1989

Iowa
Turfgrass
Research
Report
j

IOWA STATE
Ames, Iowa 50011
FG-456I July 1989

The following research report is the ninth yearly publication of the results of turfgrass research
projects performed at Iowa State University. The first was published for the 1981 field day, which
was held June 18, of that year. The others were published in conjunction with the 1982, 1983,
1984, 1985, 1986, 1987, and 1988 field days.
The first cultivar and management studies at the field research area were seeded in August 1979,
and many of these investigations are now in their tenth season. The research area was expanded
between 1979 and 1983 to 4.2 acres of irrigated and approximately 3.0 acres of nonirrigated
research area. Funding was obtained in 1983 to add 2.7 acres of irrigated research plots to the
existing site. This construction was completed in the spring of 1985. Several new studies were
initiated on this area in the 1985, 1986, 1987, and 1988 seasons and a map showing the location of
these studies can be found in this report.
The expansion that has taken place since 1979 would not have been possible without the
cooperation of the Iowa Agriculture Experiment Station, the Iowa Turfgrass Institute, the Iowa Golf
Course Superintendent's Association, the Iowa Professional Lawn Care Association, and the Iowa
1
Turfgrass Producers and Contractors (ITPAC) organization.
We would also like to acknowledge Richard Moore, Manager of the Turfgrass Research area, Mark
Stoskopf, Superintendent of the ISU Horticulture Research Station, and all others employed at the
field research area in the past year for their efforts in building the program.
Special thanks to Betty Hempe for her work on typing and helping to edit this publication and to
Barb Erickson for her help in editing.
Edited by Nick Christians, professor, turfgrass science; Michael Agnew, assistant professor, turfgrass
extension; and Elaine Edwards, extension communication specialist.

ENVIRONMENTAL DATA

1

TURFGRASS RESEARCH AREA MAPS

3

SPECIES AND CULTIVAR TRIALS
Results of High- and Low-Maintenance Kentucky Bluegrass
Regional Cultivar Trials - 1988

6

Low-maintenance Kentucky Bluegrasses

13

Growth and Morphological Characterization Study of Low- and High-maintenance
Kentucky Bluegrass Cultivars

20

Regional Perennial Ryegrass Cultivar Evaluation

22

Fine Fescue Cultivar Trial

24

Fine Fescue Management Study

26

Tall Fescue Cultivar Trial

27

Tall Fescue Management Study

28

Shade Adaptation Study

30

TURFGRASS DISEASE RESEARCH
Evaluation of Fungicides for Control of Dollar Spot on Penneagle Bentgrass - 1988

32

Evaluation of Fungicides for Control of Brown Patch on Bentgrass - 1988

34

Evaluation of Fungicides for Control of Leaf Spot on Park Bluegrass - 1988

36

Evaluation of Fungicides for Control of Dollar Spot on Park Bluegrass - 1988

38

Reactions of Creeping Bentgrass Cultivars to Dollar Spot - 1987-88

40

HERBICIDE STUDIES
Preemergence Annual Grass Control Study - 1988

41

Postemergence Annual Grass Control Study - 1988

43

1987 - 1988 Poa annua Control Study

45

Fertilizer and Herbicide Applications on Dormant Kentucky Bluegrass Lawns

47

Ill

STRESS STUDIES AND FERTILIZER TRIALS
Soil Percolator Test Results

49

Wetting Agent Study

52

Cultivation Intensity Study

54

The Effects of Core Cultivation on the Performance of four Nitrogen Fertilizers

55

1988 Ringer Corporation Project

58

1988 NBPT Field Study

64

Fertilizer Burn Study

69

Summer Slow Release Nitrogen Sources Comparison Study

70

The Effects of 13 Granular Nitrogen Fertilizer Sources on the Growth and Quality
of Park Kentucky Bluegrass

71

Evaluation of Liquid Fertilizer Programs on Three Kentucky Bluegrass Cultivars

72

Shady Ground Cover Trial

78

INSECT CONTROL
Comparative Effectiveness of Insecticides Against Annual White Grubs - 1988

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

80

82

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Kentucky Bluegrass Regional Cultivar Trials - 1988
N.E. Christians
The United States Department of Agriculture (USDA) has initiated several regional Kentucky
bluegrass cultivar trials currently being conducted at most of the northern agricultural experiment
stations. The test consists of either 80 or 84 cultivars, the number depending on the year the trials
were initiated, with each cultivar replicated three times.
Three separate trials are underway at Iowa State University. One is a high-maintenance study
established in 1981 that receives 4 lb nitrogen (N)/1000 ft2/yr and is irrigated as needed; another is
a low-maintenance study established in 1980 that receives 1 lb N/1000 ft2/yr in September and is
not irrigated. The third trial was established in 1985 and receives 4 lb N/1000 ft2/yr but is not
irrigated. The objective of the high-maintenance study is to investigate the performance of the 84
cultivac^ under a cultural regime similar to that used on irrigated home lawns in Iowa. The objective
of the low-maintenance study is to observe the performance of the 84 cultivars under conditions
similar to those that would be used in parks, school yards, or other low-maintenance areas. The
objective of the third study is to observe the response of 80 cultivars under conditions similar to
those found in a nonirrigated lawn that receives a standard lawn care program.
The values listed under each month in tables 1, 2, and 3 are the averages of ratings made on three
replicated plots for the three studies. Yearly means of all the months data were taken and are listed
in the last column. The first cultivar received the highest average rating for the entire 1988 season.
The cultivars are listed in descending order of average quality.
The least significant difference (LSD) value listed at the bottom of each column is a statistical value
that can be used to further evaluate the data. For cultivars to be considered different from one
another, their mean quality ratings must exceed the LSD value. For example, the yearly means for
the high-maintenance cultivars must exceed 1.4, the LSD for that column (Table 1). Ram-I with a
mean reading of 8.3 performed better than Geronimo with a reading of 6.8. However, the
performance of Ram-I was statistically the same as Apart that had a yearly mean of 7.8. The
unusually high LSD values for this year's results were due primarily to the extreme drought
conditions during the summer. This is an irrigated site, but maintaining its uniformity during a
drought of the severity of that experienced in 1988 was not possible. The result was greater
variation among replications and higher LSD values than usual.
Ram-I, Midnight, Glade, Sydsport, and Cheri were the five best cultivars in the high-maintenance trial
(Table 1). However, most of these 84 cultivars will maintain a reasonably good quality if they are
properly managed.
The nonirrigated, high-maintenance trial (Table 2) provided some very useful information following
recovery from the drought. As has been the case for several years in the low-maintenance trial, it
was the common(varieties such as Kenblue and South Dakota Common -tfcat recovered most quickly
from dormancy. Aquila also demonstrated good postdormancy recovery as did Mystic. (Mystic's
early recovery was observed in only two of the three replications.) It is interesting that even under a
higher fertility recjime, the common types seem to tolerate extended droughts better than most
improved cultivars.)
The nonirrigated study was so devastated by the drought that data were collected in May, June, and
August only. No differences were observed among the cultivars during the other months due to
complete dormancy of all varieties. This study was terminated in late August and will not be rated in
future years.

Table 1.

Ii
2.
3.
4.
5.
6.
7.
8.
9%
10.
11.
12.
13.
14.
15.
16.
ir.
18.
19.
20.
21.
22.
23.

26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
40.
Al-A2)
43.
44.
45.
46.
47.

The 1988 quality ratings for the high-maintenance regional Kentucky bluegrass test
established in the fall 1981.

Cultivar

May

June

July

Aug

Sept

Oct

Mean

Ram-1
Midnight
Glade
Sydsport
Cheri
Enmundi
CEB VB 3965
Majestic
N535
BA-61-91
Eclipse
PSU - 150
Parade
Charlotte
A20-6
NJ 735
FyIking
PSU-190
Kimono
Holiday
Merit
1-13
Bristol
P141 (Mystic)
Escort
Birka
Plush
MLM-18011
Touchdown
Welcome
Shasta
Mer pp 300
Mer pp 43
Admiral
Barblue
Monopoly
Nugget
SV-01617
Vanessa
Mosa
WW Ag 478
A-34 (Bensun)
Mona
Victa
Enoble
Merion
225

8.7
8.0
7.7
7.3
7.0
7.3
6.7
6.3
6.3
7.3
7.3
8.0
6.7
6.0
7.7
7.3
7.0
7.0
6.7
7.3
6.7
8.0
6.7
8.0
6.3
7.3
7.7
7.3
8.0
7.3
6.0
6.7
6.7
7.3
7.3
7.0
6.0
6.3
7.7
7.3
6.0
7.0
6.7
6.7
8.0
6.7
6.7

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

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

7.3
7.7
7.3
7.7
8.0
7.7
7.3
7.7
7.3
7.7
6.7
8.0
8.0
7.7
7.0
7.7
7.7
7.3
7.7
7.3
8.0
7.0
6.7
7.0
7.7
7.3
6.7
7.0
7.0
7.0
7.7
7.3
7.0
7.0
5.7
7.0
7.0
7.3
7.0
7.0
7.3
7.7
7.3
7.3
7.0
7.7
7.3

8.7
9.0
9.0
8.3
8.7
8.3
9.0
8.7
8.7
8.3
8.7
8.3
8.7
9.0
9.0
8.3
8.7
8.3
8?3
8.7
8.7
8.0
8.3
8.3
8.7
8.3
8.3
8.0
8.3
8.0
8.7
8.3
8.3
8.3
8.0
7.7
8.0
8.7
7.7
7.7
8.0
8.0
9.0
8.3
8.0
8.3
8.0

8.3
8.7
7.7
8.0
7.7
7.3
8.3
8.0
8.3
7.7
7.7
6.3
7.7
8.0
8.0
8.0
7.3
8.0
7.7
7.3
7.3
7.7
8.0
7.3
7.0
7.7
7.3
8.3
7.0
7.7
8.3
7.7
8.0
7.7
8.7
7.3
8.0
8.3
7.3
7.0
7.3
7.3
7.7
7.7
7.3
7.3
7.3

8.2
8.2
7.8
7.8
7.6
7.6
7.6
7.6
7.6
7.6
7.6
7.5
7.5
7.5
7.5
7.5
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
7.4
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
7.2
7.2
7.2

Table 1.

The 1988 quality ratings for the high-maintenance regional Kentucky bluegrass test
established in the fall 1981. (continued)

Cultivar
A».
49.
-5CT.
.5-1.
-52.

Adelphi
239
Baron
Banff
WW Ag 463
J * . Argyle
¿4. PSU-173
Apart
56. 243
Trenton
- 5S. Dormie
-59. WW AG 480
60. Bono
-61. H-7
62. A20-6A
Columbia
-64. Geronimo
,65. Harmony
-66. Bonnieblue
.67. Vantage
68. A20
6.9. SH-2
70. S.D. Common
71. Rugby
Aspen
.Z3-. Cello
-74. Bayside
American An* <c+.?
JMr. Piedmont
X t . Lovegreen
J-8. K3-178
.79. Kl-152
Wabash
,81. S-21
82. Kenblue
83. K3-179
84. K3-162
LSD

0.05

May

June

July

Aug

Sept

Oct

Mean

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

6.7
6.7
6.3
7.0
6.3
7.0
7.3
6.3
6.3
6.0
6.3
6.3
7.3
6.0
7.3
5.7
6.7
6.7
6.7
6.0
7.3
6.7
6.0
7.0
6.7
7.0
6.7
6.0
6.3
7.0
5.7
6.7
6.3
6.0
5.7
5.7
5.3

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

8.3
7.3
8.0
6.0
7.3
7.0
8.0
7.3
7.0
6.7
7.3
7.3
7.3
7.0
6.3
6.3
7.0
7.0
7.7
7.0
6.0
7.0
6.7
6.7
6.0
6.7
7.7
7.0
7.0
6.7
7.0
6.3
6.7
7.3
6.3
7.0
6.3

8.3
8.0
7.7
8.7
9.0
8.0
5.3
8.0
8.3
8.7
7.7
8.0
7.7
8.0
6.0
8.7
8.0
7.3
5.7
8.0
6.0
5.3
8.3
6.0
7.7
7.0
5.7
8.0
7.7
7.7
8.0
5.3
5.0
7.3
7.7
5.7
7.3

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

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
6.8
6.8
6.8
6.8
6.8
6 8
6.8
6.7
6.7
6.7
6.7
6.6
6.6
6.6
6.5
6.4
6.3
6.3
6.2
6.1
5.9

1.2

1.2

1.4

N.S.

N.S.

1.4

1.0

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

Table 2.

The 1988 quality ratings for the nonirrigated, high-maintenance Kentucky bluegrass trial
established in the fall of 1985.

Cultivar
1. Kenblue
F-1872 (Freedom)
1 . Aquila
4. Abl'e I
5". South Dakota
Jr. Monopoly
Wabash
8. Rugby
9. Huntsville
10. WW Ag 496
Tendos
Somerset
Mystic
Loft's 1757
-15'. Aspen
16. WW Ag 495
NE 80-14
Joy
Victa
20. BA-70-242
21. K3-178
22. NE 80-47
23. Parade
24. Welcome
25. NE 80-110
26. Georgetown
27. BAR VB 534
28. Harmony
29. WW Ag 491
30. Haga
31. Baron
©
Cynthia
33. Destiny
34. Dawn
35. 239
36. Julia
37. Challenger
38. Classic
39. BA-73-626
40. BA-72-441
41. BA-73-540
42. Liberty
43-. Glade
44-, Kl-152
45-, Trenton
M - WW Ag 468
Barzan t?«tc*tAv*.f

®

May

June

Sept

Oct

Mean

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

5.0
4.7
4.7
3.3
4.3
4.0
4.3
4.0
4.7
4.0
4.3
3.7
4.0
4.0
3.7
4.3
3.7
4.3
3.3
3.3
3.7
4.0
4.7
4.3
4.0
4.3
4.7
4.0
4.0
4.0
4.0
3.3
3.7
4.3
4.0
4.3
3.3
4.0
3.7
3.3
4.0
3.3
4.0
4.0
4.0
4.0
4.3

6.0
4.3
5.7
6.3
6.3
4.7
5.3
4.3
5.3
5.0
4.3
4.7
6.0
4.7
6.0
4.7
5.7
5.7
5.7
5.3
4.7
4.7
2.7
4.3
5.0
3.7
3.7
4.3
4.0
3.3
4.0
5.0
5.0
4.3
3.3
3.7
5.0
3.0
4.3
3.7
3.3
3.7
4.0
3.0
2.7
4.0
3.0

6.7
5.3
6.0
5.3
6.0
5.0
5.3
5.0
4.7
4.7
5.3
5.0
5.0
4.7
5.7
4.3
5.0
5.3
5.3
5.0
4.0
4.7
3.7
4.7
4.0
3.3
4.3
4.7
5.0
3.7
4.3
4.7
4.7
4.3
3.7
3.7
4.3
3.3
4.0
4.3
3.3
4.0
4.3
3.3
3.7
4.0
3.7

5.4
5.3
5.3
5.1
5.1
5.0
5.0
5.0
4.9
4.9
4.8
4.8
4.8
4.8
4.8
4.8
4.8
4.7
4.7
4.6
4.6
4.6
4.5
4.5
4.5
4.4
4.4
4.4
4.4
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.2
4.2
4.1
4.1
4.1
4.1
4.1
4.1
4.1
4.0

Table 2.

M.
51.
-52.
-53.
co>
-56.
58-.
59.

(JO).
—<.

•62.
-64.
>5.
,-66.
• 68.
.6-9.

M.

71.
72,
73.
74.

3%.
Q&

77.
(HP

CB2

The 1988 quality ratings for the nonirrigated, high-maintenance Kentucky bluegrass trial
established in the fall of 1985. (continued).

Cultivar

May

June

Sept

Oct

Mean

Sydsport
Merit
Bristol
BA-69-82
HV 97
Eclipse
Nassau
Ikone
PST-CB1
Park
Gnome
A-34 (Bensun)
Annika
BA-72-492
NE 80-88
America
Blacksburg
NE 80-50
Ram-1
BAR VB 577
BA-70-139
BA-72-500
Merion
Amazon
NE 80-48
NE 80-55
P-104
Midnight
Asset
Cheri
Compact
Conni
NE 80-30

5. 0
5.,3
6. 0
6. 0
5.,0
4. 3
6..0
5..7
5..0
4.,0
4..3
6..3
5..0
6..3
4..3
6..0
5..0
6..3
4.,7
4..3
4..3
5,.0
4,.0
4..7
5,.0
5,.7
4,.7
3 .7
4,.7
4 .7
4 .3
4 .0
4 .7

3. 7
3. 7
3. 7
4. 0
4. 7
3. 3
3..7
4. 3
3.,7
4. 3
4. 0
4. 0
3..7
4.,0
4. 3
3.,3
3..3
4..0
3..3
3..3
3..7
3..7
3..7
3..7
3..7
3..3
4..0
3..0
3 .3
3,.7
3 .0
3 .7
3 .7

4.,0
3.,3
3. 0
3..0
3.,0
3..7
3..3
2..7
3..3
4.,0
3.,7
2..7
3..7
2..7
3..3
3.,0
3..7
2..7
3..7
3..3
3..7
3 .0
3 .3
3,.0
3 .3
2..7
3..0
3 .7
2,.7
2 .3
2 .7
2 .7
2 .3

3..3
3.,7
3..3
3.,0
3..3
4..7
3..0
3..3
4..0
3.,7
3..7
2..7
3..3
2..7
3.,7
3..3
3..7
2..7
3..3
4..0
3..7
3..7
4..3
3..7
3,.3
3..3
2..7
4..0
3..0
3,.0
3 .0
3 .0
2 .7

4. 0
4. 0
4.,0
4..0
4.,0
4..0
4..0
4..0
4..0
4..0
3..9
3..9
3..9
3..9
3..9
3..9
3..9
3..9
3..8
3..8
3..8
3..8
3..8
3..8
3,.8
3..8
3 .6
3 .4
3,.4
3 .4
3,.3
3,.3
3 .3

LSD

1 .3

0 .9

1 .7

1 .7

0 .9

0.05

Quality based on a scale of 9 to 1 : 9 • best quality, 6 = acceptable quality,
and 1 - poorest quality.
Data were not collected in July and August due to complete dormancy during the
drought.

