A new approach to develop shoot fly and stem borer resistant cultivars for insect pest management in sorghum through crossing of intermediate in resistance derivatives

The released sorghum varieties and hybrids developed from temperatex tropical crosses, despite having high yield potential and agronomic traits failed to express in full due to the attack of key pests, viz., shoot fly, Atherigona soccata Rond.; stem borer, Chilo partellus (Swinhoe); midge, Contarinia sorghicola, Coq.; and earhead bug, Calocoris angustatus Leth. A new approach was adopted to overcome the ensuing problems by crossing intermediate in resistance derivative with intermediate in resistance derivative, and resistant with intermediate derivatives. This led to develop new sources of resistance, viz., PGS 3, PGS 6, PGS 12 and variety P 311 and SPV 1015 (PGS 1). Such lines could be integrated with other insect control practices to develop operational insect pest management strategy in sorghum.