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EVALUATION OF THE PERFORMANCE OF NUTRI-KOTE COATED CREEPING
BENTGRASS SEED FOR PUTTING GREEN TURF
K. Carey and E. Gunn
Guelph Turfgrass Institute and Dept. of Plant Agriculture, Horticulture Division
Sponsor:
CelPril
OBJECTIVES
The objective of this research project was
to evaluate the performance of creeping bentgrass
seed coated with Nutri-Kote+Apron compared to
an uncoated control in newly seeded USGA sand
putting greens.
Data collected included emergence time
(1st emergence and 50% emergence), speed of stand
establishment, density, height and vigor, as well
as root and shoot system growth rates.
EXPERIMENTAL DESIGN / METHODS
The treatments (Table 1) consisted of uncoated seed of two uncoated creeping bentgrass
cultivars, Cato and Penncross seeded at an industry standard rate, and the same seed coated with
Nutri-Kote+Apron at 1x the rate (by weight) as
the uncoated mixture.
Treatments were seeded into 1 x 2 m2 plots,
replicated 6 times in a randomized complete block
design. Plots were located on the low pH (siliceous) sand section of the east USGA green at the
Guelph Turfgrass Institute. The seedbed was bare
sand/peat USGA mixture rootzone. A standard
rate of a starter fertilizer was applied to all plots
before seeding. Seeding rate was 500 g 100 m-2.
Seeded plots were irrigated following seeding as
for a normal putting green grow-in.
Plots were observed and time of first emergence (days after seeding) noted. Following first
emergence, the plots were rated every other day
for emergence (visual rankings and chlorophyll
index - CM1000 chlorophyll meter), density,
height, and vigor (visual rankings). Digital photographs of representative 1 m2 areas of each plot
were taken at first emergence and along with all
subsequent ratings.
Root samples were collected at 30 days after emergence (45 days after seeding). Four cores
were taken per replicate, each core 20 cm depth,
50 cm3 volume). Cores were washed and root systems scored for depth and root system size.
Soil strength and soil compaction measurements (proving ring penetrometer) of the
plots were taken at 61 and 90 days after seeding to
determine rootzone stability and playability.
All data was analyzed using general linear
model ANOVA's and means separations where
appropriate.
Following the collection of shoot and root
growth data, the plots were maintained as putting
green type turf (4 mm mowing height, irrigation
to prevent stress), and will be assessed in spring
2002 for turf performance, winter survival, spring
greenup, and weed infestation.
RESULTS
Emergence and cover
Table 1. Treatments
Treatment
Seeding rate
(g m-2)
1 Cobra
5
2 Penncross
5
3 Cobra - coated: Nutri-Kote+Apron
5
4 Penncross - coated: Nutri-Kote+Apron
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Guelph Turfgrass Institute
Differences among the treatments in
emergence as estimated by visual ratings were
only significant on three observation dates (16,
18 and 19 days after seeding, Table 2, Figure 1).
Generally, the coated seeds were slightly slower to
emerge than the raw seed, particularly early in the
2001 Annual Research Report
21
Emergence / cover
8
Visual rating (0-10)
7
6
5
4
3
2
Cato
Cato coated
Penncross
Penncross coated
1
0
10
20
30
40
50
60
70
Days after seeding
Figure 1. Emergence/cover in seeded plots, estimated visually.
Table 2. Emergence (visual rating 0 - 10)
Treatment
Date (Days after seeding)
06/06 (14) 06/07 (15) 06/08 (16) 06/10 (18) 06/11 (19) 06/14 (22) 06/19 (27) 06/28 (36) 07/07 (45) 07/13 (51) 07/30 (68)
Cato
0.10* a
0.10 a
2.17 a
3.33 a
2.63 a
4.17 a
5.33 a
6.83 a
6.00 a
7.00 a
7.00 b
Cato coated
0.10 a
0.10 a
2.25 a
2.58 bc
2.29 ab
3.67 a
5.00 a
6.67 a
6.83 a
6.33 a
8.00 a
Penncross
0.10 a
0.10 a
2.17 a
3.00 ab
1.96 b
3.50 a
5.17 a
6.67 a
7.00 a
6.67 a
7.83 ab
Penncross coated
0.10 a
0.10 a
1.42 b
2.25 c
2.04 ab
3.17 a
4.50 a
6.33 a
7.00 a
6.83 a
8.00 a
lsd p=0.05
0
0
0.6466
0.6962
0.6616
1.8754
1.5154
1.395
1.1687
1.0602
0.8864
*Means within columns followed by the same letter are not significantly different (p=0.05, Fisher's protected lsd).