Table 3.

The 1988 quality ratings for the low-maintenance regional Kentucky bluegrass test
established in the fall 1980.

Cultivar

May

June

Aug

Mean

Vantage
Parade
3.
Kenblue
Argyle
-b. Piedmont
6. Escort
Jt. Cheri
Kimono
9. Birka
10. Monopoly
11. PSU-173
12. Plush
13. Dormie
14. Mosa
- W . A-34 (Bensun)
16. Bayside
17. K3-162
18. FyIking
19. PSU-190
20. Eclipse
21. K3-178
22. Kl-152
23. Ram-I
24. 243
25. Wabash
26. Trenton
27. Harmony
28. S.D. Common
29. Barblue
30. Enmundi
31. A20-6
32. Shasta
33- Merion
34. 239
35. S-21
36. WW Ag 478
37. Majestic
38. Merit
39. Charlotte
40. Mer pp 300
41. BA-61-91
42. Adelphi
43. PSU-150
44. Touchdown
American
,46. Vanessa
-47.' Cello

5.7
6.0
4.7
5.3
5.0
5.3
5.3
4.7
5.0
4.7
4.7
5.3
4.3
4.7
4.7
4.7
4.7
4.7
5.3
4.7
5.0
5.0
4.7
4.0
5.0
5.0
4.0
3.3
5.0
4.0
4.7
5.0
3.7
4.0
3.3
3.7
4.3
3.7
4.3
4.0
4.0
3.7
3.7
3.3
4.0
4.3
4.0

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

3.3
2.3
3.3
3.0
2.7
2.7
2.7
3.0
2.7
2.7
3.0
2.7
3.0
2.7
2.3
2.7
2.3
2.7
1.7
2.7
2.0
2.3
2.3

4.3
4.2
4.1
4.1
3.9
3.9
3.8
3.8
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.7
3.6
3.6
3.6
3.6
3.6
3.4
3.4
3.4
3.4
3.4
3.4
3.4
3.3
3.3
3.3
3.3
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.2
3.1
3.1
3.1
3.1
3.1
3.1

A.

'

3.6

1.7
2.0
2.7
3.0
1.7
2.3
2.3
2.0
2.7
2.3
2.3
2.7
2.0
3.0
2.3
2.3
2.3
2.3
2.7
2.3
2.3
2.0
2.0

Table 3.

JA.
.51.
,52.
53.
54.
.55.
-56:
57.
58.
59.
60.
61.
62.
63.
64.
65.
_66.
67.
68.
69.
70.
71.
72.
JA.
75.
76.
.-77.
Jfk.
79.
80.
8i.
„ 82.

JS84-;
*

The 1988 quality ratings for the low-maintenance regional Kentucky bluegrass test
established in the fall 1980. (continued)

Cultivar

May

June

Aug

Mean

Bonnieblue
Columbia
Apart
Mer pp 43
Mona
Enoble
NJ 735
Admiral
Aspen
MLM-18011
CEB VB 3965
Welcome
WW Ag 463
N535
Midnight
Sydsport
Lovegreen
Bristol
Victa
SH-2
K3-179
Glade
Baron
Rugby
SV-01617
Geronimo
Bono
A20
H-7
225
Nugget
WW Ag 480
A-20-6A
Banff
Holiday
P 141 (Mystic)
1-13

4. 0
4. 0
4.,0
4.,3
4..0
4.,3
4.,1
3..1
3..1
4.,3
4.,0
4.,0
4.,0
4.,3
4..0
4..0
3..3
4..0
4..3
4..7
3..3
3..7
3..7
3,.3
3,.3
3..3
4..0
2..7
3,.0
4,.0
3 .3
3 .3
3..3
3 .0
3 .0
3 .0
3 .3

3.,0
3.,3
3.,3
3.,3
3.,0
3.,0
3..0
3..0
3.,0
3.,0
3.,0
3.,0
3.,0
3..0
3.,0
3..3
3..0
3..0
3..0
2..7
3.•3
2..7
3..0
3..0
3..0
3,.0
3..0
3..0
2..7
3,.0
3 .0
3 .0
2 .7
3,.0
3 .0
3 .0
2 .7

2..3
2..0
2..0
1..7
2..3
2..0
1.,7
2.,7
2..3
1..7
2.,0
2..0
2..0
1..7
2..0
1..7
2..7
2..0
1..7
1..7
2..3
2..3
2..0
2..3
2..3
2..3
1..7
3..0
3..0
1..7
2..0
2..0
2,.3
2 .0
2 .0
2 .0
1 .7

3.1
3.1
3.1
3.1
3.1
3.1
3.1
3.1
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
3.0
2.9
2.9
2.9
2.9
2.9
2.9
2.9
2.9
2.9
2.8
2.8
2.8
2.7
2.7
2.7
2.6

LSD 0.05

N .S.

0 .7.

1 .0

0.7

Quality based on a scale of 9 to 1 : 9 = best quality, 6 = acceptable quality,
and 1 — poorest quality.
Data were not collected during July due to complete dormancy during the
drought. The study was terminated in late August.

N.E. Christians
Kentucky bluegrass (Poa pratensis L.) is the most widely used of the cool-season turfgrasses in the
northern United States. It can be found on lawns, golf course fairways and tees, cemeteries, parks,
school grounds, and other areas where a dense grass cover is desired. The reason for its widespread use is that it has a number of advantages over other alternative grasses.
Its primary advantage is its extensive rhizome system. Rhizomes are underground stems that
provide Kentucky bluegrass with its tremendous recuperative and reproductive capacity. Rhizomes
spread below the soil surface when environmental conditions are conducive to growth. If the
aboveground tissue is damaged in some way, new plants can develop from the buds on these
rhizomes and the turf area virtually repairs itself. Perennial ryegrass, chewing's fescue, and hard
fescue, which are sometimes used in combination with, or as an alternative to Kentucky bluegrass,
lack this rhizome system and the capacity for regrowth. Even tall fescue and creeping red fescue,
two alternative species that have rhizomes, lack the extensive systems of Kentucky bluegrass.
Kentucky bluegrass develops a high density turf stand, has excellent color, and mows more cleanly
than tougher bladed grasses such as perennial ryegrass. It also has a greater tolerance of cold
temperatures than either perennial ryegrass or tall fescue. When mowed at the correct mowing
height, 2 to 2.5 in, it is very competitive with weeds. Its tolerance of diseases is good when it is
properly managed.
A disadvantage of this species is its shallow root system and relatively high demand for water.
However, it has the ability to go dormant during extended droughts. A Kentucky bluegrass plant
can lose its leaf tissue and part of its root system, but the crown (the region at the soil surface from
which the new leaves arise) and the rhizomes can live for several weeks and regrowth will occur
when water is available. Some of the other cool-season grasses will remain green for a longer
period of time into a drought period, but none have the ability to recover that Kentucky bluegrass
displays when the drought ends.
More than 300 cultivars (cultivated varieties) of Kentucky bluegrass have been developed over the
past several decades. Each of the cultivars are genetically Kentucky bluegrass, but each has some
unique, reproducible characteristic that sets it apart from the rest. These differences include
variations in color, leaf angle, texture, and disease resistance, among others. These cultivars are
generally divided into two categories: common and improved.
The common types, or 'public varieties' as they are known in the turfgrass seed industry, are the
older cultivars or selections from older cultivars, most of which have been in use for many decades.
These common cultivars are characterized by an upright growth habit with a narrow leaf angle from
vertical, and a relatively high susceptibility to the fungal disease 'leaf spot' when they are intensely
managed. Their positive attributes include early spring greenup and relatively good tolerance of
environmental stress.
The improved types are newer releases, most of which have been selected or developed in the last
few decades. The first of these improved types to be released was Merion, which was selected
primarily for its tolerance of leaf spot. Since the release of Merion, many other improved cultivars of
Kentucky bluegrass have been selected and today there is a wide variety of these improved types
available on the market. As a group, the improved cultivars are known for their more prostrate
growth, a slower growth rate, and improved tolerance to a number of grass diseases.

For 25 to 30 years following the release of Merion, most research on Kentucky bluegrass adaptation
centered around the improved cultivars. These cultivars are well suited to the intense management
typified in this era of inexpensive irrigation water and heavy use of fertilizers. By the end of the
1970's, however, water shortages and the sharp increase in the cost of both water and fertilizer
began to turn more attention toward the selection of grasses that are better adapted to less intense
management regimes.
The United States Department of Agriculture (USDA) began extensive testing of Kentucky
bluegrasses at various locations around the country in 1980. For these tests, the USDA obtained
seed from grass breeders and seed distributors, divided the lots, and distributed them to
cooperators involved in turfgrass research. Data were collected monthly at each of the sites and
were compiled and summarized by the USDA at Beltsville, Maryland.
\Jn I980, 84 cultivars of Kentucky bluegrass were obtained from the USDA and were established in a
low-maintenance Kentucky bluegrass trial at the turfgrass research area at the Iowa State University
Horticulture Research Station at Ames, Iowa. Each cultivar plot was replicated three times in the
study. The area received 1 lb nitrogen (N)/1000 ft2 in September and received no other fertilization
during the year. The area was not irrigated. In 1981, a second lot of the same 84 cultivars was
obtained from the USDA and a high-maintenance trial was established on an adjacent site. This
study area received 4 lb N/1000 ft2 per year divided into four 1 lb treatments. This area was
irrigated as needed. Both areas were uniformly mowed at a 2 in mowing height and standard weed
control methods were used on both locations.
By 1983, an unexpected but interesting trend began to appear in the data from the two studies.
The 1983 season was unusually hot and dry and the grasses in the nonirrigated, low-maintenance
trial remained in a summer dormant condition for several weeks. The same 84 cultivars in the highmaintenance study were irrigated as needed through the summer and at no time were allowed to go
dormant. The trend involved in the data was a reversal in performance of the common and
improved cultivars in the studies (Table 4).
The cultivars acted as would be expected in the high-maintenance study. Improved types such as
Majestic, Midnight, and Glade ranked very high. The common types, such as Kenblue, South
Dakota Common, and S-21, that generally do not do well under intense management were ranked
near the bottom.
However, in the low-maintenance study, the opposite was true. Kenblue, South Dakota Common,
and S-21 ranked in the top five and many of the improved types ranked much lower. The reason
for the high ranking of the common varieties was the rapid recovery following dormancy. The
common types recovered and produced a green cover within 2 to 3 weeks following the latesummer rains, whereas many of the improved types required 4 to 8 weeks to recover and some did
not completely recover until spring. This same trend continued through the dry summers of 1984
and 1985 (Iowa State University Turfgrass Research Reports FG-451 and FG-452).
The summers of 1986 and 1987 were much wetter and the common types did not maintain the clear
advantage over the improved types in the low-maintenance trial, although they did rank in the upper
50% (ISU Turfgrass Research Reports FG-453 and FG-454). In 1988, the drought was so severe
that none of the cultivars in the low-maintenance test had recovered by fall. Recent observations in
the spring of 1989 found that the common cultivars were showing more rapid recovery than the
improved types, but all of the 84 Kentucky bluegrasses were showing significant damage from the
drought.
The 1988 drought did provide some good practical examples of how well the common types of
Kentucky bluegrass can survive drought. In many areas of the midwest, bluegrass turf remained in
a summer dormant condition for more than 10 weeks. It was the older parks, cemeteries, and lawns
that had been established years ago with common cultivars of Kentucky bluegrass that emerged
from the drought in the best condition. It was the improved cultivars that were killed by the drought.

The results from the 8 years of observations on the two studies should not have been so surprising
given the history of these grasses. Most of the common types were selected prior to World War II,
or were selected in later years from grasses commonly used in that time period, when low-intensity
management regimes were typically used. Less fertilizer was applied and irrigation was not widely
practiced. Kentucky bluegrass was popular because of its ability to avoid drought through
dormancy and to recover quickly in the late summer and fall. Those involved in selecting Kentucky
bluegrasses at that time would naturally choose the grasses that exhibited the best post-drought
recovery. The improved varieties were selected at a time when more intense management regimes
were becoming widely used and cultivars were selected more for their ability to tolerate diseases
and to provide a dense, dark green sward, than for their ability to recover in the fall. The
differences were always there, it was just that little attention was paid to them until the I980's.
(Jn 1985, a third Kentucky bluegrass trial was established at the Horticulture Research Station in an
area adjacent to the high- and low-maintenance studies. This trial was part of a new USDA study
that included 80 cultivars, many of which had been included in the earlier studies. This trial
received 4 lb N/1000 ft2/yr like the high-maintenance trial, but was irrigated. Weed control was
performed as in the other two trials. The management regime was meant to represent the
conditions that exist in many nonirrigated Kentucky bluegrass lawns in the northern region that are
treated by professional lawn care companies. These lawns are generally allowed to go into
dormancy in the summer and to recover in fall.
The 1985 study suffered some winter damage the first year and some reseeding was done in the fall
of 1986. Although some data were collected in 1987, the area did not fully mature and complete
data collection was not begun until the spring of 1988. The Kentucky bluegrasses in this highly
fertilized, nonirrigated trial went into summer dormancy in June 1988 because of the severe drought
and remained dormant until August. As was the case in the low-maintenance study in dry summers,
it was the common varieties that survived the drought in the best condition (Table 5). Kenblue and
South Dakota Common showed excellent recovery in October after a heavy rain in August, whereas
many of the improved types had not recovered by the end of the season.
The observations from these trials have resulted in some changes in Kentucky bluegrass cultivar
recommendations at Iowa State University. There was a time when the best cultivars from highmaintenance, irrigated trials were listed in extension bulletins and no distinctions were made as to
the type of area on which the grasses were to be used. This is no longer the case, and different
cultivars are recommended for high-maintenance areas than for low-maintenance areas.
(Vhe improved cultivars of Kentucky bluegrass are clearly the best choice when the area is to be
irrigated, or when natural rainfall is sufficient to prevent summer dormancy. Under intense
management regimes, the common cultivars prove to be disease prone and they will not perform as
well as improved types. However, if the area is to receive a less intense management regime and is
expected to go into summer dormancy during dry summers, the common cultivars will likely give
more satisfactory results. Parks, school grounds, cemeteries, grassed areas along airport runways,
low-maintenance home lawns, and other areas that may spend extended periods in dormancy would
be best suited to the common types. Cultivars currently recommended for high- and lowmaintenance areas are listed in table 6.
There are still questions that need to be answered and future recommendations will likely change as
more is learned. For instance, would the blending of seed from high- and low-maintenance cultivars
provide a quality turf that will better adapt to its environment? Over how wide a geographical area
do these observations apply? What is there about the structure and physiology of these lowmaintenance grasses that allow them to recover from dormancy so quickly? Further work will be
conducted on low-maintenance grasses. It is likely that an increased amount of attention will be
paid to this subject throughout the country as costs rise and the availability of water for turf irrigation
decreases.

Table 4. Kentucky bluegrass cultivar rankings for the low- and high-maintenance trials in 1983.
Number 1 is the top ranked cultivar in each study and number 84 is the bottom ranked
cultivar.

Cultivar
K3-162
Kenblue
S-21
Vantage
S.D. Common
Argyle
Ram-1
Vanessa
Mosa
Monopoly
PSU-173
Plush
Wabash
PSU-190
Piedmont
Victa
FyIking
Enmundi
Parade
Harmony
Mystic
Eclipse
Barblue
PSU-150
MLM-18011
WWAg478
BA-61-91
Baron
Charlotte
Apart
A-34
Mer pp 43
K3-179
Kimono
Dormie
Aspen
CEBVB3965
American
Mer pp 300
Enoble
Bayside
Escort

Lowmaint.
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

Highmaint.
80
84
73
79
77
60
6
49
46
82
21
41
78
15
75
18
19
8
57
58
50
12
13
14
25
29
38
22
27
48
61
71
64
10
43
24
11
59
36
62
39
32

Cultivar
Adelphi
Birka
Trenton
Touchdown
Welcome
Merit
Shasta
SLH-2
NH-735
Merion
Admiral
Cheri
239
SV-01617
Banff
Geronimo
WWAg463
Bono
Midnight
Sydsport
Lovegreen
K3-178
Kl-152
Rugby
Majestic
Bonnieblue
Glade
WWag480
Cello
N535
Mona
225
A20
H-7
Columbia
Bristol
243
Nugget
K3-179
Holiday
1-13
A20-6A

Lowmaint.
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

Highmaint
40
28
52
53
45
16
47
72
76
70
31
33
20
23
42
66
67
26
3
17
83
51
65
34
1
7
4
54
74
5
37
63
68
81
30
9
2
56
64
44
69
35

Table 5. The 1988 quality ratings for the nonirrigated, highly-fertilized Kentucky bluegrass trial
established in the fall of 1985.

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.

