VIEW ARTICLE

Ecology and Epidemiology

Biological Control of Eutypa lata on Grapevine by an Antagonistic Strain of Bacillus subtilis. J. H. S. Ferreira, Senior agricultural research officer, Viticultural and Oenological Research Institute, Private Bag X5026, 7600 Stellenbosch, Republic of South Africa; F. N. Matthee(2), and A. C. Thomas(3). (2)Professor of microbiology and plant pathology, University of the Western Cape, Private Bag X17, 7530 Bellville, Republic of South Africa; (3)Head, Banana Board Panama Disease Research Unit, CSFRI, Private Bag X11208, 1200 Nelspruit, Republic of South Africa. Phytopathology 81:283-287. Accepted for publication 14 May 1990. Copyright 1991 The American Phytopathological Society. DOI: 10.1094/Phyto-81-283.

An isolate of Bacillus subtilis from grapevine wood inhibited in vitro growth of Eutypa lata, the causal organism of dieback in grapevines. On potato-dextrose agar, the bacterium caused 91.4% inhibition of mycelial growth of E. lata and 100% inhibition of ascospore germination. Ascospore germination correlated negatively with time of exposure to B. subtilis. Malformation of hyphae of E. lata occurred in the presence of B. subtilis. At a concentration of ?0.8 mg/ml, an antibiotic substance in an ethanol extract from B. subtilis totally inhibited germination of ascospores of E. lata. Thin-layer chromatography of crude antibiotic extract showed five bands, two of which inhibited mycelial growth of E. lata. Spraying a suspension of the bacterium on pruning wounds before inoculation with ascospores of E. lata significantly reduced infection as compared with the unsprayed, inoculated controls.