Measures to Control Sheath Blight in Paddy Crop

February 8, 2024

Sheath blight is a pervasive and damaging disease in rice cultivation, known for its ability to severely affect paddy crops. In this blog, we will explore the causes, symptoms, and management strategies for sheath blight, providing crucial insights to help you protect and maintain the health of your rice fields.

What is Sheath Blight in Paddy Crop

Sheath Blight, caused by the fungal pathogen Rhizoctonia solani, is a major disease affecting rice crops worldwide, leading to significant yield losses and reduced grain quality. This disease primarily targets the leaf sheaths and blades, hindering the plant's ability to photosynthesize and produce healthy grains. If the disease is caught early and managed effectively, yield losses can be minimized, potentially as low as 5-10%.With moderate disease progression, yield losses can range from 20-30%. In severe cases where the disease spreads unchecked, yield losses can be devastating, reaching 50% or even higher.

Overview of Sheath Blight in Paddy crop

Type of Infestation	Disease
Common Name	Sheath Blight
Causal Organism	Rhizoctonia solani
Affected parts of the plant	Leaf sheath and leaf blade

What are the favourable factors for Sheath blight in paddy crop ?:

Warm and humid conditions (25-30°C, high humidity)
Prolonged leaf wetness
Susceptible rice varieties
Imbalanced fertilization (excessive nitrogen)
Presence of infected plant debris or sclerotia in the soil

Symptoms of Sheath Blight in Paddy:

Initial Symptoms: Oval or elliptical, greenish-grey water-soaked spots appear on leaf sheaths near the water level.
Progression: Spots enlarge, turning greyish-white with an irregular brown or purple border. Lesions may merge, covering entire tillers from the waterline to the flag leaf.
Severe cases: Infected leaves die, and the disease can reach the panicle, preventing grain filling and sticking panicles together.