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Downy Brome Management in Montana Agriculture. Cropland Weed Research Montana State University Edward Davis, Fabian Menalled. Presentation Outline. Biology and identification of brome species. Weedy characteristics Management considerations. Herbicide options. - PowerPoint PPT Presentation
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Downy Brome Management in Montana Agriculture
Cropland Weed Research
Montana State University
Edward Davis, Fabian Menalled
Presentation Outline
• Biology and identification of brome species.
• Weedy characteristics
• Management considerations.
• Herbicide options.
• Herbicide label rates and application timing.
• MSU field trial results.
Weed Science Terminology For Brome Species
“Cheatgrass”
Downy brome Bromus tectorum
Japanese brome Bromus japonicus
Cheat Bromus secalinus
Not found in MT
CheatCheat is in Oklahoma, not MT!
Pictures from Interactive Encyclopedia of North American Weeds
(Bromus secalinus)
Not found in MT!!!
Weed scientists refer to Bromus secalinus as Cheat. However, they refer to Bromus tectorum as Downy brome or Cheatgrass.
Cheat Bromus secalinus
Slide courtesy of Dr. Phil Stahlman, KSU
Not found in MT
Downy brome
Pictures from Interactive Encyclopedia of North American Weeds
(Bromus tectorum)
Japanese brome
Pictures from Interactive Encyclopedia of North American Weeds
(Bromus japonicus)
Japanese brome Downy brome
Downy brome (Bromus tectorum)Taller ligule than Japanese, more serrated ligule than Japanese
Japanese brome (Bromus japonicus)Shorter ligule than Downy, less serrated ligule than DownyMore hairy, longer hairs than Downy, especially on underside of leaf
Pictures from Interactive Encyclopedia of North American Weeds
Downy Brome Bromus tectorum
Downy brome Bromus tectorum
Slide courtesy of Dr. Phil Stahlman, KSU
Japanese brome Bromus japonicus
Slide courtesy of Dr. Phil Stahlman, KSU
Japanese brome
Slide courtesy of Dr. Phil Stahlman, KSU
Cheat (Chess)Bromus secalinus
Downy bromeBromus tectorum
Japanese bromeBromus japonicus
Downy Brome (cheatgrass)
• Bromus tectorum• Winter annual grass
weed• Reduces crop yield• Reduces soil
moisture
Downy brome
Found mostly in 6 to 22 inch precipitation zones
Grows at elevations up to 8850 ft
Prefers coarse textured soils, but grows well on all but extremely heavy or highly saline soils
Downy Brome
• Up to 400 seed/plant• 500# seed/a
– 125 million/a– 2,870/sq.ft.
• Matures 4 wk earlier than wheat
• Initial dormant period• Short soil seed life
– 2-3 yrs.
Reasons Why Annual Bromes Are Increasing
Conservation tillage
Increased fertilization
Shorter, less competitive varieties
Highly effective broadleaf herbicides
Drought years ,CRP
Cultural Control PracticesManagement
Crop rotation
Delayed seeding
Winter wheat row spacing
Winter wheat seeding rates
Competitive wheat cultivars
Fertilizer timing and placement
Weed Response to Crop RotationSidney, NE
System Dobr JGG Rye
-------- plants/sq yd --------
CW 176 109 148
WF-tillage <1 9 2
WF-herbicide <2 12 4
WSFF <2 <1 <1
WPMF <3 <1 <1
Lyon and Baltensperger 1995
Delayed Seeding
Effective for downy brome control in Effective for downy brome control in
only 1 of 6 years in Colorado.only 1 of 6 years in Colorado.
Lower yield potential and higher risks Lower yield potential and higher risks
of winter kill and wind erosion. of winter kill and wind erosion.
In Oklahoma, a 4-wk delay for cheat In Oklahoma, a 4-wk delay for cheat
control resulted in economic loss.control resulted in economic loss.
