Apple, Mite Control, 1982

Test chemicals were applied to 17-year-old apple trees at Monmouth, Maine, as dilute sprays, using a hand gun and a hydraulic sprayer operating at 100 lbs/in2 and at 300 to 350 gal/acre. Spray dates were 7 May (early tight cluster), 18 May (pink), 6 June (petal fall), 17 June (first cover), 9 July (third cover), and 19 July (fourth cover). The standard pesticide program during the course of this test consisted of Captan 80W (0.45 kg) on ten dates and Imidan 50W (0.45 kg) on five dates after blooming and Sevin 50W (0.91 kg) on 2 and 14 July. There were no mixtures of acaricides with other pesticides. There were four single-tree replications in a randomized complete block design with four ‘Red Delicious’ cultivars per treatment in Test 1, and two ‘Cortland’ and two ‘Golden Delicious’ cultivars in Test 2. From each tree, 25 leaves were collected, mostly at chest-height around the periphery. The leaves were brought into the laboratory, and brushed onto glass plates coated with a Tween 20/alcohol mixture; mites were counted the same day.