Recent rains have encouraged broadleaf weed growth in growing wheat fields.  Kochia, for the most part, is the weed in question although other weeds may also be a factor interfering with this year’s harvest activities.  

Keep in mind that there are only a small number of pre-harvest aids for controlling weeds in wheat prior to harvest.  Also, be aware of pre-harvest intervals before harvesting and feed and grazing intervals following wheat harvest.  Pre-harvest interval is the time after a herbicide application is applied before wheat harvest can legally begin.  

Always follow pesticide label rules as the “label is the law.”  In addition, be sure wheat is at least in the hard dough stage before controling weeds.  Hard dough stage occurs when wheat kernels are formed, soft, but not juicy.  Physiologic maturity occurs when wheat is approximately 30 percent moisture whereas wheat in hard dough stage will be higher than 30 percent moisture. 

Following are herbicides labeled for weed applications prior to wheat harvest: 

• 2,4-D: wheat must be in hard dough stage, pre-harvest interval is 14 days after application.  Weak on kochia.  
• Aim EC or Longbow EC: wheat in hard dough, pre-harvest interval is 3 days. Use COC 1 percent v/v. 
• Ally or Metsulfuron:  wheat in hard dough, pre-harvest interval is 10 days.  Use NIS 0.25 percent v/v. 
• Dicamba: wheat in hard dough stage, pre-harvest interval is 7 days. Will volitalize when air temps are above 85 F. Do not graze or harvest crop residue for feed. 
• Glyphosate: wheat is physiologically mature (30 percent moisture or less), pre-harvest interval 7 days.  Do not feed or graze crop residue for feed until 2 weeks after application.  Will control both grasses and broadleaves. Kochia may be glyphosate resistant. 
• Sharpen: wheat in hard dough stage, pre-harvest interval is 3 days. No grazing or feeding restrictions.  
• Valor: wheat in hard dough stage, pre-harvest interval is 10 days. MSO and AMS recommended.