Cultivar

May

June

Sept

Oct

Mean

Kenblue
F-1872 (Freedom)
Aquila
Able I
South Dakota
Monopoly
Wabash
Rugby
Huntsville
WW Ag 496
Tendos
Somerset
Mystic
Loft's 1757
Aspen
WW Ag 495
NE 80-14
Joy
Victa
BA-70-242
K3-178
NE 80-47
Parade
Welcome
NE 80-110
Georgetown
BAR VB 534
Harmony
WW Ag 491
Haga
Baron
Cynthia
Destiny
Dawn
239
Julia
Challenger
Classic
BA-73-626
BA-72-441
BA-73-540
Liberty
Glade
Kl-152
Trenton
WW Ag 468
Barzan

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

5.0
4.7
4.7
3.3
4.3
4.0
4.3
4.0
4.7
4.0
4.3
3.7
4.0
4.0
3.7
4.3
3.7
4.3
3.3
3.3
3.7
4.0
4.7
4.3
4.0
4.3
4.7
4.0
4.0
4.0
4.0
3.3
3.7
4.3
4.0
4.3
3.3
4.0
3.7
3.3
4.0
3.3
4.0
4.0
4.0
4.0
4.3

6.0
4.3
5.7
6.3
6.3
4.7
5.3
4.3
5.3
5.0
4.3
4.7
6.0
4.7
6.0
4.7
5.7
5.7
5.7
5.3
4.7
4.7
2.7
4.3
5.0
3.7
3.7
4.3
4.0
3.3
4.0
5.0
5.0
4.3
3.3
3.7
5.0
3.0
4.3
3.7
3.3
3.7
4.0
3.0
2.7
4.0
3.0

6.7
5.3
6.0
5.3
6.0
5.0
5.3
5.0
4.7
4.7
5.3
5.0
5.0
4.7
5.7
4.3
5.0
5.3
5.3
5.0
4.0
4.7
3.7
4.7
4.0
3.3
4.3
4.7
5.0
3.7
4.3
4.7
4.7
4.3
3.7
3.7
4.3
3.3
4.0
4.3
3.3
4.0
4.3
3.3
3.7
4.0
3.7

5.4
5.3
5.3
5.1
5.1
5.0
5.0
5.0
4.9
4.9
4.8
4.8
4.8
4.8
4.8
4.8
4.8
4.7
4.7
4.6
4.6
4.6
4.5
4.5
4.5
4.4
4.4
4.4
4.4
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.3
4.2
4.2
4.1
4.1
4.1
4.1
4.1
4.1
4.1
4.0

Table 5. The 1988 quality ratings for the nonirrigated, highly-fertilized Kentucky bluegrass trial
established in the fall of 1985. (continued).

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.
LSD

Cultivar

May

June

Sept

Oct

Mean

Sydsport
Merit
Bristol
BA-69-82
HV 97
Eclipse
Nassau
Ikone
PST-CB1
Park
Gnome
A-34 (Bensun)
Annika
BA-72-492
NE 80-88
America
Blacksburg
NE 80-50
Ram-I
BAR VB 577
BA-70-139
BA-72-500
Merion
Amazon
NE 80-48
NE 80-55
P-104
Midnight
Asset
Cheri
Compact
Conni
NE 80-30

5. 0
5. 3
6. 0
6. 0
5. 0
4. 3
6. 0
5.,7
5.,0
4. 0
4. 3
6. 3
5.,0
6..3
4.,3
6.,0
5.,0
6..3
4..7
4..3
4..3
5..0
4..0
4,.7
5 .0
5..7
4..7
3 .7
4..7
4 .7
4 .3
4 .0
4 .7

3.,7
3.,7
3. 1
4. 0
4.,1
3. 3
3.,7
4. 3
3.,7
4..3
4..0
4..0
3..7
4..0
4..3
3..3
3.,3
4..0
3..3
3,.3
3..7
3 .7
3,.7
3,.7
3,.7
3,.3
4 .0
3 .0
3 .3
3 .7
3 .0
3 .7
3 .7

4. 0
3. 3
3. 0
3. 0
3. 0
3..7
3. 3
2. 7
3. 3
4. 0
3..7
2.,7
3..7
2..7
3..3
3..0
3..7
2..7
3..7
3..3
3..7
3..0
3..3
3..0
3..3
2..7
3.,0
3..7
2..7
2,.3
2,.7
2 .7
2 .3

3.3
3.7
3.3
3.0
3.3
4.7
3.0
3.3
4.0
3.7
3.7
2.7
3.3
2.7
3.7
3.3
3.7
2.7
3.3
4.0
3.7
3.7
4.3
3.7
3.3
3.3
2.7
4.0
3.0
3.0
3.0
3.0
2.7

4.,0
4. 0
4.,0
4.,0
4..0
4.,0
4..0
4.,0
4..0
4..0
3..9
3.,9
3.,9
3.,9
3..9
3..9
3..9
3..9
3..8
3..8
3..8
3,.8
3,.8
3 .8
3,.8
3,.8
3..6
3..4
3 .4
3,.4
3,.3
3 .3
3,.3

1 .3

0 .9

1.

1.7

0 .9

0.05

.7

Quality based on a scale of 9 to 1 : 9 = best quality, 6 - acceptable quality
and 1 — poorest quality.
All cultivars were dormant in July and August and no data were collected in
these months.

Table 6. Kentucky bluegrass cultivars recommended for high- and low-maintenance areas.

High-maintenance
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.

Midnight
Glade
Ram-1
Majestic
Enmundi
Bristol
Kimono
Merit
Bonnieblue
Eclipse
Holiday
Cheri
Barblue

14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.

Aspen
Escort
Mosa
Sydsport
Victa
Baron
Charlotte
Columbia
Mona
Adelphi
Vanessa
FyIking
Admiral

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

Rugby
Shasta
Bayside
Banff
Dormie
Trenton
Nugget
Enoble
Apart
Touchdown
Parade
Geronimo
Plush

Low-ma int enanc e
1.
2.
3.
4.
5.
6.
7.
8.
9.

Kenblue
S.D. Common
S-21
Vantage
Argyle
Plush
Vanessa
Parade
Wabash

10.
11.
12.
13.
14.
15.
16.
17.
18.

Piedmont
FyIking
Victa
Monopoly
Mosa
Ram-1
Harmony
Barblue
Kimona

The cultivars are ranked based on their performance over a 4-year period in
high- and low-maintenance trials at Iowa State University. The grasses that
are listed were chosen as the best from a group of 84 cultivars.
(Iowa Turfgrass Grower 12(3):2-3, 1988)

Growth and Morphological Characterization Study of
Low- and High-maintenance Kentucky Bluegrass Cultivars
M.G. Burt and N.E. Christians
Kentucky bluegrass (Poa pratensis L.) is the most extensively used cool-season turfgrass in the
United States. It is a very diverse species, and its cultivars are known to differ in many shoot
morphology, growth, and root growth characteristics. Since 1950, several hundred cultivars have
been selected, developed, and released into the turf seed market. These cultivars can be very
broadly classified as common and improved types. The common-type Kentucky bluegrasses were
not developed for turf-type characteristics. They were developed mainly for high seed production
capabilities and early seed maturation. Improved Kentucky bluegrasses were selected and
developed for more desirable turfgrass growth characteristics and improved disease resistance,
especially when subjected to lower mowing heights and higher fertility levels.
Data from Kentucky bluegrass studies at Iowa State University have shown that cultivars that
performed well in low-maintenance cultivar evaluations tend to perform poorly in the highmaintenance cultivar evaluations. Similarly, the cultivars that performed well in the high-maintenance
cultivar evaluations perform poorly in the low-maintenance cultivar evaluations. Ten Kentucky
bluegrass cultivars were chosen for this study based solely on their performance over several years
in the low-maintenance trial. Five cultivars were chosen that have consistently performed well in the
low-maintenance trial. These "low-maintenance' cultivars are K3-162, Kenblue, Vantage, South
Dakota Common, and S-21. Conversely, five cultivars were chosen that consistently performed
poorly in the low-maintenance trial. These "high-maintenance" cultivars are Bonnieblue, A20, 1-13,
Lovegreen, and Columbia.
The objective of this research was to determine if certain root and shoot growth and morphological
characteristics are common to Kentucky bluegrass cultivars defined as low- or high-maintenance
cultivars. This was accomplished by closely observing these ten cultivars in the field, greenhouse,
and laboratory. These cultivars were further studied in the greenhouse to determine if their root and
shoot growth characteristics changed when grown under low- and high-nitrogen (N) levels.
All field data were collected from the low-maintenance cultivar trial. Data included turf quality ratings
based on turf color and percent live green tissue and clipping yields. During the 1987 growing
season, the quality ratings of the low- and high-maintenance cultivars did not differ significantly until
mid-July. For the remainder of the growing season and for the growing season average, the lowmaintenance cultivars were rated higher. This was typical of what has been observed during most
of the past growing seasons. The 1988 growing season differed, however. The low- and highmaintenance cultivars did not consistently differ at any time during the growing season or for the
growing season average. This could be attributed to the severity of the drought experienced in
1988. None of the cultivars in the low-maintenance cultivar evaluation performed acceptably during
1988.
The first set of greenhouse experiments utilized a clear polyethylene tube in PVC pipe system to
closely monitor the root and shoot development of individual cultivar seedlings grown for 10 to 12
weeks in a fritted clay media with slow release fertilizer. The low- and high-maintenance cultivars
differed in many of the measured root and shoot growth characteristics. The low-maintenance
cultivars rooted to greater depths in the root profile and yielded greater clipping weights at all weeks
in all experiments. The low-maintenance cultivars produced greater total root mass, and greater root
mass in the 0 to 7 in and 7 to 14 in sections of the root profile. The low-maintenance cultivars
yielded a greater percentage of their total root weight in the 7 to 14 in section, and the highmaintenance cultivars yielded a greater percentage of their total root weight in the 0 to 7 in section

of the root profile. The low-maintenance cultivars were found to have a lower shoot to root ratio and
the shoot tissue of the low-maintenance cultivars contained proportionally less moisture. The lowand high-maintenance cultivars also differed in all measured shoot morphological characteristics.
The low-maintenance cultivars had narrower leaf blades, more leaf folding, longer leaf sheaths, a
greater leaf angle from horizontal, and fewer leaves per shoot.
Stomatal density count data was taken from field grown tissue harvested from the high-maintenance
cultivar evaluation. Nitrocellulose was painted on unmowed, randomly selected, recently emerged
leaf blades from each cultivar. When dry, the nitrocellulose layer was peeled from the leaf blade
surface and stomatal impressions were observed under the microscope. When averaged, the lowmaintenance cultivars were found to have fewer stomata on their abaxial leaf blade surface. But,
much variability was observed in abaxial stomata number among the high-maintenance cultivars.
This variability among the high-maintenance cultivars accounted for much of the variability among all
cultivars.
Another set of greenhouse studies was initiated to assess the effect of a low- and a high-N fertility
level on the root and shoot growth characteristics of low- and high-maintenance cultivars. The
polyethylene tube in PVC pipe system was again utilized, but a fine, washed sand was used as the
rooting media and essential plant nutrients were supplied by a low-N and a high-N nutrient solution.
As was observed in the previous greenhouse cultivar growth and morphology character- ization
study, the low- and high-maintenance cultivars differed in many of the same growth characteristics.
Further, these relative differences between the low- and high-maintenance cultivars did not change
when grown under the two N levels.
Kentucky bluegrass cultivars are known to differ in many shoot and root growth characteristics.
Observations from this investigation have shown that the differences in many of these characteristics
separate clearly into low- and high-maintenance groups. These differences between the low- and
high- maintenance cultivars appear to be real and measurable, and observations and data from the
field and the nutrient solution greenhouse study show these differences appear to be consistent
over high- and low-nitrogen fertility levels.
It is probably a combination of many adaptations that allow some Kentucky bluegrass cultivars to
out perform others when grown under low fertility, nonirrigated culture. The root production, root
distribution, low shoot to root ratio, and low shoot moisture content characteristics were found
consistently among the low-maintenance cultivars, and these characteristics are known drought
tolerance mechanisms. (These adaptations may best explain the reliable performance of these
cultivars under low fertility, nonirrigated management.
y^
The ultimate goal of cultivar development programs is to select and develop cultivars with desired
shoot characteristics that are well adapted to a wide range of management conditions and
environmental stresses. Unfortunately, the low-maintenance cultivars possess many undesirable
shoot growth and morphological characteristics. The identification of characteristics common to the
low-maintenance cultivars that have no effect on aesthetics, such as the rooting characteristics and
low shoot to root ratios, may be beneficial for the selection and development of improved Kentucky
bluegrass cultivars, and also for the identification of existing improved Kentucky bluegrass cultivars
more tolerant to a wide range of management practices and environmental conditions. JlQ^

Regional Perennial Ryegrass Cultivar Evaluation
R.W. Moore and N.E. Christians
(jhis is the sixth year of data from the trial established in the fall of 1982 in conjunction with several
identical trials across the country coordinated by the USDA. The purpose of the trial is to identify
regional adaptation of the 48 perennial ryegrass cultivars. Cultivars are evaluated each month of the
growing season for turf quality and disease.

2

The trial is maintained at a 2 in mowing height with 3 to 4 lb N/1000 ft through the growing season
and is irrigated when needed to prevent drought. Preemergence herbicide is applied once in the
spring and broadleaf herbicide is applied once in September to control weeds)
There are no statistical differences among the first 30 cultivars in Table 7. Notice that several of the
top performers in 1988 are experimental numbered cultivars. There has been a considerable
amount of breeding and selection of perennial ryegrasses conducted in the past decade and a
number of new releases of well adapted cultivars can be expected in future years. Note that some
of these numbered cultivars have been given names, in parenthesis.

Table 7. Turf quality of perennial ryegrass cultivars in 1988.
Ratings 3
Cultivar
-3:. Diplomat
2. 282 (Citation II)
3. Cupido
Omega
HE 168
Jr. Manhattan
Prelude
8. Blazer
2 EE (Cowboy)
IA 78 (Alistar)
GT-II (Repelí)
12. Palmer
13. LP 210
14. Ranger
15. WWE 19
16. Cockade
17. SWRC-1
18. Manhattan II
19. Pennant
BT-I (Tara) GT
LP 702 (Mondial)
"22. Regal
23. Birdie
Premier pfe¿t<u*L. ?

May

June

July

Aug

Sept

Oct

Mean

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

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

7..3
6.,0
7..7
7..0
6..7
7..0
7..0
6..3
6,.7
6.,3
7..3
6..7
6..3
7,.0
6,.7
6,.3
8,.0
7..0
6,.7
6,.3
6,.7
5,.7
6 .0
6 .0

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

7.,3
8.,0
7..0
7.,0
6.,7
7..3
6..7
7..3
7..0
7. 0
7.,0
6,.3
6,.7
6,.7
6..3
6..7
7..0
6..3
6..0
6..7
6..7
7..0
7,.0
6 .3

8. 0
8.,3
8..0
7..7
7..3
7..7
7..0
7..3
7..7
8,.0
7,.7
7,.7
7,.7
7..3
7..3
7..3
7..3
7..3
7,.0
7..5
7..3
7,.7
7,.3
6,.3

7.3
7.3
7.1
7.0
6.9
6.9
6.8
6.8
6.8
6.8
6.8
6.7
6.7
6.7
6.7
6.7
6.7
6.6
6.6
6.6
6.5
6.5
6.5
6.4

Table 7. Turf quality of perennial ryegrass cultivars in 1988. (continued).
Ratings*
Cultivar
25. Derby
-26 Crown
J2r7. Fiesta
Gigil
-2V. HR-1
30. Barry
Yorktown II
-32. LP 736 (Ovation)
'33. LP 792
.34. 2ED (Birdie II)
35. Delray
36. HE 178
37. M 382
38. Dasher
39. NK 80389
40. NK 79307
41. NK 79309
42. Acclaim
'43. Citation
44. Pennfine
45. Gator
46. Pippin
47. Elka
48. Linn
Experiment Mean
LSD
a

0.05

May

June

July

Aug

Sept

Oct

Mean

5..3
6..3
6..3
5..0
7.,0
6..0
5.,7
6..3
5..7
6..3
5..3
5..7
4..7
5..3
5..0
6..0
4..7
6..0
5..0
4..7
5..3
4..3
5..3
4..7

7..0
6..0
7..0
6..0
6..0
6..7
6..3
6..3
6..3
5..3
6..3
7..0
5..3
5..3
5..3
6..0
6..3
7,.0
6..0
6..3
6..0
6..3
6..3
6..3

6..3
6..7
5..7
7..0
6,.7
6..0
7..0
6..0
6..3
6..7
5,.7
5..7
7..3
6..0
6..7
5..3
6..3
6..3
5..7
5..7
6,.0
6..3
6..0
5..7

6,.0
6..3
5..7
6..3
6.,0
6..3
6..0
6..0
5..3
5..7
6..3
5..7
6..0
7..0
5..7
6..3
6..3
4,.7
6 .3
5,.7
5,.7
5 .7
5 .0
5 .3

7..0
6,.0
6..3
6..0
6..0
6 .0
5,.7
6 .0
6..0
6..3
6 .0
5,.7
6,.0
6,.0
6,.0
5,.7
5,.7
5,.3
5,.7
6,.3
5..7
5,.7
5 .3
5 .3

6..7
6..7
7..0
7..3
6.,3
6..3
6..7
6..7
7..3
6,,7
7..3
6,.7
7..3
6..3
7.,3
6..7
6..7
6..3
7.,0
6..7
6..7
7..0
6..3
6..0

6.4
6.3
6.3
6.3
6.3
6.2
6.2
6.2
6.2
6.2
6.2
6.1
6.1
6.0
6.0
6.0
6.0
5.9
5.9
5.9
5.9
5.9
5.7
5.6

5.8

6.6

6.5

6.2

6 .4

7.1

6.4

1.2

1.5

1.1

N.S.

