Control of Fall Armyworm and Cucumber Beetle in Sweet Corn

This study was conducted to compare the efficacy of various insecticide treatments in controlling fall armyworm and cucumber beetle in sweet corn. ‘Silver Queen’ sweet corn was planted in an experimental field at the Tropical Research and Education Center, Homestead, Florida on 18 Dec, 2016. Plots were two-beds wide on 36-inch center, 30-ft long, and separated by a 5-ft alley. Plants were spaced 18 inches within the rows. Each treatment was replicated four times in a randomized complete block design. Foliar application of all treatments was made on three dates—28 Dec, and 5 and 18 Jan using a CO₂ backpack sprayer with two D-4 hollow cone nozzles/bed delivering 75 gpa at 30 psi. No adjuvant was used in this study. Treatments were evaluated on six dates—30 Dec and 3, 7, 15, 20, and 31 Jan, 2017 by carefully checking all plants/plot for FAW damage and FAW larva. A pre-spray sample was collected on 27 Dec, 2016. Effect of treatments on the control of cucumber beetle was also evaluated by carefully checking all plants for cucumber beetle adults on 27 Dec (pre-spray sample), 30 Dec, and 15 Jan.

Population abundance of FAW was medium during the trial (Table 1). On the first sampling date, mean numbers of FAW-infested plants on insecticide-treated plants did not differ from the non-treated check (Table 1). On the subsequent sampling dates, insecticide treatments significantly reduced FAW infestation when compared with the non-treated control except in a few instances. All treatments, except Fawligen, significantly reduced cucumber beetle adults on sweet corn plants on all sampling dates when compared with the non-treated control (Table 2). In each treatment, cucumber beetle adults in the post-spray sampling date were fewer than the pre-spray numbers. Overall, the insecticide treatments were effective in controlling FAW and cucumber beetle adults on sweet corn plants.

This study was supported by Helm Agro US, Inc. and AgBiTech, LLC research funding.