Potato leafroll virus

Potato leafroll virus (PLRV) is a significant member of the Polerovirus genus and a devastating pathogen affecting various Solanaceous plants. This viral disease disrupts the plant's vascular system, specifically the phloem, causing a systemic infection that severely restricts the translocation of photoassimilates to the tubers.

While potatoes are the primary host, the virus also affects tomatoes, peppers, and various weeds acting as reservoirs. PLRV is transmitted in a persistent circulative manner by several aphid species, most notably the green peach aphid (Myzus persicae). It is not transmitted mechanically via plant sap or contact, emphasizing the role of insect control.

Symptoms typically manifest as an upward rolling of the lower leaves, which become brittle and leathery to the touch. As the disease progresses, chlorosis or a reddish-purple discoloration of the foliage may appear. Severely infected plants often show stunting, and in many varieties, the tubers develop net necrosis, a brown discoloration of the internal vascular tissue.

The spread of PLRV is highly dependent on environmental conditions that favor aphid migration. Warm, dry seasons often exacerbate the issue by increasing insect populations and their mobility across fields. Early-season infection is particularly damaging, as the virus has more time to become systemic throughout the developing plant.

Economic losses result from both yield reduction and poor tuber quality, rendering the harvest unsuitable for processing or storage. Management strategies include:

• Planting certified virus-free seed potatoes.
• Implementing stringent aphid control programs using systemic insecticides.
• Removing volunteer potato plants that carry the virus.
• Using early-maturing varieties to escape late-season aphid peaks.