Cucumber Green Mottle Mosaic

Cucumber green mottle mosaic is a viral disease that can take a big bite out of cucumber, watermelon, and other melon crops. ​

Progression of cucumber green mottle mosaic virus infection in watermelon leaf (MDPI)

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This cucurbit disease is found on infected seeds and there is no known cure. It was first seen in the U.S. in 2013. Prior to that, it was only seen in Russia, China, Japan, Korea, India, Spain, and Israel. It is believed to have been brought to the U.S. on infected seed.


Cucumber green mottle mosaic symptoms

Cucumber green mottle mosaic enters plants through wounds and root-to-root contact. Symptoms of cucumber green mottle mosaic (CGMMV) are subtle. At first, infected plants may look fine. Then you may see light yellow spots on young leaves, vein clearing, or chlorotic mottling. Leaves may also become deformed. Stunting and leaf death are more commonly seen in older plants. As leaves mature, the symptoms seem to disappear, providing a false sense of security. 


By the time the disease is full-blown, it still doesn’t look terrible. The problem is, this disease causes fruit drop and reduced fruit size. Crops can be reduced by 25 to 80%. Fruit that makes it to harvestable size can also have a mottled appearance and the interior is often damaged and inedible.


Cucumber green mottle mosaic control

Since there is no cure for this contagious disease, infected plants must be removed completely, along with a few of their neighbors, to prevent it from spreading. Using certified disease-free seed and placing new plants in quarantine can help prevent this disease from infecting your soil. Since this virus can also be transported on tools, shoes, and clothing, good sanitation practices can also protect your plants.