1 .4

1.2

0.7

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

—

acceptable

R.W. Moore and N.E. Christians
This is the sixth year for the fine fescue cultivar trial established in the fall of 1982. The purpose of
the trial is to identify regional adaptation of the 32 fine fescue cultivars and blends in a full sun
exposure. Cultivars are evaluated each month of the growing season for turf quality.
The trial is maintained at a 2 in mowing height with 3 to 4 lb nitrogen (N)/1000 ft 2 through the
growing season and is irrigated when needed to prevent drought. Preemergence herbicide is
applied once in the spring and broadleaf herbicide is applied once in September to control weeds.
Banner/Checker, Shadow, Atlanta, Koket, and Scaldis/Atlanta were the best cultivars under these
conditions in 1988 -fPable-6); Most of the top ten cultivars in 1988 have consistently rated in the top
ten over the past six years of this study. Many of the cultivars have allowed the encroachment of
Kentucky bluegrass since 1982. Tournament, Pennlawn, NK 79190, NK 79191, NK 80345, NK 80347,
NK 80348, and Duar had 20 to 80% Kentucky bluegrass in two or three of their replications. This
may be due to a lack of competitiveness with Kentucky bluegrass. There also may have been some
contamination of the experimental cultivars with bluegrass seed at the time of establishment.
This trial will be eliminated in 1989. A new shade study that includes many of the fine fescues was
established in the fall of 1987. j

Table 8. Turf quality ratings of fine fescue cultivars and blends in 1988.
Ratings*
Cultivar

May

June

July

Aug

Sept

Oct

Mean

Banner/Checker
Shadow
Atlanta
z.
Koket
Jr.
Scaldis/Atlanta
Agram
<fy . Banner
TOF^WC
Jamestown
10. Checker
Ruby
JL2-. Barfalla
Pennlawn
14. Aurora
Ensylva
-16- Dawson
IX. Dawson/Pennlawn
18. Waldina
Highlight
-20. NK 80346
21. Biljart
22-, Scaldis
23. NK 79190
24. NK 79189
25^ Wintergreen
26. NK 79191
27. Fortress
28. NK 80347
29. Duar
30. NK 80348
31. Tournament
32. NK 80345

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

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

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

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

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

8.0
7.7
7.3
7.3
7.7
6.7
6.7
6.3
6.7
7.3
6.7
7.3
6.7
6.3
6.3
6.7
6.7
6.0
6.3
6.0
6.0
6.3
5.7
5.3
6.0
5.7
5.7
5.7
5.3
5.7
5.0
5.0

7.2
6.9
6.8
6.7
6.7
6.6
6.6
6.5
6.5
6.5
6.4
6.3
6.3
6.2
6.2
6.2
6.2
6.1
6.0
5.9
5.7
5.6
5.6
5.5
5.4
5.4
5.3
5.3
5.3
5.3
5.2
5.1

LSD = 0 . 0 5

1.2

1.1

N.S.

2.1

1.8

1.7

1.2

1.

a

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

N.E. Christians and R.W. Moore
The fine fescue management study includes the following cultivars:
1.
2.
3.
4.
5.

Pennlawn Red Fescue
Scaldis Hard Fescue
Ruby Red Fescue
Atlanta Chewings Fescue
K5-29 Red Fescue

6. Dawson Red Fescue
7. Reliant Hard Fescue
8. Ensylva Red Fescue
9. Highlight Chewings Fescue
10. Jamestown Chewings Fescue

Each cultivar is maintained at two mowing heights: 1 and 2 in. Each plot is divided into two fertilizer
treatments: 1 and 3 lb nitrogen (N)/1000 ft2, applied as IBDU. Each plot is irrigated as needed. The
study was established on September 8, 1979.
The quality ratings in table 9 are the means of monthly ratings taken on replicated plots from May to
October. Again this year, Reliant and Scaldis hard fescue and Jamestown chewings fescue had the
best overall quality (Table 9).
These same three grasses performed satisfactorily even under the extreme conditions of a 1 in
mowing height and 1 lb N/1000 ft2/year. This is particularly impressive considering this was the
tenth season for this study. There has been no overseeding during that 10 year time period. Some
of the other lower rated grasses are being overtaken by creeping bentgrass and other species, but
these three grasses have resisted any encroachment from weeds.
Table 9. The effects of mowing height and nitrogen fertilizer on the quality of 10 fine fescues in
1988.

Mowing Height
1 inch
2 inch
N Rate
N Rate
1 lb a
3 lb
1 lb
3 lb
1. Pennlawn Red Fescue
-T. Scaldis Hard Fescue
3. Ruby Red Fescue
Atlanta Chewings Fescue
5. K5-29 Red Fescue
6. Dawson Red Fescue
7. Reliant Hard Fescue
8. Ensylva Red Fescue
9. Highlight Chewings Fescue
10. Jamestown Chewings Fescue

4.9 b ' c
6.7
4.2
5.6
4.4
4.7
7.3
4.9
3.1
6.2

4.9
7.1
4.4
5.1
4.1
4.8
7.2
4.8
3.1
6.2

4.7
6.7
4.8
5.6
4.8
5.2
7.1
5.1
3.6
6.0

4.9
6.8
5.2
5.3
4.2
5.4
7.0
5.2
3.2
6.2

Overall
Mean
4..9
6,.8
4..7
5.,4
4..3
5..0
7..2
5..0
3..3
6..2

2
N rates are in lb N/1000 ft /yr. The N source is IBDU.
k Values are the means of monthly observations from May to October.
c
Quality based on a scale of 9 to 1: 9 - best quality, 6 - acceptable
quality, and 1 « poorest quality.
a

M.L. Agnew and N.E. Christians
The 65 tall fescue cultivars were established in the fall of 1987 at the+torticulture Research Station,
The study is maintained at a 2 in mowing height and fertilized with 2 lb N/1000 ft2/yr. The area is
unirrigated and receives no fungicide or insecticide applications.
The data presented in table 10 reflects recovery following the drought of 1988. Sixty-three of the 65
cultivars adequately recovered from the drought. Monthly data will be collected in future years.
Table 10. Quality rating of Tall Fescue following drought (October 1, 1988).
Tall Fescue
Cultivar
Mesa
—2"7 Normarc 25
- s r Trailblazer
Hubbard 87
—5". Tribute
Williamette
Finelawn 5GL
— e r KWS-BG-5
9. PST-50L
PE-7
11. Syn Ga
-JÄ-T Trident
Legend
Normarc 99
JJrr
Pick GH6
Wrangler
J * .
Carefree
PE-7E
PST-5AP
,20. KWS-DUR
Pick 845PN
Jtir.
Jaguar II
Arid
Rebel II
-257 Thoroughbred
PST-5F2
Monarch
Adventure
PST-DBC
PST-5EN
Tip
J*-as-. Taurus
Normarc 77
—34r. Jaguar

tt-.

Visual
Quality
8.0
8.0
8.0
8.0
8.0
8.0
8.0
7.7
7.7
7.7
7.7
7.7
7.7
7.7
7.7
7.7
7.7
7.7
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.3
7.0
7.0
7.0
7.0
7.0
7.0

Tall Fescue
Cultivar

-è*.
^ r .
JAr.

j a .

xs&r.

PST-50L
Apache
Rebel
JST.
^èfff.
JB-2
Finelawn I
BAR Fa 7851
"St. Fatima
Falcon
—•TT. Olympic
Pacer
PST-5AG
Pick SLD
Richmond
Pick DM
J&.
Aztec
Cimmaron
r. Titan
-5T. PST-5BL
--5T. PST-5DM
Chieftan
— 5 5 7 PST-5D1
— 5(r. Bel 86-1
—ST: Ky-31
Pick TF9
Sundance
Bel 86-2
Pick 127
J&.
PST-5HF
—
Bonanza
PST-5D7
Pick DDF
LSD (0.05)

Visual
Quality
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
7.0
6.7
6.7
6.7
6.7
6.7
6.7
6.7
6.7
6.7
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.3
6.0
6.0
5.3
5.0
1.2

R.W. Moore and N.E. Christians
This is a report of the fifth year of data from the experiment. It is|d£signed to compare the
response of Falcon^Houndog, Kentucky 31, Mustang, and Rebel tall fescue at 0-, 2-, and 4-lb
nitrogen (N)/1000 ft /yr and cutting heights of 2 and 3 in. One pound of N was applied once during
each month of May and September for the 2-lb treatment and during April, May, August, and
September for the 4-lb treatment. In the strip-split plot arrangement, all six combinations of the two
management factorsj*re placed in a 2 ft by 3 ft block within each cultivar with the five cultivars
replicated three times.
The 3 in cut resulted in higher quality turf for all cultivars ^Cabte-44). Turf quality increased with
each increment of N for all of the cultivars at both mowing heights. Each cultivar performed best at
a 2 in mowing height and 4 lb N/1000 ft2/yr. The 3 in cut appeared to respond better to the
drought in 1988 than the 2 in cut.
Mustang was the best cultivar under higher maintenance conditions in 1988. In general, each of the
turf-type cultivars performed better than Kentucky 31.

Table 11. Turf quality of tall fescue cultivars at two clipping heights arid three fertility levels in 1988.

Cultivar

Clip
Hgt
inch

Ratingsc

lb N/
1000
ft 2

May

June

July

Aug

Sept

Mean

Mustang

2
2
2
3
3
3

0
2
4
0
2
4

5.0
6.7
8.3
4.3
6.7
8.7

6.3
6.3
8.0
6.7
6.3
8.0

5.0
5.7
6.7
5.0
6.0
7.0

5.0
6.0
7.0
5.0
6.0
7.0

0..0
0,.0
0 .0
0..0
0..0
0,.0

5.3
6.2
7.5
5.3
6.3
7.7

Houndog

2
2
2
3
3
3

0
2
4
0
2
4

4.7
7.0
8.0
4.3
7.0
8.3

6.0
7.0
8.0
6.0
7.0
8.0

5.3
5.3
7.0
5.3
5.0
7.0

5.0
5.7
6.7
5.0
6.0
7.0

4..7
5..7
6..0
4..3
5..3
6..0

5.1
6.1
7.1
5.0
6.1
7.3

Rebel

2
2
2
3
3
3

0
2
4
0
2
4

5.0
6.7
7.7
4.0
6.7
8.3

6.0
7.0
8.0
6.0
7.0
8.0

5.3
5.7
6.7
5.0
5.7
6.7

5.0
6.0
7.0
5.0
6.0
7.0

4..3
5 .7
5..7
4..7
5..3
6,.0

5.1
6.2
7.0
4.9
6.2
7.2

Falcon

2
2
2
3
3
3

0
2
4
0
2
4

4.7
6.7
8.3
4.3
6.3
8.0

6.0
6.7
7.7
6.0
7.0
8.0

5.3
5.7
7.0
5.3
6.0
7.0

5.3
6.0
7.0
5.3
6.0
7.0

4.,7
5..3
6..0
5..0
5..3
6..0

5.2
6.1
7.2
5.2
6.1
7.2

Kentucky
31

2
2
2
3
3
3

0
2
4
0
2
4

4.7
6.0
8.7
4.7
7.0
8.3

6.0
6.7
7.7
6.0
7.0
7.7

5.0
5.7
6.7
5.0
5.7
6.7

5.0
6.0
7.0
5.0
6.0
7.0

4..3
5..3
5..7
4..3
5..0
5..7

5.0
5.9
7.1
5.0
6.1
7.1

0.3
0.8

0.2
0.3

0.5
0.1

0.2
0.6

.6
.5

0.2
0.8

LSD cultivar averages
LSD managements
a

Quality based on a scale of 9 to 1: 9
quality, and 1 - poorest quality.

0.
0.

best quality, 6 = acceptable

N.E. Christians
The shade adaptation study was established in the fall of 1989 to evaluate the performance of 35
species and varieties 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 (Poa trivialis).
The area is located under the canopies of a mature stand of Siberian elm trees at tee Horticulture
Research Station. The grasses are mowed at a 2 in height and receive 2 lb nitrogen (N)/1000
ft2/year. No weed control has been required on the area. Irrigation was used during the fall of 1987
and through the summer of 1988. No irrigation is planned for the area in future years.
Data collection did not begin until full establishment of the plots in June. Monthly quality data were
taken through October. Of the first 20 cultivars, 16 were fine fescues (either C.R.F., C.F., or H.F.),
three were tall fescues, and one was a rough bluegrass (Poa trivialis) (Table 12). Estica C.R.F. was
the highest rated cultivar in 1988. Ram-I was the only Kentucky bluegrass that maintained season
long acceptable quality. The five most poorly adapted species were all Kentucky bluegrasses.
Reliant hard fescue was sodded in May 1988 and deteriorated in quality during the season due to
the drought.
This was the first year of the study. Itis anticipated that the ranking order of grasses will change in
future years as further maturity occurs.?

Table 12. Turf quality ratings of shade trial in 1988. (Seeded in Fall 1987)
Cultivar
Estica
(C.R.F.)
Spartan
(H.F.)
Victor
(C.F.)
Jr. St-2 (SR 3000)
(H.F.)
Ensylva
(C.R.F.)
Waldina
(C.F.)
^f. Banner
(C.F.)
Shadow
(C.F.)
Jamestown
(C.F.)
¿<r. Biljart
(H.F.)
Pennlawn
(C.R.F.)
(C.F.)
¥Z. Agram
(T.F.)
. 13. Rebel
y*. Apache
(T.F.)
15: Atlanta
(C.F.)
16. Falcon
(T.F.)
. Art".
Scaldis
(H.F.)
Ur. Sabre (Poa trivialis)
IT. Koket
(C.F.)
J2&. Mary
(C.F.)
Ram 1
(K.B.)
22. Wintergreen
(C.F.)
Waldorf
(C.F.)
24. Rebel II
(T.F.)
•25. Arid
(T.F.)
26. Bonanza
(T.F.)
27. BAR Fo 81-225
(H.F.)
28. Chateau
(K.B.)
-2T. Reliant
(H.F.)
3a. Highlight
(C.F.)
31. Glade
(K.B.)
Coventry
(K.B.)
33. Bristol
(K.B.)
-34T. Nassau
(K.B.)
35. Midnight
(K.B.)
4 :

LSD

0.05

June

July

Aug

Sept

Oct

Mean

8.0
7.7
7.7
8.0
7.0
6.7
7.0
7.7
7.0
6.7
7.3
7.3
6.7
6.0
7.0
6.0
7.3
6.7
7.3
6.7
5.7
6.3
6.3
5.0
4.3
5.0
4.7
4.7
8.0
5.0
4.0
4.3
4.3
4.3
2.3

7. 0
7. 3
7. 3
7. 3
6. 3
6. 7
6. 7
7. 0
5. 7
5. 7
6. 7
6. 0
5. 0
5. 0
6. 3
4. 7
6. 0
5. 7
6. 7
5. 3
5. 3
5. 7
5. 3
4. 3
4.,3
4. 3
5.,3
3.,7
6.,0
4.,0
3..3
3..3
3..0
3..0
2..0

7.7
7.3
6.3
7.0
7.0
7.0
6.3
6.3
6.3
6.7
5.7
6.3
7.3
7.3
6.0
7.7
6.0
6.0
5.7
5.7
6.7
5.7
5.7
6.7
6.7
6.3
5.7
6.0
3.3
5.0
6.0
5.0
5.3
4.3
2.0

7.7
7.7
7.0
6.3
7.3
7.0
6.3
6.3
6.7
6.3
6.3
6.0
7.3
7.7
6.7
8.0
6.0
7.0
5.3
6.3
6.7
6.0
6.0
7.3
6.7
6.7
6.3
6.3
4.3
5.3
6.7
5.3
5.3
5.0
2.7

8.0
8.0
8.0
7.7
8.0
8.0
8.0
7.3
7.7
8.0
7.3
7.7
7.3
7.3
7.0
6.7
7.0
6.7
6.7
7.7
6.7
6.7
7.3
6.7
7.0
6.7
6.7
6.3
5.0
6.0
5.7
6.3
6.0
4.7
3.0

7.7
7.6
7.3
7.3
7.1
7.1
6.9
6.9
6.7
6.7
6.7
6.7
6.7
6.7
6.6
6.6
6.5
6.4
6.3
6.3
6.2
6.1
6.1
6.0
5.8
5.8
5.7
5.4
5.3
5.1
5.1
4.9
4.8
4.3
2.4

1.3

1..6

2.0

1.8

1.4

1.2

Quality based on a scale of 9 to 1: 9
and 1 = poorest quality.
T.F.
C.F.
H.F.
C.R.F.

-

Tall Fescue
Chewings Fescue
Hard Fescue
Creeping Red Rescue

best quality, 6 - acceptable quality,

of Dollar Spot on Penneagle Bentgrass - 1988
M.L. Gleason
Trials were conducted on the Turfgrass Research Plots at the Horticulture Research Station of Iowa
State University near Ames, Iowa. Fungicides were applied to Penneagle bentgrass maintained at a
5/32 in cutting height with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2.
The experimental design was a randomized complete block plan with four replications. Treated plots
were alternated with untreated plots, so that treated plots did not adjoin each other.
All plots measured 4 ft by 5 ft. Fungicides were applied on a 14-, 21-, or 28-day schedule (Tafete
Applications began on June 7 and continued through August 15. Plots were evaluated for
severity of leaf spot symptoms on July 20 and August 19. Disease ratings for dollar spot were
made by counting the number of dollar spot infection centers per plot. No disease developed until
August 19, when one dollar spot appeared in two of four check plots. Disease pressure was thus
insufficient to make meaningful comparisons among treatments for control of dollar spot.
On July 20, a slightly enhanced green color of turf was noted for SAN 619F at 0.2 g and 0.3 g
"treatment levels and 21-day spray interval. All three treatments of Spotless 25W showed more
pronounced browning qf turf than SAN 619F on August 19; however, the degree of browning was
still slight to moderate.

