Effect of sowing dates and weather conditions on Rhizoctonia root rot disease incidence and green pod yield of French bean

Abstract

Maximum seed germination (88.91%), lowest pre-emergence (11.02%) root rot were recorded when the French bean crop was sown on 19th September. But lower post emergence (14.59%) and maximum yield (65.7q/ha) were recorded when the crop was sown on 29th September. The crop sown on 19th October and 29th October recorded average maximum pre- and post-emergence root rot disease incidence to the extent of 21.84 percent and 23.25 percent, respectively. Average temperature, relative humidity, soil temperature, rainfall and sunshine favoured pre- and post-emergence root rot disease development. Pre-emergence and post-emergence root rot disease incidence was highly significantly positively correlated with minimum soil temperature but pre-emergence and post-emergence root rot disease incidence was non-significantly negatively correlated with maximum, minimum temperature and maximum soil temperature during 2014-15. Highly and positive significant correlation was observed between the average maximum and minimum temperature, seed germination and green pod yield with sowing dates during 2014-15 and 2015-16 cropping seasons. However, there was a negative and significant correlation between the pre and post-emergence and sowing dates during 2014-15 and 2015-16 cropping seasons. Average humidity, rainfall and sunshine showed non-significant correlation with disease incidence and green pod yield in both 2014-15 and 2015-16 cropping seasons.