SUSCEPTIBILITY OF SOME SOYBEAN VARIETIES TO CERTAIN PIERCING-SUCKING INSECTS UNDER THE FIELD CONDITIONS OF NORTH DELTA

Abstract

Tolerant varieties to insect species represent one of the simplest and important methods of insect pest control to minimize the insecticide hazards. Therefore, susceptibility of five soybean varieties to infestation with some piercing-sucking insects: aphids, Aphis spp.; whitefly, Bemisia tabaci (Genn.) and leafhoppers, Empoasca spp. were evaluated at Sakha Agric. Res. Station Farm, Kafr El-Sheikh Governorate during 2016 and 2017 seasons. The obtained results showed significant differences in susceptibility between the tested soybean varieties to the mentioned insects for every season and from season to another. In general, the population density of whitefly and aphids were higher in the first season than the second one, while the reverse was found for leafhoppers. Based on the grand mean number of the two study seasons, variety Crawford was significantly the most infested variety to infestation with leafhoppers and aphids, while the least infested variety for aphids was Giza35 and for leafhoppers was Hybrid30. As for the whitefly, Giza35 significantly was the most infested variety, while Crawford was the least infested one. In respect to the resistance status of the tested varieties to the insects, Crawford and Hybrid30 showed susceptiblity to aphid infestation, while the other varieties exhibited low resistance. Giza111 and Giza35 appeared as susceptible for whitefly, Giza21 and Hybrid30 showed low resistance, while Crawford was moderately resistant. Concerning leafhoppers, Giza111 and Crawford were susceptible. Giza21 showed low resistance, while Hybrid30 was moderately resistant.