European Red Mite Control on Apple, 1993

The test was conducted in a 9 acre commercial apple orchard south of Chelan, WA. Trees were about 12 feet tall, and spaced 12 × 18 ft. apart. Irrigation was provided through overtree impact sprinklers. Replicated plots, three per treatment, were 9-10 rows by 15-19 trees, or about 0.94 acres in size. Treatments were applied on 15 Jul with an airblast sprayer calibrated to deliver 100 gpa. Omite and Kelthane were combined with an adjuvant (Latron AG-44M, 0.25% (v/v)). Mite counts were taken at about weekly intervals. Samples consisted of 100 leaves, 25 from each of 4 trees in the center of the plot (trees 9 and 11 in rows 4 and 6 of each plot). Mites were removed from leaves with a leaf-brushing machine and counted with the aid of a binocular microscope. Motile stages of all species of phytophagous and predatory mites were recorded, as were egg, of ERM and WPM. ERM was the primary phytophagous species in this test, and WPM was the primary predator.