Management of Sclerotinia stem rot disease with newer molecules for enhancing the yield of rapeseed-mustard in Bihar

Abstract

Rapeseed-Mustard are usually called as “Oilseed brassica”, is the world’s third most important source of edible oil after soybean and oil palm. India is the third largest producer of rapeseed-mustard after Canada, China and contributing to around 14% of world’s total production. Now in India, rapeseed-mustard rank 1st in oilseed production and is an important Rabi oilseed crop contributing 11.3% of world’s edible oil supply. It is grown all over India covering 918.32lakh ha of area producing 131.16 lakh tonnes with 1444 kg/ha average productivity contributing 33.24% of total oilseed production. Bihar produces 122.48 thousand tonnes from an acreage of 96.98 thousand ha with average productivity of 1263 kg/ha. Sclerotinia stem rot, caused by Sclerotinia sclerotiorum, is a persistent and devastating disease of rapeseed-mustard in Bihar, leading to substantial yield losses under high humidity and low temperature conditions. This study evaluated the efficacy of newer fungicidal molecules manage stem rot disease and enhance the yield. Field experiments were conducted during the 2021-22 and 2022-23 Rabi season and result showed that all tested fungicides significantly suppressed disease incidence and severity compared to the untreated control. Foliar application of Tebuconazole 50% + Trifloxystrobin 25% WG @ 0.1% (T1) at the time of flowering was the most effective treatment in reducing disease incidence and lesion length, and in enhancing yield compared to other fungicidal treatments and the untreated control. The treatment recorded the lowest pooled disease incidence (4.1%) and lesion length (3.2 cm), along with the highest pooled yield (1670.5 kg ha⁻¹) and maximum yield increase over control (750.9 kg ha⁻¹).