Root rot: Macrophomina phaseolina

Symptoms:

• Reddish brown lesion on stem
• Branches and leaves exhibit sagging
• White mycelial growth covers decaying stem
• Bark shredding
• Rotten tissues contain black or dark brown, thick walled sclerotia

Bark shredding

Pathogen:

• Mycelium : Hyaline to dull brown
• Sclerotia thick walled and dark brown

Macrophomina phaseolina

Favourable Conditions:

• High soil temperature (30-35 ⁰C)
• Low soil moisture

Mode of Spread and Survival:

• Fungus remains dormant as sclerotia in soil and on infected debris
• Primary spread: Soilborne and seedborne sclerotia
• Secondary spread: Irrigation water, human, implements, cattle, etc.

Management:

• Crop rotation
• Destruction of plant debris
• Seed treatment with T. virideat 4 g/kg of seeds or carbendazim @ 2 g/kg of seeds
• Spot drench with carbendazim 50 WP @ 1 g/litre
• Soil application of Bacillus subtilis @ 2.5 kg/ha with 500 kg of well decomposed FYM at 30 DAS