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of Brown Patch on Bentgrass - 1988
M.L Gleason
Trials were conducted on two adjoining bentgrass greens at Veenker Golf Course at Iowa State
University, Ames, Iowa. (Fungicides were applied to bentgrass maintained at 5/32 in 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 plan with four replications. Treated plots were alternated
with untreated plots, so that no treated plots were adjacent to each other. All plots measured 4 ft
by 5 ft. Fungicides were applied on a 14-, 21-, or 28-day schedule {Table 44). Applications began
on June 7 and continued through August 15. Brown patch symptoms appeared on about July 16.
Plots were evaluated for percent of diseased turf on July 19 and August 19J
Brown patch development on July 19 was severe on check plots. By August 19, disease
development on check plots was light to moderate. Several treatments had brown patch
development that was not significantly less than the check plots. Of these, the most consistently
ineffective product was Terraneb SP at the rates tested. Most treatments reduced brown patch
symptoms significantly below levels in check plots, and nine of these treatments gave 100%
suppression of brown patch on both rating dates.
Several treatments produced a slightly enhanced green color in the turf on both rating dates. These
included: SAN 619F, SAN 832F at both rates, and ICIA 0523 at both rates. Spotless 25W, at the
0.25 a.i. rate and both 14- and 21-day treatment intervals, caused a slight browning of the turf in

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Evaluation of Fungicides for Control
of Leaf Spot on Park Bluegrass - 1988
M.L. Gleason
Trials were conducted on the Turfgrass Research Plots at the Horticulture Research Station of Iowa
State University near Ames, Iowa. Fungicides were applied to Park bluegrass, maintained at a 2 in
cutting height, with a modified bicycle sprayer at 30 psi and a dilution rate of 5 gal/1000 ft2. The
experimental design was a randomized, complete-block plan with four replications. Treated plots
were alternated with untreated plots, so that treated plots did not adjoin each other. All plots
measured 4 ft by 5 ft. Fungicides were applied on a 7-, 14-, 21-, or 28-day schedule fFable-45).
Applications began on June 7 and continued through August 15. Plots were evaluated for severity
of leaf spot symptoms on July 20 and August 19.
Leaf spot was present at very low (trace) levels on both rating dates. Although two treatments had
leaf spot levels significantly below the check on July 19, disease pressure was insufficient to make
meaningful comparisons among treatments for leaf spot control on either rating date. No
phytotoxicity symptoms were noted on either rating date.

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of Dollar Spot on Park Bluegrass - 1988
M.L. Gleason
Trials were conducted on the Turfoj^ss Research Plots at the Horticulture Research Station of Iowa
State University near Ames, Iowa, f Fungicides were applied to Park bluegrass maintained at a 2 in
cutting height with a modified bicyCIe sprayer at 30 psi and a dilution rate of 5 gal/1000 ft 2 . The
experimental design was a randomized block plan with four replications. Treated plots were
alternated with untreated plots, so that treated plots did not adjoin each other. All plots measured
4 ft by 5 ft. Fungicides were applied on a 7-, 14-, 21-, or 28-day scheduie-(Tabte~+6). Applications
began on June 7 and continued through August 15. Plots were evaluated for severity of disease
symptoms on July 20 and August 19.
NOTE: The trial was set up and fungicides were selected for control of leaf spot. However, dollar
spot also appeared during the trials. Development of dollar spot is rated in this report.
Dllar spot appeared in early July. Disease pressure was very low on the first rating date, and low
iu moderate when the second rating was made. Symptoms took the form of generalized browning
and yellowing within plots, rather than the infection centers that often typify dollar spot outbreaks.
Two treatments, Dyrene 4F at the 4 oz rate and Chipco 26019 FLO at the 4 oz rate, did not
suppress disease development significantly better than the check treatment. All other treatments
gave control that was significantly better than the check during at least one of the rating periods.
The best disease suppression over both rating times was obtained with: Spotless 25W at 0.4 oz
a.i., 14-day interval; 3336 F, 8 oz rate, 14-day interval; and Prochloraz 40 EC, 4.5 oz rate, 14-day
interval. No phytotoxicity symptoms were observed during either rating time.

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Reactions of Creeping Bentgrass Cultivars
to Dollar Spot - 1987-88
M.L. Gleason and N.E. Christians
Three creeping bentgrass cultivars were sown June 4, 1985, in a study originally designed to
evaluate effects of Pythium root dysfunction. The experimental design was a split plot, randomized,
complete-block design, in which main plots (20 ft by 60 ft) were Pythium treatments and subplots
(6.7 ft by 20 ft) were cultivars. Prior to seeding, the entire plot was rototilled; materials incorporated
into main plots were Pythium arrhenomanes growing on 50 kg cornmeal, 50 kg cornmeal alone, or
no added material. The substrate consisted of 80% mason sand, 10% soil (Nicollet, fine-loamy,
mixed mesic), and 10% hypnum peat. The turfgrass was maintained at 5/32 in cutting height and
fertilized with 3 lb nitrogen (N)/1000 ft2/yr. The plots were irrigated, and a single application of a
fungicide (Chipco 26019, 2 oz/1000 ft2) was made immediately after the 1987 rating date. Dollar
spot evaluations were made using a visual rating system)where 0 = no disease, 1 = 0 to 2%
coverage by dollar spots, 2 = 2 to 5% coverage, 3 = 5 to 10%, 4 = 10 to 20%, 5 = 20 to 30%, 6
= 30 to 40%, 7 = 40 to 50%, 8 = 50 to 70%, and 9 = 70 to 100%. Weather preceding the
evaluations was warm and moist in 1987 and hot and dry in 1988: \
Development of dollar spot was moderate to severe in 1987 and light in 1988. Significant
differences between cultivars were observed in both years. No symptoms of P. arrhenomanes
infection appeared at any time, and there was no significant effect of Pythium treatment on
development of dollar spot and no significant treatment x cultivar interaction (ANOVA, P = 0.05).
Table 17. Disease rating of dollar spot on three creeping bentgrass cultivars.

Cultivar

Disease Rating (Dollar Spot)*
Jul 24, 1987
Aug 26, 1988

Penncross

5.1 a

1.1

Penneagle

3.7b

Emerald

5.7 a

2.7 a

LSD (P - 0.05)

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b

1.1b

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Means followed by the same letter are not significantly different according
to the LSD test (N = 9).

Preemergence Annual Grass Control Study - 1988
M.G. Burt and N.E. Christians
The 1988 preemergence annual grass control study was located at the Horticulture Research Station
on a Park Kentucky bluegrass turf that had been established on a Nicollet (fine-loamy, mixed mesic,
Aquic Hapludall) soil with a pH of 7.2, 15 lb/A phosphorus, 120 lb/A potassium, and 2.3% organic
matter.
The area had a natural stand of crabgrass in the 1987 growing season. However, to assure
sufficient weed pressure, the turfgrass on the plot area was mowed at 1 in, the area was vertical
mowed, and seeded with crabgrass at a rate of 0.5 lb/1000 ft 2 on April 14, 1988.
The treatments included Balan, Team, and Gallery from Elanco, Dacthal from Fermenta; Bensulide
from Stauffer; Prodiamine from Sandoz Chemical; Pendimethalin from Lesco; Weedgrass Control,
Turf Weedgrass Control, and Turf Fertilizer (34-4-4) + Pre-E from O. M. Scott; DFF and Ronstar from
Rhone-Poulenc; Mon 15151 from Monsanto; and Crab-Spray with Team from Spring Valley. fFabte18)*.
Treatments were applied to 25 ft2 plots in three replications on April 15,-4988-in the equivalent of 3
gal water/1000 ft2. The repeat application of Ronstar ffteatmont 10} was made on May 24. The __
repeat applications of Team, Pre-M, and Balan fTreSTrYiSnTS^rSr-B) were made on June 16, 19887]
The 1988 growing season was unusually dry and hot. The area was irrigated to keep the bluegrass
from going dormant, but the dry conditions resulted in very little late summer crabgrass germination.
The crabgrass and Oxalis counts were made only on August 1, 1988. No change in weed
infestation was observed by September, and no additional ratings were required at that time.
fMany treatments provided very effective season long crabgrass control. These included Gallery at
both rates, and Gallery in combination with Team and Pre-M, Balan, Team, Prodiamine at both rates,
Bensulide, Turf Fertilizer (34-4-4) + Pre-E, Turf Weedgrass Control, Ronstar in both formulations, and
Mon 15151 at the four highest rates.
Several treatments in the study provided unacceptable crabgrass control. These included Dacthal,
Pendimethalin, Weedgrass Control, DFF, Mon 15151 at the three lowest rates, and the Spring Valley
'Team' products.
No significant treatment differences were found in control of Oxalis. No phototoxicity was observed
on any of the treated plots at any time during the season.j

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Postemergence Annual Grass Control Study - 1988
M.G. Burt and N.E. Christians
The 1988 postemergence annual grass control study was located at the Horticulture Research
Station on a stand of Park Kentucky bluegrass. The soil on the site is a Nicollet (fine-loamy, mixed
mesic, Aquic Hapludall) with a pH of 7.2, 15 lb/A phosphorus, 120 lb/A potassium, and 2.3 percent
organic matter.
The turfgrass on the plot area was mowed down to 1 in, and the area was overseeded with
crabgrass at a rate of 0.5 lb/1000 ft 2 on April 28. At time of treatment application, the area had a
uniform stand of crabgrass at the 3-leaf to 1-tillersfage.
Treatments included American Hoechst's Acclaim in the EC and EW formulations, and an
experimental - HOE 360. Acclaim 1 EC also was used in combination with Turflon amine, Breakthru,
and dicamba. Other treatments included a Monsanto experimental Mon 15151 alone and in
combination with Acclaim 1EC, and the BASF experimental BAS 51400H alone and in combination
with Acclaim 1EC (Table f9).
The herbicides were applied on June 16, 1988. All treatments were applied in the equivalent of
3 gal water/1000 ft 2 with the exception of the Acclaim EC, Acclaim EW, HOE 360, and Acclaim in
combination with Breakthru, Turflon amine, and dicamba, which were applied in the equivalent of
130 gal water/A.
No phytotoxicity was observed on any of the plots during the trial.
The crabgrass count was taken on August 1, 1988. A second crabgrass count was planned in
September, but due to the extreme summer drought there was very little late summer crabgrass
germination so a second count was not necessary.
The only treatments providing adequate or near adequate crabgrass control were the experimental
from BASF at the high rate alone and in combination with Acclaim, and the Mon-15151 at both rates
and in combination with Acclaim.
The less than favorable summer moisture levels resulted in poor postemergence crabgrass control
by many of the products in this study. Acclaim in both formulations, at all rates, and in combination
with the broadleaf herbicides provided little crabgrass control. The experimental HOE 360 at each
rate, and the BAS 51400H at the lowest rate also provided little crabgrass control. The crabgrass
control for the MON 15151 improved as the chemical rate increased, but inadequate crabgrass
control was obtained at all rates up to 0.75 lb. a.i./AJ

Table 19. Postemergence annual grass control study - 1988.

Rate
(lb ai/A)

Treatment

August 1
Percent
crabgrass
control

1.

Control

2.

Acclaim 1EC

0. 18

30

3.

Acclaim

0.5 EW

0. 18

35

4.

Hoe 360

0.5 EW

0. 09

23

5.

Hoe 360

0.5 EW

0. 12

30

6.

Acclaim 1EC (1986)

0. 18

32

7.

Acclaim 1EC

0. 25

27

8.

Acclaim 1 EC + Breakthru
+ Turflon Amine + Dicamba

0. 25 + 0.125 +
2.,5 pts/A + 0 . 1

18

Acclaim 1EC + Breakthru
+ Turflon Amine

0.,25 + 0.125 +
2.5 pts/A

28

10.

Acclaim 1EC + Turflon Amine

0..18 + 2 . 5 pts/A

25

11.

Acclaim 1EC + Turflon Amine

0..25 + 2 . 5 pts/A

25

12.

Mon - 15151 1EC

0.25

12

13.

Mon - 15151 1EC

0.38

43

14.

Mon - 15151 1EC

0.50

57

15.

Mon - 15151 1EC

0.75

63

16.

Mon - 15151 1EC + Acclaim 1EC

1..25 + 0.09

98

17.

Mon - 15151 1EC + Acclaim

0..25 + 0.09

77

18.

BAS 51400H 50 WP

0..5

17

19.

BAS 51400H 50 WP

1..0

93

20.

BAS 51400H WP + Acclaim 1EC

1,.0

9.

LSD

0

+ 0.18

0.05

85
33

Plots measure 5 ft x 5 ft.
All treatments were applied on June 16, 1988.
The study is located on a stand of Park Kentucky bluegrass.
This area was seeded with crabgrass on April 28. At time of spraying, this
area had a uniform stand of crabgrass at the 3-leaf, 1-tiller stage.

N.E. Christians, M.G. Burt, and Z.J. Reicher
The objectives of the 1987 - 1988 Poa annua control study were to observe the effects of Prograss
(Ethofumesate) on the population of Poa annua in a Penncross creeping bentgrass green.
The location of the study was the practice green at Veenker Memorial Golf Course in Ames, Iowa.
( j f i e soil on the site is a Coland clay loam (fine-loamy, mixed, mesic Cumulic Haploquoll) with a pH
of 7.7, 19 ppm phosphorus (P), 116 ppm potassium (K), and 5.3% organic matter. The area
receives approximately 4 lb nitrogen (N)/1000 ft2/yr. The Poa annua population ranged from 30 to
60% of the green's surface in the fall of 1987]
The treatments were applied at rates and on dates specified in table 20 in the equivalent of 3 gal
water/1000 ft 2 . All plots were 5 ft by 5 ft and the study was replicated three times.
Soil temperatures were monitored at the 2 in depth and were recorded as follows:
Date

Soil temp

Air temp
F

9/19
10/12
11/5
4/6
5/10
6/3

59
53
45
52
68
73

60
75
74
75
72
76

[There was severe winter kill of Poa annua on the entire green during the winter of 1987-88. By
June 1988, much of the Poa annua had germinated and populations on much of the green ranged
from 15 to 30% of the greens' surface. Counts were taken on 6 in by 6 in grids divided into 2 in by
2 in squares that were randomly tossed on three areas of each plot in June and September of 1988
(Toblo 20). The control plots contained an average of 25 P. annua plants/sq ft in June. No P.
annua plants were found in any of the other plots. By September, the population in the control
plots had increased to 86 plants/sq ft
and some increase in P. annua population
was observed iirtreatments 2, 3, and 4. No P. annua was found in plots treated with a follow-up
application of Prograss in June {treatment 5) or in plots treated in the spring with Bensulide
-trrsirrnBnt^
Observation of P. annua recovery in the spring of 1988 indicated that much of the spring
germination took place after the May Prograss treatment (No. 4) and before the June treatment
•{No. 5)7 Complete control with Prograss was established on plots treated after all P. annua had
germinated, or on plots treated with the preemergence herbicide Bensulide.

3

No phytotoxicity was observed on any of the plots at any time during the study

Table 20. Poa annua counts in June and September of 1988 on Penncross creeping bentgrass
greens treated with Prograss.

Rate
Material

lb ai/A

Poa annua
plant counts
June
Sept

Date of application
Sept

Oct

Nov

Apr

May

June

1988

1988

-plants/sq ft1. Control

---

2. Prograss

.75

X

X

X

3. Prograss

.75

X

X

X

4. Prograss

.75

X

X

X

5. Prograss

.75

X

X

X

.75
8.00

X

X

X

6. Prograss
Bensulide+

LSD

*

0.05

September 1987 to June 1988.

X
X
X
X

25

86

0

9

0

3

0

12

0

0

0
0

4
0

5

37

Fertilizer and Herbicide Applications on
Dormant Kentucky Bluegrass Lawns
M.G. Burt and N.E. Christians
The severe, prolonged drought of 1988 presented some unique situations to lawn care specialists
and turfgrass managers. In much of Iowa, nonirrigated turfgrass was completely dormant for much
of the summer. Most lawn care companies were faced with making at least one program application
over completely dormant turfgrass. Homeowners and lawn care companies questioned the benefits,
and many feared a possible detrimental effect of this practice. A study was conducted at Iowa State
University to determine the effect of the application of fertilizer and fertilizer plus various herbicides
on the recovery of dormant Kentucky bluegrass turf.
f j h i s study was located at the4Hortk>uftttfe-4^^
a stand of nonirrigated Ram-I
Kentucky bluegrass. The soil on the site is a Nicollet (fine-loamy, mixed mesic, Aquic Hapludoll) with
a pH of 7.2, 15 lb/A phosphorus, 120 lb/A potassium, and 2.3 percent organic matter.
Treatments were set up to represent several potential lawn care summer programs. These
treatments included a control, urea at two rates, sulfur-coated urea, and urea in combination with
Pendimethalin, Dacthal, Trimec, and Pendimethalin + Trimec
Treatments were applied on July 8, 1988, over the turf plot area which had been completely dormant
for seven weeks. It was 95° F and sunny on the day of application and the treatments were not
watered in. Daytime temperatures remained in the mid 90s for one week following treatment.
Treatments were applied in the equivalent of 3 gal H 2 0/1000 ft2. One week after treatment the plot
area was irrigated to bring the Kentucky bluegrass out of dormancy and to determine treatment
effects.
The plot'area was monitored for treatment differences every few days until the Kentucky bluegrass
had completely recovered from summer dormancy. There were no visible treatment differences
observed at any time during the recovery period with the exception of a slight greening of turf that
was treated with nitrogen
fertilizer.
This study suggests that the application of fertilizer and fertilizer in combination with various
herbicides to dormant Kentucky bluegrass does not have a detrimental effect on the recovery of the
turf from summer dormancy. An evaluation of positive effects of these dormancy treatments will
require further study. Although little response was observed in treated plots in this study, work in an
adjacent area did demonstrate increased recovery on treated areas. If the drought continues, more
work will be conducted on this subject during 1989^

Table 21. Fertilizer and herbicide applications on dormant Kentucky bluegrass lawns.
Rate

Treatment
1.

Control

2. Urea

0.5 lb N/1000 ft 2

3. Urea

1.0 lb N/1000 ft 2

4. Sulfur-coated urea

0.5 lb N/1000 ft 2

5. Urea + Pendimethalin 60DG

0.

.5 lb N/1000 ft 2 +

6. Urea + Dacthal 75WP

0.

