Causal Agent:
Fungus (Asperisporium papayae)
| Characteristic Symptoms: | |
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Irregular dark brown to black spots on the lower leaf surface of older leaves and slightly sunken tan spots on the upper leaf surface. |
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Black spots on fruits but not as heavy as that found on foliage. |
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Should not be confused with the black spot caused by Cercospora papayae as leaf spots of Cercospora papayae are grayish white compared to the dark brown to black spots of Asperisporium caricae. |
| Conditions for Disease Development: | |
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The disease is common in humid tropic and subtropical regions. |
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The pathogen survives between crops on crop debris and weeds of the cucurbit family. |
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Conidia/spores are air-borne and are disseminated by wind, rain splashes, tools/implements and field workers. |
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Infection requires free water and is favoured by temperatures between 26-32°C, in which the disease develops rapidly with new infections occurring every 7-10 days. |
| Management and Control: | |
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Maintain good field sanitation (i.e. early removal of infected leaves)
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Avoid prolonged moisture to minimize development and further spread of the disease.
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Spray with chemical fungicides like mancozeb (e.g. Attain M-80Ⓡ, Achem Mancozeb 80 WPⓇ, Micron 80 WOⓇ, VanzebⓇ), difenoconazole (e.g. ScoreⓇ, MontanaⓇ, PursueⓇ, BashⓇ) or propineb (e.g. AntracolⓇ). |
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