Effect of Air-Drying on Soft Rot Potential of Potato Tubers Inoculated by Immersion in Suspensions of Erwinia carotovora. J. A. Bartz, Associate Professor, Department of Plant Pathology, University of Florida, Gainesville 32611. Arthur Kelman, Professor, Department of Plant Pathology, 1630 Linden Drive, University of Wisconsin, Madison 53706. Plant Dis. 69:128-131. Accepted for publication 18 July 1984. Copyright 1985 The American Phytopathological Society. DOI: 10.1094/PD-69-128.

Potato tubers were immersed for 5 min in suspensions of Erwinia carotovora pv. carotovora or pv. atroseptica, then incubated in a mist chamber for 72–96 hr. Disease severity decreased when tubers were air-dried before incubation and when the following types were used: 1) tubers fully cured rather than freshly harvested or injured, 2) tubers with bacteria only on their surfaces rather than infiltrated, or 3) tubers exposed to extended drying periods. In contrast, increasing the numbers of E. carotovora pv. carotovora (≥5 × 10⁷ colony-forming units per milliliter) in the inoculum decreased the effect of air-drying. An increase in the drying period from 1 or 2 to 69 hr or more also suppressed disease.