Evaluation of Palisade® on Fifteen Kentucky Bluegrass
Varieties Grown for Seed in Central Oregon, 2010
Marvin Butler, Rich Affeldt, Rhonda Simmons, and Kandy Marling
Abstract
The growth regulator, Palisade® (Trinexapac-ethyl), was evaluated on 15 Kentucky bluegrass
(Poa pratensis) varieties grown for seed at the Central Oregon Agricultural Research Center.
One set of plots is a second-year stand and the other is a third-year stand. The influence of
Palisade on plant height, lodging and seed yield were documented. Treatments were applied at
early boot stage and varieties were harvested based on maturity. Despite a trend for increased
yields of 20 percent across varieties following Palisade treatments, interaction differences
between varieties and Palisade treatments have not been significant for second- and third-year
stands. The trend was for a reduction in plant height of 4 inches and reduction in lodging of 12 to
21 percent.
Introduction
Research to evaluate Palisade on Kentucky bluegrass was conducted in commercial seed fields
of ‘Merit’ or ‘Geronimo’ from 1999 to 2003. Yields were increased by 31 to 36 percent 4 of the
5 years when Palisade was applied at 22 oz/acre from the second node (Feekes growth stage 7) to
heads just becoming visible (Feekes 10.1). Late application, when the heads extended just above
the flag leaf (Feekes 10.4), produced the greatest reduction in plant size, while plants tended to
outgrow the effect of earlier Palisade applications. No differences between treatments in weight
per 1,000 seeds were observed, and percent germination was not adversely affected.
Methods and Materials
This research was conducted at the Central Oregon Agricultural Research Center (COARC) near
Madras. A split-plot design was used, with 10-ft by 60-ft main plots and 10-ft by 20-ft subplots
for comparing yields for plots treated with the growth regulator Palisade and plots left untreated.
Main plots were replicated four times in a randomized complete block design.
Palisade was applied at 24 oz/acre to both plantings on May 4 when most varieties were in the
early boot stage. Application was made with a CO2-pressurized, hand-held boom sprayer at 40
psi and 20 gal/acre water using TeeJet 8002 nozzles. Plant height was measured at both plantings
on June 7; percent lodging was estimated on June 29 for the second-year field (2008) and on July
2 for the third-year field (2007). A 6-ft by 17-ft section of each plot was swathed as varieties
matured from July 7 to July 15. This was followed by combining of the plots at an appropriate
timing. Equipment used was a plot-sized swather and Wintersteiger plot combine. Seed samples
were transported to the Hyslop Farm near Corvallis, Oregon where they were debearded, run
through a small-scale Clipper cleaner, and clean seed weight was determined.
17
Results and Discussion
There were no significant interactions between the 15 Kentucky bluegrass varieties and Palisade
treatments. However, there was a trend for increased seed yield following application of
Palisade, with one exception on the second-year field and two exceptions on the third-year field.
Yield across all varieties averaged 19 percent higher (141 lb) on the second-year field and 25
percent higher (132 lb) on the third-year field (Tables 1 and 2). The trend was a reduction in
plant height of 4 inches across both stand ages, with a 12 percent reduction in lodging for the
second-year field and 21 percent for the third-year field. There were stand problems with the
2007 planting (third-year field) following the first year of production. As a result, less confidence
should be given to results from the third-year field.
Overall Project Discussion
The first planting was made in 2007, with a second planting in 2008. Design of these plots
includes nonthermal residue management. Following harvest, straw was baled and remaining
residue was removed mechanically using a Grass Vac to simulate field conditions following
baling in the large plot variety evaluations off station. Harvest in 2008 was one first-year field,
harvest in 2009 included a first-year and second-year field, harvest in 2010 was a second-year
and third-year field, with an expected final harvest in 2011 of the final third-year field. When the
project is completed we will have data for three ages of fields across two planting dates. This
design also provides a comparison of results for the same age field across two different
production years. There were stand issues for the 2007 planting following the first production
year. This creates less confidence in the second- and third-year data from this field, and less
weight should be given to these results.
