Peach, Lesser Peach Tree Borer Control, 1979 and 1980

Abstract

Abstract A 15-yr-old block of Sunqueen and Red Haven peaches was used in these tests. The objective of the 1979 experiment was to determine the effects of timing and interval between applications on the performance of Thiodan. The objective in 1980 was to compare the effectiveness of several insecticides for lesser borer control. In each year, 10 trees arranged in a randomized block design were used for each treatment. Sprays were applied to the trunk and scaffold limbs with a hydraulic sprayer equipped with a hand-gun and operated at 250 pst. Trees were sprayed until the bark, and especially old borer injuries, were thoroughly soaked, which required approximately 4 gallons of spray per tree. The timing of sprays coincided with the emergence of 1st generation moths, as measured by pupal case counts and pheromone trap catches. Timing of applications in 1979 using Thiodan 50WP 0.75 lb Al/100 gal is given in Table I; application dates in 1980 were Jun 6 and 26. The treatment effectiveness was determined by weekly counts of pupal cases, which was indicative of the number of larvae and pupae able to complete their development in the treated trees (1980) and the successful establishment and completion of development by the generation following treatment (1979, 1980). Pupal cases were removed as counted.