Raspberry plants are particularly susceptible to viral diseases.
A wide variety of diseases can affect raspberry plants, including different types of pest, cane botrytis, anthracnose, leaf curl, mosaic disease, and venous chlorosis. Some of these raspberry diseases are caused by an invasive fungus, while others are viral in nature. Experts recommend purchasing plants that are certified virus-free, due to the raspberry plant’s particular susceptibility to viral diseases.
The fungus can cause disease in raspberries.
Many raspberry diseases stem from the presence of a fungus that negatively affects specific areas of the plant. In the case of sugarcane rust, the fungus enters the site of a wound on the branch that may have been caused by insect damage, pruning, or injury during transplantation. This disease is most commonly seen in black raspberries. Sugarcane botrytis affects the older leaves of the plant with brown spots or grayish streaks. In later stages, the plant will develop dark blister-shaped sores. Anthracnose causes purple or red spots on the leaves, branches, stems or fruits of the raspberry plant.
Spore blight, which affects the branches and leaves of the raspberry plant, usually starts as an infection on the edges of the leaves that spreads inward. This condition is most common in red raspberries and can prevent buds from blooming. Rust has a dual cause, as the disease-causing fungus can enter the plant through damaged tissue caused by mosquito larvae. It is one of the raspberry diseases that can cause structural damage to the plant. Leaf spot is evidenced by dark green spots or holes in the plant’s leaves, a condition that can be reduced with proper pruning or fungicide use.
Some raspberry diseases are caused by a virus. Leaf curl manifests as a twisting and bleaching of the branches and leaves of the raspberry plant, with any fruit produced being extremely dry and full of seeds. This condition usually occurs due to wild raspberry spot infection. Mosaic disease is one of many raspberry diseases that affect the fruit and leaves, as well as reducing the overall size of the plant. The chlorosis of the veins leads to the whitening and distortion of the raspberry leaf, as well as the general shortening of the plant.
To prevent or control fungal diseases of raspberry, experts recommend keeping plants with plenty of air circulation through proper weeding and pruning. For plants that are watered by an irrigation system, avoiding long periods of excessive humidity can help reduce fungal invasion. Fungicides can help treat fungal diseases once they have emerged. A condition like mosquito rust is most effectively treated with an insecticide.