Control of Fall Armyworm in Pre-Tassel Sweet Corn in Minnesota, 1995

This test was conducted at the University of Minnesota Rosemount Agricultural Experiment Station, Rosemount, MN. ‘Jubilee’ sweet corn was planted 12 Jun in plots consisting of a single 30 ft row on 30 inch centers. Each plot was separated by one untreated border row on each side and 7 ft alleys at each end. Treatments were arranged in a RCB design with four replications. FAW egg masses, obtained from USDA-ARS at Mississippi State, MS, were placed in the whorl of each plant 28 Jul. A single application of each treatment was made 5 Aug. Applications were made using a CO2-pressurized back-pack sprayer with one nozzle per row or a hand shaker to evenly distribute granular materials. The sprayer was calibrated to apply 30 gpa at 35 psi. Average temperature for all applications was 79°F. By 5 Aug, most FAW larvae were late 2nd to early 3rd instars, reflecting a 4 day delay in optimum (planned) treatment timing due to inclement weather. Treatments were evaluated 23 Aug by randomly selecting 25 ears per plot (100 per treatment) and recording the number of ears with late-instar FAW larvae and/or feeding damage.