netherlands). All
species were isolated from the roots of diseased A g r o s t i s p a l u s t r i s on golf greens.

P y th iu m

There is little to be gained by future adventitious root inoculation studies with isolates of P y t h i u m . It
is clear that most will infect, but severity of disease and the environmental requirements for disease
vary with each isolate of a given species. Future work must begin to examine the genetics of
pathogenicity of P y t h i u m isolates and the physiology of the diseases they cause. Although controlled
inoculations of A . p a l u s t r i s adventitious roots do not kill plants, it often severely stunts their growth.
The stunting is remarkable in that the infection is often light and relatively superficial in the root
tissue. This suggests that potent growth regulating substances are produced (hormones and/or toxins).
None of these relationships have been extensively researched and they may hold the key to
understanding the wide range of pathogenic responses associated with P y t h i u m infections.

63

Table 36. The Effect of Temperature on the Growth Response of A g r o s t i s
Inoculation with Various P y t h i u m Isolates
Isolate

Low temperature
growth (% of control)

P a lu s tr is

to Root

High temperature
growth (% of control)

A. Low Temperature Damage Only
PGA-3
PR-1
PV-2

49*
59*
75*

89
95
90

101
90
95

81*
53*
60*

35*
44*
59*
49*
59*
46*
74*

69*
69*
74*
84*
74*
83*
67*

B. High Temperature Damage Only
PGA-1
PGA-4
PGA-6
C. Low and High Temperature Damage
PGA-5
PT-2
PT-3
PT-5
PV-1
UP-1
PT-1
‘Significant increase or decrease in growth.

Endo, R. M. 1961. Turfgrass diseases in southern California. Plant Dis. Rep. 45:869-873.
Hodges, C. F. 1992. Pathogenicity of P y t h i u m t o r u l o s u m to roots of A g r o s t i s p a l u s t r i s in black-layered
sand produced by the interaction of the cyanobacteria species L y n g b y a , P h o r m i d i u m , and
N o s t o c with D e s u l f o v i b r i o d e s u l f u r ¡ c a n s . Can. J. Bot. 70:2193-2197.
Hodges, C. F., and Coleman, L. W. 1985.
P y t h i u m - m d u c root dysfunctio
A g r o s t i s p a l u s t r i s . Plant Dis. 69:336-340.
Kraft, J. M., and Endo, R. M. 1966. Zoospore infection of bentgrass roots by P y t h i u m
a p h a n i d e r m a t u m . Phytopathology (abstr.) 56:149.
Kraft, J. M., Endo, R. M., and Erwin, D. C. 1967. Infection of primary roots of bentgrass by
zoospores of P y t h i u m a p h a n i d e r m a t u m . Phytopathology 57:86-90.
Nelson, E. B., and Craft, C. M. 1991. Identification and comparative pathogenicity of P y t h i u m spp.
from roots and crowns of turfgrasses exhibiting symptoms of root rot. Phytopathology
81:1529-1536.
Salt, G. A. 1979. The increasing interest in ‘minor pathogens’. In Soil-borne plant pathogens.
Edited by B. Schippers and W. Gams. Academic Press, London, pp. 289-312.
Smiley, R. W., Demoeden, P. H., and Clarke, B. B. 1992. Compendium of turfgrass diseases. 2nd
edition. Am. Phytopathol. Soc. Press. St. Paul, MN.
Smith, J. D., Jackson, N., and Woolhouse, A. R. 1989. Fungal diseases of amenity turf grasses. 3rd
edition. E. & F.N. Spon, London.

Acknowledgement
The research presented was supported in part by grants from the Iowa Turfgrass Institute and the Iowa
Golf Course Superintendents Association.
64

Comparative Effectiveness of Insecticides
Against Annual White
, 1992
D. R. Lewis and N. E. Christians

Damage to turfgrass by annual white grubs (
aspp.) is a common, but spotty
ycloeph
C
severe problem in Iowa. The amount of damage varies greatly from place to place and from year to
year, depending on several factors such as grass variety, cultural maintenance practices, irrigation and
weather. Root feeding by these masked chafer larvae characteristically causes grass to wilt, turn tan
and finally die, usually in late August or early September. Several granular and sprayable insecticide
products are registered for white grub control. Timing of insecticide application is very important in
achieving effective control of white grubs before damage becomes severe.
The objective of this study was to evaluate and compare the efficacy of several registered and
experimental insecticides against annual white grubs infesting turfgrass.
The trial was conducted on the Turfgrass Research Plots at the Horticulture Research Station of Iowa
State University near Ames, IA. The study site was a healthy and vigorous 8-year old stand of
Majestic Kentucky bluegrass established on a Nicollet (fine loamy, mixed, mesic Aquic Hapludoll) soil
with a pH of 6.7, 3.4% organic matter, 9 ppm phosphorous and 86 ppm potassium. The turfgrass
received 3 to 4 lbs N/1000 ft2 annually, was maintained at a 2 - 3 inch mowing height and irrigated as
needed. The plot area was on level ground and had less than 1/4 inch of thatch.
Grubs were not present in the plot area through mid- to late-summer. Two thousand annual white
grubs were collected from a natural infestation beneath a street light at the south edge of Ames, IA on
September 29 & 30 and transferred immediately following collection to the treatment plots. A sod
cutter, set to cut 1 3/4 inch deep, and a spade had been used to remove the sod from a 12 by 18 inch
area (1.5 sq ft) in the center of each plot before the grubs were collected. The loose sod was lifted
and 45 mixed age white grubs (75% third instar, 25% second instar) were uniformly scattered on the
soil surface and the sod piece gently replaced.
The insecticide treatments were applied 9 to 14 days following establishment of the grubs at the
treatment site. The granular insecticides were applied on October 8; liquid sprays were applied on
October 12.
The experimental design consisted of 12 treatment plots and one untreated check plot, randomly
assigned in each of three replications. Each plot consisted of a five foot square area (25 ft2). All
insecticides were applied at the rate specified on the manufacturer’s label or product guidelines.
Liquid and dry flowable insecticides were diluted with water. Sprays were applied with a carbondioxide, back pack sprayer, connected to a hand-held, three-nozzle boom. The sprayer operated at 20
psi and was equipped with number 8006 nozzles. The boom covered a 5-foot wide area, and diluted
insecticide spray was applied to the test plots with alternating perpendicular passes over the treatment
plot. The amount of spray solution applied to each plot was the equivalent of 131 gallons per acre or
3 gal/1000 ft2. Granular insecticides were premeasured into round, cardboard containers and applied
uniformly over the plot by shaking through a perforated lid.
A light rain fell overnight following granular application and 1/2 inch mechanical irrigation of the
entire trial was applied immediately following the liquid spray applications. An additional 1 inch of
irrigation was applied on October 21 and on October 27. There was no significant rainfall between
application and data collection.

65

Annual white grub population counts were made on October 27, 15 days after the final treatments and
watering in. Surviving grubs were counted by lifting the cut sod piece from the center of each plot
and examining the soil surface and underside of the sod for grubs. Soil beneath the cut sod was
removed to a depth of 6 inches and carefully pulverized by hand, the grubs removed and counted.
The insecticides used in this project, the formulation, rate of application and mean number of white
grubs per square foot are given in Table 37. The number of grubs per square foot was calculated from
the total number found in each 1.5 ft2 plot sample. Experimental insecticides covered by a
confidentiality agreement are not included in this table.
Significant differences among treatments and between treatments and the untreated check were
determined by analysis of variance. Means followed by the same letter are not significantly different
at the 0.05 level.
The average number of grubs surviving in the untreated check plots was approximately 10 per square
foot, a population density that is considered likely to cause significant damage to turfgrass. However,
the grass in the plots looked very good at the time of the grub counts with evidence that the cut sod
was rooting to the soil.
The ANOVA analysis reported in Table 37 shows that all products significantly reduced the number of
grubs surviving in the treated plots. Converting the surviving number of grubs to "percent control"
by dividing the difference between the treated and control counts by the number in the check, as is
often done for comparison purposes, indicates a 41 to 80% population reduction by the insecticides.
The top performing compounds in this study were Turcam, Mocap, diazinon and an experimental
Miles product, soon to be released under the trade name Merit. High levels of control achieved by
Turcam products in this test contrast with results in earlier Iowa trials, but compares to results
achieved in other states. Sevimol and Triumph significantly reduced the number of grubs in the plots,
but not as well, in this test, as the other products. The level of control for Sevimol (active ingredient
carbaryl) was about what was expected based upon other tests. Triumph has been a top-performing
compound in earlier Iowa tests and in other trials around the country and its relatively low
performance in this trial came as a surprise.
The relatively low rates of control (40 to 80%) achieved in this test may be due to the time and
method of this study. The study was conducted later than the optimum time for grub treatment
because cool, rainy weather in July through September slowed grub development and eliminated the
chances of doing the study at a naturally infested site. The number of grubs in the check indicates
only a 32% survival rate for transplanted grubs. During the final sampling, grubs were found at
depths up to 6 inches in all plots, indicating they were already migrating deep into the soil in
preparation for winter. If these grubs migrated downward at the time they were transplanted, they
would have escaped the toxic effect of surface applied insecticides that are generally confined to the
top layers of soil.
No phytotoxicity was observed in any of the treatment plots.

66

Table 37.

1992 Insecticide E fficacy Trial for W hite Grubs

Insecticide
Product

Rate
lb ai/A

Mean number white grubs
per square foot

Check

9.8

A

Percent
Control

R-P Chipco Sevimol (4 E)

8.0

5.8

B

41

Ciba-Geigy Triumph 4 E

2.0

4.7

BC

52

Miles BAY NTN 33893

6.0 oz

3.5

CD

64

Ciba-Geigy Diazinon 14 G

4.0

3.3

CD

66

Nor-Am Turcam 2.5 G

3.0

3.1

CD

68

Nor-Am Turcam 76 WP

3.0

2.7

CD

73

R-P Chipco Mocap 5 G

5.0

2.5

D

75

Nor-Am Turcam 2.5 G

2.0

2.0

D

80

Means followed by the same letter are not significantly different.

