Submitted to: Soybean Rust Workshop
Publication Type: Proceedings
Publication Acceptance Date: 9/30/2006
Publication Date: 11/14/2006
Citation: Mueller, T.A., Traynor, P.S., Miles, M.R., Hartman, G.L. 2006. The use of an air-assist sprayer to improve canopy penetration and coverage of soybean with fungicides. National Soybean Rust Symposium. Interpretive Summary:
Technical Abstract: With the potential for increased fungicide usage in the U.S. to control soybean rust, it is important to maximize fungicide coverage in the soybean canopy. There are a number of ways to increase fungicide coverage on soybean plants, including the use of air-assist sprayers. Two experiments were completed using a JACTO air-assist sprayer with the objective of increasing fungicide coverage on soybean plants. One experiment compared different nozzle types with and without the air-assist. Another experiment compared the angle of the boom with and without the air-assist. Both experiments were set up in a randomized complete block design in 12 row plots of 76 cm row spacing using 24 meters row lengths for each experimental unit. A dye (Vision Pink) was tank mixed with the fungicide and 18 Kromekote spray cards were placed at 1/3 and 2/3 canopy height (nine each) when plants were at growth stage R5. The spray cards were analyzed with the software program DropletScanTM for percent coverage, droplet size, number of drops and estimated volume output per area. In the experiment comparing nozzle types, the air-assist significantly improved canopy coverage; there was a significant difference between different tips for coverage, droplet size, number of drops, and estimated volume output. In the experiment comparing boom angles, zero degrees had significantly more coverage than when the boom was pointed 30 degrees forward. This information is useful to researchers and growers as they consider using air-assist sprayers to control soybean rust.