Downy Brome Management in Montana Agriculture

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


(Bromus tectorum)

Japanese brome


(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


Downy Brome Bromus tectorum

Downy brome Bromus tectorum


Japanese brome Bromus japonicus


http://www.lib.ksu.edu/wildflower/grass/japanesebrome2.jpg

Japanese brome


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:


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.


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

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Downy Brome Management in Montana Agriculture