Apple chlorotic leaf spot virus

Apple chlorotic leaf spot virus (ACLSV), taxonomically defined as Trichovirus mali, is a pervasive plant virus that impacts a broad spectrum of pome and stone fruit species. As a systemic infection, it colonizes the plant vascular tissue, often persisting for many years without showing immediate lethal effects, yet causing chronic economic losses.

The host range of this virus is extensive, including apples, pears, plums, cherries, and various other rosaceous plants. Its ability to infect multiple species makes it a persistent challenge for nurseries and commercial orchardists alike, as it can be transmitted across different types of fruit trees if grown in close proximity.

Symptoms are highly variable depending on the host variety and environmental conditions. Typical signs include chlorotic spots, mosaic patterns, and rings on the foliage. In more severe cases, trees may exhibit reduced vigor, stunted growth, and distorted fruit development, which renders the produce unsuitable for the fresh market.

Transmission occurs primarily through vegetative propagation using infected scion wood or rootstocks. In addition, certain aphid species may act as vectors in the orchard environment. Human intervention, such as improper pruning practices or contaminated grafting tools, serves as another primary route of dissemination throughout an orchard.

Management of this virus centers entirely on exclusion and sanitation practices. There are no curative chemical treatments for infected trees. Consequently, planting certified virus-free rootstock is the most critical strategy. Orchard sanitation, including the sterilization of pruning equipment and the removal of infected trees, is essential to minimize the spread within established plantations.

• Use certified virus-free nursery stock
• Sanitize pruning tools with alcohol or bleach
• Control aphid populations to prevent spread
• Conduct routine diagnostic tests for detection