Early Season ECB Control, 1990

This study was conducted at the University of New Hampshire Kingman Farm located in Madbury, N.H. The experimental design was a randomized complete block with 8 insecticide treatments applied at 2 different growth stages of corn (total of 18 treatments) and an untreated control replicated 4 times. 'Honeymoon' sweet corn was hand-planted 16 May in rows on 36 inch centers. Each plot consisted of a single 30-ft row of corn. Each insecticide treatment was applied 2 times 7 d apart starting at either the whorl growth stage (15-20 inches tall with no tassel growth visible in the whorls) or the pretassel growth stage (most of the plants with tassel growth visibly emerging from the whorls). The insecticide treatments were applied using a R & D CO2-pressurized (40 psi) single-nozzle hand held sprayer. Each treatment was applied in a single pass over the row directed into the whorls at a delivery rate of 14.4 gal/acre. Evaluation of the percentage of plants showing ECB leaf feeding injury prior to the first whorl treatment was made on 2 Jul. The percentage of injured stalks and ears was determined at harvest time (14 Aug) by examining all the plants in each replicate for ECB feeding injury.