Position and date of seed tuber inoculation byErwinia carotovora ssp.atroseptica and appearance of potato blackleg

Summary The date of inoculation and the part of the potato seed tuber inoculated both influenced the number of blackleg plants appearing in June, July and August. In winter, inoculation of the heel end was more effective than inoculation of the rose end of seed tubers, but there were no significant differences following inoculation earlier, in autumn, or later, in spring.