AVRDC International Cooperators'
Fact Sheet

Cucurbit Diseases


Anthracnose
Colletotrichum lagenarium (Glomerella cingulata var. orbiculare)


Found worldwide
leaf symptoms on cucumber


Damage Symptoms

The disease is particularly damaging to watermelon, cucumber, and cantaloupe, but also may occur on most other cucurbit crops. On cucumber and cantaloupe, leaf lesions are circular and brown up to 1 cm in diameter, while on watermelon the leaf lesions are black and somewhat smaller. Petiole and stem lesions are elliptical in shape and sunken. Fruit lesions appear at or near maturity as watersoaked spots that develop into sunken, circular lesions lined with dark fungal stroma bearing masses of pink spores.
symptoms on melon

Symptoms on melon
   

Conditions for Development

Disease is favored by extended periods of rain and warm temperatures. The pathogen persists in crop debris, is seedborne, and may survive on volunteer crop plants or cucurbit weeds. In the field, watersplash and windblown rain disperse the fungus.


Control

Use resistant cultivars when available. Fungicidal sprays generally are necessary when susceptible cultivars are grown under conditions conducive for disease development.

 


Last updated: 2001. 
Information from:
Vegetable Diseases: A Practical Guide. Lowell L. Black, AVRDC.
 

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