Insect pest control and yield patterns in Central Queensland cotton crops

Abstract

During 1957-1960, six field trials were carried out mainly to investigate the status of Heliothis armigera (Hubn.) as a pest of cotton under a variety of agronomic conditions. Heavy fertilizer dressings and hormone applications were used to increase the potential yields of seed cotton per acre in both rain-grown and irrigated crops. Early-season control of H. armigera is shown to exert the same influence under all agronomic conditions encountered, i.e. higher early-pick yields with no increase in total yields.
In two trials in which severe infestations. of Pectinophora scutigera Hold. were experienced, DDT applications resulted in considerably increased yields. Results of one trial indicated that relatively small populations of leaf-eating insects during the early and major square and boll production period can depress yields. Fertilizer is shown to have potential value in irrigated cotton, but the use of alpha naphthalene acetic acid sprays did not increase yields.