,5 lb N/1000 ft 2 + 10.5 lb ai/A

7. Urea + Trimec

0.

.5 lb N/1000 ft 2 +

3.5 pt ai/A

8. Urea + Pendimethalin 60DG + Trimec

0.

.5 lb N/1000 ft 2 +
+ 3 . 5 pts ai/A

1.5 lb ai/a

1.5 lb ai/A

o

All plots measured 25 f tr.
Treatments were applied on July 8, 1988, to a nonirrigated stand of Ram-I
Kentucky bluegrass which had been completely dormant for seven weeks prior to
treatment application. It was 95°F and sunny at the time of treatment
application and treatments were not watered in. Treatments were applied in
the equivalent of 3 gal ^ 0 / 1 0 0 0 ft^ with the exception of sulfur-coated urea
that was applied as a granule.
One week after treatment application the plot area was irrigated to bring the
Kentucky bluegrass out of dormancy and to determine treatment effects.

R.G. Roe and N.E. Christians
Vthe-pnrpose of this study was to determine if the Ross Daniels product, Soil Percolator ( R & D
number of 88:1117), has an effect on the movement of water and nutrients in the soil. It was
compared with an industry standard, the product 'Aqua Gro' liquid by Aquatrols Corporation. The
test was conducted on Glade Kentucky bluegrass turf established on a Nicollet (fine-loamy, mixed
mesic, Aquic Hapludall) soil with a pH of 6.9, 9.05 ppm phosphorus (P), 98.48 ppm potassium (K),
and 2.3% organic matter. Individual treatment cells measured 5 ft by 5 ft and were randomized in a
complete-block design with three replications. The turf was mowed at 2 in and water was applied
as requireS^ Treatments are listed in table 22.
Treatments were applied on October 12, 1988, with the use of a backpack carbon dioxide sprayer,
followed by 15 minutes of irrigation. Each plot also received 2 lb P/1000 ft 2 (Triple Super Phosphate
0-46-0) and 2 lb K/1000 ft 2 (potassium chloride 0-0-60) on October 13 followed by 1 in of irrigation.
An additional 2 in of irrigation was applied in two applications at weekly intervals. The area also
received approximately 9/10 in of rainfall prior to the taking of core samples the week of November
14 and November 21. The treatments were replicated three times.
The set of soil cores taken on November 14 was cut at the soil line, removing the thatch and grass.
The second set, taken the following week, included the thatch with the grass cropped to the thatch
line. ¿These cores were then tested in the lab using the water percolation test following the methods
developed by the United States Golf Association. This equipment tests the rate at which water flows
through the soil cotesj Intact cores, in copper tubes, are placed on an infiltration rack and water is
passed through at a constant hydraulic head. Output is measured for three consecutive time
periods of the same length.
Soil samples were taken on November 18 for P and K analysis. Five samples per treatment cell
were collected from the 2-, 4-, and 6-in depths. These samples were analyzed by the Iowa State
University Soil Testing Lab for P and K.
Tables 23 and 24 contain the data obtained from the core samples that were tested using the water
percolation test equipment. The results are reported as water flow through the core in ml per 5
minutes of percolation time.
Aqua Gro was the only material to significantly improve water movement as compared with the
control in the first test (Table 23). Results of test 2 were highly variable and no significant
differences were observed (Table 24).
The following graphs show the results obtained from the soil samples. These graphs show the
levels of P and K per treatment, as well as the levels of P and K at 2-, 4-, and 6-in depths. ¿There is
no significant difference in the level of P retained in the soil. There is an improvement in the level of
K retained at the 8 oz/1000 ft 2 rate of R & D 88:1117 (Graph 1). There appears to be little
difference in the movement of P through the soil, however the movement of K to the 4- and 6-in
depths appears to be enhanced at the 8 oz/1000 ft 2 rate of R & D 88:1117
I The Ross Daniels Soil Percolator provided no improvement in water or nutrient movement in the
Nicollet soil at the recommended rates for application for this product. When Soil Percolator was
applied at the 8 oz/1000 ft2, a rate equivalent to the industry standard - Aqua Gro, some
improvement in water and K movement was observed, but it showed no advantage over the Aqua
Grg

j

Table 22. Treatments for Soil Percolator test.

Treatment
Water
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Aqua Gro

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

Actual
application

Rate

1
2
4
6
8
8

oz/10,000
oz/10,000
oz/10,000
oz/10,000
oz/ 1,000
oz/ 1,000

ft 2
ft 2
ft 2
ft 2
ft 2
ft 2

0..074
0..148
0..296
0..444
5..92
5..92

Water
285
285
285
285
285
285
285

ml
ml
ml
ml
ml
ml

Table 23. Results obtained from the first set of core samples, without thatch.
Treatment
1.
2.
3.
4.
5.
6.
7.

Water
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Aqua Gro

Average ml water/5 minutes

Rate

1
2
4
6
8
8

oz/10,000
oz/10,000
oz/10,000
oz/10,000
oz/ 1,000
oz/ 1,000

ft 2
ft 2
ft 2
ft 2
ft 2
ft 2

LSD 0.05

4.0
0.5
1.0
5.2
2.0
10.8
24.9
15.3

Table 24. Results obtained from the second set of core samples, with thatch.
Treatment
1..
2.,
3.,
4.,
5..
6,.
7..

Water
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Soil Percolator
Aqua Gro

Rate

1
2
4
6
8
8

oz/10,000
oz/10,000
oz/10,000
oz/10,000
oz/ 1,000
oz/ 1,000

LSD 0.05
*

NS - no significant difference.

Average ml water/5 minutes

ft 2
ft 2
ft 2
ft 2
ft 2
ft 2

54.5
71.3
58.5
32.2
51.6
45.5
66.2
NS*

ml
ml
ml
ml
ml
ml
ml

GRAPH I

GRAPH II

W M 4»
E2e

3

4

TREATMENTS

5

GRAPH III

R.W. Moore, N.E. Christians, and M.L Agnew
The objective of this study was to observe the reduction of dew formation and the phytotoxicity
created by three wetting agents, each applied at three rates.
This study was applied to a 10-year-old stand of Emerald creeping bentgrass, established on a
1:1:1 ratio of sand:soil:peat mix. The pH of this soil is 8.1 with available phosphorus and potassium
being 4 lb and 34 lb/acre, respectively. The plots were established in a randomized, complete-block
design with three replications containing three control plots each.
The materials used were Lesco's Lescowet "A", Lescowet "B", and Aqua Gro. Each product was
applied at 4-, 8-, and 16 lb/1000 ft2.
Two applications were made, one on June 24 and another on August 8, 1988. After the first
treatment, data were taken on phytotoxicity. There was no dew at this time due to hot and dry
conditions. Following the second application, data on dew reduction were taken, but no significant
phytotoxicity was observed.
Data for dew (Table 25) were based on a 9 to 1 scale: 1 = 90 to 95% dew reduction, 4 =
acceptable, and 9 = no dew reduction. Data for phytotoxicity (Table 26) also were based on a 9 to
1 scale: 9 = no damage and 6 = lowest acceptable rating.
On June 25, the first phytotoxicity data were taken. On June 27, a second set of data were taken.
Phytotoxicity was observed on June 25, but no extreme damage b e t e w w a s evident. Tip
burn was present but was removed after three mowings.
The 16-lb rate of Lescowet granular "A" and "B" produced the greatest amount of phytotoxicity. The
8-lb rate of granular "B" and 16-lb rate of Aqua Gro also produced some phytotoxic symptoms. On
June 27,?no ratings below 7 were observed. Conditions were too hot and dry for dew to be
observed, and no dew reduction data were taken.
On August 9, the first dew reduction data were taken. This data suggested that all three products
at the 16 lb and 8 lb/1000 ft2 rates were successful in reducing dew. The 16-lb rates received the
highest rating
while the 8-lb rates received a
and 3* rating. The granular "B" product at the
4-lb rate received a
an acceptable levef. One week later on August 15, granular
"B", at the 16-lb rate was the only treatment which continued dew reduction at an acceptable rating
- t i t 3 j No significant phytotoxicity was observed from the August application.

Table 25. Dew reduction.
Rate
lb/1000 ft 2

Treatment
Control
Control
Control
Granular
Granular
Granular
Granular
Granular
Granular
Aqua Gro
Aqua Gro
Aqua Gro
LSD
a

A
A
A
B
B
B

4..0
8..0
16.,0
4..0
8..0
16..0
4,.0
8,.0
16..0

(0.05)

Dew Reduction Rating a
Aug 9
Aug 15
9..0
9..0
9..0
4..7
2..7
1..0
3..7
2..7
1..0
4..3
3..0
1..0

9.0
9.0
8.7
8.7
7.7
4.7
7.3
6.0
3.0
8.7
8.0
6.0

0 .8

1.5

Dew reduction ratings are based on a 9 to 1 rating: 9 = heavy dew, 4 or
below = acceptable rating, and 1 = no dew.

Table 26. Phytotoxicity.
Rate
lb/1000 ft 2

Treatment
Control
Control
Control
Granular
Granular
Granular
Granular
Granular
Granular
Aqua Gro
Aqua Gro
Aqua Gro
LSD
a

...
A
A
A
B
B
B

(0.05)

4.0
8.0
16.0
4.0
8.0
16.0
4.0
8.0
16.0

Dew Reduction Rating3Aug 9
Aug 15
9.0
9.0
9.0
8.3
8.0
6.7
8.0
7.0
6.3
9.0
8.0
7.0

9.0
9.0
9.0
8.0
8.0
7.0
8.3
7.7
7.0
8.3
8.3
7.0

1.2

1.1

Phytotoxicity rating is based on a 9 to 1 rating: 9 = no damage, 6 or above
= acceptable rating, 1 = dead turf.

M.L. Agnew and R.W. Moore
A cultivation study was initiated in the spring of 1986 on a 1-year-old stand of Midnight Kentucky
bluegrass. The purpose of this study was to investigate the effects of core cultivation and grooving
on thatch prevention and thatch removal.
The turfgrass is maintained at a 2 in mowing height with clippings returned to the soil. The area is
fertilized with 4 lb nitrogen (N)/1000 ft 2 /growing season using sulfur coated urea.
Thatch depth was measured on May 23, 1987, and May 15, 1988. Measurements were taken by
pulling a 6 in diameter core from each plot. The thatch was compressed using a 2 kg weight and
the depth was measured in mm. Visual quality ratings were made on September 20, 1988, and
shoot density was measured on June 15, 1988. Quality is based on a scale of 1 to 9: 9 = best
quality, 6 = acceptable quality, and 1 = dead turf. Shoot density is the number of tillers/15 sq in.
Table 27. The effects of cultivation equipment and timing of application on thatch accumulation,
visual quality, and shoot density.
Cultivation
equipment

Timing of
application

none

none

11.3

2.1

9.0

91

coring
coring
coring
coring

May
Sept.
May, Sept.
May, July, Sept.

9.3
10.4
9.5
12.3

2.6
0.9
0.8
2.1

9.0
9.0
9.0
8.3

81
85
72
87

grooving
grooving
grooving
grooving

May
Sept.
May, Sept.
May, July, Sept.

9.8
10.3
7.1
4.0

-0.9
1.1
-1.4
-2.5

7.8
8.0
5.8
6.8

73
96
95
73

2.5
NS
NS e

2.2
NS
NS

0.7
0.9
NS e

NS
NS
NS e

LSD (0.05) equip.
LSD (0.05) timing
LSD (0.05) equip. X timing
a

Thatch Accumulation
1987-1988
1986-1987

Visual
quality

Shoot
density

Cultivation equipment included coring = Ryan Lawn Aire IV; grooving = Ryan
Mat-away.
k Thatch accumulation is the thatch depth in May less the original thatch
depth.
c
Visual quality on September 20. Rated on a scale of 1 to 9: 9 = best
quality, 6 - minimum acceptable level, and 1 - dead turf.
^ Shoot density = number of tillers per 15 sq in.
e
Significant at the 0.10 level.

The Effects of Core Cultivation on the Performance
of Four Nitrogen Fertilizers
M.L. Agnew and R.W. Moore
This study compares the Effects of core cultivation on the performance of four granular nitrogen
sources. It was established on May 20, 1988, and is to continue for three years. The turf is Park
Kentucky bluegrass that was established in the fall of 1987. The grass is mowed at 2 in and
watered to prevent drought stress. Other than preemergence crabgrass control, no pesticides are
applied to the treatment area. The four nitrogen (N) sources are milorganite, Blue Chip, methylene
urea (41-0-0), and an experimental organic product (listed as ISU Exp).
Treatments were applied on May 20 and August 15, 1988. Each fertilizer source was applied at a
2 lb N/1000 ft2 rate. Fertilizers were applied following core cultivation and without any cultivation to
plots measuring 5 ft by 10 ft. Quality ratings were taken on a monthly basisj Visual quality is rated
on a scale of 1 to 9: 9 = best quality, 6 = acceptable quality, and 1 = no live grass. ^Shoot density j X
based on the number of tillers/15 sq in was measured on June 15, 1988/ Both the qaafity and
density data are included in table 28. Clippings were collected with each mowing. These were
dried and weighed and are represented as biomas in table 29.
The quality data in table 28 suggest that methylene urea provided quick greenup and maintained
quality through mid-June. ¡Jhe ISU experimental was slower to greenup but maintained quality
through the first of July. Other fertilizer treatments did not give the same level of quality. This could
be due to the dry subsoil condition during 1988. There was very little effect of core cultivation for
the first year. Only one treatment date showed any response to cultivation.,
The clipping data in table 29 suggest that the ISU experimental and methylene urea have the ability
to provide nitrogen on a continual basis. The release of nitrogen from blue chip and milorganite
was greatest following fertilizer application. There were no responses to the cultivation treatment.

*

Table 28. Effects of fertilizer source and core cultivation on the quality of Park Kentucky bluegrass.
Quality Rating3,
Fertilizer
Source

Cult

5/28

6/02

6/12

6/28

7/24

8/26

9/07 10/19

None
None

None
Coring

6.0
6.0

5..0
5,,0

5.0
5.0

5.0
4.7

5..0
5..0

4.0
4.0

4.0
4.0

4.0
3.0

53.7
52.8

Milorg.
Milorg.

None
Coring

6.3
6.3

7,.3
7..3

7.0
7.0

7.7
8.0

7..0
7..0

7.0
6.3

7.0
7.0

6.7
6.7

54.0
56.7

Blue Chip
Blue Chip

None
Coring

6.7
7.0

6..7
7..3

6.0
6.0

5.7
6.0

6..0
6..0

7.0
6.7

6.0
6.3

5.3
5.0

42.2
38.7

M. urea
M. urea

None
Coring

8.0
8.0

8..7
8..7

8.0
7.7

7.3
7.3

7,.0
7.,0

7.0
7.3

7.3
7.7

7.7
8.0

61.5
52.3

ISU Exp
ISU Exp

None
Coring

6.0
6.0

8..0
8,.3

8.0
8.0

8.3
8.7

7..3
7,.0

7.3
7.7

8.0
9.0

7.7
8.0

58.2
52.3

LSD (0.05)
LSD (0.05)

Fert
Cult

0.4
N.S.

0..6
N,.S.

0.2
N.S.

0.6
N.S.

0 . .2
N..S.

0.9
N.S.

0.6
0.3

0.6
N.S.

a

Shoot
Density^

8.6
N.S.

Visual quality is rated on a scale of 1 to 9: 9 - best quality, 6.5 acceptable quality, and 1 = no live grass,
k Shoot density = number of tillers/15 sq in. Data collected on July 15,
1988.

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M.A. Boyle and N.E. Christians
The objective of this study was to observe the effects of Turf Restore® and Greens Restore«
(granular materials from the Ringer Corporation) on thatch reduction, water infiltration rates, soil
chemistry, and turf quality. Included for comparison are urea and an experimental ISU (ISU Exp)
product. Data collected included water infiltration rates, bulk density, salt reduction, cation exchange
capacity, nutrient availability, thatch reduction, and turf quality.
The study was initiated in May 1988 and will continue over a 3-year period. It is being conducted at
the Iowa State University Horticulture Research Station Turfgrass Plots north of Ames, Iowa. The turf
was established in 1984 on a Nicolett (fine-loamy, mixed mesic, Aquic Hapludoll) soil (pH 7.5, 2.3%
organic matter). Twenty-one 5 ft by 10 ft plots of Glade Kentucky bluegrass make up the test area.
The turf is irrigated as needed to prevent drought stress.
The study was designed in a randomized, complete-block arrangement with three replications each
of seven treatments. Three applications were applied throughout the first year (May, July, and
September) at the rates of nitrogen (N) listed in table 30. The last two applications in July and
September 6\ Turf Restore® and Greens Restore® were 1 lb N and 0.6 lb N, respectively. The
granular materials were all applied by hand and the urea was sprayed.
Field data for infiltration rates and bulk density were taken with a 'nondisturbed' soil core sampler
and tests were conducted at ISU. The thatch layer was cut from the top of each core and
measured when compacted. Cheesecloth was secured to the bottom of the cylinders with rubber
bands to keep the soil in place. The cores were placed on a USGA specified infiltration rack and
water was passed through them for 24 hours. Water infiltration rates were measured at 5 min
intervals with three replications and an average was calculated. Infiltration rates were adjusted to
ml/hr with the following formula:
R =

QL
51.5* x H

R
Q
L
H

=
=
=
=

infiltration in/hr
the averaged rate ml/hr
2.3125 = length of cylinder (inches)
3.43
= hydraulic head (inches)

* 51.5 = t r 2 (16.4 cc/cu in)
Bulk densities were calculated by:
oven dried wt. - cylinder wt. (cheesecloth + rubber band)
volume =

119.1 cm

An average of 10 cores from each plot were obtained with the use of a 1 in diameter soil probe,
combined, and subsamples were submitted to Harris Laboratories, Inc., Lincoln, Nebraska, for
chemical analysis.