Emergence
Chlorophyll index (0-1000)
170
150
130
110
90
Cato
Cato coated
Penncross
Penncross coated
70
15
25
35
45
55
65
75
Days after seeding
Figure 2. Emergence/cover in seeded plots, estimated using chlorophyll index.
Table 3. Emergence (chlorophyll index 0 - 1000)
Treatment
Date (Days after seeding)
6/11 (19) 6/15 (23) 6/19 (27) 6/21 (29) 6/28 (36) 7/01 (39) 7/04 (42) 7/13 (51) 7/18 (56) 7/23 (61) 7/31 (69) 8/09 (78)
Cato
75.48* a 81.53 ab 87.16 a
96.60 a 111.58 b 108.36 ab 135.58 ab 142.89 b 134.81 b 155.59 b 130.69 c 114.37 b
Cato coated
75.97 a
82.56 a
86.68 a
99.44 a 118.28 a 112.05 a 139.70 a 146.98 a 141.83 a 162.86 a 137.10 a 118.55 a
Penncross
75.19 a
80.36 b
85.75 a
96.51 a 111.35 b 107.06 b 136.13 ab 145.32 ab 139.58 a 159.88 a 134.60 b 118.26 a
Penncross coated
73.68 b
78.11 c
82.31 b
92.58 b 112.13 b 105.01 b 132.03 b 142.47 b 138.52 ab 159.47 a 134.40 b 117.52 a
lsd p=0.05
1.1003
1.783
2.6589
3.172
4.361
3.7204
4.9217
3.7132
4.225
3.4841
2.2743
*Means of 20 readings per replicate x 6 replicates. Means within columns followed by the same letter are not significantly different (p=0.05, Fisher's
protected lsd).
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Guelph Turfgrass Institute
2001 Annual Research Report
trial. First emergence for all treatments was at 14
days, and 50% cover was between 28 and 30 days
after seeding.
Emergence as measured by the chlorophyll
index (Spectrum CM1000 chlorophyll meter)
showed similar small differences among treatments (Table 3, Figure 2). Where differences were
significant, generally the Cato treatments were
ahead of the Penncross treatments in emergence
and cover. Within the cultivars, the coated Cato
seed generally emerged faster than the raw, while
the raw Penncross seed emerged faster than the
coated. The chlorophyll meter is not useful at
early emergence stages, so no estimate is available from this data of date of first emergence.
Similarly, without further calibration it is not
possible to estimate the date of 50% cover using
this data.
Table 4. Uniformity of turf cover (visual rating 0-10)
Date (Days after seeding)
Treatment
6/19
7/07
7/13
7/30
(27)
(45)
(51)
(68)
Cato
6.50* a
6.00 a
5.50 a
5.83 b
Cato coated
5.17 a
8.00 a
7.50 a
7.50 a
Penncross
6.17 a
6.67 a
6.33 a
7.50 a
Penncross coated
5.33 a
7.33 a
6.67 a
7.50 a
lsd p=0.05 2.23
2.06
2.25
1.55
*Means within columns followed by the same letter are not
significantly different (p=0.05, Fisher's protected lsd).
Turf uniformity
The coated seed treatments generally rated
higher for turf uniformity, particularly later in the
trial (Table 4, Figure 3), but the differences among
the treatments were not statistically significant.
