Vein clearing, scattered chlorotic flecks, followed by chlorotic mottling along veins leading to interveinal chlorosis and characteristic curling, twisting and deformation of leaves
In a few cultivars vein banding, vein thickening and green island - symptoms are also seen
Intense interveinal chlorosis or yellow flecking of leaves results in poor spike and berry formation
Internodes of vines become abnormally short leading to stunting of plants
Infected vines have reduced vigour and yield
They continue to decline and remain unproductive for a long period without dying
Management
Raise cuttings from disease free vines and also avoid normal vines from infected gardens
Uproot the infested vines along with the roots and destroy
Spray Dimethoate 30 EC (2 ml/ litre of water) against vectors
Dept of Agriculture Development 
SFAC Kerala