When applying a non-residual herbicide (glyphosate) to a field, a window of 7-10 days is open for rain or irrigation activation. This is important to consider when applying so that the herbicide gets the maximum amount of time to activate.

A typical burn down contains herbicides that are rain-activated. Missing a burndown application is not a large factor due to a second chance for application, which will be right behind the planter. When applying, remember these herbicides are subject to being tied up in soil. Dust can cause a loss in application, especially after a period of dry weather. Slowing down can prevent some of this by not agitating dry topsoil as much.

A residual herbicide in the soil is of utmost priority to begin a season. A residual is best when it is optimized for longevity in the field. In corn, you can apply a smaller amount of atrazine at burndown, then apply a larger amount at planting to maximize its possibility of being rain activated (1qt up front and 1.5qt post). As Dr. Charlie Cahoon says you want “something so that you start clean” this season

With little rain in our future forecast, scouting and applying herbicides when needed is of the utmost importance.