Apple, Late Season Control of The Leafroller Complex, 1982

Mature York trees on semi-dwarf rootstocks were selected early in the growing season for this test. Imidan 50W was applied in the first 5 cover sprays at 3 lb/A in 100 gal water with a conventional airblast sprayer. Test materials were applied on Aug 19 and Sep 2 when late season leafrollers were active. Sprays were applied to runoff using a Bean 35 gal/min hydraulic sprayer operating at 400 psi. Mite populations were evaluated on Jul 19 and found to be at low levels. An Aug 30 evaluation, following the first application of test materials, showed mites to be increasing slightly, but not to critical levels for this date. Fruit evaluations were made at harvest, Oct 11. Fifty fruit from each of the four replicates per treatment and examined for leaf-roller injury. The injuries were categorized as having occurred early (1st generation) or late in the season following commencement of the test.