67

Fertilizer Trials

The Effects of Granular Nitrogen Fertilizer Sources
on the Growth and Quality of ’
Kentucky Bluegrass
M. L. Agnew and S. M. Berkenbosch

Turfgrass manager are presented with many choices of nitrogen fertilizers. Slowly available nitrogen
sources are promoted to provide longer residual nitrogen response, decreased foliar bum, and deceased
loss of nitrogen through leaching and volatilization. Slowly available nitrogen sources may be
classified as either natural organic, synthetic organic, or coated.
The objective of this study is to measure the efficacy of several slowly available nitrogen fertilizer
sources and the rate of nitrogen application on the growth and development of Kentucky bluegrass.
Research was conducted at the Iowa State University Horticulture Research Station. Treatments
included fertilizer source and fertilizer rate of application. With the exception of Pursell Industries
products, all slowly available nitrogen sources were applied at a 1 and 2 lb N/1000 ft2 rated. A 1-lb
N/1000 ft2 rate of urea and a non-fertilized control were included for comparison purposes. All
treatments are listed in Table 38. The turf was a ’Vantage’ Kentucky bluegrass. Plots measure 2.5’ X
10’ and are replicated 3 times in a complete randomized block design. Fertilizers were applied on
May 8 and August 18.
All plots were mowed at a 2-in height with all clippings removed. The plots were irrigated with a
minimum of 1.0 in water/growing week when sufficient rains did not occur. The early part of the
summer was very dry, however rainfall was ample after June 15.
Data collected included visual quality and clipping yields. Visual quality is based on a scale of 9 to 1:
9 = dark green turfgrass, 6 = minimum quality, and 1 = straw-colored turf. Clipping yields were
obtained at each mowing by collecting all leaf tissue within a 1.75 ft by 10 ft (17.5 ft2) area.
Clippings were dried at 65°F for 48 hours and weights recorded.
Due to the size of this study, the visual quality data is separated into four tables. Tables are separated
as synthetic slow release nitrogen sources (Table 39), natural organic nitrogen sources (Table 40),
combination fertilizer source; ie. nitrogen sources that contain a natural organic nitrogen source and
another nitrogen fertilizer source (Table 41), and resin coated fertilizer provided by Pursell Industries
(Table 42).
For synthetic slow release nitrogen sources, the 2 lb N application rate substantially improved the
overall quality of turfgrass plants over the 1 lb N treatment (Table 39). Scott’s methylene urea,
Norman’s Nutralene, Noram’s MUAS, and Lesco’s SCU elite provided the best overall quality for
synthetic slow release nitrogen sources at the 2 lb N applications. Scott’s 42-0-0 treated plots
exhibited the best overall quality at the 1 lb N applications.
For natural organic nitrogen sources, the 2 lb N application rate improved visual quality over the 1 lb
N rate (Table 40). Corn Gluten meal, Terrene 5-2-0, and Turf 10-2-6 exhibited the best overall quality
of the natural organic nitrogen sources at the 2 lb N levels, while Com Gluten meal, Turf 10-2-6,
Sustane 5-2-4, Terrene 5-2-0, and Naturall 8-1-3 treated plots performed best at 1 lb N levels.
For the combination fertilizer sources, the 2 lb N application rate improved visual quality over the 1 lb
N rate (Table 41). There was essentially no difference between fertilizer sources at either the 1 and 2
lb N application rates levels.

68

For the Pursell Industries products, the fertilizer sources applied at the 1 lb N rate had an overall
visual quality rating similar to the fertilizer sources applied at the 2 lb N rate (Table 42). The 4 lb N
application rate provided excellent season long quality of Kentucky bluegrass.
As with the visual quality data, the clipping yield data is separated into four tables. Tables are
separated as synthetic slow release nitrogen sources (Table 43), natural organic nitrogen sources (Table
44), combination fertilizer source (Table 45), and resin coated fertilizer provided by Pursell Industries
(Table 46).
For synthetic slow release nitrogen sources, the 2 lb N application rate increased clipping production
when compared to the 1 lb N rate (Table 43). Scott’s 42-0-0, Noram’s Nutralene, Lesco’s SCU elite,
and Noram’s MUAS produced the greatest amount of clippings at the 1 and 2 lb N rates.
For natural organic nitrogen sources, the 2 lb N application rate improved clipping yields for com
gluten meal, Turf 10-2-6, Milorganite 6-2-0, and Terrene 5-2-0 over the 1 lb N rate (Table 44). UHS
3-4-2 produced the least amount of clippings of the natural organic nitrogen sources.
For the combination fertilizer sources, the 2 lb N application rate increased clipping yields for UHS
12-1-1, UHS 9-4-4, and UHS 12-2-8 (Table 45). There was essentially no difference between
fertilizer source at either the 1 or 2 lb N application rates levels.
For the Pursell Industries products, there was very little difference in clipping yields between fertilizer
sources applied at the 1 and 2 lb N rates (Table 46). The 4 lb N application rate produced the greatest
amount of clippings total for all fertilizers tested.

Table 38. List o f treatments.

Fertilizer Source

Nutralene 40-0-0
Nutralene 40-0-0
MU AS 32-0-0
MU AS 32-0-0
Ureaform 38-0-0
Ureaform 38-0-0
Scott’s 42-0-0
Scott’s 42-0-0
LESCO SCU 37-0-0
LESCO SCU 37-0-0
LESCO SCU elite 29-0-0
LESCO SCU elite 29-0-0
Com Gluten 10-0-1
Com Gluten 10-0-1
Turf 10-2-6
Turf 10-2-6
Milorganite 6-2-0
Milorganite 6-2-0
Naturall 8-1-3
Naturall 8-1-3
UHS 3-4-2
UHS 3-4-2
Sustane medium 5-2-4
Sustane medium 5-2-4
Terrene 5-2-0
Terrene 5-2-0
Terrene 6-2-0
Terrene 6-2-0
Ringer Fairway/LCO 12-2-6
Ringer Fairway/LCO 12-2-6
UHS 12-1-1
UHS 12-1-1
UHS 9-4-4
UHS 9-4-4
UHS 12-2-8
UHS 12-2-8
Earthgro 8-2-4
Earthgro 8-2-4
Sustane + Polyon 10-2-10
Sustane + Polyon 10-2-10
Sustane + Polyon 12-2-8
Sustane + Polyon 12-2-8
Urea 46-0-0
Control
Pursell 44.5-0-0
Pursell 42.5-0-0
Pursell 43-0-0
Pursell 44-0-0
Pursell 42-0-0

#N/1000 ft2/application

1.0

2.0

1.0

2.0

1.0

2.0

1.0
2.0
1.0
2.0
1.0
2.0
1.0
2.0

1.0

2.0

1.0
2.0
1.0
2.0
1.0
2.0

1.0

2.0

1.0

2.0

1.0
2.0
1.0
2.0
1.0
2.0
1.0
2.0
1.0
2.0

1.0

2.0

•

1.0
2.0
1.0
2.0
1.0
0.0
1.0
2.0
1.0

2.0

4.0 (spring only)

70

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05

Perennial Ryegrass Fertilizer Study
M. L. Agnew and S. M. Berkenbosch

Many golf courses are currently converting their fairways and tees to perennial ryegrass. The goal is
to use a species of grass that is more resistant to traffic stress and easy to establish if injured by stress..
However, mowing perennial ryegrass at heights less than 1 inch places additional stress on the plant.
Most recommendations on fertility levels for perennial ryegrass are based on mowing heights near 2
inches.
The objective of the study is to investigate the effects of nitrogen fertilizer source, rate of nitrogen
application, and potassium application on the growth and development of fairway height perennial
ryegrass.
Research was conducted at the Iowa State University Horticulture Research Station. Treatments
included four fertilizer sources, two nitrogen application rates, and two potassium application rates
Table 47. Manhattan II, perennial ryegrass was maintained at a 1 inch mowing height to simulate a
golf course fairway. Plots were irrigated to prevent moisture stress.
Data collected included visual quality and clipping yields. Visual quality is based on a scale of 1 to 9:
9 = dark green turfgrass, 6 = minimum quality, and 1 = straw-colored turf. Clipping yields were
obtained at each mowing by collecting all leaf tissue within a 1.75 ft by 10 ft (17.5 ft2) area.
Qippings were dried at 65°F for 48 hours and weights recorded.
Visual quality data is presented in Table 47 and 48. All fertilizer sources provided acceptable quality.
Plots treated with Scott’s Poly- S 39-0-0 had a spring and fall mean of 7.3, Nutralene treated plots had
a spring mean of 6.9 and a fall mean of 7.0, Corn Gluten Meal treated plots had a spring mean of 6.9
and a fall mean of 6.8, and Milorganite treated plots had a spring mean of 6.6 and a fall mean of 6.8.
Plots fertilized at the 2 lb N rate substantially improved plant quality over the 1 lb. N rate. Additional
potassium did not affect the visual quality during the first year.
Dried clipping weights are presented in Table 49 and 50. Plots treated with Scott’s Poly- S 39-0-0
had the greatest amount of clippings with 385 g in the spring and 124 g in the fall. Com Gluten Meal
and Nutralene treated plots produced the next greatest amount of clippings with an average 353 g and
343 g of clippings in the spring and 117 g and 114 g in the fall, respectively. Milorganite treated
plots produced the least amount of clippings, with an average 284 g of clippings in the spring and 90
g in the fall. Plots fertilized at the 2 lb N rate substantially increased the amounts of clippings over
the 1 lb N rate.
These plots were severely injured by low temperature stress during the winter of 1993. Bare spots
have been overseeded and treatments applied for 1993.

79

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Table 48. T he effects o f fertilizer, rate, and potassium on visual quality o f perennial ryegrass.
August
Fertilizer Source

K
Rate

27

15

23

12

Fall
Application
Average

Nutralene 40-0-0

1

0

7.3

7.7

6.7

7.0

7.2

Nutralene 40-0-0

1

1

7.7

8.0

7.0

6.3

7.3

Nutralene 40-0-0

2

0

8.7

9.0

7.3

6.3

7.8

Nutralene 40-0-0

2

1

9.0

9.0

7.7

6.7

8.1

Scotts 39-0-0

1

0

7.3

8.0

7.7

7.7

7.7

Scotts 39-0-0

1

1

6.7

8.0

7.3

7.0

7.3

Scotts 39-0-0

2

0

8.7

9.0

8.3

7.7

8.4

Scotts 39-0-0

2

1

8.7

9.0

8.7

7.7

8.5

Com Gluten 10-0-1

1

0

6.7

7.7

7.3

6.7

7.1

Com Gluten 10-0-1

1

1

6.0

7.7

7.3

6.3

6.8

Com Gluten 10-0-1

2

0

6.7

9.0

8.0

7.0

7.7

Com Gluten 10-0-1

2

1

6.7

9.0

8.3

7.0

7.8

Milorganite 6-2-0

1

0

6.7

7.0

6.3

6.7

6.7

Milorganite 6-2-0

1

1

6.3

7.0

6.3

7.0

6.7

Milorganite 6-2-0

2

0

7.3

8.3

7.3

8.0

7.8

Milorganite 6-2-0

2

1

7.0

8.7

7.3

8.0

7.8

Control

0

0

5.7

5.7

5.3

6.3

5.8

Control

0

1

6.0

6.0

5.7

6.3

6.0

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0.3

0.2

0.3

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0.2

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0.3

0.2

0.3

0.6

0.2

N.S.

N.S.

0.2

N.S

N.S.

(0 0 5

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LSD (o05) K

81

September

October

N
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Table 49. The effects o f fertilizer, rate, and potassium on clipping production o f perennial ryegrass.

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Table 50. The effects o f fertilizer, rate, and potassium on clipping production o f perennial ryegrass.
September

October

Fertilizer Source

N
Rate

K
Rate

14

24

15

Clipping
Yield
FaU

Nutralene 40-0-0

i

0

56.3

17.5

33.1

106.9

Nutralene 40-0-0

i

1

67.9

22.4

34.2

124.5

Nutralene 40-0-0

2

0

108.9

31.4

47.0

187.3

Nutralene 40-0-0

2

1

118.2

29.5

43.3

191.1

Scotts 39-0-0

1

0

66.7

29.8

44.6

141.1

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1

1

62.4

21.2

41.7

125.4

Scotts 39-0-0

2

0

102.9

35.9

55.9

194.7

Scotts 39-0-0

2

1

116.2

35.9

53.2

205.3

Com Gluten 10-0-1

1

0

56.9

23.6

35.4

115.9

Com Gluten 10-0-1

1

1

59.3

19.2

36.2

114.7

Com Gluten 10-0-1

2

0

120.5

33.3

47.1

200.9

Com Gluten 10-0-1

2

1

114.7

33.2

48.9

196.8

Milorganite 6-2-0

1

0

39.3

14.0

30.4

83.7

Milorganite 6-2-0

1

1

37.4

12.4

27.6

77.4

Milorganite 6-2-0

2

0

84.4

25.7

42.7

154.8

Milorganite 6-2-0

2

1

81.0

27.7

41.8

148.6

Control

0

0

16.0

5.8

16.6

38.4

Control

0

1

14.6

6.5

16.6

37.7

LSD (o.o5) Fert

6.7

3.3

3.4

11.9

DSD

5.8

2.8

2.9

10.3

N.S.

