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Highlights

Foliar banding with 40-degree flat fan tips may reduce pesticide use.

Abstract. The study characterized the spray deposits for broadcast sprays and foliar band sprays made to cotton in the field under a steady mean lateral wind velocity of 1.1 m s^-1. Five over-the-top spray treatments included broadcast TX-12 hollow cone spray tips, broadcast XR 8002 flat fan tips, banding 40-015 flat fan tips, banding 40-02 flat fan tips, and banding TX-12 hollow cone tips. Malathion spray deposits in the foliage were sampled with water-sensitive paper (WSP), top and bottom leaf sides, cotton terminals, and Petri dishes placed on the ground between rows. Cumulative droplet sizes were generally grouped for TX-12 hollow cone nozzles versus a group for 40° and 80° flat fan spray tips. Flat fan spray nozzles outperformed hollow cone spray nozzle based on mean spray-rate adjusted WSP coverage for both broadcast and banding applications. The hypothesis for poor banding performance by the TX-12 hollow cone tip was attributed to the light wind of 1.1 m s^-1 that predominately blew at about right angles to the rows. Mean spray rate-adjusted leaf top malathion residues were statistically the greatest for broadcast TX-12 hollow cone spray tips, broadcast XR 8002 flat fan spray tips, and for banding 40-015 spray tips. Mean spray rate-adjusted leaf bottom malathion residues were not significantly different. The spray-rate adjusted cotton terminal malathion residue levels were statistically the greatest for the broadcast TX-12 hollow cone spray tips. The spray-rate adjusted Petri dish malathion residue levels were statistically the greatest for the broadcast TX-12 hollow cone spray tips and broadcast XR 8002 flat fan tips, perhaps due to a gap between rows. Rank order of spray-rate adjusted deposits between spray treatments depended to some degree based on the foliar spatial location and geometric differences attributed to samplers. This is important for targeting different insects located within the foliage structure.