Squash vein yellowing

Squash vein yellowing (SqVYV) is a destructive plant disease caused by a virus belonging to the genus Ipomovirus, family Potyviridae. It is recognized as a significant constraint for cucurbit cultivation, capable of causing devastating crop losses in both open fields and greenhouse conditions.

The disease primarily targets plants within the Cucurbitaceae family. Watermelon is particularly susceptible to this pathogen, often showing severe symptoms. In addition to watermelons, the virus affects crops such as cantaloupe, pumpkins, squashes, and cucumbers, posing a challenge for multi-crop production systems.

Symptoms typically manifest as yellowing of leaf tissues surrounding the veins, which gives the disease its characteristic name. As the infection progresses, this chlorosis can cover the entire leaf surface. Infected plants often exhibit stunted growth, reduced fruit set, and deformed, poor-quality fruit, leading to significant economic impact.

The virus is transmitted by the silverleaf whitefly (Bemisia tabaci) in a persistent, semi-circulative manner. The insects acquire the virus by feeding on infected host plants and efficiently spread it to healthy vegetation. Environmental conditions that promote rapid whitefly population growth, such as warm and humid climates, facilitate the widespread transmission of the virus.

Management and prevention strategies focus on limiting the insect vector and reducing the viral reservoir:

• implementing integrated pest management (IPM) to control Bemisia tabaci populations;
• removing weeds and volunteer crops that serve as virus reservoirs;
• using physical barriers like insect-proof netting in early growth stages;
• maintaining good hygiene during cultivation and harvesting;
• selecting resistant or tolerant varieties developed through plant breeding programs.