Apple, Aphid Control, 1986

Test chemicals were applied on 24 Jul to 18-year-old apple trees at Monmouth, Maine, as dilute sprays using a hand gun and a hydraulic sprayer operating at 250 psi at 350 gal/acre. There were 2 single tree replicates in each treatment in a randomized complete block design. The standard pesticide program during the course of this test consisted of Captan 80W (0.7 lb/100), Imidan 50W (1 lb/100), and Thiodan 50W (1 lb/ 100) applied on 1 Aug. Prior to treatment, 5 succulent terminal shoots were tagged around the periphery of each tree at a height of 1 to 2 m. Evaluation was based on a count of all live aphids on the distal 4 unfurled and 1 furled leaves and on each terminal stem included by these leaves. Weather during this test was generally wet; also 1 inch of rain occurred on 26 Jul. For 3 days following application of aphicides, maximum temperatures were 84° to 89°F.