PROGRESS OF FUNGAL FOLIAR DISEASES IN RELATION TO WEATHER PARAMETERS IN COTTON

Abstract

Progress of fungal foliar diseases as influenced by different weather parameters in two BG II cotton hybrids (Jaadoo and RCH 2) and one straight variety (L 1060) was studied during kharif 2019-20.Disease severity was scored by adopting a standard scale of 0 to 4 in ten plants tagged randomly in each plot. Weather parameters were recorded at the meteorological observatory, RARS, Lam, Guntur.Correlation and multiple regression analysis were carried out between per cent disease index and weather parameters using MS-Excel program version 2010. Multiple regression analysis revealed certain differences in weather factors influencing the progress of diseases in different genotypes.Sunshine hours, the number of rainy days and wind speed are the common critical parameters contributing to the development of Alternaria and Corynespora leaf spots; minimum temperature and wind speed in case of grey mildew; RH II for rust are favourable parameters in cotton