Control of Downy bromein grass grown for seed

Daniel A. Ball, CBARC

Sandra M. Frost

Bromus tectorum L.

Mediterranean

Aggressive winter annual weed

Spring forage

Problem in winter wheat and perennial grass

Bromus tectorum L.

• Fine hairs on leaves

• Panicle dense, slender

• Seeds narrow with awns

Bromus tectorum L.

• Annual precip 6 to 22 inches

• Many soil conditions and habitat types

• Seed germinates late summer

• Seed mature after 1800 GDD (base 32F)

• Seeds viable in soil 2 to 3 years

Labeled for Downy brome

• Outlook (6EC) at 14 to 21 oz product / A– Dimethenamid

• Sencor 75DF at 0.5 lb/A (75W)– metribuzin

• On established, dormant grasses

Cultural control

• Crop rotation

• Moldboard plow

• Tillage before seed emergence– 1800 GDD, base 32F

• Pre-plant control– Tillage– Herbicides – Roundup

CRP tolerance trial

• Established stand seeded 9/2000

• PRE applications 9/2001

Herbicides

Herbicide Timing Weeds

Prowl PRE Foxtails

Outlook PRE Foxtails + Downy brome

Dual Magnum PRE Suppresses Downy brome

Axiom PRE Foxtails

Sencor 75DF PRE Suppresses Downy brome

Prowl + Outlook PRE Downy brome

Plateau + MSO POST Downy brome

Timothy tolerance

Timothy

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 3 1 1

Outlook 1 pt 11 3 14

Dual Magnum 1 pt 4 1 3

Axiom 9 oz 54 15 3

Sencor 75DF 5 oz 78 53 25

Prowl + Outlook 5 pt + 1 pt 20 3 4

LSD (0.05) 19 15 18

Thickspike wg tolerance

Thickspike wheatgrass

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 3 0 0

Outlook 1 pt 8 1 0

Dual Magnum 1 pt 3 3 0

Axiom 9 oz 43 9 3

Sencor 75DF 5 oz 40 5 0

Prowl + Outlook 5 pt + 1 pt 13 5 8

LSD (0.05) 17 7 8

Bluebunch tolerance

Bluebunch wheatgrass

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 1 1 0

Outlook 1 pt 1 1 0

Dual Magnum 1 pt 0 1 0

Axiom 9 oz 24 5 0

Sencor 75DF 5 oz 38 4 0

Prowl + Outlook 5 pt + 1 pt 6 0 0

LSD (0.05) 10 5 0

Sandberg tolerance

Sandberg bluegrass

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 0 3 0

Outlook 1 pt 4 0 0

Dual Magnum 1 pt 3 0 0

Axiom 9 oz 8 0 0

Sencor 75DF 5 oz 20 0 0

Prowl + Outlook 5 pt + 1 pt 4 0 0

LSD (0.05) 6 3 0

Big bluegrass tolerance

Big bluegrass

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 1 0 0

Outlook 1 pt 5 0 0

Dual Magnum 1 pt 1 3 0

Axiom 9 oz 23 4 0

Sencor 75DF 5 oz 54 1 0

Prowl + Outlook 5 pt + 1 pt 6 0 0

LSD (0.05) 13 5 0

Sheep fescue tolerance

Sheep fescue

Treatment Prod/A 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt 1 1 0

Outlook 1 pt 18 1 5

Dual Magnum 1 pt 14 1 11

Axiom 9 oz 83 1 31

Sencor 75DF 5 oz 93 4 0

Prowl + Outlook 5 pt + 1 pt 20 5 14

LSD (0.05) 12 6 10

CRP tolerance trial

• Established stand seeded 2000

