Bacterial Leaf Blight (BLB) of Rice

Disease Overview –

• Causal Organism: Xanthomonas oryzae pv. oryzae (bacteria)
• Affecting Stage: Seedling to reproductive stage (leaves)
• Symptoms: Leaf blight, wilting, and scorched leaves

Symptoms –

Leaf Blight Phase :

• Water-soaked lesions near leaf tips or margins
• Yellow to straw-colored streaks
• Lesions progress downwards, causing drying and wilting

Kresek Phase (younger plants):

• Yellow, wilted, and curled leaves
• Plant wilting without distinct lesions
• Stunted growth and potential death

Favorable Conditions :

• High humidity (70-80%) and temperatures (25-34°C)
• Heavy rainfall and wind
• Excessive nitrogen fertilizers
• Dense planting and standing water

Control Measures :

Cultural Control –

1. Use resistant varieties (e.g., IRBB-21, IR-64, Pusa Basmati-1121)
2. Seed treatment with antibiotics (Streptomycin sulfate)
3. Balanced nitrogen fertilizer application
4. Drain excess water
5. Proper plant spacing
6. Remove infected debris

Organic Control –

1. Pseudomonas fluorescens (biological control agent)
2. Neem extracts and plant-based oils
3. Cow urine or cow dung slurry (antimicrobial treatment)

Chemical Control –

1. Streptomycin sulfate + Tetracycline
2. Copper-based bactericides (Copper oxychloride, Copper hydroxide)
3. Bleaching powder (in standing water)

Trade Names of Chemicals –

1. Streptocycline (Hindustan Antibiotics Limited)
2. Blitox (Indofil)
3. Nordox (Indofil)

Effective Management :

By implementing these control measures, farmers can effectively manage Bacterial Leaf Blight and protect their rice crops from significant yield loss.