Cover Crop Management in a Chardonnay/99 Richter Vineyard in the Coastal Region, South Africa. 2. Effect of Different Cover Crops and Cover Crop Management Practices on Grapevine Performance

Soil Management in the Breede River Valley Wine Grape Region, South Africa. 3. Grapevine Performance

“…Pool et al (1990) and Ingels et al (2005), however, reported no difference, whereas Anonymous (1984) reported higher yields for grapevines with a permanent cover crop in comparison with grapevines in which other soil cultivation practices were applied. Grape yield under winter growing cover crops controlled chemically before bud break was significantly higher than that of grapevines in which chemical clean cultivation (Buckerfield & Webster, 1996;Fourie et al, 2006b;Fourie et al, 2007) and mechanical clean cultivation (Fourie et al, 2006b;Fourie et al, 2007) were applied. Buckerfield & Webster (1996) observed that the yield of grapevines with full surface straw mulch was significantly higher than that of grapevines in which clean cultivation was applied.…”

“…Grape yield and pruning mass were significantly affected by soil cultivation practices applied to both non-irrigated (Van Huyssteen & Weber, 1980) and irrigated (Fourie et al, 2006b) medium textured soils in the Mediterranean Coastal wine grape region, as well as to an irrigated sandy soil in the semi-arid Olifants River Valley (Fourie et al, 2007). Fourie et al (2006b) indicated that N-fixing species should not be used continuously as cover crops over the long term on medium textured soils, as it may eventually cause vigorous grapevine growth and a decline in the production of quality grapes.…”

“…Fourie et al (2006b) indicated that N-fixing species should not be used continuously as cover crops over the long term on medium textured soils, as it may eventually cause vigorous grapevine growth and a decline in the production of quality grapes. This, however, did not occur on the less fertile sandy soils of the semi-arid Olifants River Valley, but instead allowed for a significant reduction in the annual application of inorganic N after bud break (Fourie et al, 2007).…”

“…A higher grapevine petiole N was observed where a cover crop was disked in during early spring in comparison with a vineyard in which weeds were disked in (Ingels et al, 2005;Fourie et al, 2007) or in comparison with a vineyard in which the cover crops were slashed (Ingels et al, 2005). Nitrogen fixing cover crops, such as the Vicia and Medicago species, resulted in significantly higher grapevine petiole N in comparison with vineyards in which no cover crops were sown and either mechanical or chemical control was applied in the work row (Fourie et al 2006b;Fourie et al, 2007).…”

“…Van Huyssteen (1990), Fourie et al (2006b) and Fourie et al (2007), however, reported significant differences in total titratable acids (TTA) of grape juice between soil cultivation treatments. The differences in TTA were attributed to differences in crop size (Fourie et al, 2006b) and vegetative growth (Conradie, 2001;Fourie et al, 2006b). A permanent green cover in the work row competed with the grapevines for nutrients during the growing season, which resulted in the must being either low in ammonium-N (Dupuch, 1997) or N deficient (Van Huyssteen, 1990).…”