The occurrence of polyscitalum puspulans on potatoes in Yugoslavia

Abstract

Polyscitalum puspulans was discovered for the first time in our country on seed the potato cv. Kennebec imported from Canada. In latter research this pathogen was also attested on the potato cv. Jaerla, Bintje and Desiree, which were grown in locality of Stanisinci, Goč. P. puspulans causes bud and germ tip necrosis. Infected parts become dark and stunt. A large number of diseased buds dies. From the eyes in which infected germs decay, new ones are formed which rarely become diseased. P. puspulans forms white to gray powdery colonies. No sclerotia formation was observed in culture. Hyphe are septate, narrow and hyaline. Conidiophores are long or short with oval, unicellular conidia formed in long chains which readily fragment. P. puspulans grows on different nutritient media at a temperature interval between 5 and 30° C. Pathogenicity was proven by artificial inoculation of germs at 5, 16 and 25° C. At lower temperatures, P. puspulans displays more pathogenicity.