Abstract
Deposition of ragweed pollen released from a point above a corn crop was directly observed on foliage, and the number of particles deposited was related to the concentration of pollen in the air, the wind within the crop, and the foliage characteristics. At winds of 1–2 m s−1 deposition on the foliage both at the top and at the middle of the plants was primarily by sedimentation; while at winds of 3–4 m s−1, deposition was enhanced at the top about threefold. Since 20 μm particles impact inefficiently on corn plants for usual wind speeds within the crop, they should penetrate far through the canopy before settling out by gravity.