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Lack of rain affecting weed programs

A University of Wisconsin weed specialist says the lack of rain has given some weeds an advantage over crops.

Rodrigo Werle tells Brownfield it was dry for more than ten days before Thursday’s storm system, which was good for planting but not good for weed control. “We’ve planted a lot of crops. We’ve sprayed our pre’s (pre-emergent herbicides), but then we didn’t have timely rains to activate our pre’s.”

Werle says he’s seeing weeds getting established because pre-emerge herbicides didn’t have rain to activate them, so farmers might have to go back out with the sprayer. “I’ve scouted in a lot of fields but what I’m seeing is giant ragweed breaking through. I’m seeing grasses breaking through, so assuming the giant ragweed is not glyphosate-resistant, or you have grasses breaking through, that should be an easy fix.”

Werle says at this point, he’s not recommending more residual herbicides, and says a glyphosate application can do a lot of good if Roundup-ready crops are established. “We’re going to have to deploy an intervention, unfortunately, earlier than we anticipated here, so scouting is going to be very important coming up with plans B and C and being proactive so the weeds don’t get out of control here on us.”

Werle says many Wisconsin farmers terminated their cover crops last week and says rye for example had good biomass and helped suppress more weeds.

AUDIO: University of Wisconsin Weed Scientist Rodrigo Werle discusses early season weed issues with Brownfield’s Larry Lee