Potato leafroll virus

The Potato leafroll virus (PLRV) is the causative agent of one of the most destructive viral diseases in potatoes. It belongs to the Polerovirus genus and primarily affects the plant's phloem, causing a systemic disruption of the translocation of photosynthates from the leaves to the tubers.

While potatoes are the primary host, this virus also affects other members of the Solanaceae family, including tomatoes, peppers, and various nightshade weeds. These weeds serve as critical reservoirs, allowing the virus to survive and spread to new crops during the growing season.

Symptoms are most visible on the lower leaves, which roll upward along the midrib and become leathery and brittle. In plants grown from infected tubers, the entire plant may show stunted growth, upward curling, and, in some varieties, an anthocyanin discoloration that gives the foliage a reddish or purplish tint.

The virus is transmitted in a persistent, circulative manner by several aphid species, most notably the green peach aphid Myzus persicae. Environmental conditions that favor large aphid populations, such as mild winters and warm, dry summers, significantly increase the rate of virus transmission across fields.

The economic impact of PLRV is severe, with yield reductions ranging from 20% to 80% depending on the potato variety and the timing of the infection. Furthermore, some varieties exhibit net necrosis in the tubers, rendering them commercially unacceptable for both the fresh market and processing industries.

• Utilize high-quality, certified virus-free seed potatoes.
• Implement rigorous aphid control programs using appropriate insecticides.
• Remove and destroy symptomatic plants (roguing) as soon as they are spotted.
• Maintain spatial isolation between seed potato crops and consumer potato fields.
• Control weeds in and around fields to eliminate alternate host plants.