Studies on the reinfection and yield of virus‐tested and commercial stocks of rhubarb cv. Timperley Early

Ten commercial stocks of rhubarb cv. Timperley Early were found to be infected with turnip mosaic, arabis mosaic and to a lesser extent cherry leaf roll, strawberry latent ringspot and cucumber mosaic viruses. Significant yield differences were recorded between the stocks in forcing experiments, but these were not related to virus incidence. The performance of a mixture of these infected commercial stocks was compared with that of virus-tested stocks in canning, early green-pulled, and forcing experiments. A significant yield advantage was recorded in the first 2 years from the virus-tested stock harvested for canning, but not in the other two experiments. Of the five viruses isolated, turnip mosaic most frequently reinfected virus-tested stocks and there appeared to be a connection between reinfection of the healthy plants and subsequent reduction in their yield.