WW KB 01
Secondary metabolism as a deteminant of grape and wine quality
Bindon, K A
University of Stellenbosch. Department of AgriSciences. Department of Viticulture and Oenology
Myburgh, P A
Strever, A E
Du Toit, G
Du Toit, W J
In the local and international wine industry, trends in the management practices for vineyards have emerged over the past 5 years which are based on unsubstantive evidence, which could potentially be of detriment to the production of high quality grapes and wines. Two primary areas where this apparent ‘folklore’ is influencing the practices of grape growers is (i) The belief that small berries resulting from water stressed vines produce a higher concentration of red-coloured compounds and thus higher quality wines and (ii) That the irrigation of grapevines results in a proportional decrease in wine quality. Recently, evidence accumulated has shown that these two perspectives are faulty, and cannot be proven statistically (Roby et al., 2004; Bindon, 2004). Furthermore, the original observations which led to these perspectives being formed were more likely the result of metabolic changes within the fruit in response to environmental (water) stress rather than directly due to an alteration in berry size or vine water status. If these perspectives are not addressed within the wine industry at large, the potential exists that incorrect irrigation methods, attempting the application of water stress as a technique to improve wine quality could reduce yields and negatively impact the industry in the long term. Thus, there is an urgent need to approach some of these ideas from a scientific perspective, to produce accurate, statistically sound data which can provide guidelines to growers as to the (i) the quantity and type of environmental stress which can positively impact grape quality and (ii) the type of irrigation practice which will best serve a given winegrowing region. The proposed project will make use of established experimental trials in the Stellenbosch area to investigate the proposed aims more broadly in terms of grape and wine quality, together with glasshouse trials on potted vines to explore the questions at a biochemical level.
Du Plessis, C S, Myburgh, P and Bindon, K A. 2006. The effect of irrigation on grape and wine phenolics. Poster presented at the 29th National Congress of the South African Society for Enology and Viticulture. 14-17 November, Somerset West, South Africa.
Human, M A and Bindon, K A. 2006. The effect of sunlight on the anthocyanin profile of Vitis vinifera cv. Crimson Seedless. Poster presented at the 29th National Congress of the South African Society for Enology and Viticulture. 14-17 November, Somerset West, South Africa.
Engelbrecht, G, Myburgh, P and Bindon, K A. 2006. The effect of site variability on plant water status and grape composition (Vitis vinifera cv. Cabernet Sauvignon). Poster presented at the 29th National Congress of the South African Society for Enology and Viticulture. 14-17 November, Somerset West, South Africa.
Bindon, K A Du Plessis, C S, Oberholster, A and Myburgh, P. 2007. Phenolic profiling of Vitis vinifera cv. Merlot grapes and wines produced under varying conditions of grapevine water status. Poster presented at the 13th Australian Wine Industry Technical Conference. 28 July – 2 August, Adelaide, Australia.
Bindon, K A. 2007. Influence of plant water status on the production of C13-norisoprenoid precursors in Vitis vinifera L. cv. Cabernet Sauvignon grape berries, Journal of Agricultural and Food Chemistry, v. 55 (p. 4493-4500)
Ristic, R, Downey, M O, Iland, P G, Bindon, K A, Francis, I L, Herderich, M, Robinson, S P. 2007. Exclusion of sunlight from Shiraz grapes alters wine colour, tannin and sensory properties, Australian Journal of Grape and Wine Research, v. 13 (2) (p. 53065)