Apple, Synthetic Pyrethroid Evaluation Test, 1983

Treatments were applied to single-tree plots (8-yr-old) in a randomized block design consisting of two replicates ‘York Imperial,’ two replicates of ‘Stayman,’ and two replicates of ‘Delicious.’ Treatments were applied with a Myers Mighty Mist Sprayer at 50 gal/acre per full spray driven at 2 mph. Spray dates for the alternate side treatments were: 8 and 17 Jun., 9 and 19 Aug. For the 8 and 17 Jun. sprays an error in calibration resulted in 16% less material applied. Rates for treatments are listed as amounts per acre per both sides spray. Effectiveness on the AA was evaluated by counting aphid infested leaves per 20 terminals. Effectiveness of test chemicals on ERM was evaluated by counting mites several times during the season on sample of 15 leaves per tree, 90 leaves per treatment. Effects of sprays on the predator S.punctum was evaluated by 3-min counts of adults and larvae around the periphery of test trees. Effectiveness of chemicals on fruit feeders was assessed by scoring for injury all drops after 1 July and one harvest sample on 20 Sept. Apple samples averaged 63 fruits per replicate, 378 fruits per treatment.