N.S.

N.S.

N.S.

Q) Rate

(0 5

LSD (o.o5) K

83

Scott’s Poly-S Study
M. L. Agnew and S. M. Berkenbosch

The objective of this study was to evaluate 3 formulations of resin-coated nitrogen sources for the
O. M. Scotts Company. The fertilizers ratio were 40-0-0, 39-0-0, and 38-0-0. Each were applied at
both a 2 lb N application rates on May 8 and August 18 and a 1 lb N application rate on May 8, June
29, August 18 and September 15 1992. A non fertilized control was added for comparison purpose.
The turfgrass was a "Envy" perennial ryegrass mowed at 1 inch with all clippings removed. The site
was irrigated to prevent moisture stress.
The 1993 growing season ended early with a killing frost early in October, thus, the effect of the final
fertilization was not fully realized.
Data collected included visual quality and clipping yields. Visual quality is based on a scale of 1 to 9:
9 = dark green turfgrass, 6 = minimum quality, and 1 = straw-colored turf. Clipping yields were
obtained at each mowing by collecting all leaf tissue over 2 in with a 1.75 ft by 10 ft (17.5 ft2) area.
Qippings were dried at 65°F for 48 hours and weights recorded.
Visual quality data is presented in Table 51. Generally, the 2 lb N rate provided superior quality.
However, no fertilizer rate had an unacceptable quality. There were no differences between fertilizer
source for either the 1 or 2 lb N rates.
Clipping yield data is presented in Table 52. Applying fertilizers at a 2 lb N rate substantially
increased the amount of clippings that were produced. This was most evident just after the May and
August application dates. There were no differences between fertilizer source for either the 1 or 2 lb
N rates.
In conclusion, the Poly-S fertilizers are probably best applied at the 1 lb N rate. The 2 lb N rate
created excessive growth that more then likely biased visual quality ratings.

84

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rJ

Plant and Soil Response to Nitrogen Fertilizer Source
M. L. Agnew, N. E. Christians, and J. N. Ryan

Turfgrass managers have several nitrogen sources from which to choose. Quick-release sources
provide fast green-up and are relatively inexpensive. Slow-release sources extend the feeding time by
slowing the release rate of available nitrogen. Some advantages claimed from using slow-release
sources are reduced chance of fertilizer bum, less volatilization, and less leaching.
With the environmental concerns currently surrounding fertilizers and the leaching of nitrates into the
groundwater, it is important to understand the possible differences among nitrogen sources as they
pertain to nitrogen use efficiency and the movement of nitrates in the soil.
This study will evaluate 8 fertilizer sources as to their effects on plant growth and nitrogen content in
plant tissue. In addition, the movement of nitrates through the soil will be monitored. The study was
initiated in the spring of 1991 on an established turf of ’Glade’ Kentucky bluegrass mowed at 2 in.
All treatments were applied at a rate of 1 lb N/1000 ft2 on (May 2, June 10, August 15, and September
15, 1991) and (May 8, June 29, August 20, and September 17, 1992). The study was replicated three
times in a randomized complete-block design. Individual plots measured 5 ft by 9 ft. The following
is a list of the treatments:
(1)

(2)
(3)
(4)
(5)

(6)

(7)
(8)
(9)

Coron 28-0-0
Nutralene 40-0-0
Sulfur-coated Urea 37-0-0
Urea 46-0-0
Ringer Lawn Restore 10-2-6
Ureaform 38-0-0
N-Sure 28-0-0
ISU Experimental 10-1.5-.5
Control — no fertilizer

Measurements of plant growth included weekly observations of visual quality, clipping yields, and
chlorophyll content. Plant development was monitored by measuring plant density, thatch depth,
thatch organic matter content, rhizome weights, and root distribution. These measures were taken
prior to the first treatment, in the middle of summer, and at the end of the season.
Nitrogen content in leaf tissue was measured weekly and nitrate content in the soil at several different
depths up to 3 ft were taken initially, in midsummer, and at the end of the season.
Quality data is presented in Table 53. All fertilizer sources provided acceptable quality. However,
plots treated with sulfur coated urea, urea, Nutralene, Ringer Restore, and com gluten meal had
consistently darker green color.
Dried clipping weights are presented in Table 54. Plots treated with urea and sulfur coated urea
produced the most clippings, while N-Sure, Ureaform, and Coron produced the least clippings.
Total chlorophyll content data is presented in Tables 55. Total chlorophyll is a quantitative measure
of plant color. Urea-treated plots tended to have higher chlorophyll content.

86

Root data is presented in Tables 56 and 57. Unlike 1991, there were no differences in root mass
production. Root mass varied greatly between replications, thus causing too much variability. This is
most likely due to drought spring conditions and wet summer conditions.
Soil nitrate data is presented in Table 58. There were no differences between fertilizer treatments in
1992.

87

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1992 Soil Activator Study
R. W. Moore and N. E. Christians

The objectives of this study were to compare the "Harmony" soil activator turf program to an
untreated control and a Scotts fertilizer (Table 59). The study was initiated on June 15, 1991, and will
continue through the 1992 season. The study was conducted on a 1-year-old stand of non-irrigated
South Dakota Common Kentucky bluegrass turf. The soil is a Nicollet (fine-loamy, mixed, mesic
Aquic Hapludoll) with a pH of 6.8 and 2.3% organic matter, a P content of 29 lbs/A, and a K content
of 216 lbs/A. The plots measured 5 ft by 10 ft and were replicated three times in a randomized
complete-block design.
The control plot received no treatment, while the Scotts plots received a 32-3-10 at a rate of 0.83 lb of
N/1000 ft2, applied in May, August, and September. The Harmony program (Table 60), consisted of a
Microbial Soil Activator applied at 1.6 oz/1000 ft2 on May 20 and September 20; a 25-15-10-3S turf
food applied at 0.25 lbs/1000 ft2 on June 1, July 1, August 1, and September 1; and a 3-4-3 organic
fertilizer applied at 40 lb/1000 ft2 on May 1 and September 1. The total N applied was 2.49 lbs
N/1000 ft2 in the Scotts program and 2.65 lbs N/1000 ft2 in the Harmony program in the May 20
through September 20 time period.
Data collected included visual quality and clipping yields as fresh weight. Quality data was based on
a 9 to 1 rating: 9 = best, 6 = acceptable, and 1 = no live grass. Qipping yields were obtained by
taking a 21-inch swath through the 10 ft plot (17.5 ft2) at a 2-in cutting height.
The grass in the control plots did not receive an acceptable quality rating of 6 or better during the
1992 season (Table 61). The Scotts plots received higher quality ratings on 7 out of 9 dates. There
was no period of dormancy in 1992 as the central Iowa area received record rainfall in the summer
months.
There were significant differences in clipping yields (Table 61). Scotts plots had a consistently greater
amount of clippings produced throughout the year. The Harmony program did demonstrate near equal
or better quality ratings, as well as clipping yields in the dryer and warmer months.

Table 59. Treatments in the 1992 soil activator fertilizer study.

When Applied

Treatment
1.
Control
2.
Harmony Program

3.

Microbial Soil Activator @ 1 . 6 oz/1000 ft2
3-4-3 organic fertilizer @ 40 lbs/1000 ft2
25-15-10-3S Turf Food @ 0.25 lbs/1000 ft2
25-15-10-3S Turf Food @ 0.25 lbs/1000 ft2
25-15-10-3S Turf Food @ 0.25 lbs/1000 ft2
25-15-10-3S Turf Food @ 0.25 lbs/1000 ft2
Microbial Soil Activator @1 . 6 oz/1000 ft2
3-4-3 organic fertilizer @ 40 lbs/1000 ft2

May 20, 1992
May 20, 1992
June 1, 1992
July 1, 1992
August 1, 1992
September 1, 1992
September 20, 1992
September 20, 1992

Scotts 32-3-10 applied @ 0.83 lbs N/1000 ft2
Scotts 32-3-10 applied @ 0.83 lbs N/1000 ft2
Scotts 32-3-10 applied @ 0.83 lbs N/1000 ft2

May 20, 1992
August 1, 1992
September 10, 1992

Scotts

91

92

Table 60. 1992 soil activator trial -- quality ratings.

TheEffects of Application Rate of Sprint 330
on the Quality of ’Penncross’ Creeping Bentgrass
M. L. Agnew

In Iowa the pH of sand-based golf greens ranges from 7.8 to 8.3. The availability of micronutrients,
especially iron, can be reduced at these pH levels. Thus, many golf course superintendents apply
supplemental micronutrients to alleviate deficiencies attributed to high pH.
The objective of this study was to evaluate the quality of creeping bentgrass when treated with four
levels of Sprint 330. Sprint 330 is a chelated iron source.
Treatments included :
Sprint
1.
Sprint
2.
Sprint
3.
4.
Sprint
5.
None

330
330
330
330

Fe
Fe
Fe
Fe

at
at
at
at

1
2
3
4

oz/1000
oz/1000
oz/1000
oz/1000

ft'
ft:
ft:
ft'

Treatments were replicated three times in a randomized complete-block design. Plots were rated for
color as visual quality 1, 2, 4, 6, 9, and 13 days after application (DAA). Visual quality was based on
a scale of 9 to 1: 9 = dark green turf, 6.5 = minimum acceptable quality, and 1 = dead turf.
Research was conducted at the ISU Horticulture Research Station, on a modified sand green
constructed with 80% sand, 10% hypnum peat, 10% soil and 8.1 pH. ’Penncross’ creeping bentgrass
greens were fertilized with .5 lb N/1000 ft2 DAA.
All rates of Sprint 330 improved visual quality over the non-treated control (Table 62). No rate of
Sprint 330 fell below the minimum acceptable quality rating of 6.5. Sprint rates of 2, 3, and 4
oz/1000 ft2 were statistically better than the 1 oz/1000 ft2 rate from DAA 1 to 4. After nitrogen was
applied on DAA 5, there were no differences between Sprint 330 rates.
Golf course superintendents could use Sprint 330 rates as low as 1 oz/1000 ft2 if added to a regular
nitrogen fertility program. If the superintendent wishes to reduce nitrogen rates, then a minimum of 2
oz/1000 ft2 would be needed to enhance color and quality.

