Insecticide Sprays for Control of the Sugarcane Borer (SCB), Large-Plot Field Trial, 1980

Foliar spray concentrates were applied from an airplane to a field of first stubble crop sugarcane (Var. CP 65-357) at Little Texas Plantation near NapoleonviIle, LA, for control of season-long SCB infestations. A randomized complete block experimental design was employed with treatments replicated 5 times. Each plot consisted of a single block (cut) of sugarcane surrounded by drainage ditches or headlands; the size of these plots ranged from 1.8 to 3.4 acres. Each spray concentrate was applied in water to the crop canopy on 48 ft swath-widths (8 rows) and at a rate of 2 gal of finished formulation per acre, per application. The first application of insecticides was begun after internodes were visible and when 5% of the stalks harbored larvae in leaf sheaths (Jul 25). The second application was made Aug 12 when that level of infestation was again detected in Guthion-treated plots. However subsequent applications (applied Sep 13 and Oct 7) were made to facilitate long-term pesticide residue studies and without consideration of the level of SCB infestation existing in the field trial. The efficacy of insecticide treatments was evaluated at crop harvest (Oct 20-21) by comparing percentages of internodes damaged by seasonal populations of SCB larvae in treated plots to that found in untreated (check) plots; then (10 stalks) samples, randomly selected in each plot, were scanned for external signs of stalk-penetration by SCB larvae. Significant differences in bor