| Bulb rot/ basal rot: Fusarium oxysporum f.sp. cepae |
Symptom:
- Occur in patches
- Leaves - turn yellow and then dry up slowly
- Entire plant shows complete drying of the foliage
- Bulb - shows soft rotting and the roots get rotted
- Whitish mould growth on the scale
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Soft rotting |
Rotten roots |
White mould growth on scales |
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Identification of pathogen:
- Produces many chlamydospores which are thick walled resting spores
- Microconidia – one celled and thin walled
Mode of spread and survival:
- Soil borne
- Infection occurs through root, either directly or through wounds
- Soil insects are common carriers
Epidemiology:
- High temp and low level of soil moisture - favourable for high disease incidence
- Temp- 28 to 32°C
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Management:
- Field sanitation - destruction of infected plant debris
- Soil drenching - COC-0.25%
- Pre planting treatment of bulbs - benomyl 15%+ mancozeb 60%
- Local Bellary, Poona Red Globe, Patna Red, White Large - resistant varieties
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Source of Images:
http://pnwhandbooks.org/plantdisease/onion-allium-cepa-fusarium-basal-rot
http://learningstore.uwex.edu/assets/pdfs/A3114.pdf
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