Table 62. Effects of application rate of Sprint 330 on creeping bentgrass quality.8
DAAb
Rate

1

2

4

1 oz

7.0

7.0

7.3

13

6

9

8.0

8.0

8.0
8.0

2 oz

7.7

7.7

8.0

8.0

8.0

3 oz

8.0

8.0

8.0

8.0

8.0

8.0

4 oz

8.0

8.0

8.0

8.0

8.0

8.0

None

4.0

4.0

4.0

5.7

6.0

7.0

LSD(o.o5)

0.5

0.5

0.5

0.6

0.5

NS

“Visual quality is based on a scale o f 9 to 1 with 9 = dark green turf and 1 = brown turf.
bDAA = days after application. Treatment was applied June 2, 1992.

93

Soil Relation Studies

The Effects of Soil Compaction on Soil Physical Properties
and Plant Growth of Five Cultivars of Tall Fescue
D. L. Anderson and M. L. Agnew

Soil compaction and wear are serious problems for athletic fields and thus play a role in the selection
of the turfgrass used. Tall fescue is a good grass to use on sport fields because it possesses excellent
wear tolerance. However, when subjected to soil compaction, K-31 tall fescue did not perform as well
when compared to perennial ryegrass and Kentucky bluegrass. Improved varieties of tall fescue have
been developed, but it is not known how these new varieties will perform when subjected to soil
compaction.
Soil compaction is often described as a hidden stress, not revealing its presence until a turf stand is
under stress conditions. Compaction increases a soil’s bulk density by destroying the soil structure.
Large soil pores are destroyed resulting in the reduction of air porosity and thus soil aeration and
water permeability are decreased.
Compaction generally occurs within the top 3 cm of soil surface, resulting in a limited space in which
oxygen is able to permeate. In situations where oxygen is limiting to a root system, root extension is
inhibited and adventitious rooting is promoted. The plant produces a root system that has the majority
of its roots near the soil surface, increasing the chances of a plant to die when it becomes stressed.
The measurement of soil compaction generally requires extensive soil sampling in order to calculate
the bulk density. The problem with soil sampling is that the soil is disturbed when the sampling takes
place, decreasing the accuracy of the test. A new method for calculating soil compaction entails the
use of a soil strain gauge. When the strain gauge is set into the soil it can measure the change in
compression caused by a compactive force. The use of this system for measurement in turfgrass
situations has great potential and requires evaluation.
The objectives of this research project are to compare 5 tall fescue cultivars when subjected to soil
compaction and to compare the strain gauge to soil physical properties for soil compaction studies.
On May 3, five cultivars of tall fescue were seeded at a rate of 2.7 Kg 90 m'2 at the Iowa State
research farm. Three replicated plots of each cultivar were created in a completely randomized design,
measuring 6 m by 4.5 m. Individual treatment plots will be .75 m by 3 m. The five cultivars to be
studied are K31, Crossfire, Rebel II, Rebel Jr, and Twilight. Three levels of compaction were applied
in the fall of 1992 using a smooth power roller. The three levels were Ox, lOx and 20x. lx equals 1
pass with a smooth power roller at 0.193 MPa. Prior to the compaction treatments, strain gauges will
be placed in the soil to measure the compactive force being applied.
The plots are irrigated using athletic field type sprinkler heads at a rate of 2.5 cm per week to prevent
moisture stress. Fertilization is applied at a rate of 1 lb/1000 ft2 in May, August, and September. The
grass is maintained at a mowing height of 2 inches. Herbicides are used as needed to prevent weed
populations from developing.
Data collected includes root density May 1993, shoot dry mass, visual quality, shoot density, bulk
density, water retention, and strain gauge measurement. Visual quality was based on a scale of 9 to 1:
9 = best quality, 6 = acceptable quality, and 1 = poorest quality.
Data is included in Table 63. Soil compaction decreased both clippings and visual quality. K-31 tall
fescue performed poorly, while Crossfire and Reble Jr. had the highest quality ratings.
94

Table 63. E ffect o f soil com paction and tall fescue cultivars on clipping production and visual quality.

Gipping Weights
Cultivar

Visual Quality

Compaction
Treatment

9/15

9/22

10/6

9/15

9/22

10/20

0

30.4

21.0

25.2

6.0

6.3

6.0

10

26.9

18.4

22.7

4.0

4.0

4.7

24.8

18.3

4.0

4.0

4.7

0

33.1

22.0

23.2

7.7

8.0

8.0

10

23.6

16.0

17.7

5.7

6.3

6.7

22.1

14.4

17.1

5.7

5.3

6.3

33.7

20.9

21.3

7.3

6.7

6.7

22.2

13.7

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Modification of Disturbed Soils
M. L. Agnew

The construction of new houses is a sign of a healthy economy. When housing starts are up, the sod
production and landscape contracting industry will benefit. However, too little monetary resources are
placed on the turfgrass and landscape development. This results in either the removal or burial of
topsoil. All too often, only subsoil clays remain. Lawns and landscape plants demonstrate poor
growth when established on these soils
The objective of this study is to investigate the effects of soil amendments on disturbed soils derived
from the parent material.
This study was conducted in the Iowa State University greenhouses in Ames Iowa. The soil was
obtained from a construction site on campus. It consisted of 30% clay, 44% sand and 26% silt. The
soil was shredded prior to the addition of amendments. The soil amendments included:
Earthgro Compost I (ECI) (chicken manure based compost),
Earthgro Compost II (ECU) (lawn clippings based compost),
Rebuild (RB) (organic bio-remediation product),
Organic Technologies Compost (OTC) (local yard waste compost), and
Sphagnum Peat Moss (SPM).
Soil amendments were mixed at the following volumes with the soil in a soil mixer: 10%, 20%, and
30%. A non-amended soil was used as a control. Each soil/soil amendment treatment was placed in
PVC containers with a 15 cm. diameter and a 60 cm. depth. Each container was irrigated and allowed
to settle. Perennial ryegrass was seeded at a rate of 3 lb. per 1000 ft2. The turfgrass was fertilized at a
rate of 1 lb. N/1000 ft2 at 6 weeks after seeding. Irrigation was added to prevent moisture stress until
the plant were established. On September 21, the container received enough water to bring the soil to
saturation. Water was withheld from the containers until October 26. Each container was then
irrigated and an undisturbed soil sample was taken from each container. Visual quality ratings and
clipping weights were taken throughout the dry down cycle.
Visual quality data is presented in Table 64. Prior to the dry down cycle, all treatments had equal
quality with the exception of ECI - 30%. This is not surprising, since this material contains chicken
manure. Fifteen days after irrigation (Oct. 6), only treatments amended with SPM exhibited quality
ratings less than 6.0. Only ECI (20% and 30%), and RB (20%) exhibited acceptable quality by the
termination of the dry down cycle on October 26. Clipping weight (both fresh and dry) support the
visual quality data (Tables 65 and 66). ECI (30%) maintain the best growth by the end of the dry
down cycle. Treatments amended with SPM had substantially less fresh and dry clipping weight.
SPM amended soils also had a lower relative water content in the plant (Table 67). The ECI (30%)
had the lowest relative water content prior to the dry down cycle, but had the highest relative water
content by the end of the dry down cycle.
Soil physical property data is presented in Table 68. ECI (20% and 30%), ECU (10%), RB (20% and
30%), OTC (20% and 30%), and SPM (30%) amended soils had bulk densities less than the control.
Total pore space was improved over the control by ECI (20% and 30%), RB (30%), OTC (30%) and
SPM (30%). In general, a minimum application of 20% is needed to amend soil.

96

Table 64. The effects of 5 different organic matter sources and three volumes on visual quality of perennial ryegrass.

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Amendment
Volume

Bulk
Density

Total Pore
Space

Earthgro Compost I

10%

1.27

47.5

Earthgro Compost I

20%

1.09

52.1

Earthgro Compost I

30%

1.01

54.3

Earthgro Compost II

10%

1.16

50.0

Earthgro Compost II

20%

1.24

49.8

Earthgro Compost II

30%

1.18

48.5

Rebuild

10%

1.25

46.3

Rebuild

20%

1.06

48.4

Rebuild

30%

1.04

60.6

Organic Tech

10%

1.27

45.5

Organic Tech

20%

1.15

50.4

Organic Tech

30%

1.15

52.1

Sphagnum Peat

10%

1.29

49.5

Sphagnum Peat

20%

1.18

51.3

Sphagnum Peat

30%

1.05

58.5

-

1.33

44.9

0.16

7.0

Soil Amendment

Control
L S D (0.05)

101

The Effects of Compost Topdressing on Compacted Soils
M. L. Agnew and S. M. Berkenbosch

Soil compaction is considered by many to be the number one stress of turfgrasses. It predisposes the
turfgrass plant to injury by environmental stress and disease activity. Previous research has
demonstrated that compacted soils have low oxygen levels and high soil strength. The most common
means of alleviating soil compaction is to core cultivate the site. However, core cultivation may not
be the total answer in soils that receive repeated traffic. It would be important in these situations to
amend the soils so that they are less prone to compactive forces. Many turfgrass managers believe
that the application of pure sand to the soil surface will amend the compacted soil condition. Instead,
the result is a layered soil profile which results in a shallow root system. One possible amendment
that may prove to be beneficial is the application of organic matter to the soil surface. This type of
soil amendment is not as drastic of a change in physical properties as is sand.
The purpose of this study is to investigate the influence of compost topdressing on compacted soils.
The study was established at the Turfgrass Research Plots at the ISU Horticulture Research Station on
August 10, 1992. The soil is fine silt loam. Treatments were applied to a ’Nassau’ Kentucky
bluegrass stand. Plots were fertilized at a 1 lb N/1000 ft2 on September 15. Plots were irrigated to
prevent moisture stress. Individual treatments are as listed in the tables. Soil compaction treatments
consisted of 20 passes with a smooth power roller that exerted a pressure of 0.193 MPa per pass. Fall
compaction was applied on August 10, 1992. Compost treatments were applied on August 21, 1992.
Compost sources were from the Earthgro Company, Lebanon, CT. Earthgro Compost I is derived
from a low moisture, dehydrated and composted manures. It has a 2-1-1 fertilizer analysis. Earthgro
Compost II is derived from composted yard waste. Core cultivation treatments were applied as 2
passes with a Cushman Ryan Lawnaire 28 with 1.9 cm diameter tines, spaced 8.75 cm by 12.5 cm and
a soil penetration of 7.5 cm. Cultivation treatments were applied just prior to the application of the
topdress.
Qipping yields and visual quality were collected during the fall of 1992 and are presented in Tables
69 and 70. Compost source and soil compaction affected both clipping yields and visual quality.
Earthgro Compost I had the greatest amounts of clippings produced (Table 69). This is not surprising,
since this compost contains a minimum amount of nutrients. Earthgro Compost II improved clipping
production over the non-topdressed control treatment. Both Earthgro compost sources improved the
visual quality ratings when compared to the non-topdressed control (Table 70), however there were
very little differences between compost sources. The 1/4 inch topdressing rate improved visual quality
over the 1/8 inch topdress rate. Clipping yields and visual quality ratings were decreased by soil
compaction.
This study will be carried on through 1993. Treatments will be applied in both the spring and fall.
Data to be collected include clipping yields and plant quality (bi-weekly), root growth (October), soil
bulk density and water holding capacity (April and October), and earthworm counts (October).

102

Table 69.

The effects o f com post, rate, core cultivation, and soil com paction on clipping
production o f Kentucky bluegrass.

