Using pre-emergent herbicides in developing corn is vital in controlling weeds, reports Southwest Farm Press.

“Any weed that’s growing during the six-week interval from when the corn comes up and reaches canopy is going to compete, and you’re going to lose yield,” according to Michael Flessner, Virginia Cooperative Extension weed specialist.

A recent study found pre-emergent herbicide applied in corn was optimal when adequate rainfall coincided with its application. On fields that received no rainfall for three weeks after the herbicide was applied, weed control was negligible. This indicated that the herbicide will dissipate over time to some degree.

“To preserve maximum yield potential, which is the name of the game, you need to control weeds and pre-emergent herbicides are usually the way to go. In some cases, if you don’t get early rainfall to activate, it may be a little risky, but I still recommend pre-emergent herbicides,” Flessner said.