Efficacy, Persistence, and Phytotoxicity of Aldicarb Applied as a Pretransplant Treatment to Eggplant for Colorado Potato Beetle (Coleoptera: Chrysomelidae) Protection

Abstract

Aldicarb was applied pretransplant to potted eggplant, Solanum melongena L., to determine the duration of Colorado potato beetle, Leptinotarsa decemlineata Say, control and residues in fruit relative to aldicarb application time and dose. The influence of pretreatment temperature on aldicarb phytotoxicity was also investigated. Eggplants, treated 1 week pretransplant with 0.4, 0.8, or 1.6 g of aldicarb 15G per 425 cm3 of potting soil, were protected from L. decemlineata for >3 weeks after transplanting; no residues of aldicarb were detected in first-harvest fruit. Foliage protection for this period would eliminate three to five of the foliar sprays currently being applied for early-season L. decemlineata control. Aldicarb phytotoxicity to eggplant was acclimation temperature dose dependent. Plants exposed to high acclimation temperatures (21–30°C) displayed significantly greater phytotoxicity when treated with 0.8 g of aldicarb compared with 0.4 g. Regardless of dose, little phytotoxicity was observed on plants exposed to low acclimation temperatures (13–18°C); thus, aldicarb phytotoxicity to eggplant can be eliminated by acclimating plants at temperatures ranging from 13 to 18°C for 1 week before treatment.