Submitted to: National Agricultural Aviation Association Meeting
Publication Type: Proceedings
Publication Acceptance Date: 12/8/2005
Publication Date: 12/8/2005
Citation: Fritz, B.K., Hoffmann, W.C., Martin, D.E. 2005. Aerial application methods for increasing spray deposition on wheat heads. In: Proceedings of the National Agricultural Aviation Association Meeting, December 4-7, 2005, Reno, Nevada. Paper No. AA05-006. Interpretive Summary: Fusarium head blight (FHB) is a major disease of wheat and barley in several grain production regions in the U.S., for which cultural practices, resistant cultivars, and fungicides have had limited effectiveness and erratic results. Fungicide applications can suppress FHB, but thorough coverage of the wheat head must be achieved. Spray deposition on wheat heads and artificial targets close to the wheat heads was investigated using six aerially applied treatments spanning several different droplet sizes, spray rates, and application technologies. Generally, lower spray rates along with larger droplet sizes resulted in greater spray deposits. Additionally, application with electrostatic technologies resulted in near maximum deposition amounts. Higher spray rates, regardless of droplet size, and rotary atomizers resulted in the least deposition on wheat heads. These results provide guidance to aerial applicators for optimizing aerial spray deposits on wheat for suppression of Fusarium head blight.
Technical Abstract: Fusarium head blight (FHB) is a major disease of wheat and barley in several small grain production areas in the United States and, as such, the development and evaluation of aerial application technologies that enhance the efficacy of fungicides with aerial spray applications is one of the research priorities of the United States Wheat and Barley Scab Initiative. This research was initiated to assess aerial spray technologies in an effort to increase spray deposits on wheat heads. Conventional hydraulic nozzles at two sprays rates and two droplet sizes along with rotary atomizer and electrostatic treatments were investigated. Based on results from collectors and visual analysis, the optimal spray treatment for deposition on wheat heads was hydraulic nozzles at 18.7 L/ha (2 gpa) and a 350 micrometer droplet size, which agrees with work done previously. The results from this study are expected to provide guidance for aerial fungicide applications for increased deposition on wheat heads.