Apple, Integrated Test, 1976

Abstract

Abstract Several insecticide-acaricide programs were evaluated for insect control, mite suppression, and influence on the predator Stethorus punctum. Sprays were applied to 2-tree plots in a randomized block design with each plot consisting of a Red Delicious and a Golden Delicious tree. Each treatment was replicated 3 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 the insecticide treatments were: April 30, May 5, 13 and 24, June 3, 11 and 22, July 2, 16, 23 and 30, August 6 and 20. One plot was sprayed on all the dates listed with 114 g Guthion 50W and 1 lb Zolone 25W/acre/alternate side. Four other plots were sprayed with the same mixture except on July 16, 23 and 30, and August 6. On all four of these dates one plot was treated with 228 g GCP-5126 50W/ acre/alternate side spray. Another plot was treated with 1 lb GCP-5126 50W/acre on both sides on July 16 and 30. A third plot was treated with 114 g GCP-5126 50W/acre/alternate side spray on July 16, 23 and 30, and August 6. A fourth plot was treated with 342 g GCP-5126 50W in complete sprays on July 16 and 30. Fungicides applied as 6X concentrates as needed during the season were: Cyprex, Polyram, sulfur, Benlate, captan, and zineb. Average temperatures were: May 57.74° F, June 71.30° F, July 70.09° F, August 67.92° F, and September 62.78° F. Rainfall in inches averaged: May 5.68, June 2.63, July 4.86, August 2.62, and September 4.49. Effectiveness of the test chemicals on the European red mite was evaluated by making several counts of mites on samples of 20 leaves/tree, 60 leaves/treatment. The effectiveness of sprays on the predator. S. punctum was evaluated by 3-min counts of adults and larvae around the periphery of the test trees. European red mite and S. punctum data were taken from Red Delicious trees. Effectiveness on the apple aphid was evaluated by counting the number of infested terminals/10 terminals/tree and calculating the percent infested. The number of aphid infested leaves/terminal was also determined. For each treatment the number of apple aphids/most infested leaf/infested terminal was also counted. Effectiveness of the treatments on the tufted apple budmoth (TABM) was determined by counting the number of live larvae/tree and the number of larval sites or shelters/ tree. Effectiveness in preventing fruit injury by TABM larvae was evaluated by scoring: (1) all drops after July 1; (2) 100 Red Delicious and 50 Golden Delicious apples on the plot trees on Aug 23; and (3) a harvest sample of 100 Golden Delicious apples/plot tree on Sep 20. Russeting of Golden Delicious apples was scored by rating 50 apples/plot tree as having: no russet, slight russet, moderate russet and severe russet. The categories were ranked 1, 2, 3 and 4, respectively.