Blueberry necrotic ring blotch virus

Blueberry necrotic ring blotch virus (BCRV) is a significant viral pathogen affecting highbush blueberry (Vaccinium corymbosum) plantations. While historically linked to the Ilarvirus genus in some early studies, modern research clarifies its viral nature and specific impact on plant tissue. The virus causes physiological disruptions that severely impair the health of the host plant.

The host range is primarily limited to blueberry cultivars. The disease is recognized as a major threat in several commercial berry-growing regions. Once a plant is infected, the virus spreads systemically throughout the vascular system, leading to long-term chronic symptoms that persist throughout the growing season.

The hallmark symptoms include necrotic ring blotches appearing on the foliage. These spots start as chlorotic lesions, gradually expanding into distinct necrotic patterns with dark margins. As the disease progresses, leaves may become distorted or experience premature senescence and abscission, which weakens the plant and reduces its ability to accumulate energy for the next season.

Disease transmission occurs via biological vectors, and potentially through contaminated pruning tools during routine maintenance. The virus thrives in conditions favorable to vector activity and active plant growth. Because the virus is systemic, it can be spread through vegetative propagation, making it essential to source nursery stock from virus-tested, disease-free programs.

The economic impact of BCRV is significant, as it leads to reduced fruit size, lower yields, and overall plant decline. Management focuses on strict phytosanitary practices. Producers must prioritize the use of certified clean stock, implement rigorous insect pest management to suppress potential vectors, and practice immediate rogueing—removing and destroying symptomatic plants to prevent further spread within the field.