VIEW ARTICLE

Ecology and Epidemiology

Effect of Seed Piece Inoculation with Plant Growth-Promoting Rhizobacteria on Populations of Erwinia carotovora on Potato Roots and in Daughter Tubers. J. W. Kloepper, Former assistant professor, Plant Pathology Department, University of California, Berkeley 94720, Current address: Advanced Genetic Sciences, Inc., P.O. Box 1373, Manhattan, KS 66502; Phytopathology 73:217-219. Accepted for publication 16 June 1982. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-217.

The application of plant growth-promoting rhizobacteria (PGPR) to potato seed pieces prior to planting resulted in significantly reduced root zone populations of Erwinia carotovora (Ec) in field trials. The percentage of daughter tubers infested naturally with Ec from plants treated with PGPR also was significantly reduced. Reductions resulted from inoculations with PGPR strains singly or in mixtures of two or more strains and were observed in three distinct geographic areas. The results suggest that PGPR may be useful in management of potato blackleg and soft rot diseases. A modified medium developed for Erwinia spp. was more sensitive than McConkey-pectate medium. This medium eliminated pectolytic pseudomonads that can interfere with development of colonies of pectolytic Erwinia spp.