If you'd like to boost your no-till corn yields by 15 to 20 bushels an acre, the best place to start this spring may be with early season weed control.

Data from the Syngenta Learning Centers indicates applying a pre-emergence residual herbicide for early season weed control boosted corn yields by an average of 18 bushels of corn per acre compared to relying on a total post herbicide treatment.

The key is giving no-till corn an early start without weed competition, says Bob Kacvinsky, a Syngenta Crop Protection technical support rep in the western Corn Belt.

The 18-bushel difference in corn yields was found between making an early residual treatment with Lexar plus glyphosate compared to a total post treatment with glyphosate only.

Early Weeds Unnoticed.

One of the major problems is that farmers don’t notice 1- to 2-inch-tall weeds, says Kacvinsky. Uncontrolled early season weeds outnumber corn by a ratio of 40-to-1, soak up available moisture more quickly, consume nutrients faster and reduce the yield potential early in the season.

Studies have demonstrated that 3- to 5-inch-tall weeds that compete with 5-inch-tall corn cause water loss that’s three times faster than when there are no weeds in the field. Saving just 1 inch of water with early season weed control is worth $8 per acre.

Kacvinsky says another major profit-buster is the amount of nitrogen contained in uncontrolled early season weeds.

“There was 1% more nitrogen available to the corn crop with early weed treatment,” he says. “The corn…