Spray Droplet Penetration in Cotton Canopy Using Air-Assisted and Hydraulic Sprayers

The effectiveness of three sprayer configurations, air-assisted, over-the-top, and drop-nozzle sprayers, was evaluated using four different insecticides to control lepidopterous insect pests in cotton. Seed cotton yields during 1998 were negatively correlated with insect damage counts. Bioassays of leaves from the top, middle, and bottom of plants treated with Tracer with the three sprayer types indicated that all three sprayers provided coverage in the top of the plant, but the air-assist sprayer provided the best coverage throughout the plant while the over-the-top sprayer had the poorest coverage in the bottom of the plant. Air-assist and drop nozzle sprayers had good coverage in the middle of the plant.