• Applications made– PRE 9/2001– POST 11/2001

Timothy tolerance

Timothy

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

-----------% injury---------------

Prowl 5 pt PRE 1 1 15

Outlook 1 pt PRE 10 0 15

Dual Magnum 1 pt PRE 4 0 5

Axiom 9 oz PRE 40 3 4

Sencor 75DF 5 oz PRE 65 13 24

Prowl + Outlook 5 pt + 1 pt PRE 9 1 9

Plateau + MSO 4 oz + 1.5 pt POST 0 80 60

LSD (0.05) 15 11 23

Bluebunch wheatgrass

Bluebunch wheatgrass

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

-----------% injury---------------

Prowl 5 pt PRE 1 1 0

Outlook 1 pt PRE 4 0 0

Dual Magnum 1 pt PRE 3 1 0

Axiom 9 oz PRE 18 3 0

Sencor 75DF 5 oz PRE 40 1 0

Prowl + Outlook 5 pt + 1 pt PRE 4 0 0

Plateau + MSO 4 oz + 1.5 pt POST 0 8 0

LSD (0.05) 10 4 0

Sandberg bluegrass

Sandberg bluegrass

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt PRE 3 0 NA

Outlook 1 pt PRE 2 0 NA

Dual Magnum 1 pt PRE 1 0 NA

Axiom 9 oz PRE 14 0 NA

Sencor 75DF 5 oz PRE 23 0 NA

Prowl + Outlook 5 pt + 1 pt PRE 4 0 NA

Plateau + MSO 4 oz + 1.5 pt POST 0 3 NA

LSD (0.05) 6 3 NA

Big bluegrassBig bluegrass

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt PRE 5 0 0

Outlook 1 pt PRE 9 3 0

Dual Magnum 1 pt PRE 3 0 4

Axiom 9 oz PRE 23 0 3

Sencor 75DF 5 oz PRE 59 0 0

Prowl + Outlook 5 pt + 1 pt PRE 6 0 0

Plateau + MSO 4 oz + 1.5 pt POST 0 13 0

LSD (0.05) 12 4 5

Perennial ryegrass

Perennial ryegrass

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt PRE 3 0 0

Outlook 1 pt PRE 9 1 0

Dual Magnum 1 pt PRE 1 0 0

Axiom 9 oz PRE 10 0 0

Sencor 75DF 5 oz PRE 18 1 0

Prowl + Outlook 5 pt + 1 pt PRE 9 0 0

Plateau + MSO 4 oz + 1.5 pt POST 0 74 74

LSD (0.05) 8 12 10

Chewings fescue

Chewings fescue

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

-----------% injury---------------

Prowl 5 pt PRE 1 0 3

Outlook 1 pt PRE 5 1 0

Dual Magnum 1 pt PRE 1 0 0

Axiom 9 oz PRE 14 1 4

Sencor 75DF 5 oz PRE 69 5 19

Prowl + Outlook 5 pt + 1 pt PRE 8 3 3

Plateau + MSO 4 oz + 1.5 pt POST 0 38 29

LSD (0.05) 11 9 22

Tall fescue

Tall fescue

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

-----------% injury---------------

Prowl 5 pt PRE 3 0 0

Outlook 1 pt PRE 14 0 1

Dual Magnum 1 pt PRE 6 0 0

Axiom 9 oz PRE 18 0 5

Sencor 75DF 5 oz PRE 29 0 1

Prowl + Outlook 5 pt + 1 pt PRE 13 0 0

Plateau + MSO 4 oz + 1.5 pt POST 0 80 93

LSD (0.05) 12 2 5

Kentucky bluegrass

Kentucky bluegrass

Treatment Prod/A Timing 10/2/01 4/19/02 5/22/02

----------------% injury--------------------

Prowl 5 pt PRE 3 3 3

Outlook 1 pt PRE 8 3 28

Dual magnum 1 pt PRE 3 1 34

Axiom 9 oz PRE 48 0 25

Sencor 75DF 5 oz PRE 65 1 25

Prowl + Outlook 5 pt + 1 pt PRE 9 1 33

Plateau + MSO 4 oz + 1.5 pt POST 0 8 14

LSD (0.05) 15 6 33