Control of Insect Pests on Peach, 1996

Treatments consisting of experimental and registered insecticides were applied to single-tree plots in a randomized block design consisting of 2 replicates of ‘Cresthaven’, 2 replicates of ‘Redhaven’, and 3 replicates of ‘Sunhigh’. The trees were planted at a spacing of 20 X 30 ft and were 12 years old. All treatments were applied with a Myers Mity Mist sprayer calibrated to deliver 75 gpa, driven at 2.4 mph. All plots received a regular maintenance schedule of fungicides (Rovral 4F, sulfur, Indar 75WSP and Topsin M 75WSP). GPA was sampled weekly by counting the number of new colonies found in a 3-min examination of each plot tree. Each new colony was tagged with ribbon and the number of leaves infested with one or more live aphids was determined. Each tagged colony, up to 10 colonies per tree, was then rated weekly for the number of live aphids using the following categorical rating system: 1 = 1 to 10 aphics, 2 = 11 to 20 aphids, 3 = 21 to 40 aphics, 4 = 41 to 80 aphids, 5 = 81 to 160 aphids, and 6 = > 161 aphids. OFM shoot injury was assessed by determining the number of injured shoots per tree in a 5-min examination on 11 Jun and a 3-min examination on 12 Jul and 1 Aug. Effectiveness of chemicals on fruit feeders was assessed by scoring for injury 75 mature peaches from each tree. The sampling date for the various cultivars was as follows: 5 Aug (‘Redhaven’), 14 Aug (‘Sunhigh’), and 4 Sep (‘Cresthaven’). Please note the fruit sampling dates as related to the various dates of application. Larvae found inside the pick samples were collected and identified. Pest pressure was moderate to high throughout the season.