Cranberry, Fruitworm Control, 1982

The test was conducted on a uniformly vined, 35-year-old section of State Bog in East Wareham, Mass. The experimental design was a randomized complete block with eight treatment plots replicated four times. Plots (15 by 7 ft) were separated within blocks by 5-ft pathways and between blocks by 10-ft pathways. Two postbloom applications were made on 21 and 29 July, with a 10-gal, powered ground sprayer delivering ca 0.6 gal/min at 50 lb/in2. All treatments were diluted to the rate of 400 gal/acre. A spray disc (4/64 inch orifice) and long distance nozzle tip allowed the applications to simulate those achieved commercially with overhead sprinkler systems. Difolatan was applied on 18 June, 8 and 27 July, to prevent infection by fruit rot organisms. Temperatures during July and Aug. were markedly below normal and precipitation was slightly below normal. During the 3rd week of Oct., berries from five randomly selected, square-foot areas within each plot were harvested by hand and frozen. These were later inspected for injury by A.vaccinii. Data transformed to arc sine of the square root of proportion were subjected to an analysis of variance.