Sheath Blight Disease
Causal organism: Rhizoctonia Solani Kuhu.
Symptoms:
· In sheath blight disease of rice, the leaf discoloration starts from tip.
· Leaf become yellow or orange yellow.
· Rust colour spots develop on the leaf sheath specially on the leaf near of water line.
· Special resting structure sclerotia are formed on these rust-coloured spots.
· These sclerotia drops and added into soil (which help in perennation) and irrigation water (which carries the infection from one plant to another plant).
Favorable condition:
· Temperature= 28-32 degree.
· Relative humidity= 95-100%
Disease cycle:
Perennation:
· Through sclerotia present in soil and plant debris.
Primary infection:
· Through sclerotia present in soil and plant debris.
Secondary infection:
· Through sclerotia which spreads in the field with the help of irrigation water.
Diagram of sheath blight disease cycle:
Management:
Cultural method
· Remove plant debris and weed host before field preparation.
· Proper sanitation application applies in the field. E.g.: soil solarization.
· Proper spacing maintain row to row and plant to plant.
· Remove infarcted part of the plant.
· Deep ploughing in summer and burring of stubbles.
Chemical method
· Spray Carbendazim 500g/ha.
· Foliar spray P. fluorescens at0.2% at boot leaf stage and 10 days later.
· Soil application of P. fluorescens@ of 2.5kg/ha after 30 days of transplanting (product should be mixed with 50 kg of FYM / Sand and applied).
Biological method
· Apply organic amendments (improvement) viz., neem cake@150kg/ha of FYM12.5 tons/ha. Avoid flow of irrigation water from infected field to heathy fields.
