Annual Bluegrass Control on Golf g Putting Greens with Spring A li ti

Annual Bluegrass
g
Control on Golf
Putting Greens with Spring
A li ti
Applications
off M
Methiozolin
thi
li
SHAWN D. ASKEW
VIRGINIA TECH, BLACKSBURG, VA
&
SUK J. KOO, MOGHU RESEARCH CENTER,
DAEJONG, S. KOREA
Introduction
y Methiozolin (MRC-01)
(MRC 01) was recently registered in South
y
y
y
y
Korea and is under development for US as a herbicide to
control annual bluegrass
g
on creeping
p g bentgrass
g
g
golf
greens and other turf sites.
More effective on Poa in fall.
Typically applied both fall and spring but fall treatments
are generally understood to be most important.
C it work
Can
k in
i spring?
i ?
Recent research indicates increased number of
applications at lower rates controls Poa better than fewer
high-rate treatments.
Objective
j
y Evaluate
E l t effect
ff t off 4 k
kg ai/ha
i/h methiozolin
thi
li
applied in spring with 4, 6, or 8 applications
compared to a traditional spring/fall
program and a paclobutrazol program for
annual bluegrass control
y Evaluate
E l t putting
tti green quality
lit and
d NDVI
response to various annual bluegrass control
programs
Methods
y RCBD,
RCBD 3 reps, two
t
locations
l ti
(Blacksburg
(Bl k b
&
y
y
y
y
Harrisonburg, VA)
30 gal/A,
l/A 38
8 psi,
i Teejet
j TTI04
Visual estimate annual bluegrass and creeping
bentgrass cover, turf quality, annual bluegrass
control, and creeping bentgrass injury
Ball speed assessed with stimp meter
NDVI assessed with Crop
p Circle Spectral
p
Analyzer
y
Locations
Spotswood Green = mown 0.125 in (3 mm),
Pushup 1962
1962, 15 cm of 70/30 sand/soil mix on
top, Penncross/L93 with 60% annual bluegrass
VT Golf Coursecover
= mown 0.125 in (3 mm), Pushup
1973 sandy soil,
1973,
soil Putter/Penncross with 70%
annual bluegrass cover
€
€
Annual bluegrass cover over time at Spotswood
Country Club
Club, Harrisonburg,
Harrisonburg VA
80
NS
12
15
11
11
18
9
10
6
70
60
50
40
30
20
10
0
NTC
8 Apps
A
6 Apps
4 Apps
Spr./Fall
Annual bluegrass cover over time at Virginia Tech
Golf Course
Course, Blacksburg
Blacksburg, VA
100
90
80
70
60
50
40
30
20
10
0
NS
18
20
11
9
25
6
7
NTC
8 Apps
6 Apps
4 Apps
S /F ll
Spr./Fall
Paclo
MRC-01
C 0 Spring
Sp g Programs
og a s Trial
a at Spots
Spotswood
ood CC
6 apps
8 apps
NTC
4 apps
8 apps
NTC
NTC
8 apps
pp
MRC-01
C 0 Spring
Sp g Programs
og a s Trial
a at Spots
Spotswood
ood CC
Measuring
g NDVI
NS
NS
NS
0.016
0
0.023
0
0.043
0
0.049
0
0.8
8
NS
Effect of Herbicides on NDVI
0.75
07
0.7
0.65
06
0.6
0.55
05
0.5
0.45
0.4
4
NTC
8 Apps
6 Apps
4 Apps
pp
Spr./Fall
NS
0.845
0
NS
0.763
0
0.942
0
0.865
0
0.865
0
NS
0.043
0
9
NS
NS
Effect of herbicides on q
qualityy at Spotswood
p
8
7
6
5
4
3
Core
Aeratio
n
NTC
8 Apps
6 Apps
4 Apps
pp
Spr./Fall
Mar 4
Mar 18
Apr
4
Apr 28
May 13
May
26
Jun 15
Oct 1
Oct
Apr 15
Jun 3
Nov 17
Measuring
g Stimp
p
Effect of MRC-01 on Stimp Readings at
Spotswood
Spots
ood CC, Ju
Junee 3, 2011
0
10.5
A
10
A
A
A
Stimp (ft)
9.5
9
B
8.5
8
7.5
8 Apps 500
g/ha
6 Apps 667
g/ha
4 Apps 1000 3 Apps 1120
g/ha
g/ha
MRC-01 Treatments
Nontreated
Conclusions
y Spring
S i programs off repeated
t d MRC
MRC-01 treatments
t t
t
appear to be a viable approach to annual bluegrass
control on golf putting greens infested with high
percentage of annual biotypes of Poa.
y Fewer,
F
hi
high-rate
h t ttreatments
t
t control
t l annuall
bluegrass less than frequent, low-rate treatments.
y Once annuall bl
bluegrass iis controlled,
ll d turff quality
li and
d
ball speed may increase.