Apple, European Red Mite Control with Acaricides, All-Season Test, 1986

A 16 year-old apple orchard, varieties ‘Yellow Delicious’ and ‘Red Delicious’ was used in this test. Single tree plots, replicated 3 times in a randomized complete block design, were sprayed to runoff (ca 5 gal/tree) with a hydraulic sprayer equipped with a handgun and operated at 300 psi. Treatments were applied 4 Apr, half inch green tip (Vz G); 25 Apr, pink (P); 7 & 8 May, petal fell (PF); 22 May, first cover (IC); and other dates (on table). For disease control the entire orchard was treated with Captan and Polyram as needed. ERM counts were made by randomly picking 25 leaves/tree, brushing mites onto glass plates coated with Triton B-1956, and counting motile mites. Mite-days were calculated as follows: MD = MD1 + [(Ml + M2)/2 x Y], where MD1 = mite-days already accumulated, Ml = avg ERM/ leaf on a given counting date, M2 = avg ERM/leaf on the next counting date after Ml and Y = no. of days between Ml and M2. Stethorus = avg no. of S. punctum larvae, pupae and adults/3 min count/tree.