A simplified slice method for assessing tuber susceptibility of potato cultivars to Erwinia carotovora subsp atroseptica

The susceptibility of 24 potato cultivars to soft rot caused by Erwinia carotovora subsp. atroseptica was assessed in a simplified form of a tuber slice test described previously. Freshly made wounds on tuber slices were inoculated with drops (0–02 ml) containing 108, 107 or 106 cells/ml and incubated aerobically for 3 days at 15° or 20°C. At 20°C differences between cultivars were clear at all concentrations but at 15°C less so at the lowest concentration unless incubation time was extended. The rank order of cultivar susceptibility was similar to that found in previous seasons.