DEVELOPMENT OF POTATO WART SUSCEPTIBILITY TESTING IN SCOTLAND

Sprouts of cvs Arran Chief, Pentland Kappa and Golden Wonder were inoc ulated with fresh wart tissue using the Glynne-Lemmerzahl (GL) method and results of tests carried out using five different incubation regim es were compared. When tubers of Arran Chief and Pentland Kappa were i ncubated uncovered in the light, rotting of sprouts was reduced and th ere was more extensive development of summer sporangia. Similar result s were obtained on a range of cultivars when inoculations were done us ing summer or winter spores. Winter spores, which germinate freely in distilled water, can readily be extracted from dried rotted wart tissu e to provide a reliable and continuous supply of inoculum. At the Scot tish Agricultural Science Agency, wart susceptibility testing using th e GL method has been done with winter spores since 1987.