ARS | Publication request: Aerial methods for increasing spray deposits on wheat heads

Submitted to: American Society of Agricultural Engineers Meetings Papers
Publication Type: Proceedings
Publication Acceptance Date: August 3, 2004
Publication Date: August 3, 2004
Citation: Kirk, I.W., Fritz, B.K., Hoffmann, W.C. 2004. Aerial methods for increasing spray deposits on wheat heads. Proceedings of the American Society of Agricultural Engineers, August 1-4, 2004, Ottawa, Ontario, Canada. Paper No. 04-1029.

Interpretive Summary: Fusarium head blight (FHB) is a disease of wheat and barley that reduces yields and in severe cases causes the grain to be unmarketable for normal uses. Aerial spray application methods have not been studied or optimized for maximum spray deposits on small grain heads. Three large-scale field studies of aerial spray application methods showed that fine droplet sprays deposit more material on wheat heads than medium droplet sprays. Rotary atomizers gave the highest deposits on wheat heads. These methods will be further evaluated for improved disease control.

Technical Abstract: Fusarium head blight (FHB) is a major disease of wheat and barley in northern regions of North America. Large-scale field studies were conducted to assess aerial spray technologies that could increase spray deposits on wheat heads to improve control of FHB. The goals of the effort were to: 1) identify the capability of conventional aerial application practice to deposit sprays on wheat heads and determine the properties of those spray deposits; 2) determine if the amount of spray deposits on wheat heads can be enhanced through the use of very fine sprays produced by rotary atomizers, and characterize those spray deposits; and 3) determine if aerial sprays applied from two directions would increase deposits on wheat heads, and characterize those spray deposits. Three studies were conducted to achieve these goals. Samples of wheat heads and artificial collectors were collected and analyzed to characterize spray deposits from the specified treatments. Fine droplet spectrum sprays applied with rotary atomizers gave the highest spray deposits on both wheat heads and artificial samplers. Medium droplet spectrum sprays gave the lowest deposits on wheat heads regardless of spray rates between 19 and 94 L/ha (2 and 10 gal/acre). Results from these studies on optimizing aerial spray deposits will be implemented in disease control studies for control FHB.