Apple, Integrated Test, 1975

Several insecticide-acaricide programs were evaluated for insect control, mite suppression, and influence on the predator, Stethoruspunctum. Sprays were applied to 4-tree plots in a randomized block design with each plot consisting of a York Imperial, Red Delicious, Jonathan, and Stayman Winesap. Each treatment was replicated 4 times. Treated plots were separated by others not sprayed with insecticides. Treatments were applied as 6X concentrates with a Friend Airmaster 393 sprayer at 25 gpa/alternate side spray driven at 2 mph. Spray dates for insecticides-fungicides were: May 20 and 27; June 4, 11, 18 and 25; July 2, 9, 16, 23 and 30; August 7, 13, 20 and 27; and September 3. Polyram 80W, 2.0 lb/acre and sulfur 95W, 1.5 lb/acre were applied to all plots except the Dikar plot from May 20 to June 11; captan 50W, 1.5 lb/acre and sulfur at the same rate above were applied from June 18 to July 16; and captan by itself at the above rate was applied after July 16. Zolone 25W, 10 oz/acre was substituted for the rate listed in all plots receiving the Guthion-Zolone combination except the Dikar plot from June 18 to July 30. Lannate 25W, 0.25 lb/acre was applied only on July 2, 9, 16 and 23; the rate was changed to 0.5 lb/acre on July 30, August 7, 13, 20 and 27. Thiodan 50W, 1.0 lb/acre was applied on June 18 and 25 to all plots. Plictran 50W, 2 oz/acre was applied with the first 4 treatments on July 3 to stabilize the mite populations. Effectiveness of the treatments on fruit feeders was assessed by scoring for injury all drops from the variety Stayman Winesap after July 1 and a picked sample 14 days after the last spray. Apple samples averaged 121/replicate and 484/treatment. Effectiveness on the white apple leafhopper was evaluated by counting nymphs on the underside of 25 leaves/tree, 2 trees/replicate for both generations. Effectiveness of treatments on the European red mite was evaluated by counting the mites several times during the season on samples of 20 leaves/replicate (Stayman Winesap only), 80 leaves/treatment. The effect of sprays on the predator S.punctum was evaluated by 3 minute counts of adults and larvae around the periphery of the test trees (Stayman Winesap and York Imperial). May 61.08°F, June 68.98° F, July 72.97° F, August 73.89° F, and September 61.13° F. Rainfall in inches averaged: May 4.05, June 7.60, July 3.12, August 2.01 and September 13.8.