The susceptibility of potato varieties to internal rust spot

SummaryIn tubers of ten potato varieties the incidence of internal rust spot lesions increased and the calcium concentration decreased when the concentration of calcium chloride supplied to the plants fell from 9 to 1 mM. A simple linear model relating the probit transformation of internal rust spot incidence to tuber calcium concentration for each variety showed that there were substantial differences in varietal susceptibility to internal rust spot which were not related to tuber calcium concentration.