Effects of Travel Speed, Application Volume, and Nozzle Arrangement on Deposition and Distribution of Pesticides in Apple Trees. J. W. Travis, Department of Plant Pathology and Horticultural Science, North Carolina State University, Raleigh 27695. W. A. Skroch, and T. B. Sutton. Department of Horticultural Science, and Department of Plant Pathology, North Carolina State University, Raleigh 27695. Plant Dis. 71:606-612. Accepted for publication 28 January 1987. Copyright 1987 The American Phytopathological Society. DOI: 10.1094/PD-71-0606.

The effects of travel speed, application volume, and nozzle arrangement on the deposition and distribution of heavy metal compounds in apple trees were determined. The effect of sprayer travel speed was tested at 40, 54, 67, and 80 m/min; the effect of application volume was tested at 374, 617, 935, and 3,742 L/ha; and nozzle arrangement was tested as a ratio of percent total volume applied to the top one-third of the tree to the percent total volume applied to the bottom two-thirds of the tree (34:66, 50:50, 66:34, and 80:20). Each treatment application was replicated on the same six medium and small Golden Delicious apple trees. Under the conditions of this study, a travel speed of 54 m/min and a volume of water of 617 L/ha with a nozzle arrangement of 66:34% (top/bottom) on medium size trees and 50:50% (top/bottom) on small trees resulted in the highest mean deposit throughout the tree and the lowest variance of deposit.