Field Studies on the Chemical Control of the Stem Borer Chilo partellus on Hybrid Sorghum in India12

Abstract

In field experiments at the Indian Agricultural Research Institute, New Delhi, during 1963 and 1964, 4 weekly applications of the following insecticides at comparable low and high rates of active ingredients in spray and granular formulations were effective for control of Chilo partellus (Swinhoe) (= zonellus Swinhoe) on hybrid grain sorghum: carbaryl (1.0 and 1.5 kg/ha), endrin (0.2, 0.3 kg/ha), lindane (0.13, 0.20 kg/ha), and benzene hexachloride (1.0, 1.5 kg/ha). Grain yields (kg/ha) in treated plots ranged from 1005 to 1624 and from 3083 to 4212, compared with 199 and 336 in the untreated controls. There was no significant difference in efficacy between the granular and spray formulations, and the high rates of these formulations were not consistently superior to low rates in increasing yields. In a 2nd experiment, to determine the effect of increasing numbers of weekly applications of endrin granules (0.2 kg/hectare), 4 and 5 applications were superior to 2 and 3 applications in reducing borer damage and increasing yields. In a 3rd trial, to compare imported and locally produced granular formulations of insecticides, 4 weekly applications of imported 2% endrin granules, 2% endrin granules supplied locally (0.2 kg/hectare), and experimental 10% dimethoate granules formulated locally (1.0 kg/hectare) effectively reduced borer damage and increased yields, while experimental local formulations of 2% endrin granules on coconut shell and on clay were less effective. The grain yield increases resulting from borer control with the more effective insecticides in these trials have demonstrated that chemical control of C. partellus on hybrid sorghum is necessary for maximum production of grain and is also economically feasible.