Pea leafroll

Pea leafroll is a viral disease primarily caused by the Pea leafroll virus (PLRV), which belongs to the Luteoviridae family. This pathogen is phloem-limited, meaning it restricts its activity to the vascular tissues of the plant, systematically blocking the translocation of photosynthates and leading to significant physiological distress and stunted growth.

The host range of the virus includes a variety of legume species, most notably field peas (Pisum sativum), alfalfa, and clover. In many agricultural regions, perennial forage legumes serve as the primary overwintering reservoir for the virus, facilitating the cyclic reinfection of annual pea crops every spring season.

Symptoms of Pea leafroll typically include a pronounced yellowing or chlorosis of the younger, upper leaves, which subsequently curl upwards along the midrib. Affected plants exhibit severe stunting, reduced internode length, and a dramatic decrease in pod production. In severe cases, the entire plant may appear rigid and brittle, leading to a significant reduction in grain yield and quality.

• Chlorosis and yellowing of the terminal growth.
• Distinctive upward leaf rolling or curling.
• Significant stunting and reduced plant height.
• Abortion of flowers and reduced pod set.
• General decline in vigor and yield potential.

The virus is transmitted in a persistent, circulative manner exclusively by aphid vectors, most commonly the pea aphid (Acyrthosiphon pisum). Once an aphid acquires the virus from an infected host, it remains capable of transmitting the pathogen for the remainder of its life, allowing for rapid field-wide dissemination during peak aphid migration periods.

Management strategies focus on breaking the disease cycle rather than direct treatment, as there are no chemical virucides. Key practices include the use of certified virus-free seed, implementation of spatial separation from perennial legume pastures, and rigorous control of aphid populations using systemic insecticides during the early growth stages of the pea crop to prevent initial colonization.