Chicory necrosis virus

Chicory necrosis virus (Nepovirus cichorii) is a significant viral pathogen affecting various horticultural and vegetable crops. As a member of the nepovirus genus, it represents a complex challenge for farmers due to its specific transmission mode, which relies on soil-borne vectors such as nematodes, making traditional sanitation difficult once the soil is contaminated.

The primary hosts of this virus are members of the Asteraceae family, with chicory (Cichorium intybus) being the most economically affected crop. Beyond cultivated chicory, the virus can persist in alternative wild hosts, including various weeds that survive between seasons, acting as a perennial source of inoculum in agricultural landscapes.

Symptoms of infection are diverse and often include chlorotic spots, mosaic patterns, and distinctive necrotic rings on the foliage. As the disease progresses, infected plants show stunted growth, distorted leaf shapes, and reduced vigor, which directly impacts the photosynthetic efficiency and final yield quality of the chicory roots or leaves.

The virus spread is highly dependent on the population density of specific soil-dwelling nematodes, particularly those of the Longidorus genus. These vectors facilitate the transmission of the virus from root to root. Moist soil conditions typically enhance nematode activity, creating a window of high risk for rapid secondary spread throughout the field.

Integrated management is essential for controlling this viral disease.

• Prioritize the use of certified, virus-tested seeds.
• Implement long-term crop rotation schemes to disrupt nematode life cycles.
• Monitor and treat soil for high nematode populations before planting.
• Maintain strict weed control to remove virus reservoirs.
• Adopt rigorous phytosanitary measures to prevent cross-contamination between fields.