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Know when to terminate when planting green

A University of Wisconsin weed scientist says planting green is great for suppressing weeds but doing it wrong leads to corn yield losses.

Rodrigo Werle tells Brownfield their southern Wisconsin trials show early May planted corn into green cereal rye does well but, “The moment you plant that corn crop, you want to terminate that rye immediately, because if we plant green and let that cover crop grow for another week or two weeks, this is when we see tremendous impact in our yield, and we’re talking about 40, 50, 60 bushels.”

Werle says the yield losses are not bad with April and early May planted soybeans. “You can plant green and then you can continue to let that cereal rye cover crop grow until that knee-hight, and when it gets to that boot stage and then terminate it. That usually does not impact yield, even in a dry year.”

Werle says if the cover crop is allowed to keep growing after the boot stage, it’s using about three-tenths of an inch of precipitation every day, which means waiting a week too long to terminate the rye takes two inches of water away from the soybeans.