Project Number
P04000083
Project title
Evaluation of existing wine grape rootstocks for their ability to withstand the environmental challenges in South Africa
Project leader
Volschenk, C G
Team members
Volschenk, C G
Hunter, J J
Fouche, G W
Van Schalkwyk, D
George, V A
Marais, A J
Paulse, C
EXECUTIVE SUMMARY
Objectives and Rationale
South Africa is a water-scarce country, and water will become less available for agriculture. The focus of this project was to evaluate rootstocks for their level of drought tolerance and contribution to increase sustainability of viticulture.
Methods
Sauvignon blanc vines, grafted onto 14 rootstocks, were planted in the research vineyard on the ARC-Robertson research farm. The vineyard was irrigated to full field water capacity in winter, while four irrigation treatments were applied annually during the growth season. Physiological, growth and production measurements were conducted to evaluate rootstocks.
Key Results
Physiological activity increased with increased irrigation volume.
Highest survival rates under non-irrigated conditions occurred for Ramsey, 143 B, Ruggeri 140, US 8-7 and Paulsen 1103.
Cane mass and yield performance of rootstocks Ramsey, Paulsen 775 and 143 B Mgt seemed best at this stage of the project under deficit irrigation conditions as evaluated on the ARC-Robertson research farm.
Key Conclusion of Discussion
Patterns in the performance of Sauvignon blanc vines grafted onto the different rootstocks regarding growth and production were evident when vines were subjected to deficit irrigation treatments; all combinations are, however, still developing at this stage of the project, and final deductions cannot be made.
Take Home message for Industry
In general, vine performance was reduced and delayed by deficit irrigation. Non-irrigation affected survival. Deficit irrigation hampered the initial development of all rootstocks, but some vines continued to develop year after year. Yield increased in parallel with the increase in vine development. Performance is still improving. Termination of the project nullifies specific rootstock performance outcomes.
Presentation(s)
Volschenk, C G and Hunter, J J. 2013. Evaluation of existing wine grape rootstocks for their ability to withstand the environmental challenges. Paper presented at the 35th South African Society for Enology and Viticulture Congress. 13-15 November, Somerset West, South Africa.