No significant differences among treatments, other than visual quality, were found in the study.
Tables 31, 32, and 33 list the May 1988 data taken prior to any treatments and the October 1988
data taken at the end of the season. Table 30 lists the amount of water in inches passing through
the soil in one hour. The October 1988 results are highly variable. This may be because of the
difficulty i p obtaining soil cores without cracks or small holes. Tables 31 and 32 list bulk density
(gm c m " ) and thatch (mm). There were no significant changes between treatments. The soil test
results are in tables 33 and 34 with data prior to treatments and data taken at year's end,
respectively. In these tables, soluble salts are reported in mmhos/cm. Sodium, phosphorus,
potassium, magnesium, and calcium are in ppm. Potassium, magnesium, calcium, and sodium with
an asterisk are all listed in percent of total CEC. These data also show no significant difference
between treatments.
All treatments provided acceptable visual quality through the latter part of the season (Table 35).
The Turf Restore« at 2 lb N/tmt and the ISU-2 at 2 lb N/tmt provided the highest quality ratings
throughout the fall.
All data submitted in this report are from the first year of a planned 3-year study. The lack of
significant differences is not unusual in the first year of this type of study. The study will be
continued in 1989.

Table 30. Infiltration (in/hr).
Rate
(lb N/1000 ft 2 )

May 88

October 88

1. Urea

0.5 lb N

.34

23..41

2. Turf Restore
(10-4-4)

1.5 lb N

.30

00,.42

3. Turf Restore
(RenPro)
(10-4-4)

2.0 lb N

.22

00..25

4. Greens Restore
(6-1-3)

0.9 lb N

.28

13..92

5. ISU-1
(10% N)

1.0 lb N

.92

00..53

6. ISU-2
(10% N)

2.0 lb N

.75

06..38

7. Urea

1.0 lb N

.15

18..75

LSD

0.05

NS

NS

Table 31. Bulk Density (gm-1 cm-3).
Rate
(lb N/1000 ft 2 )
1. Urea
2. Turf Restore
(10-4-4)
3. Turf Restore
(RenPro)
(10-4-4)
4. Greens Restore
(6-1-3)
5. ISU-1
(10% N)
6. ISU-2
(10% N)
7. Urea
LSD

May 88

October 88

0.5 lb N
1.5 lb N

1.73
1.77

1.72
1.76

2.0 lb N

1.75

1.77

0.9 lb N

1.73

1.74

1.0 lb N

1.68

1.73

2.0 lb N

1.67

1.69

1.0 lb N

1.76

1.77

NS

NS

May 88

October 88

0 .5 lb N
1 .5 lb N

14.0
13.7

12.7
15.0

2..0 lb N

16.3

13.0

0..9 lb N

14.3

15.0

1,.0 lb N

15.0

13.7

2. 0 lb N

15.0

14.0

1. 0 lb N

14.0

13.3

NS

NS

0.05

Table 32. Thatch (mm).
Rate
(lb N/1000 ft 2 )
1. Urea
2. Turf Restore
(10-4-4)
3. Turf Restore
(RenPro)
(10-4-4)
4. Greens Restore
(6-1-3)
5. ISU-1
(10% N)
6. ISU-2
(10% N)
7. Urea
LSD

0.05

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Table 35. 1988 Ringer visual quality*.
Rate
(lb N/1000 ft 2 )

9/9

9/16

9/23

9/30

10/6

10/14

Mean

0.5 lb N

6. 0

5. 7

6. 0

6..0

5.,3

5.3

5.,7

2. Turf Restore
(10-4-4)

1.5 lb N

7..3

6. 7

7.

7

6..7

6..7

6.7

6.,9

3. Turf Restore
(RenPro)
(10-4-4)

2.0 lb N

8..3

7.,7

8.,7

7..7

7.,7

7.0

7.,8

4. Greens Restore
(6-1-3)

0.9 lb N

5..7

5.,7

6.,7

6..0

5..3

6.0

5..9

l.

Urea

5. ISU-1
(10% N)

1.0 lb N

6..3

6..7

7..7

7,.0

6..7

7.0

6..9

6. ISU-2
(10% N)

2.0 lb N

8..3

8..0

8..7

8..0

7..7

7.7

8..1

7. Urea

1.0 lb N

7,.0

7..0

7..0

7,.0

5..7

6.3

6..7

1 .3

1..3

0..9

0.5

1 .0

0.8

0..7

LSD 0.05

Quality based on a scale from 1 to 9 : 9 » best quality, 5 - acceptable
quality, 1 - dead turf.

1988 NBPT Field Study
G.T. Spear and N.E. Christians
Urea is an organic nitrogen (N) fertilizer source with several properties that make it a desirable
source of N for the turf industry. Urea is a highly soluble granule that tank mixes with many lawn
pesticides for one step application. It has a relatively low salt index and is one of the least
expensive sources of N available for the turf industry.
Unfortunately, urea has weak points, too. Application of granular urea to moist turf can burn the
leaves unless it is washed off. Loss of surface-applied urea N to the atmosphere in the form of
gaseous ammonia (NH3) can also be a problem (Terman, 1979).
Many approaches have been taken to lessen the risk of losing urea N as NH3. They include using
a chemical to inhibit soil urease activity, coating urea to decrease its rate of dissolution, and
improving urea management techniques (Hauck, 1984).
The effectiveness of N-(n-Butyl) thiophosphoric triamide (NBPT) for retarding urea hydrolysis in soil
was shown by Bremner and Chai in several studies (Bremner and Chai, 1986; Chai and Bremner,
1986). From these studies NBPT was shown to merit consideration as a fertilizer amendment for
retarding hydrolysis of urea by urease in turfgrass sod.
This study was designed to test the effects of NBPT-treated granular urea from Enichem Americas
versus untreated urea on Kentucky bluegrass in hot, dry weather. Observations included both color
quality and tipburn that may result from application of the fertilizers at varied rates. Also, clipping
dry weights were measured periodically to compare growth following the treatments.
The turf used in the study had been established on a Nicollet (Aquic Hapludoll, fine-loamy, mixed
mesic) soil (pH 7.5, 2.3% organic matter) with Park Kentucky bluegrass (Poa pratensis L.). The
investigation was conducted in 1988. The turf was irrigated regularly to prevent drought stress.
Experimental units were 5 ft by 5 ft each with three replications of seven different treatments.

V

The study was arranged in a randomized, complete-block design with two treatments and repeated
measurements on the same plot areas in three replications. The treatments included granular urea
applied at 1 lb N/1000 ft2 (49 kg N/ha) and 1.5 lb N/1000 ft2 (73.5 kg N/ha) with NBPT at 0, 0.25,
and 0.5% of the weight of N. No urea was applied to the control treatments. The treatments were
initially applied the last week of May and were repeated the third week of July^ Treatments were
applied manually in two different directions to obtairLuniform application. Datafon color and tipburn
ratings were based primarily on visual evaluations. VQolor and tipburn ratings were taken weekly
following the treatments, until symptoms ceased. Clipping weights were recorded weekly, as growth
conditions permitted, at a 2 in (5 cm) mowing height./
Ilhe effect of NBPT on turf color and the occurrence of tipburn varied with the NBPT rate (Tabtes-36•€trrc^37)-. Treatment effects were fairly consistent between both applications and among weeks
following the treatment. Color ratings of the NBPT treatments were not different from the
corresponding urea treatments and tipburn was greater in plots that received the NBPT treatments.
Clipping yield was not affected by NBPT (Tabte-38)?- Clipping yield decreased steadily in the weeks
following application of treatments but relative treatment effects remained constant throughout the
studyjf

Bremner, J.M. and H.S. Chai. 1986. Evaluation of N-butyl phosphorothioric triamide for retardation
of urea hydrolysis in soil. Commun. Soil Sci. Plant Anal. 14:905-913.
Chai, H.S. and J.M. Bremner. 1986. Effects of phosphoramides on ammonia volatilization and nitrite
accumulation in soils treated with urea. Agronomy Abstracts, p. 176.
Hauck, R.D. 1984. Technological approaches to improving the efficiency of nitrogen fertilizer use by
crop plants. In R.D. Hauck (ed.) Nitrogen in Crop Production. American Society of Agronomy,
Madison, Wl. pp. 551-560.
Terman, G.L. 1979. Volatilization of nitrogen as ammonia from surface-applied fertilizers, organic
amendments and crop residues. Advanced Agronomy 31:189-223.

M.L. Agnew and R.W. Moore
This is the second year of a 2-year study designed to compare the effects of three fertilizer sources
and three water dilution rates on fertilizer burn. The three fertilizer sources include N-Sure,
formolene, and urea. Each fertilizer source was diluted into 1-, 2-, and 4-gal of water/1000 ft 2 . Each
fertilizer/water dilution rate was applied to a 5 ft by 5 ft plot at a rate of 1 lb nitrogen (N)/1000 ft 2 .
Treatments were applied on Kentucky bluegrass (Poa pratensis) cv. Ram-I. Irrigation was provided
to the plots to prevent drought stress. All plots were maintained at a cutting height of 2 in.
Treatments were applied on July 29, 1988, and August 8, 1988, on separate sites. The fertilizer sat
in solution for seven days before the July 29, 1988, treatment and two hours before the August 8,
1988, treatment. Visual quality data were collected four days after fertilizer application. Visual
quality for this study is a measurement of discoloration due to fertilizer treatments -{9 • no visualjdiscoieratiorr and 1 » dead-grass).

ri

-

-

There was a significant interaction between fertilizer source and water dilution rate for the August 8
application date (Tabfe-3§). Formolene diluted into 1 gal of water caused significantly more injury
than when diluted in either 2 or 4 gal of water. The temperatures during this time period were
extremely hot. N-Sure applied at the same date did not cause any appreciable damage.
In summary, urea caused the most burn damage at all water dilution rates, while N-Sure caused the
least amount of injury. Leaving the formolene in solution for over seven days obviously caused
polymerization, thereby lessening damage./

Table 39. Effects of fertilizer source and water volume on foliar burn of Kentucky bluegrass.
Burn Rating a
July 31
Aug. 12

Fertilizer
Source

Water
Volume

Urea
Urea
Urea

1 gal
2 gal
4 gal

6.7
7.0
7.0

5.0
5.7
5.0

N-Sure
N-Sure
N-Sure

1 gal
2 gal
4 gal

8.3
8.0
9.0

8.7
9.0
8.7

Formolene
Formolene
Formolene

1 gal
2 gal
4 gal

7.7
7.7
8.0

5.0
8.0
8.3

0.6
N.S.
N.S.

0.6
0.6
0.7

LSD fertilizer (0.05)
LSD water
LSD fertilizer by water
a

Burn ratings are based on a scale of 1 to 9: 9 = no burn, and 1 = dead
turfgrass.

Summer Slow-Release Nitrogen Sources Comparison Study
M.L Agnew, N.E. Christians, and R.W. Moore
The purpose of this study was to compare eight slow-release nitrogen (N) sources when applied
during the late spring and summer. Thisjstudy was initiated in the spring of 1985 and will be
terminated in the spring of 1989. The turf I s Glade Kentucky bluegrass, established in September
1984. In all years except 1988, the turf was watered to prevent drought stress. Periodic drought
stress was allowed during the drought of 1988. Individual treatment cells measured 5 ft by 5 ft and
were randomized in a complete-block design with three replications. The turf was mowed at 2 in
and preemergence herbicides were used to prevent crabgrass.
Treatments included eight slow-release N sources £Fabte-46) applied at 2 lb N/1000 ft 2 /season split
into two equal applications on May 20 and August 10. Each treatment received 2 lb N/1000
ft 2 /season of urea (46-0-0) split into two equal applications on April 10 and September 20. One
additional treatment, using combinations of Powder Blue and urea, was applied for comparison.
This treatment applied 0.25 lb N (Powder Blue)/0.75 lb N (urea) in April and September, and 0.5 lb
N (Powder Blue)/0.5 lb N (urea) in May and August. The N-Sure treatments began in 1986, while all
other treatment began in 1985.
Visual quality data were taken on May 5, May 25, June 27, July,24, and October 19, 1988. Water
was withheld from plots during August and early September., |D9ta taken on May 25, June 27, and
July 24, reflect the spring application of fertilizers. In this case, all treatments responded equally.
Following the drought, the Powder Blue/urea treatment provided the best quality, while there was
little or no difference between other fertilizer sources.
Thatch depth and quality will be measured in the spring of 1989, after which time this study will be
' id. A new fertilizer trial comparing fertilizer sources and programs is planned for the spring

Table 40. Effects of nitrogen source in summer fertilization of Kentucky bluegrass.
Nitrogen
source

5/05

Visual Quality 3
5/25
6/27
7/24

Powder Blue
Fluf
Formolene
N-Sure
IBDU
SCU/TVA
SCU/CIL
Azolone
Powder Blue/Urea
LSD (0.05)

5.0
5.3
5.0
5.3
6.0
5.3
5.3
5.3
5.7
N.S.

8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
N.S

a

8.0
8.0

8.0

8.0
8.0
8.0
8.0
8.0
8.0
N.S.

8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
8.0
N.S.

10/19
7.3
6.7
6.3
7.0
6.7
7.0
6.7
7.0
8.0
0.7

Shoot
Density13
61.2
62.3
67.0
64.0
65.5
57.2
62.7
64.2
64.7
N.S.

Visual quality is rated on a scale of 1 to 9: 9 - best quality, 6 acceptable quality, and 1 = no live grass,
k Shoot density = number of tillers/15 sq in. Data collected on July 15,
1988.

The Effects of 13 Granular Nitrogen Fertilizer Sources
on the Growth and Quality of Park Kentucky Bluegrass
M.L. Agnew and R.W. Moore
The purpose of this study was to evaluate the performance of 13 granular nitrogen (N) sources.
This study was established in June 1988. T h e grass is a Park Kentucky bluegrass that was
established in the fall of 1987. It is mowed at 2 in and watered to prevent drought stress.
The treatments include urea, urea + .25% NBPT, urea + .50% NBPT, sulfur-coated urea CIL, sulfur- v \
coated urea TVA, O.M. Scott sulfur-coated urea, IBDU (fine), Blue Chip, Milorganite, Triazone
experimental (a product of Arcadian), methylene urea 41-0-0, Nu Tech, ISU experimental (organic N
source), and a control with no fertilizer. All treatments were applied at 1 lb N/1000 ft2 on June 6,
August 15, and September 15. This study is replicated three times in a randomized, complete-block
design. Plot size is 4 ft by 8 ft. J

Table-44-~provides~tbe <iata-eft^e monthly qua^

The quality data of June 12, 1988, reflect
the immediate effect of the fertilizer on quality. (Ttie fertilizers containing high levels of water
insoluble N, i.e. IBDU, Blue Chip, and Milorganite, were slow to greenup. All formulations of urea,
yysulfur-coated urea, and methylene urea provided immediate green color. In addition, the urea
formulations, sulfur-coated urea, and methylene urea fertilizer sources generally provided better
quality throughout the growing season. 7

Table 41. Effects of 13 granular fertilizer sources on the visual quality of Park Kentucky bluegrass.
Fertilizer
Source
Urea
Urea+.25% NBPT
Urea+.50% NBPT
SCU (CIL)
SCU (TVA)
SCU (Scotts)
IBDU
Blue Chip
Milorganite
Triazone (exp)
Methylene Urea
(41-0-0)
Nu Tech
ISU (exp)
Control
(no fertilizer)
LSD
a

(0.05)

6/12

6/28

Visual qualitv a
7/24
8/26
9/07

8..0
8..0
8..0
7..7
7..3
8,.0
5..0
6..0
5..7
6..7

7.3
8.0
7.7
8.0
7.3
7.3
6.3
6.0
7.0
7.3

7..3
8..0
8..0
8,.0
7..7
7..7
7..0
6..7
7,.3
8..0

7..0
8..0
7..3
7..7
8..3
7..7
6..7
6..3
5..7
5..7

8..0
8..3
8 .3
8 .3
8..3
8 .7
8 .0
6 .0
7,.0
7,.0

7..3
6..7
7,.3
6..3
7..7
8..0
5..3
4..0
4..7
6..7

7.5
7.8
7.8
7.7
7.8
7.9
6.4
5.8
6.2
7.0

7..3
7.,0
7..3

7.3
7.0
7.7

7.,7
7..0
7..3

6..7
7..0
6..3

8.,0
7..3
7..3

7.,3
5.,7
6. 0

7.4
6.8
7.0

5..3

5.3

6..0

4..3

4,.0

3..0

4.7

0.

0.8

0.

1.

1.

1.

0.7

.6

.9

.7

,1

10/19

Ave.

