Strawberry necrotic shock

Strawberry necrotic shock is a viral disease caused by the Strawberry necrotic shock virus (SNSV), which is a member of the genus Ilarvirus. This pathogen acts as a systemic infection that colonizes the vascular tissues of the host plant, resulting in significant physiological disruption and stunted growth. It poses a severe risk to commercial strawberry production worldwide.

The primary host for this disease is the strawberry plant (Fragaria × ananassa). The virus is known to be transmitted through infected nursery stock, which is the most common way it enters new planting sites. Additionally, pollen transmission is a significant factor in the field, as bees and other pollinators carry the virus between susceptible plants, facilitating the rapid spread of the disease.

Visible symptoms often include chlorotic spots, necrotic streaks, and severe leaf deformation. Infected plants frequently display distinct ring-spot patterns on their leaves, which subsequently necrotize and die. During the growing season, plants infected with SNSV show reduced vigor, shortened petioles, and a marked decline in fruit production and quality compared to healthy specimens.

• chlorotic spotting and ring-spot formation on foliage;
• necrosis and death of leaf tissue patches;
• stunted growth and diminished plant size;
• significant reduction in berry yield and fruit size;
• leaf crinkling and overall morphological distortion.

The development and dissemination of the disease are highly dependent on the presence of pollinating insects and the density of host plants. Cool, humid spring conditions can exacerbate the stress on plants, making them more susceptible to the onset of systemic symptoms. Once established in a field, the virus can persist and spread annually if preventative cultural practices are not strictly observed.

Effective management relies entirely on prevention, as there are no chemical treatments available for infected plants. Growers must utilize certified, virus-indexed planting material obtained from reputable nurseries. If an infection is identified, the infested plants should be promptly rogued and removed from the field to minimize the secondary spread of the virus to adjacent healthy crops.