Apple, Insecticide Tests, 1976

Dilute sprays were applied to apple trees at 200 psi with a no. 2 gunjet until run off. Test plots at the Horticultural orchard, Arlington, Wl , included 10 frees each and 30 to 40 trees each at the Potter Preserve Orchard, Baraboo, W l . At Baraboc the fungicides Polyram and Captan (2 lbs each) were applied prebloom (April 29 , May 7) and at petal fall (May 26) . Polyram was applied with insecticide treatments at petal fall and with covers (June 9 , 25; July 13, 24; August 11 , 25) . Dipel (1lb) was applied to control plot (May 26 to suppress a cankerworm infestation. At Arlington insecticides were applied June 4 (petal fall) and covers (June 10, 26; July 13, 24; August 11 , 24). Sumithion was omitted in the third cover (July 13) for both orchards. Differences in injury by curculio (Arlington) and red-banded leafroller (both orchards) were tested by comparing each treatment with every other treatment using ts (approximates t distribution, d.f. = ™, for arcsin transformed data).