Apple, Vendex-50 Miticide Selective Action, 1975

The Vendex-50 label (ADP 75-109) claims control of European red mite at 1-3 lb/A, and claims the product to be relatively non-toxic to unspecified “beneficial mites”. The miticide was evaluated for effect on the predaceous mites Z.mali and A.fallacis at the manufacturer’s minimum recommended rate (1 lb/A) and at 2 lower rates, 8 and 6 oz/A. A no-miticide control was included for comparison. A single application was made on June 10, 1975 to 5-year-old Golden Delicious trees (MM106 rootstock), 1 qt/tree (27 gpa). Each treatment was replicated on 4 single tree plots. There were 4 blocks in the experimental design, with 1 tree of each treatment in each block. Application was made with a hand-held compressed air sprayer. Oil was withheld from all trees. The maintenance sprays were applied by air blast sprayer, 1 gal/tree (108 gpa); and consisted of 3 prebloom applications of Cyprex 65 WP, 1 lb/A, and 6 postbloom sprays of captan 50 WP, 6 lbs/A with Imidan 50-W, 3 lbs/A. Twenty-five leaves were collected from each tree, equally from the inside and outside of the lower half of the crown. Predaceous mites were first counted on individual leaves under a microscope and then European red mites were brushed off leaves and counted on a glass plate.