Apple, Early Season Insecticide Treatments, 1983

Experimental materials were applied to 8-year-old semi-dwarf ‘York’ trees using a Bean 35 gal/min hydraulic sprayer operating at 400 lbs/in2. Trees were sprayed until the spray ran off. A randomized block design was used and each treatment was replicated four times. Treatments were applied at the periods of delayed dormancy (18 April) and/or petal-fall (13 May). For one treatment a 3-in band of Cygon was applied with a paint brush to tree trunks 18 in above ground level using undiluted 4E formulation. White apple leafhopper density was estimated on 18 May by counting nymphs and adults on 10 leaves per replicate. European red mite density was estimated on 23 May by randomly selecting 10 leaves per tree and counting motile mites with the aid of a hand lens.