Reproduction of bacterial quick decline of fruit trees after soil inoculation with Dickeya dadantii

Abstract

Recently, quick decline (QD) of fruit trees (Japanese pear, peach, and apple), causing leakage of red-brown exudates and rapid death, has become more frequent in Japan. Previously, the rapid death could only be reproduced on cuttings or dormant cut branches, but here we reproduced it by adding Dickeya dadantii to well- or poorly draining soils in pots with root-wounded seedlings of Japanese pear, peach, and apple and confirmed to be the QD pathogen based on Koch’s postulates. Thus, D. dadantii in soils was found to be a main source of inoculum.