Clippings

■

Clipping
Yield
Total

Rate

Coring

Compaction

9/5

9/16

10/17

Earthgro I

1/8"

no

no

39.4

29.4

30.7

99.5

Earthgro I

1/8"

no

yes

38.0

28.5

30.0

96.5

Earthgro I

1/8"

yes

no

41.9

35.4

31.3

108.6

Earthgro I

1/8"

yes

yes

40.7

32.5

32.5

105.7

Earthgro I

1/4"

no

no

52.0

37.1

31.4

120.5

Earthgro I

1/4"

no

yes

41.3

32.7

33.4

107.4

Earthgro I

1/4"

yes

no

57.1

37.0

32.0

126.2

Earthgro I

1/4"

yes

yes

38.0

28.1

26.4

92.4

Earthgro II

1/8"

no

no

33.2

27.2

28.4

88.8

Earthgro II

1/8"

no

yes

28.1

23.7

28.4

80.2

Earthgro II

1/8"

yes

no

40.9

30.8

31.6

103.3

Earthgro II

1/8"

yes

yes

32.9

25.3

25.2

83.4

Earthgro II

1/4"

no

no

43.6

33.2

36.0

112.8

Earthgro II

1/4"

no

yes

28.5

22.2

24.1

74.8

Earthgro II

1/4"

yes

no

39.4

30.0

31.7

101.1

Earthgro II

1/4"

yes

yes

28.5

24.0

25.2

77.7

Control

-

no

no

25.6

23.0

21.7

70.3

Control

—

no

yes

27.3

21.7

23.9

72.9

Control

-

yes

no

32.0

25.2

23.7

80.9

Control

-

yes

yes

35.0

22.2

23.1

80.3

LSD (0.05) O.M.

5.3

2.9

2.4

9.1

LSD (0.05) Rate

NS

NS

NS

NS

LSD (0.05) Core

NS*

NS

NS

NS

LSD (0.05) Comp

4.3

2.4

1.9

7.4

Compost

* Significant at a 0.10 level

103

Table 70.

T he effects o f com post, rate, core cultivation and soil com paction on visual quality o f
K entucky bluegrass.

Quality Ratings
9/16

10/5

Mean

8.7

8.0

7.7

8.1

yes

8.0

7.7

7.7

7.8

yes

no

8.7

8.7

7.7

8.3

1/8"

yes

yes

8.7

8.0

8.0

8.2

Earthgro I

1/4"

no

no

8.7

8.7

8.0

8.4

Earthgro I

1/4"

no

yes

9.0

8.3

8.0

8.4

Earthgro I

1/4"

yes

no

8.7

8.0

8.0

8.2

Earthgro I

1/4"

yes

yes

9.0

7.3

7.7

8.0

Earthgro II

1/8"

no

no

8.0

8.0

8.0

8.0

Earthgro II

1/8"

no

yes

7.7

7.7

7.7

7.7

Earthgro II

1/8"

yes

no

8.0

7.7

7.3

7.7

Earthgro II

1/8"

yes

yes

7.7

7.7

7.3

7.6

Earthgro II

1/4"

no

no

9.0

9.0

8.0

8.7

Earthgro II

1/4"

no

yes

8.0

8.0

7.7

7.9

Earthgro II

1/4"

yes

no

8.3

8.3

8.0

8.2

Earthgro II

1/4"

yes

yes

8.3

8.0

8.0

8.1

Control

—

no

no

7.3

6.7

7.0

7.0

Control

—

no

yes

7.3

7.0

7.0

7.1

Control

—

yes

no

7.7

7.0

7.0

7.2

Control

-

yes

yes

7.3

7.0

7.0

7.1

LSD (0.05) O.M.

0.3

0.3

0.2

0.2

LSD (0.05) Rate

0.2

N.S.

0.1

0.2

LSD (0.05) Core

N.S.

N.S.

N.S.

N.S.

LSD (0.05) Comp

N.S.

0.2

N.S.

0.1

Compost

Rate

Coring

Compaction

Earthgro I

1/8"

no

no

Earthgro I

1/8"

no

Earthgro I

1/8"

Earthgro I

104

9/4

The Effects of Compost Topdressing on Existing Thatch
M. L. Agnew and S. M. Berkenbosch

Thatch buildup on Kentucky bluegrass lawns is a normal process. Excessive amounts are detrimental
to turfgrass growth and development. Thatch removal can be expensive and the disposal of debris
may be difficult. Any process that can improve microbial content within the thatch layer can
theoretically decrease the thickness of the thatch.
The purpose of this study is to investigate the influence of compost topdressing on thatch
decomposition.
The study was established at the Turfgrass Research Plots at the ISU Horticulture Research Station on
August 15, 1992. The soil is fine silt loam. Treatments were applied to a ’Ram I’ Kentucky
bluegrass stand. Plots were fertilized at a 1 lb N/1000 ft2 on September 15. Plots were irrigated to
prevent moisture stress.
Treatments are listed in the tables. Compost treatments were applied on August 21, 1992. Compost
sources were from the Earthgro Company, Lebanon, CT. Earthgro Compost I is derived from a low
moisture, dehydrated and composted manures. It has a 2-1-1 fertilizer analysis. Earthgro Compost II
is derived from composted yard waste. Core cultivation treatments were applied as 2 passes with a
Cushman Ryan Lawnaire 28 with 1.9 cm diameter tines, spaced 8.75 cm by 12.5 cm and a soil
penetration of 7.5 cm. Cultivation treatments were applied just prior to the application of the topdress.
Earth random thatch measurement were taken to determine thatch depth. The average depth was 1
inch + or - 1/10 inch.
Clipping yields and visual quality were collected during the fall of 1992 and are presented in Tables
71 and 72. Compost source affected both clipping yields and visual quality. Earthgro Compost I had
the greatest amounts of clippings produced (Table 71). This compost contains a minimum amount of
nutrients. Both Earthgro compost sources improved the visual quality ratings when compared to the
non-topdressed control (Table 72), however there were very little differences between compost sources.
This study will be carried on through 1993. Treatments will be applied in both the spring and fall.
Data to be collected include clipping yields and plant quality (bi-weekly), root growth (October), soil
bulk density and water holding capacity (April and October), and earthworm counts (October).

105

Table 71. T he effects o f com post, rate, core cultivation on clipping production o f Kentucky bluegrass.

Qippings
Compost

Rate

Coring

8/10

8/26

9/14

Earthgro I

1/8"

no

94.0

51.0

56.6

50.0

251.5

Earthgro I

1/8"

yes

76.6

38.8

47.2

45.4

208.0

Earthgro I

1/4"

no

88.2

45.7

46.5

42.4

222.8

Earthgro 1

1/4"

yes

73.8

42.4

43.6

44.8

204.7

Earthgro I

1/2"

no

74.2

37.7

36.7

38.6

187.2

Earthgro I

1/2"

yes

74.3

37.3

39.8

44.7

196.1

Earthgro II

1/8"

no

81.2

42.3

44.6

39.3

207.4

Earthgro II

1/8"

yes

75.1

40.8

40.0

37.9

193.7

Earthgro II

1/4"

no

55.2

35.4

40.0

41.3

172.0

Earthgro II

1/4"

yes

65.1

36.5

40.7

41.1

183.3

Earthgro II

1/2"

no

59.1

34.2

40.4

39.0

172.7

Earthgro II

1/2"

yes

54.9

31.3

33.8

36.3

156.4

Control

—

no

65.4

41.7

36.7

35.5

179.3

Control

-

yes

80.8

39.5

36.6

31.2

188.0

Control

-

no

65.4

41.7

36.7

35.5

179.3

Control

-

yes

80.8

39.5

36.6

31.2

188.0

LSD (0.05) O.M.

NS*

NS*

6.2

6.7

24.6

LSD (0.05) Rate

NS

NS*

NS

NS

NS

LSD (0.05) Core

NS

NS

NS

NS

NS

* Significant at a 0.10 level

106

10/16

Clipping
Yield
Totals

Table 72. The effects o f com post, rate, core cultivation on visual quality o f Kentucky bluegrass.

Quality Ratings
Compost

Rate

Coring

8/4

8/26

9/16

Earthgro I

1/8"

no

7.7

6.7

7.3

7.0

7.2

Earthgro I

1/8"

yes

7.7

6.3

8.0

7.0

7.3

Earthgro I

1/4"

no

8.0

6.7

7.7

7.0

7.3

Earthgro I

1/4"

yes

8.0

7.0

7.7

7.0

7.4

Earthgro I

1/2"

no

7.7

7.0

7.7

7.0

7.3

Earthgro I

1/2"

yes

6.7

6.0

7.7

7.7

7.0

Earthgro II

1/8"

no

7.3

5.7

7.7

6.3

6.8

Earthgro II

1/8"

yes

6.3

6.7

7.7

6.3

6.8

Earthgro II

1/4"

no

7.0

6.0

8.3

6.7

7.0

Earthgro II

1/4"

yes

6.0

7.0

8.0

6.7

6.9

Earthgro II

1/2"

no

7.0

5.3

8.3

7.7

7.1

Earthgro II

1/2"

yes

5.7

6.0

7.7

6.7

6.5

Control

-

no

6.7

5.7

7.0

6.0

6.3

Control

-

yes

6.3

6.3

7.3

5.7

6.4

Control

-

no

6.7

5.7

7.0

6.0

6.3

Control

-

yes

6.3

6.3

7.3

5.7

6.4

LSD (0.05) O.M.

0.4

NS

0.5

0.5

0.4

LSD (0.05) Rate

NS

NS

NS

NS

NS

LSD (0.05) Core

0.3

NS

NS

NS

NS

* Significant at a 0.10 level

107

10/16

Means

The Effects of Topdress Sand Source and Potassium Level
on the Growth and Development of Creeping Bentgrass Greens
M. L. Agnew

Many golf courses currently have greens constructed either from native soils or a mix consisting of 1
part soil, 1 part peat, and 1 part sand. Most of these greens have either poor or no subsurface
drainage. Many superintendents are currently using a 100% sand topdress to create a more porous
medium for root growth. These sand sources range from calcareous sands to silica sands.
This project investigates the effects of 3 sand sources (silica, g-sand, and calcareous) and traffic on the
growth and development of creeping bentgrass. The topdress portion of this field project was initiated
at the 1991 field day. Traffic treatments were initiated in the spring of 1993. Data to be collected
include root and shoot growth and soil physical data.

Treatments:
Trt#

1

2
3

4

5
6

Sand Source

Traffic Level

G-Sand
G-Sand
Silica
Silica
Calcareous
Calcareous

OX
2X
OX
2X
OX
2X

Plots will be topdressed every 30 days beginning April 15 each spring. Nitrogen fertilizers will be
applied at a rate of 0.5 lb N/1000 ft2 every 20 days. Potassium applications will be applied at rate of
1.0 lb of K/1000 ft2 as potassium sulfate every 45 days. Traffic is split across topdress treatments.

