Apple, Tufted Apple Bud Moth Control Tactics, 1993

Abstract

Abstract Experimental sprays were applied to 12-15 tree plots in a randomized block design. Each plot consisted of alternating trees of ‘Yorking’, and ‘Golden Delicious’. These trees were spaced 18 × 25 ft apart and were 14 years old. Experimental sprays were applied with a Friend Airmaster ‘309’ calibrated to deliver 100 gpa at 2.4 mph, except for the second Lorsban plus Lannate treatment which received 50 gpa at 2.8 mph. Applications timings were based on accumulated degree days following various biofix points (i.e., 1st egg hatch). Degree day calculations were based on minimum and maximum developmental thresholds of 45°F and 91°F, respectively. The first table contains a listing of treatments, degree day calculations and percent hatch estimates for each brood of TABM. All applications were complete sprays, except where noted. A routine schedule of fungicides (Penncozeb 80WP, Rubigan 1EC, Captan 50WP and Benlate 50DF) was maintained throughout the experiment. Alternate row middle (ARM) applications of Vendex 4L at 0.5 lb Al/acre on 19 and 27 May and of Omite 30WP at 1.2 lb Al/acre (expressed as amount/acre for a complete spray) on 6 Jul were applied for mite control and ARM of Swat 8E at 0.625 and 0.75 lb Al/acre (expressed as amount/acre for a complete spray) were applied on 24 Jun and 6 Jul, respectively for control of the spirea aphid. The effect of the sprays on the WALH was evaluated by counting nymphs/25 injured leaves/tree. STLM was evaluated by a 5-min count of mites around the periphery of the trees (cv. Yorking) at the end of the second generation flight. Effectiveness of test chemicals on ERM and ZM was evaluated by counting these mites several times during the season on samples of 25 random leaves/tree (cv. Yorking), 100 leaves/treatment. The effect of sprays on S. punctum was evaluated by 3-min counts of adults and larvae around the periphery of the same trees. Effectiveness of chemicals on fruit feeders was assessed by scoring for injury all dropped apples on 12 and 24 Aug and 25 apples on 22 Sep and an at harvest sample on 27 Sep of 75 fruit per tree from each of two trees for ‘Golden Delicious’. For ‘Yorking’ injury was assessed on all dropped fruit on 12 and 24 Aug and 50 dropped fruit from each of two trees on 18 Oct and a harvest sample of 125 fruit/tree from 4 trees in the center of each replicate from 18 Oct to 22 Oct. Pest pressure was moderate throughout the season.