COMPARISON OF INSECTICIDES AGAINST WOOLLY APPLE APHID, 2012

Field tests were conducted in a research orchard at the Cornell University’s Agricultural Experiment Station in Geneva, NY to compare the efficacy of several chemicals known to have activity against the woolly apple aphid (WAA). Treatments were arranged in a RCB design and replicated four times in 2 tree blocks of ‘McIntosh’. These plots were sprayed using handgun application at 300 gpa. A full list of treatments including materials used, application timings and rates is listed in Table 1. Because WAA is a sporadic pest, two applications of Mesurol 75W (12.0 oz/A) were applied to the test orchard on 6 Jun and again on 5 Jul in an attempt to flare populations in the test orchard. WAA was sampled pre-application to determine population levels, as well as post application (approx.7, 14, 28, 35 days PT) to determine efficacy. Because there are no recommended treatment threshold levels for WAA in NY apple orchards, treatments were applied when infestation levels exceeded 30.0% in all the plots. Threshold was reached on 24 Jul and applications were made on 25 Jul. Treatments were sampled by counting the presence or absence of live WAA colonies on 100 terminals in each replicate. Data was transformed and subjected to an AOV with JMP. Means were separated with Student’s t-test.