Researcher: Francois Halleen
New Winetech funded project 2019: The aim of this project is to identify factors that may reduce or shorten the productive lifespan of rootstock mother blocks. In this study, physical, physiological and pathogenic detail will be considered on the same mother material. This approach has not been followed before and may provide answers that are hitherto unknown.
Attempts have been made in the past to link physiological and physical dimensions of graft material to performance of grafted vines. Field observations indicated that poor performance could be rootstock, terroir and/or cultivation related, without the conclusive involvement of pathogens.
Accumulation of pathogen infections inside rootstock mother vines will occur over time through pruning wounds. Currently the risks associated with ageing rootstock mother blocks are unknown as most of these infected rootstock canes will visually appear as healthy. In practice it is unknown at what age mother blocks require replacement.
Results from this project can provide local grapevine nurseries, rootstock mother block owners and the Plant Improvement Scheme with scientifically based information and guidelines on how the productive lifespan of rootstock mother blocks can be managed. This allows for proper planning for replacement of such mother blocks in order to ensure sustainability at farm level. It could potentially make a positive contribution towards higher take percentages in nurseries. However, more importantly it will improve the phytosanitary status of grafted vines which will lead to better establishment success and healthier vines with a longer productive lifespan for the wine industry.
Image credit: Charles Visser