Insect Control, Hudson Valley Lab, Highland, NY, 1989

Abstract

Abstract 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 2.7 to 4.2 gal spray/tree or 262 to 407 gal/acre, depending upon foliage present and weather conditions. Trees were 25 yr-old, 10 ft high, spaced 15 by 30 ft, and on the EMU rootstock. The EXP-60145A treatments were all tested in a seasonal program with sprays applied at pink, 4 May, petal fall, 22 May, and in cover sparys on 7 Jun, 22 Jun, 7 Jul, 24 Jul, 8 Aug, and 24 Aug. DB-8518829 was applied 4 May, 22 Jun, and 8 Aug, while Imidan was applied at 24.0 oz/100 gal on 22 May and 7 Jun, and 16.0 oz/100 gal on 7 Jul, 24 Jul, and 24 Aug. Danitol was applied 4 May, 22 May, 7 Jul, and 8 Aug, with Guthion applied in the remaining cover sprays. Orthene was applied 4 May and 8 Jun with Guthion applied in the remaining sprays. Additional treatments included; Morestan applied 4 May along with Guthion and followed by Guthion in all succeeding sprays; Andalin 2.1 L applied at the 4 and 8 oz/100 gal rates on 22 Jun with Guthion in all other sprays starting at 22 May; Andalin 1 L at 8 oz on 22 Jun followed by Andalin 2 L 8 oz/100 gal on 24 Jul, with Guthion in other cover sprays; and Safer Insecticidal Concentrate plus Sunspray oil 6 E + applied 22 May, 8 Jun, and 7 Jul. Applications over the entire block primarily for disease control included: Agway Spray oil 6 E 1 gal/100 plus Supracide 2 E 1 qt/100 gal plus Difolatan 80 S 5 lb/100 gal, 11 Apr; Rubigan 1 EC 3.0 oz/acre plus Dithane M45 80 W 1.5 lb/acre, 4 May and 14 May; Rubigan 1 EC 9 oz/acre plus Dithane M45 80 W 6 lb/acre, 24 May and 1 Jun; Nova 60 W 2 oz/acre; 8 Jun; Polyram 80 DF 4 lb/acre, 23 Jun; Manzate 200 80 DF 4 lb/acre; 15 Jul; and Benlate 50 W 6 oz/acre plus Captan 50 W 6 lb/acre, 17 Aug. Naphthaleneacetic acid (Klingtite formulation) was applied in thinning sprays on 25 May using from 42 to 96 ml/100 gal, depending upon the cultivar and apparent fruit set. European apple sawfly and plum curculio were evaluated prior to “Jun drop” by examining all of the fruits in 50 fruiting clusters on one Greening' tree/plot on 5 Jun. Apple aphid and/or spirea aphids were evaluated by examining 25 terminals for the presence of live aphid colonies on one 'McIntosh' tree/plot on 2 Jun and 10 Jun. Rosy apple aphids were evaluated in a similar manner on 2 Jun using 'Cortland' as the cultivar. Spotted tentiform leafminer was evaluated 19 Jun by counting the number of mines on 25 'McIntosh' leaves/plot. White apple leafhopper was evaluated by counting the number of nymphs on 25 'Empire' leaves/plot on 14 Jun. Insect damage to the fruit was assessed at harvest by examining 100 fruits/cultivar/plot from 'Jersey Mac', 4 Aug; 'McIntosh', 18 Sep; and 'Golden Delicious', 26 Sep. 'Golden Delicious' fruit finish was evaluated using a russet rating from 1 (best finish) to 3 (worst finish). Temperatures were generally cooler than normal due to the continually overcast conditions found during much of the summer. An extended bloom period resulted in greater than normal insect pressure especially from European apple sawfly and plum curculio. Rainfall was above normal during May, Jun and Aug.