Sucking pests and predator dynamics in Stand non Bt cottons grown in traditional and non traditional locations

摘要

Population dynamics of sucking pests and predators was studied in Bt non Bt and desi cotton genotypes grown in traditional and non traditional areas. Mean incidence of all sucking pests and arthropod predators was relatively lower in Annigeri as compared to Hanumanamatti. At both locations the incidence of sucking pests was higher in inter specific hybrid than intra specif hybrids and desi genotypes. At Annigeri thrips incidence in MRC 7918 BG-II was 14.6 against 20.3 /3 leaves in Hanumanamatti. In desi cotton it was 2.7 and 6.1/3 leaves in these respective locations. Incidence of leaf hoppers did not cross ETL (2 / leaf) in any genotype throughout the season but for November 1st fortnight in inter specific Bt and non Bt cotton hybrids (10/3 leaves). On the contrary it was always above ETL (upto 15/3 leaves) in all genotypes except desi cotton (DDhC 11) at Hanumanamatti in September and December months. On the contrary aphid incidence reached far above ET level (upto 56/3 leaves) at both locationsduring November to January months, higher being in desi cottons. Whitefly incidence was low irrespective of genotypes and locations. The dynamics of predators was mainly corresponding to aphid incidence.