South Africa Wine Research Projects

2. VITICULTURE RESEARCH COMPLETED PROJECT

DETERMINING FACTORS THAT MAY REDUCE/SHORTEN THE PRODUCTIVE LIFESPAN OF ROOTSTOCK MOTHER PLANTATIONS

P04000235 Prof Francois Halleen, ARC Infruitec-Nietvoorbij, Stellenbosch Project was co-funded by the ARC Infruitec-Nietvoorbij Project completed: 2023

AIM AND INDUSTRY RELEVANCE: The Vine Improvement Scheme provides multiple requirements, but none address the productive lifespan of rootstock mother blocks. This study aimed to simultaneously determine the incidence of trunk disease pathogens, - physiological status, and morphological dimensions of rootstock canes across mother blocks of different ages to manage and plan for the replacement thereof. A survey was conducted in a selection of mother blocks to assess these aspects across three seasons and to evaluate the occurrence of trunk pathogens of vine heads in mother blocks over two seasons. The impact of infection on callus formation and performance of nursery vines was also investigated. Important grapevine trunk disease pathogens were identified in the mother blocks’ vine heads and canes, which pose certain challenges during propagation or in newly established vineyards. The results show that one-year-old canes serve as an inoculum source in newly grafted vines. They are also responsible for shortening the lifespan and compromising the capacity of mother blocks to yield healthy canes. The morphological and physiological data from the one-year-old canes were influenced by season and not by rootstock mother vine age, but total pathogen incidences increased with vine age. It is, therefore, of the utmost importance that grapevine trunk diseases in rootstock mother blocks be managed more effectively and replacement planning done at a younger age.

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SOUTH AFRICA WINE RESEARCH 2024