Garlic mite-borne filamentous virus

The Garlic mite-borne filamentous virus, caused by Allexivirus filumallii, is a widespread viral pathogen affecting members of the Allium genus. As a member of the Allexivirus genus, this virus significantly impacts the cultivation of garlic and onion worldwide, often leading to severe yield reductions in affected plantations.

The primary hosts of this virus are garlic (Allium sativum) and various onion species. Because the virus causes systemic infection, it colonizes all parts of the plant, including the bulb, which facilitates its persistence through successive planting seasons if infected bulbs are used for propagation.

Symptoms are distinct and usually include leaf mosaic, chlorotic streaking, and severe leaf twisting, where the leaves become thin and filamentous. Infected plants exhibit stunted growth, reduced bulb size, and poor shelf life. These symptoms are often more pronounced in the second and third generations of plants grown from infected cloves.

Transmission occurs primarily through the garlic mite (Aceria tulipae), which acts as a vector, spreading the virus from plant to plant while feeding. Additionally, mechanical transmission during agricultural activities, such as clipping or handling planting material, significantly contributes to the spread of the pathogen throughout a field.

Effective management requires an integrated approach to break the cycle of infection.

• Start with certified virus-free or tissue-cultured planting material.
• Implement strict phytosanitary measures to control the population of garlic mites.
• Rogue out and destroy any plants displaying symptoms of viral infection immediately.
• Practice proper crop rotation to minimize soil-borne vectors and carry-over.
• Ensure isolation between new plantings and older, potentially infected crops.