Cucumber Green Mottle Mosaic

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

Leaf symptoms of cucumber green mottle mosaic virus (Aviv Dombrovsky and Elisheva Smith) CC BY 3.0

This cucurbit disease comes in on infected seeds. And there is no known cure. Before 2013, it was only in Russia, China, Japan, Korea, India, Spain, and Israel. Scientists believe it came to the U.S. on infected seed. Cucumber green mottle mosaic enters plants through wounds and root-to-root contact.

​Cucumber green mottle mosaic symptoms

Symptoms of cucumber green mottle mosaic (CGMMV) are subtle. At first, infected plants may look fine. Then pale yellow spots may appear on young leaves, vein clearing, or chlorotic mottling. Leaves may also become deformed. Stunting and leaf death are more common in older plants. As leaves mature, these symptoms fade, providing a false sense of security.

Even when the disease is full-blown, it still doesn’t look terrible. The problem is that this disease causes fruit drop and reduced fruit size. Crop loss can be up to 80%. Harvestable fruit may have a mottled appearance, and the interior is often damaged and inedible.

Cucumbers infected with cucumber green mottle mosaic (A. Dombrovsky and E. Smith) CC BY 3.0

Cucumber green mottle mosaic control

​Since there is no cure for this contagious disease, remove infected plants and a few of their neighbors to prevent it from spreading. Using certified disease-free seeds and placing new plants in quarantine can help prevent this disease from infecting your soil. Since this virus can travel on tools, shoes, and clothing, good sanitation practices can help protect your plants.