WSU Extension


Cucumber, Pumpkin, Squash
Angular leaf spot 
Cucumber mosaic virus 
Curly top (Beet curly top virus) 
Pollination failure 
Powdery mildew 
Root rot 
Verticillium wilt 
White mold 
Brown marmorated stink bug 
Spider mites 
Squash bug 
Western spotted cucumber beetle 

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Caption: Curly top virus symptoms on tomato
Photo by: R.S. Byther
Cucumber, Pumpkin, Squash : Curly top (Beet curly top virus)
(revision date: 6/3/2014)

Curly top is caused by a virus transmitted by the beet leafhopper. Many crops are affected, including tomato, bean, squash, cucumber, and pepper. In cucumbers, growth is slow and older leaves are yellowed. The terminal leaves may be unusually dark, and the plant is stunted. Yield is low, and fruits are small and of poor quality. Young squash plants may be killed without showing symptoms. Older plants show yellowing of older leaves, dwarfed new growth, overall stunting, and upward rolling of leaves. Runners often bend upward at the tip. Diseased plants may fail to set fruit. The virus is also found in annual flowers and weeds. Curly top is not a problem in western Washington.
Management Options

Non-Chemical Management
  • Pull out and destroy infected plants.
  • Control of beet leafhoppers is ineffective for preventing curly top.
  • Since leafhoppers avoid feeding on shaded plants, shading plants may help prevent infection.
  • There are no resistant cucumber varieties. The squash varieties 'Umatilla Marblehead' and 'Yakima Marblehead' show resistance.
Select non-chemical management options as your first choice!

Chemical Management

None recommended


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Caption: Curly top virus symptoms on tomato
Photo by: R.S. Byther