The challenge for the fruit grower in the 21st century is to apply pesticides precisely to the target areas.This paper discusses research projects by the Cornell University Spray Team on developing new canopy sprayers to increase spray deposition within the canopy. Trials have been conducted to evaluate modern nozzle design, nozzle orientation, air volume andvelocity in relation to canopy density and timeliness throughout the growing season.Novel developments have been made such as a louvre air restrictor, deflectors and variable speed fans to reduce and direct airflow from the sprayer in an attempt to match air volume and speed with an increase in canopy growth, results from field trials have shown improvements of up to 30 percent increase in deposition and a 75 percent reduction in drift.An intensive on-farm study of 10 orchard sprayers fitted with sonic sensing devices has been made and results show an average of nine percent saving in pesticide use, with up to 19 percent saving at one orchard. Savings vary according to canopy density and growth stage.A vertical patternator was designed and developed for on-farm construction to measure spray liquid emitting from the canopy sprayer. Reduction in pesticide application of 20 percent was obtained and field results show the importance of cor-rect nozzle orientation if pesticides are to be applied effectively onto the target.The paper also describes the latest research in a real-time canopy-sensing sprayer which automatically adjusts air and liquid flow as the sprayer progresses along the rows of apple trees.
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