Evaluation of Insecticides Against Lepidopterous Pests During Bloom on Blueberries, 1997

Abstract

Abstract This study was conducted in a ‘Bluecrop’ blueberry field near Whitesbog, NJ. Blueberry bushes were approximately 5 ft tall and spaced 9 X 4 ft apart. Treatments were arranged in a RCB design, replicated 4 times with each replication consisting of 6 bushes in 2 rows. Two unsprayed rows between blocks and 8 unsprayed bushes between treatments within a block served as buffers. Insecticides were applied with a CO2 pressurized Model T backpack sprayer (R & D sprayers) equipped with a Tee Jet hollowcone (4 VS) nozzle calibrated to deliver 30 gal/acre at 40 PSI. Insecticides were applied twice on 8 May and 18 May approximately at 30 and 65% bloom, respectively. Latron B-1956 at 0.12% vol/vol was included in Confirm and emamectin benzoate treatments as an adjuvant. In all other treatments Nu-Film 17 at 4 oz/acre was included. GM eggmasses were obtained from USD A-APHIS facility at Otis Air Base in Cape Cod, MA, to augment larval populations in the field plots. Eggmasses were stapled to the bush on 28 April at the rate of one eggmass per bush. Eggmasses began hatching on 30 April and larvae were well distributed on the bushes within a week after hatching. Larval populations were assessed by sampling 25 clusters from each of 4 randomly selected bushes/replicate for a total of 100 leaf and flower clusters/replicate on 7 May (pre-treatment count), and 16 May and 28 May (post-treatment counts). Leaf and clusters were randomly selected from the top, middle, and bottom thirds of each bush.