Cucumber mosaic virus

Pathogen and disease type. The Cucumber mosaic virus (CMV), belonging to the genus Cucumovirus, is a highly destructive systemic plant pathogen. It interferes with the plant’s physiological processes, causing metabolic disorders and disrupting the integrity of its vascular system, which ultimately leads to severe stunting and abnormal growth.

Host range. This virus is notorious for its extremely broad host range, infecting over 1,200 species of plants worldwide. It primarily affects economically significant crops such as cucumbers, melons, squashes, tomatoes, and peppers, but it also frequently strikes legumes, ornamentals, and various common weeds that serve as reservoirs for the virus.

Symptoms and signs. Typical symptoms include a distinct mosaic pattern of light and dark green patches on leaves. In addition, infected plants often exhibit leaf curling, vein clearing, severe deformation of the foliage, and stunted internodes. Fruits are often misshapen, mottled with yellow or green, and show significant reductions in quality and size.

Development and transmission. CMV is primarily transmitted by aphids in a non-persistent manner, meaning the insect can acquire and transmit the virus within seconds of feeding. It is also spread through mechanical transmission during pruning or cultivation practices and can be transmitted via seeds in certain host species. High populations of aphids and mild temperatures generally favor rapid spread.

Harmfulness and prevention. The virus causes substantial agricultural losses by rendering fruits unmarketable and reducing overall plant vigor. Since there is no curative treatment for viral infections, management focuses on prevention:

• Planting resistant or tolerant cultivars and hybrids.
• Implementing strict aphid control programs using appropriate insecticides.
• Removing and destroying weeds that act as virus reservoirs.
• Sanitizing pruning tools and equipment between rows.
• Ensuring the use of certified, virus-free seeds and transplants.