Symptoms caused by plant viruses are chlorosis (disappearing of chlorophyll of green part, at places, leaving yellowish spots). The presence of yellow spot at places, in the green tissue appear like a ''Mosaic'' pattern. Yellowing complete disappearance of chlorophyll, vein clearing and vein banding, necrosis, ringspots etc. Symptoms caused by fungi are withering and wilting, damping off, leaf spot, shot-hole, scab, cankers, rotting, gumnosis and fluxes, leaf and fruit dropping, galls and tumours, hypertrophy, atrophy etc. Symptoms caused by bacteria are curling, spotting and blotching of leaves, cankers, crown gall and leafy gall etc.