SAGWRI ES 22-01
Formulation and evaluation of microbial consortia for biological control of grapevine fungal pathogens
South African Grape and Wine Research Institute, Department of Viticulture and Oenology, Stellenbosch University
Co funded by:
Project is co-funded by the Department of Science and Innovation (DSI) and the National Research Foundation (NRF).
The study’s main objective is to construct yeast-bacterial consortia that have antifungal activity against grey rot and mildew disease agents in grapevines and can be used as biocontrol agents. Existing biocontrol agents are mainly single species formulations which are sometimes ineffective under varying environmental conditions.
Globally, there is growing interest in reducing the number of chemical fungicides used to control grapevine pathogens such as Botrytis cinerea, Plasmopara viticola and Erysiphe necator. Alternative biological formulations comprising microbial strains are commercially available for use in vineyards. However, not all of them work effectively and consistently under varying field conditions. Consequently, further research is necessary to identify new biological agents with higher efficacy. In the current study, we aim to generate multispecies microbial consortia for the biological control of bunch rot, powdery mildew and downy mildew. Existing biological control agents are based on single microbial species. We believe that multi-species consortia comprising strains with different modes of action that grow optimally under different environmental conditions will offer more efficacy in field conditions. By selecting organisms that do not negatively affect wine fermentation and are tolerant to chemical fungicides currently in use, we believe we can generate biological control agents that can complement existing fungicide spray programs and reduce chemical fungicide use.