Apple, Insecticide Test, 1974

Experimental sprays were applied to run-off to single-tree plots in a randomized block design with 4 replicates of Golden Delicious. Treated single-trees were separated by others not sprayed with insecticides. Experimental sprays were applied with a John Bean sprayer, 35 gpm pump, equipped with a spray mast carrying 7 spray guns arranged to wet the uniformly trimmed trees. Spray dates for the test insecticides were: May 14, 30, June 13 (UC-49035 treatments dropped after June 13), June 27 and 28, July 19 and 20, and August 8. The fungicide mixture 1.5 lb captan 50W plus 1.5 lb Polyram 80W/acre was applied with an airblast sprayer on May 29, June 10 and 25, July 8 and 23, August 5 and 19. Average temperatures were: May 59.16° F, June 65.62° F, July 72.87° F, August 72.24°F, and September 63.23° F. Rainfall in inches was: May 3.31, June 5.05, July 1.56, August 2.73, and September 4.88. 1974 was a light crop year. Effectiveness of the insecticides on the codling moth-oriental fruit moth complex was evaluated by scoring for injury all drops after July 1 and a picked sample of 25 apples/replicate, 544/treatment taken on August 26, eighteen days after the last spray. Apple samples averaged 136/replicate, 544/treatment. Effectiveness of the insecticides on the European red mite and on Z.mali was determined by making counts of mites on samples of 20 leaves/tree, 80 leaves/treatment. Effect of the sprays on the predator S.punctum was evaluated by 3-min counts of larvae, pupae and adults around the periphery of the test trees. Effectiveness on apple aphids was determined by collecting 4 terminals from the top of the tree and 4\terminals from around the bottom of the tree. Then the number of aphids on the most infested leaf from each terminal was counted.