Evaluation of Insecticides for Control of Eastern Grape Leafhopper, 1991

The experiment was conducted in a mature vineyard at the Erie County Field Research Laboratory in North East, PA. Treatments were applied to Concord grapes trained to the single curtain (no tie) system. Treatments consisted of 6-vine plots arranged in a randomized complete block design and replicated 4 times. Each treatment row was separated by 2 untreated buffer rows. Applications were made using a Friend, small plot sprayer equipped with an FMC, vineyard boom. Treatments were applied at 100 gal/acre with pressure adjusted to 100 psi. The treatments were applied on 12 Jul. Precipitation for Apr, May, Jun, Jul, Aug and Sep was 3.64, 1.00, 0.75, 3.49, 3.07 and 3.25 inches, respectively. A pre-treatment count of leafhopper nymphs was taken on 9 Jul. Post-treatment evaluations was conducted 5, 14, 21 and 31 days after application. Evaluations consisted of randomly selecting 10 injured leaves per plot and recording the number of leafhopper nymphs.