VIEW ARTICLE

Ecology and Epidemiology

Distribution of Rickettsia-like Bacteria in Peach, and Their Occurrence in Plum, Cherry, and some Perennial Weeds. J. M. Wells, Research plant pathologist, Southeastern Fruit and Tree Nut Laboratory, Science and Education Administration, U.S. Department of Agriculture, Byron, GA 31008; D. J. Weaver(2), and B. C. Raju(3). (2)Research plant pathologist, Southeastern Fruit and Tree Nut Laboratory, Science and Education Administration, U.S. Department of Agriculture, Byron, GA 31008; (3)Research associate, Department of Plant Pathology, University of California, Davis 95616. Phytopathology 70:817-820. Accepted for publication 9 February 1980. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1980. DOI: 10.1094/Phyto-70-817.

Rickettsia-like bacteria (RLB) were approximately × 10 more concentrated in 0.1 M KOH extracts of root sections of peach trees with symptoms of phony disease than in twig sections. RLB also were present in symptomless trees in orchards with 7 and 52% disease incidence. Positive symptoms of phony disease followed within 3–12 mo of detection of RLB in eight of 10 initially symptomless trees examined. RLB counts in roots and twigs of peach trees in phony-infected orchards were significantly higher in May than in February, August, or November. RLB also were found in several species of cherry and plum, and in perennial weeds surrounding peach orchards. Positive immunofluorescent tests for RLB were obtained with extracts from Mazzard cherry (P. avium), Shiro plum (interspecific Prunus hybrid), and Johnson grass (Sorghum halapense).