The effect of separate infections by potato viruses X and S on Netted Gem potato

Numbers and specific gravity of Netted Gem potato tubers were unaffected by mottle and latent strains of potato virus X (PVX) and by potato virus S (PVS). Neither latent PVX nor PVS affected yield but mottle PVX alone and latent PVX combined with PVS reduced tuber size and yield (P = 0.05).