AVRDC International Cooperators'
Fact Sheet

Cucurbit Diseases


Alternaria Leaf Spot
Alternaria cucumerina


Found worldwide
Leaf symptoms on cantaloupe



Damage Symptoms

Each pathogen is highly specialized attacking only a single crop species. Plants may be affected at any stage of growth. Young seedlings are killed or severely stunted. Older plants begin to wilt at midday for a few days, then permanently wilt and die. Vascular bundles are discolored becoming yellow or brown.


Conditions for Development

The pathogens can persist in the soil for many years. The disease can move from field to field in soil on farm machinery, infected crop debris, and irrigation water. High soil temperatures favor disease development.


Control

Use resistant varieties when available. Avoid known infested fields for production of a susceptible crop. Wash equipment when moving from one field to another. Flooding fields for rice production reduces pathogen survival in the soil.

Leaf symptoms on cantaloupe
Leaf symptoms on cantaloupe
 

leaf symptoms on watermelon

Leaf symptoms on watermelon
     


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

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