St. Paul, Minn.  – Minnesota’s farmers face a unique season marked by contrasting weather conditions. A dry winter followed by heavy rains in mid-May has created challenges for planting, particularly for soybeans, according to Dr. Joe Ikley, Extension weed specialist at North Dakota State University. 

Despite planting corn and soybeans in line with five-year averages, cool, wet conditions have hindered crop and weed growth. Dr. Debalin Sarangi from the University of Minnesota advises close monitoring of fields and using Group 15 residual herbicides like Warrant, Dual, or Outlook to manage weeds such as waterhemp, which can grow an inch daily in optimal conditions. 

Pre-emergence herbicides have been effective where applied, but post-emergence treatments have struggled due to slow weed growth. Herbicide effectiveness may take longer to gauge under current conditions, and drift concerns are heightened with increasing wind speeds. 

Farmers are urged to optimize spraying times to minimize drift and maximize herbicide activity, preferably during sunny midday periods. Adjustments in herbicide strategies may be necessary due to varying application windows and growing conditions. 

Herbicide resistance is a growing concern, with some waterhemp populations showing resistance to six different herbicide actions. Dr. Sarangi emphasizes using multiple herbicide sites of action and other integrated weed management strategies to preserve herbicide efficacy. 

For more detailed information and updates, visit University of Minnesota Extension’s website or contact Extension Communications at