Raspberry mosaic

Raspberry mosaic is a serious viral disease caused by a complex of viruses that affects common raspberries (Rubus spp.). It is a systemic infection, meaning the pathogen spreads throughout the entire plant, including the roots, canes, and leaves, leading to long-term physiological decline.

The visual symptoms typically appear on the foliage as a mottled pattern of light green, yellow, and dark green spots. In many cases, the leaves become crinkled or puckered, and the leaflets may exhibit distortion. As the season progresses, infected plants often show reduced vigor and stunted growth compared to healthy ones.

The primary vector for the mosaic virus is the large raspberry aphid (Amphorophora rubi). These insects acquire the virus by feeding on infected canes and transmit it when moving to healthy plants. Another common path of infection is the propagation of infected nursery stock, which introduces the virus into new plantings.

The economic impact of this disease is significant. The infection leads to a substantial decrease in fruit quality and yield. Over time, the affected canes become brittle and unproductive, eventually leading to the total decline of the patch. Since there is no cure once a plant is infected, the entire plant must be treated as a source of inoculum.

Integrated management is essential for minimizing the risk of infection. Practical steps include:

• Sourcing only certified virus-free nursery plants.
• Implementing strict aphid control programs using appropriate insecticides.
• Rogueing (removing and destroying) infected plants immediately upon detection.
• Maintaining clean cultivation by removing wild Rubus species nearby that may act as reservoirs.