Apple, Mite Control, Insecticide Block, Hudson Valley Lab, Highland, N.Y., 1987

Treatments were applied to 8 tree plots replicated 3 times in a randomized complete block design. All treatments were applied dilute to runoff using a high-pressure handgun sprayer at 400 psi delivering from 3.8 to 4.2 gal spray/tree or 364 to 403 gal/acre. Trees were 23 yr old, 10 ft high, spaced 15 by 30 ft, and on M.2 rootstock. A Pounce spray was applied on 21 Apr (pink); Brigade was applied 13 May (petal fall), and 29 May (first cover); and Imidan was applied 14 and 30 Jun, 17 Jul, and 4 and 18 Aug in the first treatment. Danitol treatments were applied 21 Apr, 13 May, 14 Jun, and 4 Aug, followed by Guthion in the remaining cover sprays 29 May, 30 Jun, 17 Jul, and 18 Aug. Danitol was also applied at a high rate along with Spray oil on 13 May. This treatment was followed with Guthion applications in the remaining cover sprays commencing 6 Jun. DPX-EY059 was applied at three different rates on 21 Apr, 13 May, 14 Jun, and 4 Aug. EF-667 and EF- 667 + Lorsban were applied starting 13 May; Fenoxycarb and Guthion treatments were initiated 21 Apr, with all four treatments applied in cover sprays 29 May, 14 Jun and 30 Jun or 1 Jul, 17 Jul, and 4 and 18 Aug. Additional applications over the entire block included Difolatan 80S 15.5 lb/acre, 12 Apr; Cyprex 65W 1.5 lb/acre, 13 and 23 May; and Rubigan 1EC.7 lb/acre, 14 Jun. Naphthaleneacetic acid was applied in thinning sprays on 23 May using from 0 to 10 ppm depending on the cultivar. Mite populations were evaluated by sampling 25 leaves from one 'Red Delicious' tree/plot at biweekly intervals throughout the summer. The leaves were brought into the laboratory where they were brushed with a mite-brushing machine, and the mites and eggs were examined and counted using a binocular microscope. An early spring resulted in an early and prolonged bloom period. Rainfall was above average throughout most of the season; temperatures were generally normal for the area.