| Popis: |
Five treatments were evaluated for efficacy against the Japanese beetle and grape berry moth in an experimental vineyard of Concord grapes at Wooster, Ohio. Plots consisted of 2 grape vines, with 4 replications/treatment in a randomized complete block design. Treatments were applied as foliar sprays at a rate of 100 gal/acre (935 1/ha) on 18 Jul and 31 Jul, using a hand-held CO2 sprayer operating at 45 psi (3.2 kg/cm2) and equipped with a 9505-E-TeeJet nozzle. BIOASSAY FOR JAPANESE BEETLE: After treated foliage was dry, 10 grape leaves were removed at random from the outside canopy of each plot for use in the bioassay. Leaves were brought into the laboratory on 0, 1, 3, 7 and 9 d after first treatment and placed inside ventilated 1 gal ice cream containers with 10 Japanese beetles. The 1-gal containers were modified by placing plastic liners inside and cheese cloth over the top. After holding beetles on treated foliage for 24 h, a count of the number of live beetles surviving was taken. The insect holding room was maintained at 75°F (23°C) with ca. 75% RH. FIELD STUDIES JAPANESE BEETLE: In addition to the bioassay, a reading of the number of live JB present in the field plots was taken at 1 h pretreatment and 0, 1, 3, 7, and 9 d posttreatment. This was accomplished by counting the number of live beetles present on the outside grape foliage on both sides of each plot. GRAPE BERRY MOTH EVALUATION: On 19 Sep, 10 grape clusters were randomly removed from each replicate and examined for the number of berries infested by grape berry moth. |
