Chemical control and species composition of thrips in Arkansas cotton fields

摘要

Field trials were conducted in 2000 on the Southeast Branch Experiment Station near Rohwer, AR to examine the efficacy of seed treatment, in-furrow, and foliar insecticides against early-season thrips on cotton. The effect of the treatments on standcount, thrips damage, and lint yield was also examined. All treatments controlled thrips compared with the untreated check. However, seed treatments (Adage and Gaucho) and in furrow treatments (Temik 15GR) were more effective against thrips than a single application of foliar treatments (Orthene 90SP, Centric 40WG, Actara 25WG). After three applications were made, foliar treatments tended to give better thrips control than the in-furrow or seed treatments. Thrips damage was significantly lower in the Adage ST, Gaucho ST, and Temik 15GR plots than any other treatment. Lint yield was not statistically different among treatments including the untreated check. However, the seed treatments (Adage and Gaucho) yielded numerically higher than all other treatments while Actara 25WG (0.0473 lb ai/ac) produced numerically the least yield. Western flower thrips were the predominant thrips species early in the 2000 growing season in Arkansas cotton fields. Because of the western flower thrips tolerance to many ofthe insecticides used against thrips, control failures of standard thrips insecticides were reported from many areas in the state. Accurate species identification of thrips infesting cotton is the key to any successful management program.