This disease which is caused by viruses is noticed in parts of Kannur, Kasaragod, Kozhikode, Wayanad and Idukki Districts of Kerala and Kodagu, Hassan and Uthara Kannada districts of Karnataka. The vines exhibit shortening of internodes to varying degrees. The leaves become small and narrow with varying degrees of deformation and appear leathery, puckered and crinkled. Chlorotic spots and streaks also appear on the leaves occasionally. The yield of the affected vines decreases gradually.
Two viruses namely Cucumber mosaic virus and a Badnavirus are associated with the disease. The major means of spread of the virus is through the use of infected stem cuttings. The disease can also be transmitted through insects like aphids and mealy bugs.
The following strategies are recommended for the management of the disease.
- Use virus free healthy planting material
- Regular inspection and removal of infected plants; the removed plants may be burnt or buried deep in soil
- Insects such as aphids and mealy bugs on the plant or standards should be controlled with insecticide spray such as dimethoate (0.05%).