Cucumber green mottle mosaic virus

The Cucumber green mottle mosaic virus (CGMMV) is a highly contagious plant pathogen belonging to the Tobamovirus genus. It is renowned for its extreme environmental stability, as the virus particles can remain infective for years in soil, on plant debris, and on contaminated greenhouse structures or agricultural tools, making it a persistent challenge for farmers.

This virus primarily affects members of the Cucurbitaceae family, including cucumbers, melons, watermelons, and squashes. Commercial production systems are at the highest risk, particularly in hydroponic or greenhouse environments where high plant density and frequent human intervention facilitate rapid mechanical spread across the crop.

Symptoms of CGMMV infection are often manifested as distinctive green or yellow mottling on the foliage. As the infection progresses, affected leaves may show distortion and blistering. Fruit symptoms can be severe, characterized by mottling, bumpy surfaces, and internal rot in advanced cases. The overall vigor of the plant declines, leading to stunted growth and significant reductions in marketable yield.

Transmission occurs mechanically through the sap of infected plants, which can be spread via contaminated hands, tools, or clothing during harvesting, pruning, and tying. Seed transmission is another critical pathway, as the virus can be carried on the seed coat or internally. Furthermore, root-to-root contact in soil or nutrient solutions allows the virus to move between adjacent plants quickly.

Management of CGMMV relies entirely on strict biosecurity and integrated pest management (IPM) practices. Since there is no curative treatment, growers must focus on planting virus-free certified seeds and practicing rigorous sanitation. This includes disinfecting all surfaces and tools with appropriate chemical agents and ensuring that equipment used in affected areas is not moved to healthy zones.

• Use of certified pathogen-free seeds.
• Rigorous sanitation of greenhouse surfaces and tools.
• Immediate rogueing and disposal of infected plants.
• Crop rotation with non-host plant species.