1997 New Jersey Vydate Insect Study with Chemical Thinning Treatments in Apple Win Cowgill, Dean Polk, Jeremy Compton Rutgers Cooperative Extension 4 Gauntt Place Flemington, NJ 08822
			This experiment was carried out in a commercial orchard consisting of twelve year old Red Chief Red Delicious on MM111 planted at a row spacing of 15 x 20 feet located in Hunterdon County, NJ. Treatments were replicated 6 times with single tree plots in a randomized complete block design. All treatments were applied at 10mm fruit expansion on May 19 with a 100-gal FMC sprayer operated at 200 psi. Treatments were applied with a handgun until run-off. A grower applied spray program consisted of normal fungicide and insecticide cover sprays. Agrimek was applied in a petal fall spray followed by Imidan and Guthion applications. White apple and rose leafhoppers and spotted tentiform leafminers were evaluated on each tree on 10 June, 2 July, 18 July, and 30 July. Samples consisted of 100 leaves from each tree, with the total number of leafhoppers or leafminer mines recorded as the number of leafhoppers or leafminers per leaf. European red mite populations were evaluated on 25 June, 9 July and 23 July. Samples consisted of 10 leaves per tree, with populations recorded as mites per leaf. The emphasis of this study was to evaluate the efficacy of Vydate and Vydate combinations as an apple chemical thinner. Insect control from the insecticide applied under afruit thinning protocol was also evaluated. Grower applied Agrimek suppressed both leafminer and red mite populations. Populations of these pests remained low throughout most of the season, and experimental treatments had no visible effect on these pests. The experimental treatments did have an effect on leafhopper populations. First generation white apple leafhopper populations are reflected in the 10 June and 2 July counts. By using these materials as thinning treatments, it may be possible to eliminate additional insecticides intended for specific control of leafhoppers.