Acaricide Evaluation, 1994

This experiment was conducted in a 2.1 acre block of 9-yr-old trees on M 7A rootstock. The trees measured 11.5 ft in height and 10 ft in width and were planted at a spacing of 12 × 18 ft. The experimental design consisted of a single 0.35 acre plot (8 rows × 9 trees/row) for each treatment. Acaricides were applied as complete sprays to both sides of the tree with a Swanson DA500A airblast sprayer, which traveled at 2.3 mph and delivered a spray volume of 100 gpa. Other materials applied separately to all treatments were Captan, Ethrel, Guthion, Kocide, Lorsban, Nova, Penncap-M, Penncozeb, Rubigan, Streptomycin, Topsin-M, and Ziram. Treatments were evaluated by counting pests on the periphery of 4 trees in the center two rows of each plot. ERM control was determined by sampling 25 leaves per tree, removing mites with a mitebrushing machine, and counting motile stages with a binocular microscope. Effect of treatments against RLH and WALH was evaluated by counting nymphs on the underside of 25 leaves per tree. Control of STLM was determined by counting tissue-feeding mines observed on each tree during a 5 min period.