Relationship of Pectolytic Clostridia andErwinia carotovoraStrains to Decay of Potato Tubers in Storage

Abstract

Prevalence of pectolytic clostridia and Erwinia spp. was assessed in samples of 100 partially decayed potatoes collected from each of 7 commercial storage bins maintained at 5.degree. C. Pectolytic clostridia were present in 22%, E. carotovora ssp. carotovora (Ecc) in 13% and E. carotovora ssp. atroseptica (Eca) in 45% of the samples. In 58% of the samples from which clostridia were isolated, Ecc and/or Eca were also present. When healthy tubers from storage bins were injured uniformly and incubated at 20.degree. C for 96 h in a mist chamber, the proportion of clostridia to Erwinia isolates was significantly higher than in isolations directly from storage bin samples. In vitro, clostridia and Ecc, but not Eca, grew more rapidly at temperatures from 18.degree. to 36.degree. C.