Remarks Reported to control this plant, although data are lacking in the Pacific Northwest.
Site of action Group 4: synthetic auxin
Chemical family Phenoxy acetic acid
Wild cucumber is a perennial vine that regrows each year from an enormous root. The plant spreads by seed, not by root fragments. The harmful effect of wild cucumber is mostly a result of the top growth that crowds, shades, and deforms the crops. Any type of physical control has temporary results because of the food storage in the root. This food reserve also means that if herbicides are to be effective, they must move to the root and block production of new shoots. Any control plan should call for treatment for several years.
2,4-D LV ester or 2,4-D amine
Rate 2 to 3 lb ae/A in non-cropland and 1 lb ae/A as a selective treatment
Time Apply early in cress growth stage; control is minor after bud stage. In cereals, apply 2,4-D before weeds reach boot stage.
Remarks When possible, use 2,4-D on whitetop plants before plowing fields in spring. Re-spray in fall if new growth appears.
metsulfuron (Escort and others)
Rate Escort: 0.3 oz ai/A (0.5 oz/A)
Time Apply to actively growing plants.
Remarks Using a nonionic or silicone surfactant increases effectiveness. Application sites differ between products, see label.
Caution Apply only to pasture, rangeland, and non-crop sites.
glyphosate (Rodeo and others)
Rate 2 to 3.75 lb ae/A broadcast, 2% to 5% solution through hand-held equipment, or 33% solution with wiper applicators
Time Apply to actively growing cordgrass any time from late June until first killing frost.
Comfrey was a food and feed crop, but has become weedy in gardens and fields of the Pacific Northwest. Naturally aggressive spread is accelerated by tillage that moves plant parts. A 1970s experiment in western Oregon determined the activity of several herbicides on comfrey. Relatively high rates were used, but only a few herbicides were effective. Most problems with comfrey are in gardens, so use caution in recommending any herbicide. One of the few options is to repeatedly (about every 3 weeks) remove plants down as far as practical below the soil surface.
glyphosate
Rate 2.25 lb ae/A
Time Apply to actively growing plants from bud to early flower.
Remarks Glyphosate is nonselective and will kill or injure vegetation that might compete with new chervil seedlings.
Site of action Group 9: inhibits EPSP synthase
2,4-D ester
Rate 6 lb ae per 100 gal of spray solution for spot treatments. Add crop oil, diesel oil, or surfactant to increase wetting.
Time Apply before cattail heads appear in spring.
Remarks Foliage must be thoroughly wet. 2,4-D does not control as well as glyphosate but is less expensive. 2,4-D must be reapplied to give satisfactory control.
fluazifop (Fusilade DX)
Rate 0.25 to 0.375 lb ai/A (1 to 1.5 pints/A)
Time Apply to actively growing reed canarygrass.
Remarks Apply with 1% v/v crop oil concentrate or 0.25% v/v nonionic surfactant. Acts very slowly, taking at least 2 weeks and often 4 weeks to show effectiveness. Do not apply to stressed grasses. If weed regrows, repeat application.
aminocyclopyrachlor + chlorsulfuron (Perspective)
Rate 1.2 to 1.8 oz/A aminocyclopyrachlor + 0.5 to 0.7 oz/A chlorsulfuron (3 to 4.5 oz/A of product)
