Citrus leprosis

Citrus leprosis is a destructive viral disease that affects various citrus species. It is caused by viruses such as Citrus leprosis virus C (CiLV-C), which significantly impacts fruit quality and tree health. In many citrus-producing regions, this disease is considered a major quarantine threat due to its economic consequences.

The biology of the disease is inextricably linked to its vector, the flat mite of the genus Brevipalpus. The virus cannot be transmitted mechanically or through seeds; it relies entirely on these mites. Once a mite acquires the virus by feeding on infected plant tissue, it remains a vector for the rest of its life, effectively spreading the disease within an orchard.

Symptoms are manifested as lesions on leaves, stems, and fruits. These lesions typically appear as circular spots with a necrotic center and a chlorotic halo. Heavy infections lead to premature leaf drop, dieback of twigs, and the production of unmarketable, deformed fruit, which ultimately leads to reduced yields and tree decline.

Environmental conditions play a critical role in the spread of Citrus leprosis. Warmer and drier weather patterns promote the proliferation of Brevipalpus populations, accelerating the rate of viral transmission. The spatial distribution of the disease often follows the movement of mite colonies between adjacent branches and neighboring trees.

Effective management requires a combination of strategies aimed at breaking the disease cycle. Primary control involves the rigorous application of acaricides to suppress mite populations. Additionally, strict phytosanitary measures, such as the use of healthy propagation material and pruning heavily infected wood, are essential to prevent the further spread of the virus throughout the plantation.