Apple, All Season Insecticide Test, 1986

A 16-year-old apple orchard, varieties ‘Yellow Delicious’ and ‘Red Delicious’ was used in this test. Single tree plots, replicated 4 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. Treatment dates were 14 Apr, tight cluster (TC); 25 Apr, pink (P); 8 May, petal fall (PF); 27 May, first cover (1C); 13 Jun, second cover (2C); 7 Jul, third cover (3C); 25 Jul, fourth cover (4C); and 25 Aug, fifth cover (5C). For disease control, the entire orchard was sprayed with Captan and Polyram as needed. ERM counts were made by randomly picking 25 leaves per 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 = number of days between Ml and M2. Sampling methods for other insects are as follows: Stethorus = avg no. of S. punctum larvae, pupae and adults/3 min count/tree; WALH = avg no. of WALH/3 min count/tree; WALHa = avg % WALH damaged leaves/tree; EASF = avg no. of EASF damaged fruit/100 fruit clusters/tree; STLM = avg no. of STLM mines/3 min count/tree; RAA = avg no. of RAA colonies/tree; AA = avg no. of AA/terminal (10 most infested terminals counted/tree); CM, TABM, RBLR, PC, and San Jose scale = avg no. of damaged fruit/100 fruit/tree (at harvest); Russet = avg % russet/fruit/tree (15 fruit/tree examined).