University of Maryland Extension

Viruses - Vegetables

Back to Vegetable Crops

virus infected squash
Virus infected squash

  • Specific virus diseases are difficult to distinguish and produce a wide range of symptoms including stunted, slow growing plants, twisted, crinkled, cupped or deformed leaves, and leaf discoloration (yellow mottling and mosaic patterns, ringspots and dark-green banding). Viruses can cause colored circles or mottling (alternate dark green and light green or yellow streaks) of fruits. 
  • Viral symptoms are usually first observed on foliage.
  • They can possibly infect bean, pea, pepper, cucumbers, squash, melon, and tomato plants.
  • Aphid, thrips and leafhopper feeding transmit most viruses common in Maryland.
  • Tobacco mosaic virus (TMV) is mechanically transmitted by tools and handling plants.
  • Viral diseases are systemic and symptoms tend to progress and worsen through the season.


  •  If viral symptoms extend to edible plant parts, the entire plant needs to be removed and discarded. Pods with minor viral symptoms are edible and will not cause health problems.
  • Control weeds around the garden and insect pests that suck plant sap.
  • Grow or purchase transplants resistant to TMV.

pepper infected with a virus
Virus symptoms on pepper fruit

virus infected butternut squash
Virus symptoms on butternut

peas infected with a virus
Virus symptoms on peas

pumpkin infected with a virus
Virus symptoms on pumpkin

tomatoes infected with spotted wilt virus
Tomato spotted wilt on tomato fruit


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