Sheath blight

Caused by: Rhizoctonia solani
Problem Category: Fungal Disease
Symptoms: : circular oblong, or elliptical, green to gray water soaked spots on leaf sheaths, leisons with pale green or white centre and purple brown margin, leisons covering leaf sheath and stem. The disease moves up the plant into the upper leaves and panicles, causing poor grain fill, lodging (falling over), and plant death.
Comments: occurs in all areas where rice is grown, most damaging and second only to blast disease, spreads rapidly through irrigation. Warm temperatures between 28°C to 32°C and high relative humidity (85–100%) accelerate the disease.
Management: 1. Excess nitrogen application increases susceptibility to the disease. 2. Resistant Varieties: Chandrama, Chilarai, Keteki Joha, Chandrama. 3. Destroy infected crop residues and alternate weed hosts. 4. Seed treatment or seedling root dip with Pseudomonas fluorescens or Trichoderma species.
Control: 5. Spray - Neem oil 2% and karanj oil 2% added with an emuslifier or soap nut extract.