1 Division of Plant Pathology, Simla-1 (H.P.)
2 Central Potato Research Institute, Simla-1 (H.P.)
Five distinct strains (Y−1–Y−5) of PVY were recorded, for the first time, from various commercial potato seed stocks and hybrids in Simla, on the basis of their reactions on four tobacco var./cv. and Nicotiana megalosiphon which can be used as PVY differentials. The necrotic strain of PVY probably does not occur in Simla-hills.
