Pennsylvania Flower Growers #268
One of the intriguing aspects of plant disease control is biological control or the use of one organism to inhibit or control another. With in creased restrictions on pesticide use, this area of research is becoming more important and receiving more attention. This report gives the results of a study designed to control Fusarium stem rot of carnation with bacteria isolated from soil. This project was supported in part by funds from the Pennsylvania Department of Agriculture (Act 159-Harness Racing Fund), The Middle Adantic Carnation Growers, and the Pennsylvania Flower Growers (Dillon Research Fund) and was carried out in conjunction with the aerated steam project. Fusarium roseum 'Culmorum* causes a basal stem rot of carnation cuttings during propagation (Fig. 1). Antagonistic microorganisms have been tested as a means of controlling F. roseumand other plant pathogens. Several workers reported that micro organisms which adversely affect the growth of plant pathogens may func tion in plant disease control. Antagonistic microorganisms have been used to control Fusarium stem and root rots of cereals and damping-off seedlings. Since relatively little work has been reported on the use of antagonistic microorganisms to reduce the stem rot disease of carnation cuttings caused by F. roseum 'Culmorum', we 1) examined soils for naturally occur ring antagonistic microorganisms; 2) tested these soil microorganisms for antagonism to F. roseum 'Culmorum' in laboratory culture; 3) tested the antagonistic microorganisms's ability to reduce the development of stem lesions on unrooted carnation cuttings; and 4) determined whether the antagonistic microorganisms remained active against the pathogen when introduced into carnation cuttings.
Keywords: Stem Rot Plant disease control F. roseum 'Culmorum' Antagonistic microorganisms pathogen