Apple, Insect and Mite Control, 1983

Abstract

Abstract Test pesticides were applied to 17-to 27-yr-old apple trees at Monmouth, Maine, as dilute sprays using a hand gun with a hydraulic sprayer operating at 100 lbs/in2 at 300 to 350 gal/acre. Trees were sprayed on 14 May (pre-pink), from 5 to 13 June (petal fall), from 16 to 23 June (first cover), from 29 June to 6 July (second cover), from 12 to 19 July (third cover), from 26 July to 8 Aug. (fourth cover), and from 9 to 17 Aug. (fifth cover). Materials were applied on dates as noted in table. The fungicide program before blooming consisted of Captan 80W (1 lb) on 6 May, Polyram 80W (0.6 lb) on two dates, Manzate 200 80W (1.5 lb) on 30 Apr. in Test 3, and Cyprex 65W (1 lb) sprayed after blooming 14 June in Tests 1 and 2. In addition, Polyram 80W (2 lb) was mixed with each insecticide treatment at each spray. There were four single-tree replications. A randomized complete block design was used, with two ‘McIntosh’ and two ‘Cortland’ cultivars in Test 1; two ‘Red Delicious,’ one ‘Cortland,’ and one ‘Mcintosh’ cultivar per treatment in Test 2; and three ‘Mcintosh’ and one ‘Spartan’ cultivar per treatment in Test 3. Except for test trees, orchards were unsprayed. On 24 and 25 Aug. 0.5 box of apples was picked from each tree, and about 360 to 450 apples were examined per treatment on 10 to 17 Sept. for external egg punctures (apple maggot), egg-laying scars (plum curculio), and typical feeding injuries (codling moth and lesser appleworm). European red mites were counted on three dates from 13 July to 22 Aug. on 25 leaves collected at chest-height around the periphery of each tree. Leaves were brought into the laboratory and brushed onto glass plates coated with a Tween 20/alcohol mixture; mites were counted the same day.