Sheath blight

Caused by: Rhizoctonia solani
Problem Category: Fungal Disease
Symptoms: Circular, oblong or elliptical, green to gray water-soaked spots on leaf sheaths; lesions with pale green or white center and purple-brown margin; lesions covering leaf sheaths and stems; poorly filled grains
Comments: Occurs in all areas where rice is grown; second only importance to rice blast; most damaging in intensive rice production; spreads rapidly via irrigation
Management: Avoid overfertilizing plants as excessive nitrogen application has been shown to increase susceptibility to the disease; applications of foliar fungicides may be required; two applications are recommended and should be timed so that the first application is made between the early internode elongation and the second application made on emerging panicles 10-14 days later
Control: spray 1% neem seed kernal extract or neemoil or pongamia oil 2% to control sheath blight