Testing potato cultivars for susceptibility to skin spot (Polyscytalum pustulans)

Summary

Three potato cultivars established in commerce and twenty-two cultivars submitted for National List Trials were tested from 1978 to 1980 for their susceptibility to skin spot (Polyscytalum pustulans) by a laboratory tuber dip test and by a field test measuring the transmission ofP. pustulans from uniformly inoculated seed tubers to stems and progeny tubers. In the field test the susceptibility of a cultivar to stem base infection was related to the percentage eyes infected on progeny tubers but cultivar susceptibility to stem infection and to eye infection was not significantly correlated with the percentage surface area affected by skin spot in the laboratory test.