Effect of Wind Speed on the Application and Distribution of Granules Applied to the Soil for Control of Corn Rootworm (Coleoptera: Chrysomelidae)

Lighter clay granules were displaced more in a wind tunnel than heavier sand granules, and displacement increased exponentially with increased wind speed and increased height of drop. Field studies with commercial equipment and controlled winds showed that wind had a significant effect on the distribution of granules on the soil surface. Higherdensity sand granules were displaced less than clay granules. Banded applications were significantly more susceptible to displacement than in-furrow applications. Our results indicate that the effects of winds perpendicular to the direction of planting is most evident in the windward, outside row of the corn planter. In leeward rows, however, applications in front of the furrow closure wheels were displaced more than applications behind them because of air funneling through the opening between the depth wheels and the closure wheels. Two possibilities for reducing drift are indicated: installing a flexible wind screen on each side of the planter, or applying the granules in-furrow.