Sea Isle 2000 on desert greens: Mowing height and ... - GCSAA

ing dates, but this trend was consistent on
almost every evaluation date. In both <strong>2000</strong>
and 2001, turf color responded positively to
fertilization rate, with improved color at the
higher levels of nitrogen fertilization. In general,
turf color was lightest in July (monsoon
period), averaging less than 6.0 in both years.
Turf color scores were noticeably higher in
October 2001 than in October <strong>2000</strong>, probably
because temperatures in fall 2001 were
unseasonably warm.
To maintain a color score of 6.0 or greater
throughout the test, turf mowed at 1 ⁄8 inch
required 0.50 pound nitrogen/1,000 square
feet/month; turf mowed at 5 ⁄32 required 0.38
pound, and turf mowed at 3 ⁄16 inch required
0.25 pound.
TURF COLOR, <strong>2000</strong> & 2001
Turf quality: <strong>2000</strong> and 2001
Mowing height had no consistent or
significant influence on visual quality, and
turfgrass quality was not influenced by the
combination of applied nitrogen fertilizer and
mowing height (Table 2).
Turf responses to fertilizer were different
each year. In <strong>2000</strong>, turfgrass quality declined
as nitrogen rate increased early in the season
(June). This showed that <strong>Sea</strong> <strong>Isle</strong> <strong>2000</strong> performed
just as well or slightly better when it
received low rates of nitrogen (0.25 and 0.38
pound/nitrogen/1,000 square feet/month).
In general, in turf that was not overseeded,
medium to high rates of nitrogen (0.50
pound/1,000 square feet/month) improved
turf quality in the spring and fall, and low rates
of nitrogen (0.25-0.38 pound/1,000 square
feet/month) provided good turf quality during
the hottest months of summer. Across both
years, turf mowed at 1 ⁄8 inch required 0.50
pound nitrogen/1,000 square feet/growing
month to produce a turf quality score of 6.0
or greater, and turf mowed at 5 ⁄32 and 3 ⁄16 inch
produced turf quality ratings of 6.0 or higher
when fertilized with only 0.25 pound nitrogen/1,000
square feet/growing month. When
not overseeded, seashore paspalum is fully
green from May to October in the desert.
Leaf widths
Leaf widths were measured in August
2001. Twelve shoots were sampled from each
plot, and leaf width was measured to the nearest
0.1 millimeter. Leaf width showed little
variation across all plots (1.4-1.7 millimeters
for the second leaf, and 1.4-1.8 millimeters
for the third leaf). Neither mowing height nor
RESEARCH
nitrogen fertilization rates produced profound
effects for leaf texture or leaf width measurements
in <strong>Sea</strong> <strong>Isle</strong> <strong>2000</strong>.
Ball roll distance: <strong>2000</strong>
In <strong>2000</strong>, ball roll distance was measured
on six calendar dates. On three of these dates,
the greens were rolled, and ball roll distance
was measured immediately after rolling. In
<strong>2000</strong>, mowing height significantly affected
ball roll distance in seven of eight measurements
(Table 3). When averaged over all
nitrogen rates, mean ball roll distance values
ranged from 4 feet, 10.4 inches ( 3 ⁄16 inch
mowing height, July 13) to 7 feet, 10.1 inches
( 1 ⁄8 inch mowing height, Oct. 31).
In <strong>2000</strong> turf mowed at 1 ⁄8 inch ranked first
for ball roll distance on four dates (July 13,
July 28, Aug. 31 and Oct. 31) when it was
mowed and not rolled and ranked first for ball
roll distance on two dates when it was mowed
and also rolled (Aug. 31, Nov. 7). When turf
was mowed without rolling, turf mowed at 5 ⁄32
inch had greater ball roll distances than turf
mowed at 3 ⁄16 inch in July and August but not
in September and October.
In general, increases in ball roll distance
were linearly related to a decrease in mowing
Mowing height (inches)
<strong>2000</strong> ratings 2001 ratings Average,
<strong>2000</strong> &
June 27 July 28 Aug. 28 Sept. 27 Oct. 30 May 17 June 25 July 23 Aug. 21 Sept. 10 Oct. 6 2001
1
⁄8 6.3 5.2 6.3 6.3 5.7 6.5 6.1 5.6 6.6 5.8 6.3 6.0
5
⁄32 6.1 6.3 6.1 6.9 6.3 7.3 6.8 5.8 6.5 6.3 6.8 6.4
3
⁄16 6.0 6.1 6.8 6.6 5.7 7.3 6.8 5.8 7.3 6.8 7.0 6.5
Test mean 6.1 5.9 6.4 6.6 5.9 7.0 6.6 5.7 6.8 6.3 6.7 6.3
LSD ns 0.44 ns ns 0.50 0.68 0.65 ns 0.60 0.87 0.60
Fertilizer rate (pounds/nitrogen/1,000 square feet)
0.25 5.8 5.4 5.8 6.0 5.3 6.1 6.4 5.4 6.3 5.9 6.0 5.9
0.38 5.8 5.7 6.3 6.0 5.4 6.8 6.1 5.8 6.7 6.3 6.3 6.1
0.50 6.1 6.2 6.4 6.8 5.9 7.3 6.8 5.9 6.9 6.2 6.8 6.5
0.75 6.8 6.1 6.9 7.6 6.8 7.9 7.0 5.8 7.3 6.9 7.7 6.9
Test mean 6.1 5.9 6.4 6.6 5.9 7.0 6.6 5.7 6.8 6.3 6.7 6.4
LSD 0.80 ns 0.81 0.40 0.67 0.51 ns ns 0.38 0.69 0.57
Note. Color was rated on a scale of 1-9, where 1 = dead, 6= fully acceptable and 9 = best possible. Values are the mean of four replications. Test mean = mean of all treatments
on that date. LSD = Least significant difference mean separation statistic. ns, not significant.
Table 1. Visual color of a <strong>Sea</strong> <strong>Isle</strong> <strong>2000</strong> paspalum putting green under selected mowing height and fertilization regimes, summer <strong>2000</strong> and 2001, Karsten Turfgrass Research
Facility, University of Arizona.
November 2005
GCM 85