Impact of Weather Parameters and Fungicides Strategies on the Management of Root & Stem Rot in Sesame Caused by Macrophomina phaseolina

Abstract

Root & stem rot caused by Macrophomina phaseolina is an important disease. It spreads through seed and soil residual materials. In India root & stem rot disease can induce 5-100% yield losses under epidemic condition. The effect of various weather parameters on the development of root & stem rot in sesame was investigated during Kharif 2023 and 2024. The various weather parameters viz., temperature (max), temperature (min), relative humidity (morning), relative humidity (evening), soil temperature, soil moisture, rainfall and rainy days under natural condition.  Two year data revealed that there is significant correlation between disease incidence and weather parameters. The weather parameters viz., temperature (minimum), relative humidity (evening), soil moisture, rainfall showed a significant negative correlation with disease incidence, while soil temperature showed a significant positive correlation during both years. Regression analysis revealed that all the weather parameters contributed 99.96% and 96.04% towards disease development during both years. Due to lack of resistance in sesame genotypes, disease is managed through fungicides. Management of root & stem rot disease in sesame was done under In vitro and In vivo conditions. Average pooled data analysis revealed that, seed treatment with Carbendazim 12% WP + Mancozeb 63% WP followed by two foliar application of Tebuconazole 50% WG + Trifloxystrobin 25% WG was found most effective in minimizing the disease incidence (20.49%) and per cent disease reduction over the control (59.51%) with yield 478.98 kg/ha and B:C ratio 1.69. The key benefit to use this fungicides against plant disease is that it provides both protective and curative activity, reduce risk of fungicide resistant development, it also offers broader spectrum of disease control, and it gives both quick action (trifloxystrobin) and extended protection (tebuconazole).