Anderson 1996Ferreira et al. 1990
Row Spacing and Seeding Rate20 site-years in Oklahoma
0
5
10
15
20
25
30
35
Wh
ea
t y
ield
(B
u/A
)
9 3 9 3
Row spacing (inches)
Weed Free
Cheat
---- 60 lb/A ---- ---- 120 lb/A ----
Epplin et al. 1996
Wheat Seeding Rate Affects CheatWheat Seeding Rate Affects Cheat20 site-years in Oklahoma20 site-years in Oklahoma
0
5
10
15
20
25
30
Wh
ea
t y
ield
(B
u/A
)
60 90 120
Wheat Seeding Rate (lb/A)
Weed Free
Cheat D 1
Cheat D 2
Epplin et al. 1996
Downy Brome Response to NPendleton, Oregon
0
12
34
5
67
89
10
0 50 100 150
Nitrogen rate (lb/A)
Nu
mb
er
/sq
yd
Plants
Tillers
Rasmussen 1995
N Timing Affects Downy BromeAkron, CO
0
50
100
150
200
250
300
350
Cu
lms
/sq
m
Time of N Application
None
Fallow
Planting
Dormancy
Prejoint
Anderson 1991
N Placement on Downy BromeWyoming
0
200
400
600
800
1000
1200
1400
No
. o
r lb
/ac
re
Plants Dry wt.
Downy brome
BdcstBand
Miller 1990
Fertilizer Placement Pendleton, OR
Dobr Dobr Wheat
Treatment tillers biomass biomass
no/sq yd g/sq yd g/sq ydN 4.1 1.1 545
N+P+S 5.8 8.7* 628*
N band 5.8 8.7 628*N bdcst 21.7* 10.6 569
Rasmussen 1995
Weed-Crop Competition
resource availability
plant and tiller density
environmental conditions
winter wheat competitiveness
time of emergence relative to wheat
Winter annual grass interference is a function of several factors including:
Weed-Crop Competition
Moderate weedy brome infestations
reduce winter wheat yields by 20 to
40%; dense infestations up to 90%.
Yield losses are most severe when
resources are limited and weeds and
wheat emerge simultaneously.
Weed-Crop Competition
Research in Kansas and Alberta
With normal wheat stands and adequate
resources, low to moderate infestations
of downy brome that emerge 3 weeks or
later than winter wheat usually do not
reduce wheat yield.
Blackshaw 1996Stahlman and Miller 1990
Winter Wheat Yield Loss
Cultivar Competitiveness
Winter wheat cultivars vary widely in their competitiveness with weeds.
Plant height is the characteristic most associated with increased competitiveness.
Early plant growth, tillering ability, and leaf area also are important.
Grass weed response to herbicides
Downy brome
Japanese brome
Less susceptible
More susceptible
Maverick
Sulfosulfuron
ALS Enzyme Inhibitor (blocks protein synthesis)
The first selective herbicide developed for control of winter annual brome species in wheat.
Controls several common winter annual broadleaf weeds
Restrictive crop rotation intervals
Olympus Propoxycarbazone-sodium
ALS Enzyme Inhibitor (blocks protein synthesis)
Main target weeds are cheat, downy brome and Japanese brome as well as a number of key broadleaves.
Olympus may control wild oat and suppress jointed goatgrass.
Olympus FLEX is a mixture of propoxycarbazone-sodium and mesosulfuron-methyl.
Osprey
mesosulfuron-methyl
ALS enzyme inhibitor (blocks protein synthesis)
Main target weeds are wild oat, Persian darnel and Italian ryegrass as well as a number of key broadleaves.
Osprey will suppress downy brome.
Wild oat
Green foxtail
Yellow
foxtail
Barnyardgrass
Dow
ny brome
Japanese brom
e
Persian darnel
Quackgrass
Foxtail barley
Beyond (CL) C C C C C C C
Everest C C S S C
Maverick S C/S C/S C
Olympus Fall S/C S/C C/C S/S C/C
Olympus Spr S/C S/S C/C S/S C/C
OlympusFlex C PC C C C PC C
Osprey C S C
What do the herbicide labels say?
Environmental Stresses
Stress reduces postemergent herbicide effectiveness.
Effectiveness generally affected more by moisture than temperature stress.
Cold temperatures after application increases risk of crop injury.
Low density weed populations generally are more easily controlled than high density populations.
