Table 6. Seedhead counts taken at each location on 27 June 1995.
5th Armored Div.
5th Armored Div.
Lane‡
Hospital
Drive I
Drive II
Memorial Drive
Reapply†
Treatments
Single*
Single
Reapply
Single
Reapply
Single
Single
1. Mefluidide, 2.3 L/ha
2.9
0.8
1.4
1.3
0.9
2.2
1.6
1.6
2. Mefluidide, 0.67 L/ha
23.2
6.8
4.7
7.4
8.6
10.9
11.8
10.5
3. Imidazolinone, 438 mL/ha
29.2
18.3
9.0
8.4
14.3
12.2
13.1
14.9
4. Imidazolinone, 136 mL/ha
39.6
21.8
10.4
7.0
16.7
11.1
14.4
17.3
5. Treatment 2 + 4
18.6
8.3
4.6
5.4
5.4
5.8
14.7
9.0
6. Mowed check
0.1
0.0
0.0
0.0
0.0
0.0
0.0
0.0
7. Unmowed check
48.2
18.8
12.7
8.7
22.0
10.1
19.4
20.0
LSD at 5%
13.2
4.8
4.9
2.7
4.1
6.3
10.9
* Single = PGR applied in 1995 only
†
Reapply = PGR applied in 1994 and 1995
‡ Hospital Lane received 1.5 times the recommended rate in 1994
seedheads/m2 at any of the locations. The num-
opment; these treatments provided about 50%
ber of seedheads produced by the unmowed check
decrease in seedhead development over the
varied widely and was probably dependent on
unmowed check. Imidazolinone provided only
soil conditions at that location and the type of turf
an average of 13 and 25% control of seedhead
growing at the site. Mefluidide applied in combi-
development for the low and recommended rates
nation with imidazolinone and at the lower rate
of application.
provided the next best control of seedhead devel-
Plant height data recorded biweekly from PGR-
treated and untreated plots at the six roadside
locations are shown in Figure 1. The unmowed
35
control produced consistently taller plants than
the mowed control. The greatest differences be-
Application Date: 2 May 1995
LSD = 2.29
tween dates occurred between 30 May and 14
June 1995, where there was about a 100% increase
30
in height. The PGR treatment was mefluidide at
the recommended rate and the mean height of
treated plants was never greater than 15 cm (6
Unmowed Check
in.). Increases in plant height did not correlate to
25
those recorded for plant weight.
In the separate area adjacent to 5th Armored
Division Drive, plant biomass production and
20
plant heights were recorded biweekly from the
mefluidide-treated and untreated mixed turfgrass
stands. Significant differences in plant biomass
were found for harvest date, PGR treatment, and
Desired Mowing Height
15
their interactions. Biweekly increases in plant bio-
mass were between 40 and 61% for the untreated
grasses and only 9 and 22% for the treated plots.
Mowed Check
The yields on the final harvest (2 June 1995) was
10
100% greater in the control as compared to the
Mefluidide
treated grasses (Fig. 2).
5
20
30
10
20
30
10
20
DISCUSSION AND CONCLUSIONS
May
Jun
Jul
Figure 1. Effect of a plant growth regulator (PGR)
Plant heights and appearance of seedheads are
on roadside vegetation maintenance (mefluidide ap-
usually the most identifiable indicators for deter-
plied at 2.3 L/ha).
mining when mowing should occur. The need for
5
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