108

Environmental
Research

Pesticide and Fertilizer Fate in Turfgrasses
Managed Under Golf Course Conditions
S. K. Starrett, N. E. Christians, T. A. Austin, and S. E. Luke

The fate of Trimec, pendimethalin, Subdue, Triump, and Dursban are currently being investigated.
The data from a 2 year field study is being analyzed and an ongoing greenhouse study will conclude
this fall. The experimental setup is similar to the setup used for the fate of fertilizer study reported on
last year. Following is an abstract from new work we concluded this winter. All research has been
funded by the United States Golf Association (USGA).
C o m p a r i n g S o l u t e T r a n s p o r t in U n d i s t u r b e d a n d D i s t u r b e d S o i l C o l u m n s U n d e r T u r f g r a s s C o n d i t i o n s

Research relating to soil leaching properties under turfgrass conditions have often been conducted on
repacked soils where the macropore structure has been destroyed. The objective of this study was to
compare the solute movement characteristics of undisturbed and disturbed soil columns under turfgrass
conditions. We studied three parameters: total solute leached, total leachate, and total solute retained
in the soil. Chloride was applied as a conservative tracer. Distilled water was applied twice daily for
7 days at a rate of 0.69 cm (0.27 in) per application. Soil columns were excavated into 4 sections.
These soil sections and the leachate samples were tested for chloride concentrations. The average bulk
density was 1.72 Mg m'3 for the undisturbed columns and 1.43 Mg m"3 for the disturbed columns. The
total amount of chloride leached was 2.0 times higher for the undisturbed columns than for the
disturbed columns, and the total quantity of leachate was 1.4 times higher for undisturbed columns
than for the disturbed columns. Total chloride found in the B layer (6.7 to 13.4 cm, 2.6 to 5.3 in) was
1.79 times higher and in the C layer (13.4 to 20.0 cm, 5.3 to 8 in) was 2.72 times higher for the
disturbed soils than for the undisturbed. For the T (thatch) layer (0.0 to 2.0 cm) the opposite was
observed, with total chloride in the undisturbed columns 2.4 times higher than in the disturbed
columns. Comparing conclusions from solute movement studies using repacked columns to actual
undisturbed field conditions could lead to errors in interpretation because the effect of the macropore
structure.

109

Table 73. Average percentage of applied chloride and irrigation that leached through 4 replications of
undisturbed and disturbed soil columns.f
Undisturbed Soil
Category

Mean

(% )

Std. Dev.

Disturbed Soil
(% )

p-value $

Mean (%)

Std. Dev. (%)

Chloride

30.0

1.6

0.0017

14.8

5.4

Irrigation

64.5

5.7

0.0335

47.5

11.0

t Values from four replications.
f t - test, based on the hypothesis that undisturbed and disturbed are the same.

Table 74. Average percentage of applied chloride in each soil layer for 4 replications of undisturbed
and disturbed soil columns.f

Undisturbed Soil

Disturbed Soil
p-values§

Layer $

Mean (%)

4.4

0.0018

T

15.7

1.9

13.0

6.9

0.8733

A

14.0

5.7

B

19.5

11.8

0.0198

B

35.0

7.4

C

19.5

2.9

<0.0001

C

53.0

17.6

Layer f

Mean (%)

T

37.5

A

Std. Dev. (%)

f Values from four replications,
f Layers
T = (0.0-2.0 cm).
A = (2.0-6.7 cm).
B = (6.7-13.4 cm).
C = (13.4-20.0 cm).
§ t - test, based on the hypothesis that undisturbed and disturbed are the same.

110

Std. Dev. (%)

\p

o'"

Q

Fig. 2. Percent of total applied irrigation collected as leachate for undisturbed and
disturbed soil columns. Bars represent 1 standard deviation.

Fig. 3. Percent of total applied chloride collected in leachate for undisturbed and
disturbed soil columns. Bars represent 1 standard deviation.
Ill

Isolation and Identification of Root-Inhibiting Compounds
from Corn Gluten Meal
D. L. Liu and N. E. Christians

Public awareness and concern for environmental protection and human safety has led to the search for
naturally occurring compounds that are able to inhibit growth and development of weed plants.
Commonly-assigned U.S. Patent 5,030,268 disclosed that com gluten meal is useful as a natural
preemergence herbicide and feed material for various plant production systems. The active
component(s) responsible for the herbicidal activity of com gluten meal could potentially be used as
natural herbicides. The objectives of this study were to select water-soluble com gluten meal related
materials and to isolate and identify the active compound(s) responsible for the inhibitory activity.
Three species of grass plants were used to test the inhibitory activity of corn gluten meal derived
samples, to select a water soluble material to be used in the isolation process. Based on the results
from greenhouse and growth chamber bioassays, it was found that an extract of the com gluten meal
was more herbicidally active than the corn gluten meal itself and was highly water-soluble. Roots
were found to be more sensitive than shoots to the inhibitory compounds.
Five root-inhibitory compounds were isolated from the water soluble extract protein from corn gluten
meal and their structures were identified. Synthetically produced samples of these five compounds
were bioassayed and their inhibitory effects on the roots of the test plant were demonstrated. Two
U.S. patent applications based on this work have been filed with the Patent Office.

112

The Use of a Natural Product for the
Preemergence Control of Annual Weeds
N. E. Christians

In 1985, it was observed that unprocessed com meal applied in large quantities to soil areas had an
inhibitory effect on the establishment of germinating plants. Further evaluations showed that there was
a naturally occurring, organic compound (or compounds) within the com meal that had a growth
regulating effect on the root system of germinating plants. Studies were conducted to determine if any
of the components of the com meal contained higher concentrations of the inhibitory substance. It
was discovered that high levels of the inhibitor were found in the com gluten meal, the protein
fraction of the corn grain.
The com gluten meal contains 10% nitrogen by weight and was shown to be a good natural source of
fertilizer nitrogen for mature plants that had well established root systems. Further studies
demonstrated that the corn gluten meal could be used as a natural ’weed and feed’ material for lawn
areas. The nitrogen in the product serves as a nutrient source to improve lawn quality, while the
inhibitory substance acts to prevent germinating weeds, such as crabgrass, from infesting the lawn.
Several grassy and broadleaf weeds have been shown to be controlled by preemergence application of
the corn gluten meal. United States patent 5,030,268 was issued for the use of com gluten meal as a
natural preemergence herbicide in July of 1991. Marketing agreements with several companies are
presently being negotiated.
Com gluten meal is a byproduct of the wet-milling process. It has been used for decades as an animal
feed for dogs, poultry, fish, and many other animal species. The product is being promoted as an
environmentally safe, natural herbicide that can be used to control weeds preemergently in turf areas
without the use of synthetic preemergence herbicides that are presently used in large quantities in the
U.S.
Work has also been conducted on other crop systems, such as strawberries, floral crops, and vegetable
crops. It anticipated that the com gluten meal will find a market for these crop systems as well as for
home gardening.
Some discussion on the registration of this material have taken place with representatives of the
Environmental Protection Agency. A package of information to initiate the registration process should
be submitted within the next few weeks.
Com gluten meal was applied to 5 ft. by 5 ft. plots at the research station during 1991 and 1992 at
levels of 0, 2, 4 , 6 , 8, and 10 lb N per 1000 sq. ft. (20, 40, 60, 80, and 100 lbs com gluten meal per
1000 sq. ft.) Data from the second year of this multiple year study on crabgrass control with com
gluten meal are shown in Figures and . Crabgrass was reduced by from 80 to 85 % at the 2 lb N
per 1000 sq. ft rate (20 lb of com gluten meal per 1000 sq. ft.). Higher levels of control were
achieved at higher rates of com gluten meal, but these rates are generally impractical for use on turf.
The control held to the end of the crabgrass season (September data) even though the late summer
time period was very wet.
Applications of this same rates of com gluten meal were applied to the same plots in the spring of
1993.

113

114

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115

Drift of Postemergence Herbicide Spray
During a Turfgrass Application
H. Hatterman-Valenti, M. Owen, and N. E. Christians

Pesticide spray drift is one of the key environmental issues receiving public attention. This is
especially true for the lawn care industry because the majority of their business is in residential areas.
Therefore, research has been conducted at Iowa State University to quantify the level of off-target
particle movement of three common lawn-care spray nozzles under varying wind conditions. A
carbon-dioxide pressurized backpack sprayer was used to apply the triethylamine salt of triclopyr at a
rate of 1.5 lb a.i./A with the addition of 1% w/v Fluorescein, a fluorescent dye. The three spray
nozzles consisted of the XR8004 VS® flat fan nozzles, the RA-6 Raindrop® swirl chamber nozzles, and
the Lesco® spray gun. The delivery rates for the three spray nozzles were 0.27, 0.54, and 3.17
gal/min, respectively. The operating pressure and ground speed was adjusted for each sprayer so that
the mean volume rates were 20, 40, and 125 gal/A, respectively.
The spray application was made along a line perpendicular to the wind direction. Three sampling
lines were set perpendicular and downwind from the spray swath edge. Sample location spacing was
approximately 1, 3, 5, and 7 ft. Each location had two mylar sheets mounted on poster board and two
tomato plants. Wind speed was recorded during the spray application. Immediately following the
application, plant samples and mylar sheets were collected and individually stored until fluorescent
analysis. One of the two tomato plants at each sampling site was returned to the greenhouse for visual
observations of triclopyr injury.
Data from the six trials showed that the percentage of application volume lost to spray drift with the
mylar or the tomatoes decreased with distance for all nozzle types (Table 75). The greatest percentage
was detected with the XR8004 VS® flat fan nozzles at all distances. This was followed by the RA-6
Raindrop® swirl chamber nozzles, with the Lesco® spray gun having the lowest percentage of
application volume detected. The measurements taken on the tomatoes returned to the greenhouse
indicated that plants within the Lesco® spray gun treatment had the least amount of injury while plants
within the 8004 VS® flat fan treatment had the greatest amount of injury (Tables 76, 77, and 78). This
was true not only for visual injury symptoms, but also height and fresh weight measurements taken
four weeks after the treatment. Distance decreased the triclopyr drift injury on tomato plants. The
least growth (i.e. height and fresh weight) occurred with plants at the 1 ft downwind location. On the
other hand, plants at the 5 or 7 ft distances were the tallest, with significant differences between them
and the control plants. Finally, the least amount of visual injury to tomato plants at all distances
occurred with the Lesco® spray gun.

116

Table 75. Percent o f application volum e lost to drift“.

Distance Downwind
Nozzle Type

30 cm

90 cm

150 cm

210 cm

Mean

Fluorescein Dye Collected on Tomato
Flat fan

5.63

1.83

0.72

0.69

2.22 c

Swirl chamber

4.37

0.61

0.49

0.31

1.48 b

Spray gun

1.03

0.17

0.15

0.08

0.36 a

Mean

3.68 b

0.87 a

0.45 a

0.36 a

Fluorescein Dye Collected on Mylar
Flat fan

27.91

4.83

4.02

2.77

9.88 b

Swirl chamber

21.13

2.75

1.41

0.91

6.55 ab

Spray gun

10.24

0.49

0.30

0.25

2.82 a

Mean

19.76 b

2.69 a

1.97 a

1.31 a

“Means within a column or row followed by the same letter do not differ significantly at the P>0.05
level.

Table 76. Mean increase in tomato height 4 weeks after treatment“.
Distance Downwind
Nozzle Type

Control

Control

8.54

30 cm

90 cm

150 cm

210 cm

Mean
8.54 a

Flat fan

1.44

3.64

5.91

8.04

4.99 a

Swirl chamber

4.11

13.69

14.03

12.89

11.18 b

Spray gun

9.44

13.56

15.97

13.97

13.23 b

5.00 a

10.30 ab

11.97 b

11.93 b

Mean*

8.54 a

“Means within a column or row followed by the same letter do not differ significantly at the P>0.05
level.