Soil strength
The penetrometer readings (Table 5, Figure 4) give an estimate of soil strength or stability
at the surface (0 cm) and compaction or soil
strength within the rootzone (5 and 10 cm). The
Cato coated and Penncross uncoated seed treatments had slightly higher soil strength values for
the surface, but the differences were not statistically significant. The only significant differences
appeared at the 5 cm depth 61 days after seeding,
when the uncoated treatments had higher soil
strength readings at that depth. This is probably
Table 5. Soil strength at 3 depths as measured by proving ring penetrometer.
7/23
8/21
Treatment
0 cm
5 cm
10 cm
0 cm
5 cm
10 cm
Cato
184.7* a 376.9 ab 478.4 a
170.4 a
371.3 a
502.8 a
Cato coated
185.5 a
361.2 c
474.2 a
176.0 a
385.8 a
505.6 a
Penncross
191.4 a
383.3 a
482.8 a
176.2 a
380.1 a
504.0 a
Penncross coated 183.0 a
369.7 bc 475.5 a
173.4 a
367.5 a
505.7 a
lsd p=0.05 12.731
13.409
13.902
12.332
25.366
17.026
*Means of 4 readings per replicate x 6 replicates. Means within columns followed
by the same letter are not significantly different (p=0.05, Fisher's protected lsd).
Soil strength
600
Proving ring penetrometer reading
Uniformity of turf cover
8
7
Rating (0-10)
6
5
4
3
2
500
400
300
200
100
0
0 cm
1
Cato
0
27
Cato
45
51
Days after seeding
Cato coated
Penncross
5 cm
10 cm
0 cm
7/23
Depth
Cato coated
Penncross
5 cm
10 cm
8/21
Penncross coated
68
Penncross coated
Figure 4. Soil strength of seeded plots, measured with
proving ring penetrometer at various depths.
Figure 3. Uniformity of turf cover, rated visually.
Guelph Turfgrass Institute
2001 Annual Research Report
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Soil moisture
25
Root system characteristics
16
14
Volumetric water (%)
20
12
15
10
8
10
6
5
4
2
0
7/23
8/21
0
Cato
Cato coated
Penncross
Penncross coated
Figure 5. Volumetric water content of seeded plots,
measured with Thetaprobe.
Table 6. Volumetric water content of
plots at time of soil strength
measurements.
Treatment
7/23
8/21
Cato
20.1* b
19.4 b
Cato coated
21.5 a
21.0 a
Penncross
20.1 b
20.3 ab
Penncross coated 21.1 ab
21.0 a
lsd p=0.05
1.217
1.0092
*Volumetric water content (%) measured by
ThetaProbe. Means of 4 readings per
replicate x 6 replicates. Means within
columns followed by the same letter are not
significantly different (p=0.05, Fisher's
protected lsd).
an indirect result of the significant differences in
soil moisture observed at the same time in the
plots (Table 6, Figure 5), since there is a strong
negative correlation between soil strength an
moisture content. There was significantly higher
soil moisture in the coated seed treatments on
both measurement dates.
Root system growth
Length (cm)
Cato
Cato coated
Rating (1-10)
Penncross
Penncross coated
Figure 6. Root system characteristics of seeded plots,.
Table 7. Root system measurements.
Treatment
Length (cm)
Root system size
rating (1 - 7)
Cato
13.02* a
3.54 a
Cato coated
13.95 a
3.88 a
Penncross
13.63 a
3.50 a
Penncross coated
14.09 a
3.79 a
lsd p=0.05
1.3333
0.6227
*Means of 4 cores per replicate x 6 replicates. Means
within columns followed by the same letter are not
significantly different (p=0.05, Fisher's protected lsd).
CONCLUSIONS
We observed only very small and generally statistically insignificant differences between
the coated and uncoated seed treatments in rate
of early emergence and establishment in this trial.
The coated seed treatments did produce a slightly
more uniform turf, with slightly larger
rootsystems, but there was no significant effect
on soil strength or stability at the surface
While the root systems of the coated seed
treatments were longer and larger (based on a root
system rating which integrates root mass and density visually) than the uncoated treatments (Table
7, Figure 6), these differences were not statistically significant
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Guelph Turfgrass Institute
2001 Annual Research Report