Understanding syntonic relationship of foliar diseases of green gram with weather variables

Abstract

Green gram with good adaptation to various eco-regions is extensively grown in India and other south Asian countries. Biotic stresses of viral, bacterial or fungal nature appear as major limiting factors which may occur singly, simultaneously, in combinations or in sequence in various eco-geographical zones. Weather variables have profound impacts on the disease occurrence, the interactions between weather variables and diseases based on long term data-sets, which can be used to point out the critical variables and the sensitive period in crop season for management practices. Good correlation was observed from 27 to 36th meteorological week (second week of July–first week of September) for the diseases such as bacterial leaf spot (BLS), Cercospora leaf spots (CLSs), Anthracnose (RLS) and weather variables. A close relationship of RF and RHe appeared with RLS, RHm, RHe and Tmin showed close relationship with BLS, whereas Tmax, SSh and RF showed a close relationship with CLS.