RELATIVE RESISTANCE OF SOYBEAN CULTIVARS AGAINST SUCKING INSECT PESTS

Abstract

A field experiment was carried out to determine the relative resistance of soybean cultivars against sucking insect pests in the experimental area of Oilseed Section, Agriculture Research Institute, Tandojam during the Kharif season of 2005. Seeds of ten soybean cultivars (FS-85, AGS-9, AG-109 MA-4085, AGS-8, E-91-=270, PR-142, AGS-20, Wales-2 and Braggs) were sown in rows 45 cm apart in a three replicated Randomized Complete Block Design. It was observed that there was a significant difference in infestation of cultivars by the sucking insect pests.The population of whiteflies and thrip were more abundant during early growth stage, while jassids were more abundant during advanced growth stage of crop. The over all means of pest population showed that thrips were more abundant (3.485 + 0.126) followed by jassid (1.015 + 0.014) and whitefly (0.902 + 0.12) per leaf. The highest thrip (4.107+ 0.369 per leaf) population was observed on cultivar E91- 270. The highest jassid (1.253+ 0.275 per leaf) population was observed on cultivar MA-4085. Where as, the highest whitefly (1.093+ 0.15 per leaf) population was found on cultivar FS-85.As far as cultivars are concerned, Wales-2, Braggs and AGS-109 were comparatively susceptible, while PR-142 and AGS-9 were comparatively resistant, however, rest were moderately resistant.