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

Submitted to: Applied Engineering in Agriculture
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: July 24, 2007
Publication Date: October 15, 2007
Citation: Fritz, B.K., Hoffmann, W.C., Martin, D.E., Thomson, S.J. 2007. Aerial application methods for increasing spray deposition on wheat heads. Applied Engineering in Agriculture. 23(6):709-715.

Interpretive Summary: Fusarium head blight 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 is critical to its management. Spray deposition on wheat heads and artificial targets close to the wheat heads was investigated using six aerially applied treatments of tracer material. The treatments included use of conventional hydraulic nozzles at two spray rates and two droplet sizes, and use of electrostatic nozzles and rotary atomizers. Hydraulic nozzles set at the lowest spray rate and largest droplet size, along with electrostatic spray nozzles resulted in maximum tracer deposits on wheat heads and artificial targets. These results provide guidance for aerial spray applications that increase fungicide deposition on wheat heads and may lead to improved control 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 critical to its management. This research was initiated to assess aerial spray technologies in an effort to increase spray deposits on wheat heads. Conventional hydraulic nozzles at two spray 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 and a 350 micrometer droplet size, which supports previous work. The results from this study provide guidance for aerial fungicide applications for increased deposition on wheat heads.