While it is common for applicators to standardize their application parameters to minimize changes in settings during a season, this practice does not necessarily provide the best delivery when targeting different plant canopies and different zones within a canopy. Label language does not generally provide guidance for treating different crops or sections of plants. Field studies were conducted with the objective to identify application parameters for maximizing spray deposition and coverage to protect against insect and disease pests. Following applications, plant sections or artificial targets were sampled to assess to measure spray deposit and coverage in the targeted treatment zones. Over the range of application parameters evaluated, flatter orientation of the spray relative to horizontal helped produce higher deposits on vertical plant sections in a wheat canopy. Vertical spray delivery was better at treating horizontal targets through a denser and deeper soybean canopy. Large droplet applications were more effective at getting spray material near the bottom of a narrow-row soybean canopy than onto the vertical heads or stems of wheat plants. Smaller droplet sizes were more difficult to deliver down through a mature soybean canopy than medium or coarse spray quality sprays. Air-assist was not effective at increasing deposits on the plant sections which were considered low density. These findings demonstrate that spray parameters can be used to more effectively treat the parts of the canopy that require protection. Application parameters should not be expected to perform similar in all canopy types and should be modified to most effective delivery of the spray to the targeted treatment zones.These results represent examples of how label language may be strengthened with the addition of crop and target specific application guidelines to improve pesticide use and environmental sustainability.

Spray deposition field studies and implications for label guidelines

248th National Meeting (2014)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.