Diseases are one of the major
factors limiting crop productivity. The problem with the disease management lies with the detection of the exact
stage of prevention. Most of the times pesticides are applied as a precautionary manner leading to the residual
toxicity and environmental hazards and on the other hand application of pesticides after the appearance of disease
leads to some amount of crop losses. Among the different diseases, the viral diseases are the most difficult to
control, as one has to stop the spread of the disease by the vectors