Blueberry shoestring virus

Blueberry shoestring virus (BSSV) is a significant viral pathogen affecting highbush blueberries (Vaccinium corymbosum). Classified within the family Secoviridae and the genus Cheravirus, this virus causes distinct morphological changes in the host plant. It is a persistent threat that can lead to long-term yield reduction and the eventual decline of infected commercial blueberry plantations.

The diagnostic symptoms of the infection include the "shoestring" appearance of the leaves, which become narrow, elongated, and distorted. Reddish or purple streaks often appear on the foliage and stems. Furthermore, the berries on infected plants often exhibit uneven ripening, poor coloration, and malformation, rendering the fruit commercially unacceptable for fresh market sale or industrial processing.

The biology of BSSV is closely linked to its primary vector, the blueberry aphid, Illinoia pepperi. The virus is acquired by the aphid through feeding on the phloem of an infected plant. Once acquired, the vector remains infectious for the remainder of its lifespan. Transmission mainly occurs through infected nursery stock, which is the primary driver for long-distance spread of the disease across different regions.

The spread of the virus is highly dependent on the population dynamics of its vector. Warm spring and summer weather facilitates rapid reproduction of Illinoia pepperi, increasing the probability of viral transmission to healthy plants. As a latent virus, BSSV can persist in the plant tissue without showing immediate symptoms, complicating early identification and containment during the initial stages of infection.

Effective management strategies focus on prevention, as there is no chemical cure for viral infections in plants. Growers should prioritize the following measures:

• Utilizing certified virus-free planting stock from reputable nurseries.
• Implementing rigorous inspection schedules to identify and rogue symptomatic plants immediately.
• Managing the vector population with well-timed insecticide applications.
• Maintaining field hygiene by eliminating weed hosts that could support aphid populations near the planting area.