Statistical analysis indicated significant interactions between the 15 Kentucky bluegrass varieties
and Palisade treatments on first-year stands, with no statistical significance in the second and
third years. Looking at trends associated with the 5 harvests across 3 production years to date,
Palisade increased seed yield by an average of 22 percent (Table 3). The average for first-year
fields was a 23 percent increase, second-year fields averaged 22 percent and the 1 year of a thirdyear field was a 25 percent increase. Reduction in plant height from Palisade averaged 2.9 inches
across 3 years, with a reduction of 1.7 inches for first-year fields, 3.8 inches across second-year
fields, and 3.4 inches for the one third-year field. Palisade reduced lodging by an average of 40
percent across 3 years, with a reduction of 35 percent in first-year fields, 39 percent in secondyear fields, and 48 percent for the one third-year field.
Evaluating the influence of Palisade by production year across stand age indicates an 11 percent
increase in seed yield in 2008, 28 percent increase during 2009, and 25 percent increase in 2010.
Palisade reduced plant height by an average of 1.3 inches in 2008, and 3.3 inches for both 2009
and 2010. Percent reduction in lodging with Palisade averaged 35 percent in 2008, 30 percent in
2009, and 52 percent in 2010.
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Table 1. Effect1 of Palisade growth regulator on seed yield, lodging, and plant height on a 2ndyear field of 15 Kentucky bluegrass varieties planted August, 2008, at COARC, Madras, OR.
Clean seed yield (lb/acre)
Variety
Check Palisade % Check
Atlantis
935
1202
129
Merit
840
718
85
Rhapsody
921
974
106
Valor
695
718
103
Bariris
390
474
122
Crest
705
984
140
Monte Carlo
790
972
123
Shamrock
1127
1493
132
A00-891
1349
1357
101
A00-1400
465
621
134
Bandera
789
955
121
Bordeaux
932
1132
121
Volt
743
894
120
Zinfandel
651
912
140
A01-299
818
863
106
Evaluation dates
6/7/10
6/29/10
Plant ht (in)
Lodging (%)
Check Palisade
Check Palisade
27
26
18
18
23
19
25
3
20
15
3
0
14
14
0
0
28
27
95
94
23
18
30
4
14
13
0
0
30
27
63
35
21
16
43
14
18
16
30
4
19
14
4
1
26
18
56
10
30
27
58
59
16
13
0
0
16
15
0
0
1
Comparison with paired t-test indicated no significant interactions between varieties and Palisade
treatments.
Table 2. Effect1 of Palisade growth regulator on seed yield, lodging, and plant height on a 3rdyear field of 15 Kentucky bluegrass varieties planted August, 2007, at COARC, Madras, OR.
Evaluation dates
6/7/10
7/2/10
Clean seed yield (lb/acre)
Plant ht (in)
Lodging (%)
Variety
Check
Palisade
% Check
Check Palisade Check
Palisade
Atlantis
369
788
214
28
24
63
9
Merit
720
1020
142
22
18
30
0
Rhapsody
958
1000
104
20
17
23
0
Valor
733
905
123
17
11
0
0
Bariris
289
632
219
28
25
99
89
Crest
1174
1228
105
22
17
35
10
Monte Carlo
1107
878
79
15
13
20
4
Shamrock
1212
1309
108
28
26
83
48
A00-891
1579
1751
111
20
16
40
15
A00-1400
792
1089
138
15
15
11
9
Bandera
1150
1055
92
19
18
5
20
Bordeaux
1207
1060
88
23
18
74
36
Volt
1167
1290
111
29
25
85
49
Zinfandel
1037
1333
129
17
14
19
0
A01-299
924
1060
115
22
17
18
0
1
Paired t-test indicated no significant interactions between varieties and Palisade treatments.
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Table 3. Three-year averages of clean seed yield, lodging and plant height for 2007 and 2008
plantings of Kentucky bluegrass with application of Palisade at COARC, Madras, OR.
Averages across varieties
Seed yield (lb/acre)
Check Palisade
2007
Planting
1st Year
2nd Year
3rd Year
2008
Planting
1st Year
2nd Year
Plant lodging (%)
% Check Check Palisade Dif.
Plant ht (in)
Check Palisade Dif.
1266
702
961
1383
822
1093
111
122
125
67
43
40
24
9
19
35
21
48
26.4
21.5
21.7
25.1
17.0
18.3
1.3
4.4
3.4
1025
810
1341
951
135
119
61
28
24
16
39
57
14.3
21.7
12.3
18.5
2.1
3.1
20