Apple, Tufted Apple BUD Moth Management Tactics, 1994

Abstract

Abstract A number of different insecticides, including insect growth regulators, Bacillus thuringiensis products and conventional organophosphates and carbamates were evaluated at different timings and methods of application to control TABM, other leafrollers, mites, leafminers, leafhoppers and to evaluate their effects on natural enemies. Experimental sprays were applied to replicated 12-15 tree plots in a randomized block design. Each plot consisted of alternating trees of ‘Yorking’, and ‘Golden Delicious’. These trees were planted to a spacing of 18 × 25 ft and were 15 years old. Experimental sprays were applied with a Friend Airmaster ‘309’ calibrated to deliver 100 gpa at 2.4 mph. Applications timings for TABM control were based on the accumulation of degree days from first adult moth capture in a sex pheromone trap (10 May) in order to predict percentage of egg hatch for each brood of TABM. Degree day calculations were based on minimum and maximum developmental thresholds of 45°F and 91°F, respectively. Treatments, timings, methods of application, and degree day calculations are listed in a table. All applications were complete sprays, except for the last Lorsban plus Lannate treatment. This treatment was applied as an alternate row middle application (ARM). A routine schedule of fungicides (Dithane 75DF, Nova 40WP, Ziram 76WP and Benlate 50DF) was maintained throughout the experiment. One ARM application of Swat 8E at 0.6 lb Al/acre (expressed as amount/acre for a complete spray) for control of the spirea aphid was made on 1 Jul. The effect of the sprays on WALH was evaluated by counting the number of nymphs per 25 injured leaves per tree (cv. Yorking). STLM were evaluated by a 5-min count of mines around the periphery of the trees (cv. Yorking) at the end of the second generation flight. Effectiveness of the treatments on SA was evaluated by counting the number of aphid-infested leaves/10 side terminals, and the number of aphids/most infested leaf, where a rating scale (0-3) was used instead of counting live aphids (0 = no aphids, 1 = 1 to 20 aphids, 2 = 21 to 100 aphids, and 3 = >100 aphids). The total number of aphid natural enemies was determined by counting the number observed on 10 terminals per tree. Effect of the test chemicals on the ERM and AF was evaluated by counting the mites several times during the season on samples of 25 random leaves per tree (cv. Yorking) or 100 leaves per treatment. The effect of sprays on SP was evaluated by 3-min counts of adults and larvae around the periphery of the same trees. Shelters of the various leafrollers were counted in a 5-min examination of each plot tree. All larvae were collected and returned to the laboratory for identification. Effectiveness of the products on fruit feeders on ‘Golden Delicious’ was assessed by scoring for injury all dropped apples on 31 Aug and 25 apples per tree on 20 Sep and on a harvest sample of 100 fruit per tree from each of two center trees per replicate on 20 Sep. For ‘Yorking’, injury was assessed on all dropped fruit on 16 and 31 Aug and 25 dropped apples from each of two trees from 3 to 6 Oct and a harvest sample of 400 apples from a total of 4 trees in the center of each plot from 3 to 6 Oct. Pest pressure was high throughout the season.