The Signs & Symptoms of a Virus on Jasmine Leaves

Mosaics

• Mosaics cause the jasmine's leaves to develop patches of light and dark green, like a mosaic. Arabis, tomato and tobacco mosaics all cause this pattern on jasmine foliage. The virus may be transmitted by insects or nematodes. Downy, star and wax jasmines are particularly susceptible to tomato mosaic (ToMV) in warm, humid climates. This virus causes chlorotic (faded) spots and lines to form on the leaves. Arabis mosaic does not confine itself to making its mosaic pattern on the foliage, but also attacks the stems, branches and roots. This virus is not only transmitted by nematodes but also by infected seeds. In addition to discoloring the leaves, tobacco mosaic (TMV) attacks the flowers and stunts the plant's growth. Although rarely lethal, tobacco mosaic can destroy the jasmine's aesthetic value.

Infectious Chlorosis

• Although little is known about infectious chlorosis, the virus causes yellowish mottling of the leaves, or may cause scattered patches of faded-looking areas on the leaves. The infection gives the foliage an overall variegated look. This infection is similar to the chlorosis caused by nutritional deficiencies as well as foliar damage due to herbicides and should be diagnosed by laboratory analysis before you attempt to treat the plant.

Ringspot

• Tobacco ringspot virus (TRV) causes chlorotic or necrotic rings to appear on the leaf, sometimes forming an oak leaf pattern. The disease appears first as yellowish circles and lines on young foliage before advancing to more mature leaves. The virus, which is transmitted by nematodes, may affect the entire jasmine plant or only one side.

Prevention and Control

• Look for jasmine varieties that have resistance to viral diseases. Check the label on nursery stock for a list of which virus, if any, the plant is unlikely to catch. These are often listed only by acronym, such as TMV and ToMV. The only practical way to treat viral infections is to try to keep the jasmine from getting them. There is usually no cure for viral infections.

  Practice meticulous sanitation. Household bleach will not decontaminate your gardening tools. Boil the tool, if possible, and wash thoroughly with strong soap or detergent. Disinfect tools in between uses to avoid spreading infection. Wash your hands for several minutes with soap and water to kill any virus on your skin and do not smoke before handling jasmine plants.

  If the viral infection is severe, remove the diseased jasmines and destroy them somewhere away from the garden. Decontaminate your hands and tools before returning to the garden afterwards. Remove and destroy weeds and other plant debris from around the jasmine and use pesticides or insecticidal oils or soaps to control insects.