Sour cherry green ring mottle

Sour cherry green ring mottle is a viral disease caused by the Cherry green ring mottle virus (CGRMV). It is a systemic pathogen that affects the vascular system of the tree, significantly impacting its vitality, growth rates, and overall longevity by disrupting the plant's normal physiological functions.

The disease primarily targets species within the Prunus genus, with sour cherry (Prunus cerasus) and its related variety, the Duke cherry (a hybrid of sweet and sour cherry), being the most common hosts. The virus often exhibits latency, meaning infected trees may show no visible symptoms for extended periods while still serving as a source of the pathogen.

Typical symptoms manifest on the foliage, appearing as chlorotic rings, spots, or bands. In many cases, these rings remain green or become yellowish, leading to leaf distortion and sometimes early leaf drop. The infection can lead to reduced fruit set, malformed fruits, and general tree decline over several growing seasons.

The primary route of virus transmission is through the movement of infected plant material, including scion wood, rootstocks, and nursery stock. Mechanical transmission can also occur in the orchard via pruning tools that have not been sterilized, making sanitation a critical aspect of disease management in commercial and private orchards.

Management strategies focus on prevention, as there is no chemical cure for this viral infection. Successful orchard hygiene involves sourcing only certified disease-free nursery stock, implementing a strict program to replace infected trees, and sterilizing pruning equipment with appropriate disinfectants after working on each tree to prevent cross-contamination.