Quackgrass (Elytrigia repens)

bromacil + diuron (Krovar I DF)

Rate 9.6 lb ai/a (12 lb/a)

Time Apply before weeds emerge.

Remarks Rain is needed to activate this herbicide.

Caution Nonselective weed control. Do not apply to areas where desirable plant roots extend.

Site of action (bromacil) Group 5: photosystem II inhibitor; (diuron) Group 7: photosystem II inhibitor

Chemical family (bromacil) uracil; (diuron) urea

dichlobenil (Casoron)

Rate 4 lb ai/a in berries; 4 to 6 lb ai/a in fruit trees and grapes

Time Apply midwinter immediately before a cold rain to reduce volatility and enhance weed suppression. Weigh and distribute uniformly exact quantities over precisely measured areas. Oregon results over 9 years suggest that perennial weeds can be suppressed with 4-, 3-, and 2-lb ai/a rates applied in 3 consecutive years. Grazing livestock is prohibited. Inhibits cellulose and cell wall formation.

Remarks Selective in trailing berries, fruit trees, and grapes.

Site of action Group 20: inhibits cell wall synthesis Site A

Chemical family Nitrile

EPTC (Eptam)

Rate 4 lb ai/a

Time Apply in early spring or fall before plowing.

Remarks This application has been promising for selective control of quackgrass in such crops as beans, potatoes, and small-seeded legumes. It does not eradicate quackgrass but does reduce growth for the season and greatly reduces amount of live roots. Before EPTC applications, soil is disked or rotated until quackgrass rhizomes are 3 to 4 inches long.

Caution Apply to soil and immediately follow with a thorough disking in two directions to uniformly incorporate 6 inches deep.

Site of action Group 8: lipid synthesis inhibitor but not an ACCase inhibitor

Chemical family Thiocarbamate

fluazifop (Fusilade DX)

Rate 0.25 to 0.375 lb ai/a (1 to 1.5 pints/a) for first application. If reapplication is needed, use 0.19 to 0.375 lb ai/a (0.75 to 1.5 pints/a).

Time Apply late spring to actively growing quackgrass 6 to 10 inches tall.

Remarks Apply with 1% v/v crop oil concentrate or 0.25% v/v nonionic surfactant. Repeat application to control established quackgrass. Acts very slowly, taking at least 2 and often 4 weeks to show effects. Do not apply to stressed grasses. Do not mix with other pesticides unless recommended on label.

Caution Do not graze treated fields.

Site of action Group 1: acetyl CoA carboxylase (ACCase) inhibitor

Chemical family Aryloxyphenoxy propionate

glyphosate

Rate Broadcast: use 1 to 2.25 lb ae/a. Nonsodded quackgrass: use 0.75 to 1.5 lb ae/a (1 to 2 quarts). Sodded quackgrass: use 1.5 to 2.25 lb ae/a (2 to 3 quarts).

Time Apply during fallow periods in cropping systems when quackgrass is in late boot to early flowering stage.

Remarks Foliage must be thoroughly wet, but avoid runoff.

Caution Glyphosate is nonselective. Re-treatment may be necessary for complete control.

Site of action Group 9: inhibits EPSP synthase

Chemical family None generally accepted

pronamide (Kerb)

Rate 2 to 3 lb ai/a

Time Apply during fall or winter when soil moisture is good and more precipitation is expected. Apply before ground freezes in the cooler areas.

Remarks Use higher application rates in heavier soil types.

Caution A restricted-use herbicide. Follow label for crop rotations.

Site of action Group 3: microtubule assembly inhibitor

Chemical family Benzamide