Management of Rice Sheath Blight with New Chemicals in Srikakulam District of Andhra Pradesh, India

Abstract

Rice sheath blight is one of the most economically important rice diseases in the world. Sheath blight, a soil-borne disease caused by the fungus Rhizoctoniasolani AG1-IA (Teleomorph: Thanatephoruscucumeris (Frank) Donk), is a devastating disease.  The disease leads to a significant drop in grain yield and quality and yield losses of up to 50% have been reported under the most favorable circumstances. Despite farmers' chemical control measures against the disease, pathogen causes serious early crop losses every year. KVK Srikakulam conducted on farm trials on Sheath blight management in paddy fields to inform farmers about new and highly effective chemicals during Kharif, 2020 and 2021. A recent new chemical, Azoxystrobin 11% + Tebuconazole 18.3% (T1) at 1.5 ml/l was effective in reducing the incidence of the disease, recorded 88.2% and 81% disease incidence during 2020 and 2021, respectively. Trifloxystrobin 11% + tebuconazole 75% (T2) at 0.4 g/l was also comparable to T1, registering disease incidence of 82% and 75% in 2020 and 2021, respectively. Whereas, in the Propiconazole 11.4% @ 1.0ml/l treatment (Farmers method), the incidence in 2020 was only 67.0% and the incidence in 2021 was 65.0%. Azoxystrobin 11% + Tebuconazole 18.3% treated plots produced higher yields compared to farmers' practices. Although the chemical is more expensive than what farmers typically use, disease incidence is significantly reduced after just one spray and results in higher product yields.