VIEW ARTICLE

Disease Control and Pest Management

Efficacy of Natural Epiphytes and Colonizers of Grapevine Pruning Wounds for Biological Control of Eutypa Dieback. G. P. Munkvold, Assistant professor, Department of Plant Pathology, 351 Bessey Hall, Iowa State University, Ames 50011; J. J. Marois, professor, Department of Plant Pathology, University of California, Davis 95616. Phytopathology 83:624-629. Accepted for publication 12 February 1993. Copyright 1993 The American Phytopathological Society. DOI: 10.1094/Phyto-83-624.

Bacteria and fungi that naturally colonize grapevine pruning wounds were evaluated for their ability to inhibit infection of grape wood by Eutypa lata. Of 770 isolates, 53 reduced infection of excised wood by more than 80%. Twelve of these isolates were tested under field conditions with artificial inoculations with the pathogen. Seven isolates significantly reduced infection in the field in at least one experiment. Consistent control was achieved with only two isolates, Fusarium lateritium and Cladosporium herbarum. These fungi were as effective as benomyl in reducing infection by E. lata under some conditions. These two isolates were more effective when inoculation with E. lata was delayed until 14 days after application of the wound colonizers, reducing infection by as much as 71%. Application of the wound colonizers with a pneumatic spraying secateur was as feffective at reducing as was application with a paint brush.