Field preparation for beans and sunflower may include Sonalan and trifluralin granule application and incorporation. Two incorporation passes are required for these herbicides. The first incorporation should occur as soon as possible after herbicide application and should not be delayed more than 24 hours after applying trifluralin and 48 hours after applying Sonalan. To optimize weed control, the second incorporation should be delayed at least five days after the first. See herbicide label information regarding general use including incorporation recommendations.



The following is a listing of postemergence herbicide options for canola that includes information on weeds controlled, application rates and timing, approximate costs, and comments.

*Assure II:

Application rate = 8 to 10 fl oz/acre. Apply with oil additive at 1% v/v to actively growing annual grasses and quackgrass. Assure II may provide excellent green foxtail control but less yellow foxtail control. Lower yellow foxtail may result from applying Assure II at reduced rates, with broadleaf herbicides, or to large or stressed plants. Reduced grass control can be avoided by applying Assure II at least 1 day before or 5 days after application of a broadleaf herbicide. Grass weeds = 2- to 6-inches tall. Quackgrass regrowth should be retreated when 4 to 8 inches tall at 8 fl oz/A. Canola stage = 30 days or more prior to harvest. Cost = $7.50 to 9.50/acre.


Use only on Liberty-resistant canola. Application rate = 34 fl oz/acre. Always apply with AMS at 2 to 4 lb/A . Weeds controlled and stages: most annual broadleaf weeds up to 3-inches tall; controls or suppresses grasses up to 2- to 3- inches tall and 1-tiller; and provides suppression of some perennial weeds. Liberty is a nonselective, nonresidual, contact-type herbicide with limited translocation and should be applied to small weeds. Lack of translocation may be the cause of poor control of large grass or certain species like yellow foxtail, wild oat, or volunteer cereals. Assure II or Poast may be tank-mixed to improve grass control. Liberty is nonresidual so multiple applications or a residual herbicide may be needed to control multiple weed flushes. Liberty has an unique mode-of-action providing resistant weed management. Canola stage = cotyledon up to early-bolting stage. Cost = $21.


Section 18 label for wild mustard control in canola grown only for seed. Application rate = 0.3 oz/acre. Apply with NIS at 0.25%. Weeds controlled and stages = Wild mustard, other mustard species, and annual smartweed up to 6-leaf stage. Canola stage = 2-leaf to beginning of bolting. Cost = $8.25/acre.


Application rate = 0.5 to 1.5 pt/acre. Apply with oil additive at 1 qt/acre. 28% UAN at 2 to 4 qt/A or 2.5 lb/A of AMS with the oil additive may increase control of volunteer corn, cereal grains and quackgrass. Grass weeds = 2- to 4-inches tall, volunteer corn = 6- to 18-inches tall. Poast provides only suppression of quackgrass. Quackgrass initially should be treated with 1.5 pt/A and regrowth 6 to 8 inches tall should be treated with 1 pt/A. Reduced grass control and crop injury can be avoided by applying Poast at least 1 day before or 5 days after application of a broadleaf herbicide. Canola stage = 60-day preharvest interval. Cost = 4 to 12$/acre.



Section 18 label for wild mustard control only on Clearfield (IMI-resistant) canola. Application rate = 4 fl oz/acre. Apply with NIS at 0.25% v/v alone or with UAN liquid fertilizer at 1 to 2 qt/A. Weeds controlled = nearly all annual grass and broadleaf weeds. Raptor is an ALS herbicide and will not control ALS resistant kochia. Provides limited residual weed control. Future crop planting restrictions exist. Canola stage = prior to bloom. Allow a 60 day preharvest interval. Cost = $15/acre.


*Roundup Ultra:

Use only on Roundup-resistant canola. Application rate = 1pt/acre with a total of two applications allowed. Add AMS at 8.5 to 17 lb/100 gal to ALL glyphosate formulations. Full labeled rates are required for broadleaf weed control. Weeds controlled = most annual and perennial weeds. Roundup is a nonselective, nonresidual, systemic herbicide. Application timing may not be appropriate for effective perennial weed control. Roundup is nonresidual so multiple applications or residual herbicide may be needed to control multiple weed flushes. Roundup has a unique mode of action and may be used as another tool in weed resistance management. Canola stage = emergence to bolting. Cost = $15 (1 pt) to 20 (second pt)/acre .



Section 18 label for Canada thistle and perennial sowthistle control. Application rate = 0.33 to 0.5 pt/acre. Weeds controlled and stages: thistle = 4- to 6-inches tall. Also controls several annual broadleaf weeds. Stinger is most effective when applied to common cocklebur, giant ragweed, volunteer sunflower, and wild sunflower up to the 6-leaf stage; common ragweed up to the 5-leaf stage; and wild buckwheat in the 3- to 5-leaf stage before vining begins. Canola stage = 72-day preharvest interval. Cost = $20-30/acre.

Refer to herbicide labels and NDSU Extension Service circular W-253 "2000 North Dakota Weed Control Guide" for required information on use.