117

Table 77. Mean increase in tomato weight 4 weeks after treatment8.
Distance Downwind
Nozzle Type

Control

Control

87.65

30 cm

90 cm

150 cm

210 cm

Mean
87.65 ab

Flat fan

46.22

61.61

79.56

89.13

69.13 a

Swirl chamber

38.93

72.81

85.07

100.56

74.34 ab

Spray gun

71.05

90.91

99.12

106.69

91.94 b

52.07 a

75.11 b

87.92 b

98.79 b

Mean*

87.65 b

“Means within a column or row followed by the same letter do not differ significantly at the P>0.05
level.

Table 78. Mean percent injury to tomato 4 weeks after treatment8.
Distance Downwind
Nozzle Type

30 cm

90 cm

150 cm

210 cm

Mean

Flat fan

61.11

41.11

26.39

14.78

35.85 b

Swirl chamber

61.38

7.50

2.22

0.28

17.85 a

Spray gun

8.61

2.50

0.01

0.28

2.85 a

Mean

43.7 c

17.04 b

9.54 a

5.11 a

“Means within a column or row followed by the same letter do not differ significantly at the P>0.05
level.

118

Ground Ivy Control with Borax
H. Hatterman-Valenti and N. E. Christians

Borax (sodium tetraborate) has been tested for two years as a herbicide to control ground ivy in a coolseason lawn. Borax is labeled for nonselective vegetation control under asphalt or for spot treatment of
johnsongrass in cotton. The application rate for these applications is 5 to 15 lb/100 ft2, depending on
which borax form (i.e. anhydrous, pentahydrate, or decahydrate) is used. The element in borax responsible
for the physiological action in higher plants is boron. Boron is an essential mineral element for all
vascular plants. There is a certain minimum requirement of boron for a plant and a certain maximum
level of tolerance. It is the toxicity from high levels of boron that has a herbicidal effect. Sensitivity to
boron varies greatly between species. Toxicity symptoms typically show first on older leaf margins as
either a yellowing or drying of leaf tissues.
The experimental design was a randomized complete block with three replications.
dimensions were 5 by 5 ft. Treatments included:

»

Individual plot

5 oz Borax/1000 ft2 (borax mixture with water)
10 oz Borax/1000 ft2 (borax mixture with water)
20 oz Borax/1000 ft2 (borax mixture with water)
1.1 oz/1000 ft2 Super Trimec®
20 oz Borax/1000 ft2 (dry or granular application)
Sharpshooter® (ready to use mixture)
Weedy control
20 MuleTeam Borax® was used for the borax applications. The borax was dissolved in a small amount
of hot water and then diluted to its final spray volume of 2.5 gal/1000 ft2. Applications of Super Trimec®
and Sharpshooter® were also included for comparison. Super Trimec® is a combination product
consisting of: 2,4-D; 2,4-DP; and dicamba while Sharpshooter® is a fatty acid based, non-selective contact
herbicide. A C 0 2-charged backpack sprayer was used to apply the liquid borax and Super Trimec®.
Herbicide applications were made 6/27/91 and 5/29/92.
Control and injury ratings were taken 4 and 8 weeks after treatments (WAT) and finally the following
spring. A summary of the results is given in Tables 79 and 80. The liquid applications of borax provided
acceptable control of ground ivy and were comparable to the Super Trimec® application for both years.
There was not as much injury to the turfgrass in 1992, however, the ground ivy control also decreased
slightly. The mild winter in 1992 may have contributed to the recovery of the ground ivy.
The study was also repeated 6/12/92 at another location. However, because of the hot dry weather during
this period, none of the treatments provided satisfactory control. Therefore, treatments were reapplied
9/29/92 along with a 30 oz borax/1000 ft2 treatment in order to assess ground ivy control in the fall and
the potential buildup of boron in the soil. Results were similar to those observed in 1991 and the May
application in 1992. The 30 oz borax treatment did cause turfgrass to turn chlorotic for approximately
4 weeks after the application, however, no injury was evident the following spring.
This year Solubor® will be compared with borax. Applications will be made on a volume to volume basis
(i.e. 3 tsp./l gal. water) which should make spot applications easier. Greenhouse studies will also be
conducted to investigate the sensitivity of ground ivy to boron.

119

Table 79. Percent control o f ground ivy.

1991

1992

Treatment

4 WAT

8 WAT

Spring

4 WAT

8 WAT

Spring

5 oz L. Borax

73.3

68.3

97.7

86.7

55.0

70.0

10 oz. L. Borax

80.0

93.3

93.3

90.0

80.0

68.3

20 oz. L. Borax

91.7

97.0

100.0

93.3

90.0

85.0

Super Trimec®

95.0

71.7

100.0

85.0

66.7

80.0

20 oz. D. Borax

56.7

51.7

94.3

50.0

46.7

53.3

Sharpshooter®

30.0

16.7

63.3

63.3

23.3

33.3

Weedy Control

0.0

0.0

11.7

0.0

0.0

23.3

LSD(0.05)

18.4

23.8

37.0

27.6

46.1

28.8

@L. Borax = Liquid Borax Mixture
D. Borax = Dry Borax Application

Table 80. Percent injury to cool-season turfgrass.
1991

1992

Treatment

4 WAT

8 WAT

Spring

4 WAT

8 WAT

Spring

5 oz L. Borax

3.3

10.0

5.0

0.0

1.7

0.0

10 oz. L. Borax

18.3

30.0

11.7

0.0

0.0

0.0

20 oz. L. Borax

13.3

40.0

10.0

0.0

1.7

0.0

Super Trimec®

10.0

8.3

1.7

8.3

15.0

0.0

20 oz. D. Borax

13.3

16.7

8.3

23.0

10.0

0.0

Sharpshooter®

10.0

16.7

8.3

23.0

10.0

0.0

Weedy Control

0.0

0.0

0.0

0.0

0.0

0.0

LSD(0.o5)

NS

21.7

NS

21.6

NS

NS

®L. Borax = Liquid Borax Mixture
D. Borax = Dry Borax Application

120

National Crabapple Evaluation Program
J. K. lies

In 1983 the National Crabapple Evaluation Program (NCEP) was established by Dr. Thomas Green,
Plant Pathologist at the Morton Arboretum, Lester P. Nichols, Professor Emeritus of Plant Pathology at
Penn State University, and Dr. Ed Hasselkus, Extension Horticulturist at the University of Wisconsin.
The purpose o f this program is to test approximately 50 of the best taxa of flowering crabapples over a
broad geographical range. Information on disease resistance and aesthetic characteristics such as fruit
color, size, persistence, flower color, plant form, and mature growth habit has been obtained. This
information will provide guidance to landscape architects, landscape contractors, nursery operators,
municipal arborists, park superintendents, and homeowners for selecting appropriate crabapple species
for the landscape.
Cooperators for the program were selected at locations in parks, universities, and arboreta in the
following states: North Carolina, Rhode Island, Ohio, Illinois, Kentucky, Michigan, Minnesota,
Wisconsin, Nebraska, Iowa, North Dakota, Colorado, Oklahoma, Utah, Oregon, Washington, and the
District of Columbia. Partial collections have also been sent to Killen, Alabama and Spartenburg,
South Carolina. Every fall, cooperators at each site evaluate their collection and submit the data for
compilation.

Fall Aesthetic Evaluation
The most important evaluation in the fall is the aesthetic rating. Certain crabapple cultivars may
demonstrate little defoliation and still have a pleasing appearance even though they are moderately or
severely susceptible to apple scab and/or cedar-apple rust. Others may defoliate but still have an
outstanding display of fruit. Therefore, the aesthetic rating attempts to answer the question, "How
does this tree look (as an ornamental) at this time of the year?" Theoretically, if the plant looks good
in the fall, it should have looked good since the time of flowering. The aesthetic rating is useful in
judging the overall aesthetic impact of the tree.

Aesthetic Rating System
0 = Perfect Tree: A tree that has a little something extra going for it such as blemish-free, darkgreen foliage, early coloration of fruit, vivid fruit display, abundant and persistent fruit, attractive form,
and good fall leaf color. The tree rated 0 stands out from all the rest.
1 = Highly Ornamental: A nearly perfect tree. Foliage may be dull green or some scab may be
present, fruit fairly abundant but less than the 0 rated tree, fruit color may be less vivid or less
persistent, and it may not have noteworthy fall foliage color.
2 = Ornamental: A totally acceptable tree but less than perfect. Leaves may have slight to severe
scab, but little defoliation occurs. Fruit may not be as abundant or particularly ornamental. For
example, the cultivar 'Indian Magic' may defoliate prematurely because of apple scab, but the
persistent orange fruit are extremely ornamental.
3 = Barely Ornamental: A tree receiving this rating is essentially a green plant with very little
ornamental value. Fruit may be dull, too large, and/or not persistent. Foliage may be infected with
scab, cedar-apple rust, or moderately damaged by insects or mites but the tree remains green with little
defoliation.

121

4 = Undesirable: Trees earning a 4 are undesirable because of defoliation from disease, ugly or

messy fruit, and/or poor form. Trees with large fruit that drop in late summer or early fall are given
this rating.
5 = Unacceptable: Trees having messy fruit, poor form, and totally defoliate because of disease fall
into this category.

122

Table 81. C om posite N C EP Evaluation (1990-1992), Iowa State University Research Station.

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49

Tree Name
’Sentinel’
Candied Apple®
’Donald Wyman’
’Indian Magic’
’Professor Sprenger’
’Adams’
zu m i ’Calocarpa’
’David’
’Profusion’
Sugar Tyme®
Centurion®
’Snowdrift’
’Henningi’
’Bob White’
Christmas Holly™
’Red Barron’
Red Jewel®
Molten Lava®
’Ralph Shay’
’Winter Gold’
b a c c a ta ’Jackii’
’Ormiston Roy’
Harvest Gold®
’Velvet Pillar’
’White Angel’
’Prairifire’
’Indian Summer’
’Mary Potter’
’Robinson’
’Silver Moon’
’Jewel berry’
h u p e h e n sis

’Red Splendor’
’Parkmanii’

h a llia n a

flo r ib u n d a

’Beverly’
’Liset’
’Red Jade’
tsc h o n o sk ii
s a r g e n tii

’Strawberry Parfait’
’Dolgo’
’Selkirk’
’Ruby Luster’
’Radiant’
’Royalty’
’White Cascade’
’Hopa’
y u n n a n e n sis var. v e itc h ii

#Trees
7
7
7
9
9
9
9
9
9
9
4
8
9
9
9
6
9
8
9
3
8
8
9
9
9
6
3
9
9
7
9
9
9
3
9
9
7
5
3
5
9
9
8
9
9
9
9
9
2

123

0
2
1
2
3
2
0
2
4
1
2
1
3
0
1
1
0
3
2
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0

1
4
5
3
3
5
8
5
1
5
4
2
0
6
4
4
4
0
0
4
2
4
4
2
2
5
1
0
3
2
4
2
1
3
0
0
2
0
0
0
1
0
0
0
0
0
0
0
0
0

2
1
1
2
3
2
1
1
2
3
2
0
5
3
3
3
1
4
5
4
0
2
2
7
7
1
5
3
3
6
0
4
5
1
2
5
0
2
1
0
0
1
0
0
0
0
0
0
0
0

3
0
0
0
0
0
0
1
2
0
1
1
0
0
1
1
1
2
1
1
1
2
2
0
0
3
0
0
3
0
2
3
3
5
1
4
6
5
3
3
2
4
5
4
4
3
3
2
2
0

4
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
1
1
0
0
0
0
0
1
0
1
0
1
4
4
4
5
6
6
7
5
0

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

Avg.
0.86
1.00
1.00
1.00
1.00
1.11
1.11
1.22
1.22
1.22
1.25
1.25
1.33
1.44
1.44
1.50
1.56
1.63
1.67
1.67
1.75
1.75
1.78
1.78
1.78
1.83
2.00
2.00
2.00
2.00
2.11
2.22
2.22
2.33
2.44
2.67
2.71
3.00
3.00
3.20
3.33
3.44
3.50
3.56
3.67
3.67
3.78
4.00
5.00

Table 82. C om posite NCEP Evaluation (1990-1992), (A il Trial Sites).

