Soybean Charcoal rot, ashy or stem blight or dry root rot: Macrophomina phaseolina
Symptom:
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This disease occurs when the plants are under moisture stress or under nematode attack or through soil compaction or may be through nutrient deficiencies.
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It is a most common basal stem and root disease of the soybean plant.
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Lower leaves become chlorotic and wilting and drying is apparent.
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The diseased tissues generally develop greyish discoloration.
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The sclerotia look like black powdery mass hence the disease is known as charcoal rot.
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Blacking and cracking of roots is the most common symptom.
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The fungus survives in soil and crop debris in dry conditions.
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Dry conditions, relatively low soil moisture and nutrient and temperature ranging from 25o C to 35o C are favourable for the disease.
Management:
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Deep ploughing in summer.
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Ensure balanced fertilization of the crop.
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Rotate soybean with cereals.
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Maintain well-drained field
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Destroy last years infected stubble.
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Seed treatment with T. viride @4g/kg or P. fluorescens @ 10g/ kg of seed or Carbendazim or Thiram 2g/kg of seed.
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Spot drenching with Carbendazim 1g/lit or P. fluorescens / T. viride 2.5 kg/ha with 50 kg FYM.
Source-
- TamilNadu Agritech Portal
