Weed Management Handbook

glyphosate

Rate 1 to 2 lb ae/A

Time When plants are at least 15 inches tall and growing rapidly.

alachlor (Lasso or Micro-Tech)

Rate 1.5 to 4 lb ai/A

Time Use a preplant incorporation application.

Remarks Selective in corn and dry beans. Controls most annual grasses and certain annual broadleaf weeds. Absorbed mainly by germinating plant shoots; seems to inhibit protein synthesis.

glyphosate

Rate 2.25 lb ae/A

Time Apply to actively growing milkweed that has reached the late bud to flower stage of growth.

Remarks Reported to control this plant, although data are lacking in the Pacific Northwest. Follow label instructions.

glyphosate

Rate 2.25 lb ae/A

Time Apply to actively growing milkweed that has reached the late bud to flower stage of growth.

Remarks After small grain harvest or mowing, let milkweed regrow to mature stage before treating. Allow 7 days or more after application before tillage.

2,4-D (various products)
alachlor (Lasso) or
bentazon (Basagran) or
bromoxynil (Buctril) or
chlorsulfuron (Glean) or
dicamba (various products) or
glyphosate (Roundup) or
metribuzin (Sencor) or
oxyfluorfen (Goal) or
paraquat (Gramoxone Max) or
picloram (Tordon)

Remarks Reported to control this plant, although data are lacking in the Pacific Northwest. Follow label instructions.

glyphosate (Rodeo)

Rate 1% solution with hand-held equipment

Time Apply to actively growing plants at full to late flowering stage. Seedlings may be effectively treated early in the season after a fall application to mature plants.

Remarks Use 0.5% v/v nonionic surfactant. Thoroughly wet foliage but avoid runoff.

2,4-D LV ester

Rate 2 lb ae/A

Time Apply at the early bud stage to actively growing plants.

Remarks Several species of lupine are poisonous to livestock.

Caution Do not graze until plants dry up after application. Avoid drift to sensitive crops.

picloram (Tordon)

Rate 1 lb ae/A

Time Apply to actively growing plants from flower stalk formation to early seed development.

Remarks Poisonous plant.

dicamba (Clarity)

Rate 0.25 lb ae dicamba mixed with 1 gal water/400 sq ft

Time Apply in late August to new regrowth since plant was cut back in June.

Remarks Apply as a basal spray to the stems at ground level.

Caution Do not apply in areas where roots of desirable plant species are growing.

The following herbicides usually control treated plants. Plants often regrow, so plan annual applications for several years. Control of regrowth and of new seedlings is much better if a competitive crop or sod is established. A perennial grass is the logical choice because, except for glyphosate, the herbicides listed here will not kill established grasses.

2,4-D

Rate 1 to 2 lb ae/A (4 to 8 lb ae/A for Russian knapweed)