Cucurbit aphid-borne yellows

Cucurbit aphid-borne yellows (CABYV) is a severe viral disease caused by a virus belonging to the Luteoviridae family. It is a phloem-limited virus, meaning it colonizes the transport vessels of the plant, which leads to metabolic disruptions and a general decline in the plant's physiological health.

The virus has a wide host range within the Cucurbitaceae family. It is particularly damaging to crops such as watermelon, melon, cucumber, and squash. In addition to commercial crops, several weed species act as reservoirs, allowing the virus to persist in the field environment throughout the year.

Clinical symptoms include distinct interveinal chlorosis of the older leaves, which progressively moves upward as the infection advances. The leaves become thick, leathery, and brittle. Infected plants show reduced fruit set and smaller, poor-quality fruit, significantly impacting the marketable yield for farmers.

Transmission occurs exclusively via aphid vectors, most notably the cotton aphid (Aphis gossypii) and the green peach aphid (Myzus persicae). The virus is acquired by aphids feeding on infected plants and is then transmitted to healthy ones. The disease spread is most aggressive during periods of high aphid density and favorable climatic conditions.

Management strategies focus on breaking the transmission cycle. Since there are no curative treatments for the virus, farmers must emphasize prevention. This includes the application of insecticides to control aphid populations, implementing strict weed management to eliminate alternative hosts, and practicing proper crop rotation to minimize infection pressure.