1
2

3
4
5

6
7

8
9

10
11
12
13
14
15
16
17
18
19

20
21
22

23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49

Tree Name
zu m i ’Calocarpa’
’Professor Sprenger’
’Donald Wyman’
Molten Lava®
Sugar Tyme®
Red Jewel®
’Snowdrift’
’David’
’Sentinel’
’Indian Magic’
Christmas Holly™
’Bob White’
’Mary Potter’
’Adams’
’Prairifire’
’Indian Summer’
’Henningi ’
’Profusion’
’Ormiston Roy’
’Red Splendor’
b a c c a ta ’Jackii’
’Ralph Shay’
’White Angel’
’Jewel berry’
Centurion®
sa r g e n tii

’Red Jade’
’Silver Moon’
’Robinson’
Candied Apple®
’Beverly’
h u p eh en sis
h a llia n a

’Parkmanii’

flo rib u n d a

’White Cascade’
’Red Baron’
Harvest Gold®
’Liset’
tsch o n o sk ii

’Strawberry Parfait’
’Winter Gold’
’Velvet Pillar’
yu n n a n e n sis var. v e itch ii
’Selkirk’
’Dolgo’
’Royalty’
’Ruby Luster’
’Radiant’
’Hopa’

0

1

2

35
35
34
38
30
18
18
23
28
19

37
43
55
39
37
32
40
39
38
49
42
49
46
56
50
36
47
52
48
32
32
50
37
34
39
34
43

23
27
24
28
38

11

3
18
5

10

14
5

8
11
5

2

3

6
3

10
8
5
5

0
6
6
0
0
1
2
2
1
1
6
0
4

1
0
0
1
0
1
1
2

22

32
26
30
25
18
27
16
27
16
16

12
18
17
13
9

2
6
4

1
2
1

21
39
29
37
30

20

43
30
46
27
42
38
27
33
55
46
58
36
34
34
33
29
38
55
40
42
34
28
39
35
37
43
42
27
31
38
37

12
18
13

12
5

10
8

124

3
7
7

2

3
16

10
12

15

8

14
7
7
14
14
13
19
15

4

5

1

0
0
1
0
0
0
0
0

3

6
8
2
4

0
3
4
3
3

1

5

1
10
2
4

11

11

12

1
2
11

15
15
7

20
18
19
17
18
15

20
9

22
19
14
23
15
25

12
20
29
37
24
28
34
48
47
44
30
31
16

7

3
4

12
8
8
7
9
18
16
9
7
15

12

17
17
15
9
9

22
33

20
36
43
35
63
55
60

3

0

Sum
103
115

122

116
123
85
109
109
118
115

3

86

3

103
116
123

0
1
0
1
0
1
3

0
0
1
2
0
0
2
5

2
0
1
0
0
0
0
0
2
0
0
2
0
0
0
8
1
1
2

3
14
14

110
114
109

110

117
108
94
130
104
93
114

102
108
89
116

100
116
87
67
105
80

110
89
94
85
95
105

112
83
105

111

97
103
113

101

Avg.
1.04
1.13
1.13
1.17
1.37
1.41
1.41
1.41
1.41
1.41
1.51
1.55
1.57
1.61

1.66
1.66
1.68

1.70
1.72
1.76
1.78
1.81
1.83
1.84
1.85
1.89
1.96
2.03
2.05

2.10
2.10
2.13
2.14

2.22
2.23
2.30
2.31
2.34
2.34
2.38
2.40
2.70
3.07
3.15
3.15
3.19
3.57
3.58
3.71

Introducing

Introducing
Iowa State University Personnel
Affiliated with the Turfgrass Research Program

Michael Agnew, Ph.D.

Associate Professor, Extension Turfgrass Specialist
Horticulture Department

Dave Anderson

Graduate Student and Research Associate
Horticulture Department M.S. (Agnew, M.)

Susan Berkenbosch

Extension Associate, Horticulture Department

Tim Bormann

Field Technician, Horticulture Department

Doug Campbell

Research Associate, Horticulture Department

Nick Christians, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Department

Jim Dickson

Field Manager, Horticulture Department

Steve Driscoll

Field Technician, Horticulture Department

Kathy Eldridge

Field Technician, Horticulture Department

Paula Flynn

Extension Associate, Plant Disease Clinic
Plant Pathology Department

Mark Gleason, Ph.D.

Assistant Professor, Extension Plant Pathologist
Plant Pathology Department

Mark Hartman

Field Technician, Horticulture Department

Harlene Hatterman- Valenti

Extension Associate, Weed Science Department
Graduate Student Ph.D. (Christians/Owen)

Clinton Hodges, Ph.D.

Professor, Turfgrass Science Research and Teaching
Horticulture Department

Donald Lewis, Ph.D.

Associate Professor, Extension Entomologist
Entomology Department

Dianna Liu

Graduate Student and Research Associate
Horticulture Department Ph.D. (Christians)

Richard Moore

Research Associate, Horticulture Department

Glenn Pearston

Computer Consultant, Horticulture Department

Gary Peterson

Extension Field Specialist - Horticulture

125

Roger Roe

Graduate Student and Research Associate
Horticulture Department M.S. (Christians/Agnew N.)

Marcy Simbro

Field Technician, Horticulture Department

Julie Smith

Field Technician, Horticulture Department

Doug Struyk

Graduate Student and Research Associate
Horticulture Department M.S. (Christians)

Steve Starrett

Graduate Student and Research Associate
Civil Engineering Department M.S. (Christians/Austin)

J. Bryan Unruh

Graduate Student and Research Associate
Horticulture Department Ph.D. (Christians)

We would also like to thank Mark Stoskopf, former Superintendent of the Horticulture Research Station,
and Adrian Lucas, William Emley, Lynn Schroeder, and A1 Morris for their support during the last year.

126

Companies and
Organizations

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 mataway, a lawn aerifier, and a Jacobson Turf King reel mower for
use at the research area in 1991; to Tri-State Turf and Irrigation for providing a Greensmaster III Triplex
Greensmower for use on the research area and a Groundsmaster 220 rotary mower.

Earthgro
P.O. Box 143
Lebanon, Connecticut 06249

American Hoechst Corporation
Agricultural Chemicals Department
Route 1 - Box 7
Brownsdale, Minnesota 55918

Enviro-Gro Technologies
P.O. Box 5036
Lancaster, Pennsylvania 17601-0036

BASF Corporation
1000 Cherry Hill Road
Parsippany, New Jersey 07054

E-Z-Go Textron
PO Box 388
Augusta, Georgia 30906

Big Bear Turf Equipment Company
10405 T Street
Omaha, Nebraska 68127

Ciba-Geigy Corporation
Agriculture Division
Greensboro, North Carolina 27049

Fermenta Plant Protection Company
PO Box 348
7528 Auburn Road
Painesville, Ohio 44077

Coron Corporation
PO Box 198
Souderton, Pennsylvania 18964

Gardens Alive
5100 Schenley Place
Lawrenceburg, Indiana 47025

Cushman Turf
5232 Cushman
Lincoln, Nebraska 68501

Grain Processing Corporation
PO Box 349
Muscatine, Iowa 52761

D & K Turf Products
8121 Parkview Drive
Urbandale, Iowa 50322

Grace Sierra
PO Box 4003
Milpitas, California 95035-2003

DowElanco
Midland, Michigan 48674
127

Grass Roots Turf
6143 Southwest 63rd
Des Moines, Iowa 50321

Lyman-Ritchie Sand & Gravel
4315 Cuming Street
Omaha, Nebraska 68131

Harmony
PO Box 846
Waterloo, Iowa 50704

Miles Laboratory
14718 Madison Circle
Omaha, Nebraska 68137

International Seeds
PO Box 168
820 First Street
Halsey, Oregon 97348

Milorganite
735 North Water Street
Milwaukee, Wisconsin 53200

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

Iowa Golf Course Superintendents
Association

Iowa Professional Lawn Care
Association

NOR-AM Chemical Company
PO Box 7495
3509 Silverside Road
Wilmington, Delaware 19803

Iowa Sports Turf Managers
Association

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

Iowa Turf Producers and
Contractors

Iowa Turfgrass Institute

Pickseed West Incorporated
PO Box 888
Tangent, Oregon 97389

Lebanon Chemical Corporation
Country Club Fertilizer Division
PO Box 180
Lebanon, Pennsylvania 17042

Professional Turf Specialties Inc
133 Kenyon Road
Champaign, Illinois 61820

LESCO Incorporated
PO Box 10915
Rocky River, Ohio 44116-0915

Pursell
P.O. Box 450
201 W. Fourth St.
Sylacauga, Alabama 35150

Loft-Kellogg Seed
PO Box 684
322 East Florida Street
Milwaukee, Wisconsin 53201

O. M. Scott and Sons
14111 Scottslawn Road
Marysville, Ohio 43041

128

R.G.B. Laboratories Incorporated
1531 Charlotte Street
Kansas City, Missouri 64108

Weathermatic Corporation
Telsco Industries
P.O. Box 180205
Dallas, Texas 75218-2005

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

Wilbur-Ellis Company
215 North Summer Street
West Burlington, Iowa 52655

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

Ringer Corporation
9959 Valley View Road
Minneapolis, Minnesota 55344

Ross Daniels Inc
1720 Füller Road
West Des Moines, Iowa 50265

Soil Technologies
Fairfield, Iowa 52556

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

Sustane Corporation
P.O. Box 19
Cannon Falls, Minnesota 55009

Terra Chemical Corporation
Box 218
Quimby, Iowa 51049

The Toro Company
Irrigation Division
Riverside, California 92500

Tri State Turf & Irrigation Co.
6125 Valley Drive
Bettendorf, Iowa 52722

United Horticultural Supply
4564 Ridge Dr. NE
Salem, Oregon 97303
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and justice for all
The Iowa Cooperative Extension Service’s programs and policies are consistent
with pertinent federal and state laws and regulations on nondiscrimination regarding race, color, natural origin, religion, sex, age, and handicap.
Cooperative Extension Service, Iowa State University o f Science and T echnology and the United States Department o f Agriculture cooperating. Robert M.
Anderson, Jr., director, A m es, Iowa. Distributed in furtherance o f the A cts o f
Congress o f May 8 and June 30, 1914.