Cucumber necrosis virus

The causative agent of the disease is the Cucumber necrosis virus (CNV), belonging to the Tombusvirus genus. This virus targets the plant's vascular system, causing systemic infection, tissue necrosis, and a significant disruption of the plant's metabolic processes.

The primary host for this virus is the cucumber plant. The disease affects both greenhouse and open-field cultivations, posing a major threat to commercial production due to its ability to spread rapidly throughout the crop population under favorable environmental conditions.

Symptoms typically manifest as chlorotic spots on leaves, which gradually develop into necrotic brown lesions. Affected plants show stunted growth, distorted leaf development, and poor fruit formation, leading to severe yield loss and decreased quality of the agricultural product.

Transmission occurs mainly through the soil and water supply. The virus is vector-borne, specifically transmitted by the soil-inhabiting zoosporic fungus Olpidium brassicae. Moist soil conditions facilitate the movement of the fungal zoospores, which penetrate the roots and introduce the virus into the plant's vascular tissue.

The economic impact of the virus is significant, often resulting in heavy yield losses. Control measures include:

• Sterilization of soil and greenhouse substrates.
• Using virus-free seeds and transplants.
• Effective management of soil moisture levels.
• Rigorous sanitation practices to prevent cross-contamination.
• Application of fungicides to control the fungal vector, if applicable.