Development of a Fixed Spraying Structure for High-Density Apple Plantings

Abstract

A configuration of micro sprinkler nozzles and supply tubing was fixed onto the support system of a high-density Red Delicious apple planting to evaluate its efficacy in applying sprays in small plots, as compared with a standard airblast sprayer. Efficacy in control of plum curculio with two sprays of azinphosmethyl, and of mites with one spray of abamectin using this system was equal to that obtained with airblast applications. A chelated iron spray was applied in July to assess spray deposit and canopy distribution patterns. Foliar analysis showed spray deposition equivalent or superior to that of an airblast sprayer. A fixed system might overcome many intrinsic inefficiencies of airblast sprayers and promote lower use rates or least-toxic materials with shorter periods of residual effectiveness.