Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 5/9/2014
Publication Date: 11/1/2014
Citation: Shapiro Ilan, D.I., Bock, C.H., Hotchkiss, M.W. 2014. Suppression of pecan and peach pathogens using metabolites or broths of from symbiotic bacteria obtained from the guts of entomopathogenic nematodes. Phytopathology. 104: S3.16.
Technical Abstract: Concentrated metabolites from the bacteria Xenorhabdus spp. and Photorhabdus spp. have previously been shown to suppress growth of peach and pecan pathogens in vitro, and reduce disease on detached leaves or terminals. The objectives of this study were 1) determine if bacterial broths (in addition to the metabolites) have suppressive ability, and 2) determine if metabolites or bacterial broths are active against pathogens in a soil medium. The pecan pathogens Fusicladium effusum and Phytophthora cactorum, and the peach pathogen Armillaria tabescens were tested for sensitivity to bacterial broths or concentrated metabolites. Treatments were applied to lesions of F. effusum on pecan terminals to ascertain effects on sporulation, to A. tabescens in soil to determine survival of mycelia, and pecan leaves inoculated with P. cactorum to ascertain effects on lesion development. The Xenorhabdus bovienii metabolite was as efficacious as the fungicide febuconazole in reducing sporulation of F. effusum. The Photorhabdus luminescens metabolite treatment reduced sporulation, but the bacterial broths had no effect. All bacterial broth and metabolite treatments suppressed lesions of P. cactorum. Only the P. luminescens metabolite suppressed A. tabescens. The results provide a basis for further research on the use of Xenorhabdus and Photorhabdus metabolites or bacterial broth for suppression of pecan and peach diseases.