October 21, 2004
Amsterdam, MT
Maximum Single Application use Rates for Downy Brome Control in Rampart Winter
Wheat. Fall Applied, Amsterdam 2005
Herbicide Oz Product % Control Bu/acre
Olympus 0.9 80 47
Osprey 4.7 53 42
Maverick 0.66 87 47
OlyFLEX 3.54 60 48
Untreated 0 34*
April 7, 2005
Amsterdam, MT
Maximum Single Application use Rates for Downy Brome Control in Rampart Winter Wheat. Spring Applied, Amsterdam 2005
Herbicide Oz Product % Control Bu/acre
Olympus 0.9 85 49
Osprey 4.7 68 48
Maverick 0.66 75 56
OlyFLEX 3.54 85 61
Untreated 0 34*
Maximum Single Application use Rates for Downy Brome Control in Rampart Winter
Wheat. Fall Applied, Amsterdam 2005
Herbicide Oz Product % Control % Injury
OlyFLEX 3.0 47 0
OlyFLEX Finesse
3.0 0.4
70 37
OlyFLEX 3.54 60 0
OlyFLEX Finesse
3.54 0.4
75 38
Untreated 0 0
Maximum Single Application use Rates for Downy Brome Control in Rampart Winter Wheat. Spring Applied, Amsterdam 2005
Herbicide Oz Product % Control % Injury
OlyFLEX 3.0 52 0
OlyFLEX Finesse
3.0 0.4
80 13
OlyFLEX in 3.54 85 0
OlyFLEX Finesse
3.54 0.4
77 15
Untreated 0 0
Product Common Name % AI
Olympus propoxycarbazone-sodium 70%
Osprey mesosulfuron 4.5%
Olympus FLEX
propoxycarbazone-sodium mesosulfuron
6.75% 4.5%
Herbicide Label Restrictions for Application Rates
Herbicide Field Rate Min appl.
Field Rate Max appl.
Maximum per season
Olympus 0.6 0.9 1.2
Osprey 3.2 4.75 4.75
Olympus FLEX
3.0 0.3 + 3.0
3.5 0.34 + 3.5
3.5 1.2 + 3.5
Possible Sequential Applications with Olympus Followed by Olympus
Fall Applied
Spring 0.0 oz
Spring 0.3 oz
Spring 0.6 oz
Spring 0.9 oz
Max per yr
Olympus 0.6 oz
0.6 oz 0.9 1.2 1.5 1.2
Olympus 0.9 oz
0.9 1.2 1.5 1.8 1.2
Possible Sequential Applications with Olympus followed by Osprey
Fall Applied Spring Osprey 3.2
Spring Osprey 4.5
Maximum per year
Olympus 0.6 oz
Oly 0.6 Osprey 3.2
Oly 0.6 Osprey 4.5
Oly 1.2 Osprey 4.5
Olympus 0.9 oz
Oly 0.9 Osprey 3.2
Oly 0.9 Osprey 4.5
Oly 1.2 Osprey 4.5
Possible Sequential Applications with Olympus followed by Osprey
Fall Applied
Spring OlyFLEX 3.0 0.3 + 3.0
Spring OlyFLEX 3.5 0.34 + 3.5
Maximum per year
Olympus 0.6 oz
Oly 0.9 Osprey 3.0
Oly 0.94 Osprey 3.5
Oly 1.2 Osprey 4.5
Olympus 0.9 oz
Oly 1.2 Osprey 3.0
Oly 1.24 Osprey 3.5
Oly 1.2 Osprey 4.5
January 13, 2006
Moccasin, MT
April 21, 2006
Moccasin, MT
Treatment % control 5-11-06
% control 6-20-06
Yield Bu/acre
Olympus 0.6 Fall 65 60 19
Olympus 0.6 Fall Olympus 0.6 Spr
85 77 20
Olympus 0.6 Fall Olyflex 3.5 Spr
94 90 19
Olympus 0.6 Fall Olyflex 3.2 Spr
95 83 19
Olyflex 3.5 Fall 80 63 19
Olyflex 3.5 Fall Osprey 3.2 Spr
96 85 20
Maverick 0.5 Fall 78 69 22
Maverick 0.66 Spr 83 63 19
Untreated 0 0 17
Acknowledgement
• Phil Stalman, Kansas State University
• Dan Ball, Oregon State University
• Brian Jenks, North Dakota State University
• Joe Yenish, Washington State University
Thanks
• MABA – MGEA
• Agricultural Chemical Industry
• Montana Agricultural Producers
Questions