During winter pruning plenty of pruning wounds are inflicted on grapevines as a result of manual and/or mechanical pruning. This also includes large wounds where arms are pruned back for renewal. When grapevines are sawed off, the wounds are even larger. Such wounds allow ingress to all the important trunk pathogens which cause premature decline in grapevines by growing in the xylem vessels thereby impeding sap flow. One of the best known and most common trunk diseases is Eutypa dieback.
Prevention of infection/wound protection
PHOTO 1. An example of a grapevine with Eutypa dieback.
- Trichoderma species are fungi that occur naturally in soil, rotting wood, compost, roots and in plants above the surface of the soil.
- Trichoderma can be selected as control agents for certain fungal pathogens. They produce toxins and/or enzymes that control the specific pathogen.
- Trichoderma are living organisms and available as powders and granules.
- Follow the storage instructions on the label and do not expose to direct sunlight. A new Trichoderma solution must be prepared each day.
- Use a brush or sponge to paint large wounds with a Trichoderma paste. Grapevines that have been pruned already, can be sprayed with a Trichoderma solution.
- Trichoderma colonise (grow) so quickly that they eliminate trunk pathogens on the pruning wounds.
Dr. Francois Halleen, senior plant pathologist, ARC Infruitec-Nietvoorbij.
James Kruger, Nexus.
Dr. Brendon Neumann, Madumbi Sustainable Agriculture.