Apple, Summer Control of European Red Mite and Spotted Tentiform Leafminer, 1994

Abstract

Abstract Pesticides were applied to 6-year-old trees in Fennville, MI (Brown Block) at a rate of 50 gpa with an FMC 1029 airblast sprayer. Treatments were arranged in a completely randomized design of 30-tree blocks (approximately 1/4 acre each), replicated four times. Applications of all materials were made on 6 Jul. Penncozeb, Dithane, Nova, and Lorsban and Ambush (on 8 Jun) were applied separately to all treatments. STLM evaluations were made on 13 Jul and 30 Aug by picking 50 randomly selected leaves from the two center trees of the block for a total of 200 leaves per treatment. Damage from STLM sap-feeding stages were recorded for comparison. ARM evaluations were made on 30 Aug by picking 50 randomly selected leaves from the two center trees (200 leaves per treatment). ERM and predatory mite (ZM and AF) evaluations were made on 30 Jun, 20, 27 Jul, 3 and 16 Aug by picking 50 randomly selected leaves from the two center trees (200 leaves per treatment). All mite counts were made by brushing leaves in a mite-brushing machine and counting ERM eggs, motile forms of ERM and ARM, and adult predatory mites (ZM and AF) under a microscope. Mite data are reported as mean mites per leaf.