VIEW ARTICLE

Antagonistic Effect of Soil Bacteria on Fusarium roseum ‘Culmorum’ from Carnation. Alan H. Michael, Graduate Assistant, Department of Plant Pathology, The Pennsylvania State University, University Park 16802, Present address of senior author: Allegheny County Agricultural Extension Service, 413 Allegheny Building, 429 Forbes Avenue, Pittsburgh, Pennsylvania 15219; Paul E. Nelson, Professor, Department of Plant Pathology, The Pennsylvania State University, University Park 16802. Phytopathology 62:1052-1056. Accepted for publication 30 March 1972. DOI: 10.1094/Phyto-62-1052.

Bacteria, isolated from soil, were antagonistic to Fusarium roseum ‘Culmorum’ in vitro and in vivo. Unrooted carnation cuttings were inoculated with antagonistic bacteria and rooted in the presence of the pathogen. The bacteria reduced the number and development of basal stem lesions, but did not inhibit rooting during the propagation period. One bacterial isolate (isolate A) was more effective than were nine other isolates. Carnation cuttings inoculated with isolate A were free of basal stem lesions 4 months after inoculation of the cuttings with F. roseum ‘Culmorum’, yet the pathogen was recovered from these cuttings. The general characteristics of the bacterium, designated isolate A, place it in the family Pseudomonadaceae.