Charcoal rot or hollow stem or stalk rot blight

C/O: Macrophomina phaseolina( Rhizoctonia bataticola)

Symptoms:

• sudden wilting and death of the diseased plant resulting in
• If the infected stalk is split open, the pith is found to be disintegrated with longitudinal shredding of the tissue into
• Small black sclerotial bodies are seen in the infected
• The stalk is weak, hollow inside and break The stem, breaks near the ground level.
• Premature ripening takes place and the heads are poorly developed.

Etiology:

The fungus produces large number of sclerotia which are round and black in colour. Sometimes, it produces pycnidia on the stems or stalks.

Favorable condition:

• soil temperature of 35⁰C and moisture stress conditions preceding crop maturity
• Application of more nitrogenous fertilizers.
• Moisture stress condition.
• More in drip than furrow irrigation.

Survive and spread:

• Seed borne(seed coat) and soil borne disease.
• Survive: sclerotia as resting structure which present on soil and crop debris. Dry soil prolong survive and in very wet soil sclerotia cannot survive for more than 7 weeks.
• Spread:transfer of infected parts and sclerotial soil.

Management:

• Irrigate the crops at the time of earhead emergence to maturity.
• Treat the seeds with Carbendazim or Captan at 2 g/kg.
• Antagonistic fungi: trichoderma viride and T. harzanium.
• Tolerant varieties.