Damping off : Pythium aphanidermatum
Symptoms
- Pre-emergence phase : Complete rotting of seedlings.
- Post-emergence phase: Infected tissues become soft and water soaked.
- Seedlings topple over or collapse.
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Infected seedlings |
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Seedling Rot |
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Sporangiophore and Sporangium |
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Oospore |
Causal organism
Pythium aphanidermatum (Edson) Fitzp.
Mycelium :
Non septate, hyaline
Pathogen :
Asexual : Zoospores bi-flagellated, thin walled. Resting spores : Oospore.
Survival and Mode of Spread
Primary Survival:
Soil, Seed, Water
Secondary Spread:
Infected debris
Favourable Conditions
High humidity, high soil moisture, cloudiness and low temperatures below 24°C for few days .
Crowded seedlings, dampness due to high rainfall, poor drainage and excess of soil solutes.
Integrated Disease Management
Cultural
Avoid stagnation of water.
Use raised beds of 15 cm height.
Chemical
Drench with copper oxychloride 50% WP @ 2.5 g/l @ 4 l/sq.m.
Treat the seeds with metalaxyl-M 31.8% ES @ 2ml/ kg of seeds 24 hours before sowing.
Biological
Treat the seeds with Trichoderma asperellum @ 4 g/kg or Bacillus subtilis @ 10 g/kg of seeds 24 hours before sowing
Soil application of Bacillus subtilis @ 2.5 kg/ha with 50 kg of FYM.
Source of Information
Crop production guide – Horticulture 2020
Acknowledgement
Dr.P.Renukadevi, Professor, Department of Plant Pathology, TNAU, Coimbatore.
Dr.N.Indra, Associate Professor, Department of Plant Pathology, TNAU, Coimbatore.
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