.2

Visual quality is rated on a scale of 1 to 9: 9 - best quality, 6.5 =
acceptable quality, and 1 = no live grass.

on Three Kentucky Bluegrass Cultivars
R.W. Moore, M.L Agnew, and N.E. Christians
This study Compares 12 liquid fertilizer programs using four nitrogen (N) sources on three Kentucky
bluegrass cultivars. The treatments were started in the spring of 1985 and will continue through
1990. The turf is maintained at a cutting height of 2 in and all clippings are removed.
The four fertilizers include Urea, Powder Blue, Fluf, and Formolene. They were applied using
different application schedules and three different application rates. Each schedule received a total
of 4 lb N/1000 ft2/growing season. The balanced program received 1 lb N/1000 ft 2 in each of the
months of April, May, August, and September. The heavy spring program received 0.5 lb N in April,
1.5 lb in May, and 1 lb N each in August and September. The late fall program required 0.5 lb N in
April, .75 lb in May, .75 lb in August, 1 lb in September, and 1 lb in November.
The three cultivars of Kentucky bluegrass are Majestic (high-maintenance grass), Vantage
(medium-maintenance grass), and Park (low-maintenance grass). Each cultivar was replicated three
times and each of the 12 fertilizer programs were randomized within each cultivar.
The data taken in 1988 include visual quality, clipping weight, thatch depth, and root weights by
depth. Treatments were rated for visual quality each month, while clippings were collected, dried
and weighed each month on random dates. Thatch depth was taken October 28. Finally, root
samples were collected in October 19887)
In comparing the cultivars (Table 42), the overall visual quality ratings were better for Majestic and
Vantage than Park. However, Majestic had substantially better quality from mid-July until fall.
Majestic produced only one-half to one-third as much clipping weight as Vantage or Park. This
difference is not surprising since Majestic is a prostrate-growing cultivar. Furthermore, thatch
remains greatest in Majestic (Table 49).
(When comparing programs-fFakle-43), the late fall program had the best visual quality rating at
spring greenup, and the lowest clipping yields for most of the season. The balanced program had
the best overall visual quality. Majestic treated with the late fall program produced the most thatch
(Table 48>.
When comparing the individual fertilizer sources, there was little difference in the overall quality of
the turf for the season. Urea and Fluf greened up earlier in May than Powder Blue or Formolene
-{Tabte-44). Urea demonstrated better visual quality longer into the fall. Urea, Formolene, and Fluf
produced the greatest amounts of clippings during the season. Effects of fertilizer source on thatch
development or root weights showed greater thatch created by urea (Table 50).
In 1988, few interactions were observed in programs vs materials, materials vs cultivars, programs vs
cultivars, or programs vs materials. Overall, thatch was affected significantly by cultivars and
programs and interactions of these two variables.
Due to the drought in 1988, irrigation was omitted on this study starting in early May.

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Table 45. Visual quality means of three cultivars for 1985 through 1988.
Visual quality means
Cultivar

1985

1986

1987

1988

Vantage
Park
Majestic

7.2
7.0
7.6

6.8
6.7
7.3

6.6
6.5
6.5

5.8
5.5
5.9

LSD

0.11

0.13

NS

0.26

Table 46. Visual quality means of three cultivars for 1985 through 1988.
Visual quality means
Program

1985

1986

1987

1988

Balanced
Heavy spring
Late fall

7.2
7.3
7.1

7.0
7.1
6.7

6.9
6.5
6.6

5.9
5.7
5.6

LSD

0.11

0.13

0.13

0.25

Table 47. Visual quality means of three cultivars for 1985 through 1988.
Visual quality means
Fertilizer

1985

1986

1987

1988

Urea
Powder Blue
Fluf
Formolene

7.6
7.0
7.1
7.3

7.4
6.5
6.8
6.9

6.6
6.5
6.6
6.7

6.0
5.5
5.7
5.6

LSD

0.13

0.16

0.17

0.29

Table 48. Interaction of cultivar and program on thatch depth in October 1988.
Program
Balanced
Heavy spring
Late fall
Mean

Vantage

Park

Majestic

Mean

16.8
17.2
15.1
16.4

13.6
14.4
14.6
14.2

16.9
19.0
20.2
18.7

15.8
16.9
16.6

Table 49. Effects of three Kentucky bluegrass cultivars on thatch depth.
Thatch depth
(May 22, 1987)

Thatch depth
(Oct 22, 1988)

(mm)

(mm)

Vantage
Park
Majestic

13.3
14.0
16.0

14.2
16.4
18.7

LSD 0.05

0.8

1.2

Cultivar

Table 50. Effects of liquid fertilizer on thatch depth.

Fertilizer

Thatch depth
(Oct 1988)
(mm)

Fluf
Powder Blue
Formolene
Urea
LSD 0.05

15.4
16.0
16.3
18.0
1.4

Table 51. Effects of liquid fertilizer programs on thatch depth.

Programs

Thatch depth
(Oct 1988)
(mm)

Balanced
Heavy spring
Late fall
LSD 0.05

15.8
17.0
16.6
NS

-

Shady Ground Cover Trial
Spring 1989 Data
N.H. Agnew, J.K. lies, and M.L. Agnew
A shady ground cover trial was established in Spring 1988 for the purpose of evaluating ground
cover species performance in Iowa. Plant materials were purchased using funds from a grant
supplied by the Iowa Golf Course Superintendents Association.
Performance data including percentage coverage, plant quality, and percentage survival were
recorded in Fall 1988 and Spring 1989. Spring 1989 data are presented in table 52. Top-ranked
species are listed in table 53. Percentage coverage is the mean of the percentage of plant cover
(based on visual observation) for each of the 2 ft by 3 ft replicate plots.
Quality observations were based on a scale from 1 to 9: 9 = excellent quality plants; 6 =
acceptable quality plants; and 1 = dead plants. Excellent quality plants were those with a healthy,
vigorous appearance, good color, good coverage or potential for coverage, and minimal damage
from insects, disease, or environmental stress. Percentage survival was the number of original
plants surviving divided by 18 (3 replicates X 6 plants/replicate) established.

Table 52. Performance evaluation of 20 shady ground cover species for Iowa.
Plant
no. Species
1.

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

Quality

Percentage
survival

21.,7
20..0
96..7
43..3
16.,7
30..0
38..3
3..3
71..7
73..3

3.,0
3..7
9..0
6..0
3..0
4..0
5..0
1 ,.7
8..3
8,.7

61
67
100
100
67
89
78
33
100
100

46..7
48..3
46,.7
76..7
33,.3
13,.3
23,.3
53 .3
43 .3
43,.3

7,.3
5,.7
6,.7
6 .7
4,.0
2,.0
3 .0
4,.3
4 .0
5 .3

100
94
100
100
94
89
72
100
100
94

96..7
73,.3
71,.7

9..0
8.,7
8..3

100
100
100

46,.7
76,.7
46,.7
43,.3

7..3
6,.7
6..7
6..0

100
100
100
100

Percentage
coverage

Aegopodium podagraria 'Variegatum'
Ajuga genevensis 'Pink Beauty'
Ajuga pyramidalis 'Metallica Crisp.a'
Ajuga reptans 'Burgundy Glow'
Astilbe chinensis 'Pumila'
Bergenia cordifolia
Galium odora tum
Hedera helix 'Thorndale'
Hosta plantaginea 'Royal Standard'
Hosta undulata 'Albo-marginata'
Lamiastrum galeobdolan variegatum
'Herman's Pride'
Lamium maculatum 'Beacon Silver'
Liriope spicata
Lysimachia nummularia
Pachysandra terminalis
Phlox divaricata 'Fuller's White'
Tiarella wherryi
Vinca minor 'Bowles'
Vinca minor 'Miss Jekyll'
Waldsteinia fragarioides

Table 53. Top-ranked species.
Plant
no. Species
3.
10.
9.
11.
14.
13.
4.

Ajuga pyramidalis 'Metallica Crispa'
Hosta undulata 'Albo-marginata'
Hosta plantaginea 'Royal Standard'
Lamiastrum galeobdolan variegatum
'Herman's Pride'
Lysimachia nummularia
Liriope spicata
Ajuga reptans 'Burgundy Glow'

Against Annual White Grubs - 1988
D.R. Lewis and N.E. Christians
Damage to turfgrass by annual white grubs (Cyclocephala spp.) is a common, but spotty and locally
severe problem in Iowa. 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 emulsifiable
concentrate 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 late-season efficacy of several
registered insecticides and one experimental against annual white grubs infesting turfgrass.
The study was conducted on a fairway of the Hyperion Golf and Country Club located in Johnston,
Iowa (Polk County). The soil at the Club is a Waukegan loam (fine-silty over sandy, mixed, mesic
typic Hapludoll) with 148 lb P/A, 480 lb K/A, and 5% organic matter. The plots were near the
bottom of a long, low, south-facing slope. The grass species in the plots was Kentucky bluegrass.
The plot area was receiving low maintenance but regular mowing (at approximately 3 in) and
irrigation as necessary. There was between one-fourth to one-half in of thatch at the test site.
Grub damage was apparent throughout the plot vicinity at the time of insecticide application. The
insecticide treatments were applied on September 21, 1988. Grub population counts were made
October 14, 1988.
The experimental design consisted of 14 treatment plots and one untreated check plot, randomly
assigned in each of three replications. Each plot consisted of a 5 ft sq area (25 sq ft). All
insecticides were applied at the rate specified on the manufacturer's label or product guidelines.
Liquid insecticides were applied with a compressed gas, back-pack sprayer, connected to a
hand-held, three-nozzle boom. The boom covered a 5 ft wide area, and diluted insecticide spray
was applied to the test plots with alternating perpendicular passes over the treatment plot. The
amount of water applied to each plot was the equivalent of 175 gal/A. Granular insecticides were
premeasured into round, cardboard containers and applied uniformly over the plot by shaking
through a perforated lid. The insecticides were watered into the turfgrass immediately after
application with approximately one-half in of irrigation.
Annual white grub population counts were made three and one-half weeks after treatment by
randomly selecting four 6 in sq sample sites within each plot, cutting the sample with a sharp knife,
removing the sod, and counting all live white grubs found. The sod was lifted from the cut area,
and the root mass carefully cut apart and examined for living grubs. The soil beneath the cut sod
was scratched loose to a depth of 2 in and similarly examined. The total number of white grubs
found in each sample was recorded. Population counts in the samples were converted to number
of white grubs/sq ft for analysis and reporting.
The insecticides used in this project, the formulation, rate of application and mean number of white
grubs/sq ft are given in table 54. Significant differences among treatments and between treatments
and the untreated check were determined by analysis of variance (ANOVA). Means followed by the
same letter are not significantly different at the 0.05 level.

The average population density in the untreated check plots was only 10 white grubs/sq ft. While
this number is lower than population densities encountered in previous years, it was sufficient to
cause damage in irrigated, healthy turfgrass.
The ANOVA analysis reported in table 54 shows that Dursban emulsifiable concentrate did not
significantly reduce grub populations. This product has been inconsistent in controlling grubs in
similar trials. In addition, poor performance of Dursban for grub control is a common complaint
within the turfgrass industry. Turcam wettable powder did not provide good grub control at this site
again this year. The granular formulation (both 2 and 4 lb ai/A) did, however, significantly reduce
grub populations. It is uncertain what this indicates, other than that further experimentation and
pooling of observations is needed.
Conclusions from this trial are suspect and must be viewed with caution because of the low number
of grubs in the check and the high variability within treatment counts. All treatments except those
already mentioned provided suppression of white grubs, even with the lateness of the insecticide
application in the season. Those insecticides providing the best control in this trial were Dylox,
Mocap, Turcam 2.5G, and the Dow experimental product granules and Sevin, Oftanol, Tempo, and
Triumph liquid sprays. Once again, the best performance in this annual trial was with Mocap
insecticide.
Table 54. Effects of commercially available insecticides on annual white grubs infesting turfgrass,
Polk County, Iowa, 1988.
Insecticide /
Formulation
Control
Turcam 76WP
Dursban 4E
Dylox 80SP
Dylox 5G
Sevin SL
Oftanol 2E
Tempo 20WP
Mocap 10G
Dow XRM-4902 1G
Dow XRM-4902 1G
Turcam 2.5G
Turcam 2.5G
Triumph 4E
Mocap 5G

Rate
lb ai/A

2..1
1..0
8,.2
6..0
8..0
2,.0
0..1
5,.0
1 .0
0 .75
2 .0
4 .0
2 .0
5..0

* Treatment date - September 21, 1988.
Population count date - October 14, 1988.

Mean number white
grubs/sq ft
10..0 a
6..0 ab
6..0 ab
5..7 b
5..3 be
5..0 be
5..0 be
c
3,.7
3,.3 be
3..3 be
3..0 be
2,.7 be
2 .3 be
2 .0 be
1 .3
c

Iowa State University Personnel
Affiliated with the Turfgrass Research Program

Dr. Michael

Agnew

Assistant Professor, Extension Turfgrass Specialist.
Horticulture Department.

Ms. Mary Boyle

Undergraduate Research Assistant.
Horticulture Department. (Christians).

Mr. Michael Burt

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

Dr. Nick

Professor, Turfgrass Science.
Research and Teaching. Horticulture Department.

Christians

Dr. Mark Gleason

Assistant Professor, Extension Plant Pathologist.
Plant Pathology Department.

Ms. Harlene HattermanValertti

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

Dr. Clinton

Professor, Turfgrass Science.
Research and Teaching. Horticulture Department.

Hodges

Dr. Young Joo

Visiting Scientist. Horticulture Department.

Dr. Donald

Associate Professor, Extension Entomologist.
Entomology Department.

Mr. Richard

Lewis

Moore

Mr. Gary Petersen

Mr. Zachary Reicher

Mr. Roger Roe

Mr. Grant Spear

Research Associate. Horticulture Department.
Jasper County Extension Director and Graduate Student.
Horticulture Department M.S. (Agnew, M.).
Graduate Student and Research Associate.
Horticulture Department M.S. (Christians).
(Graduated May 1988).
Graduate Student and Research Associate.
Horticulture Department M.S. (Christians/Agnew N.)
Graduate Student and Research Associate.
Horticulture Department M.S. (Christians).

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 Truckster, a mataway, and a Lawn-Aire IV for use at the research area in
1988; to Tri-State Turf and Irrigation for providing a Greensmaster III Triplex Greensmower for use on
the research green; to the Toro Company and Tri-State Turf and Irrigation for providing a Toro 84
Triplex mower; to Professional Turf Specialties Inc. and E-Z-Go Textron for providing two E-Z-Go
maintenance trucksters; and to John Deere Company for providing a greens mower and plot mower.
American Hoechst Corporation
Agricultural Chemicals Department
Route 1 - Box 7
Brownsdale, Minnesota 55918
The Andersons
Post Office Box 119
Maumee, Ohio 43537
Aquatrols Corporation of America
1432 Union Avenue
Pennsauken, New Jersey 08110
Arcadian Corporation
1 Gatehall Drive
Post Office Box 265
Parsippany, New Jersey 07054
Big Bear Turf Equipment Company
10405 'J' Street
Omaha, Nebraska 68127
Brayton Chemical Company
215 North Sumner Street
West Burlington, Iowa 52655-0437
CIBA-Geigy Corporation
Agriculture Division
Greensboro, North Carolina 27049

Classen Manufacturing
1403 Rouch Street
Norfolk, Nebraska 68701
Cushman Turf
5232 Cushman
Lincoln, Nebraska 68501
D & K Turf Products
8121 Parkview Drive
Urbandale, Iowa 50322
Dow Chemical
10890 Benson - Suite 160
Shawnee Mission, Kansas 66210
Dupont Incorporated
1007 Market Street
Wilmington, Delaware 19898
Elanco Products Company
5600 South 42nd Street
Post Office Box 3008
Omaha, Nebraska 68103
EniChem Americas, Inc.
Research and Development Center
2000 Princeton Corporation Center
Monmouth Junction, New Jersey 08852

E-Z-Go Textron
Post Office Box 388
Augusta, Georgia 30906

LESCO Incorporated
300 South Abbe Road
Elyria, Ohio 44035

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

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

Grain Processing Corporation
Muscatine, Iowa 52761

M & A Enterprises
4346 South 90th
Omaha, Nebraska 68127

GrassRoots Turf
6143 Southwest 63rd
Des Moines, Iowa 50321
Hawkeye Chemical Company
Post Office Box 899
Clinton, Iowa 52732
International Seeds
820 First Street
Post Office Box 168
Halsey, Oregon 97348
Iowa Golf Course Superintendents
Association
Iowa Professional Lawn Care
Association
Iowa Turf Producers and
Contractors
Iowa Turfgrass Institute
John Deere Company
Moline, Illinois 61265
Lebanon Chemical Corporation
Country Club Fertilizer Division
Post Office Box 180
Lebanon, Pennsylvania 17042

Milorganite
735 North Water Street
Milwaukee, Wisconsin 53200
Monsanto Company
Agricultural Products Division
800 North Lindbergh Boulevard
St. Louis, Missouri 63167
NOR-AM Chemical Company
3509 Silverside Road
Post Office Box 7495
Wilmington, Delaware 19803
PBI/Gordon Corporation
1217 West 12th Street
Post Office Box 4090
Kansas City, Missouri 64101-9984
Pickseed West Incorporated
Post Office Box 888
Tangent, Oregon 97389
Professional Turf Specialties Inc.
133 Kenyon Road
Champaign, Illinois 61820
Rhone-Poulenc Chemical Company
Black Horse Lane
Post Office Box 125
Monmouth Junction, NJ 08852

Ringer Corporation
9959 Valley View Road
Minneapolis, Minnesota 55344

Sustance Corporation
1107 Hazeltine Boulevard
Chaska, Minnesota 55318

O. M. Scott and Sons
Marysville, Ohio 53040

Terra Chemical Corporation
Box 218
Quimby, Iowa 51049

Par Ex
Swift Agricultural Products Corp.
518 Pauline Drive
Buffalo Grove, Illinois 60090

The Toro Company
Irrigation Division
Riverside, California 92500

Ross Daniels Ine
1720 Fuller Road
West Des Moines, Iowa 50265

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

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

UAP Special Products
Omaha, Nebraska 68100

Stauffer Chemical Company
10250 Regency Circle
Omaha, Nebraska 68114

* In the rush to prepare this information for the field day report, some companies may have
inadvertently been missed. If your company has provided financial or material support for the
research program, and is not mentioned above, please contact me so your company name can
be added in future reports.

Nick E. Christians

Cooperative Extension Service, Iowa State University of Science and
Technology, and the United States Department of Agriculture
cooperating. Elizabeth A. Elliott, interim director, Ames, Iowa.
Distributed in futherance of the Acts of Congress of May 8 and June 30,
1914.

...and justice for ali
The Iowa Cooperative Extension Service's programs and policies are
consistent with pertinent federal and state laws and regulations on
non-discrimination regarding race, color, national origin, religion, sex,
age and handicap.