Project Number
WW 12-02
Project title
Effect of lateral shoot removal as part of a canopy management programme on the metabolism, grape composition and wine quality of Vitis vinifera L. cv. Sauvignon blanc in the Robertson area
Project leader
Hunter, J J
Team members
Fouche, G W
Adams, L F
Project description
The aim of this project was to find canopy management practices which would address the negative effects of excessive growth and dense canopies and improve microclimate, grape and wine quality, and pest and disease control. In addition, the relationship between leaf size, leaf age and leaf production was determined in order to eventually quantify the yielding capacity of the canopy at any particular point during the season.
It would appear that the ripeness level-canopy manipulation treatments were successful in changing the complexity (in terms of taste and flavour) of the grapes. These factors can also affect wine quality to a great extent and may play a big role in decisions regarding the application of viticultural practices for a specific wine objective. The results would allow producers and winemakers to accentuate specific components in the grapes. It can also impact on the blending of wine. Under the circumstances, the combination of suckering-shoot positioning-topping-leaf removal (at berry set and at pea size) performed the best. In addition, it would be desirable to concentrate on a ripeness spectrum from 19B to 21B during harvesting of grapes and to use the various ways of canopy manipulation at specific times during the season in order to highlight certain characteristics. It must be stressed, however, that although the wine objective is important, other viticultural important factors and quality determining characteristics which are also light dependent, must not be neglected. Grape flavour specific manipulation of the canopy and ripeness level can, however, make a great contribution towards the attainment of different wine styles under cool as well as warm climate cultivation and specific sites.
Article
Hunter, J J, Visser, J H. 1988. The effect of partial defoliation, leaf position and development stage of the vine on the photosynthetic activity of Vitis vinifera L. cv. Cabernet Sauvignon, South African Journal of Enology and Viticulture, v. 9 (2) (p. 9-16)
Hunter, J J, Visser, J H. 1988. Distribution of 14C-photosynthetate in the shoot of Vitis vinifera L. cv. Cabernet Sauvignon. Part I. The effect of leaf position and developmental stage of the vine, South African Journal of Enology and Viticulture, v. 9 (1) (p. 3-9)
Hunter, J J, Visser, J H. 1988. Distribution of 14C-photosynthetate in the shoot of Vitis vinifera L. cv. Cabernet Sauvignon. Part II. The effect of partial defoliation, South African Journal of Enology and Viticulture, v. 9 (1) (p. 10-15)
Hunter, J J, Visser, J H. 1989. The effect of partial defoliation, leaf position and developmental stage of the vine on leaf chlorophyll concentration in relation to the photosynthetic activity and light intensity in the canopy of Vitis vinifera L cv Cabernet Sauvignon, South African Journal of Enology and Viticulture, v. 10 (p. 67-73)
Hunter, J J, Visser, J H. 1990. The effect of partial defoliation on growth characteristics of Vitis vinifera L. cv Cabernet Sauvignon. Part II. Reproductive growth, South African Journal of Enology and Viticulture, v. 11 (1) (p. 26-32)
Hunter, J J, Visser, J H. 1990. The effect of partial defoliation on growth characteristics of Vitis vinifera L. cv. Cabernet Sauvignon. Part I. Vegetative growth, South African Journal of Enology and Viticulture, v. 11 (1) (p. 18-25)
Swanepoel, J J, Hunter, J J, Archer, E. 1990. The effect of trellis systems on the performance of Vitis vinifera L. cv. Sultana and Chenel in the lower Orange River region, South African Journal of Enology and Viticulture, v. 11 (2) (p. 59-66)
Swanepoel, J J, Hunter, J J, Archer, E. 1990. The effect of trellis systems on the performance of Vitis vinifera L. cvs Cabernet Sauvignon and Chenel in the Lower Orange River region, South African Journal of Enology and Viticulture, v. 11 (2) (p. 59-66)
Hunter, J J, De Villiers, O T, Watts, J E. 1991. The effect of partial defoliation on quality characteristics of Vitis vinifera L. cv. Cabernet Sauvignon grapes. Part II. Skin colour, skin sugar and wine quality, American Journal of Enology and Viticulture, v. 42 (1) (p. 13-18)
Hunter, J J, De Villiers, O T, Watts, J E. 1991. The effect of partial defoliation on quality characteristics of Vitis vinifera L. cv. Cabernet Sauvignon grapes. Part I. Sugar acids and pH, South African Journal of Enology and Viticulture, v. 12 (1) (p. 42-50)
Hunter, J J. 2000. Canopy management effects on yield, labour input and growth compensation – new canopy utilisation perspectives, Acta Horticulturae, v. 526 (p. 81-90)
Dissertation
Hunter, J J. 1991. Physiological implications of partial defoliation of the grapevine (Vitis vinifera L. cv. Cabernet Sauvignon) PhD. University of Stellenbosch, Stellenbosch, South Africa.
Paper
Hunter, J J. 1999. Present status and prospects of wine grape viticulture in South Africa: Focus on canopy realted aspects, practices and relationships with grape and wine quality, IN: Proceedings of the 11th Meeting of the Study Group for Vine Training Systems. (p. 70-85) June 1999,