COVER CROPS in South African Vineyards

COVER CROPS IN SOUTH AFRICAN VINEYARDS

trol

The ratio of grape yield to shoot mass of the grapevines in all the treatments varied between 4.29 and 5.33 in 2002/2003, indicating that the vines were in balance. The yield of all the treatments could even be increased slightly, without being detrimental in the long term. trol

rol

6,00

5,00

4,00

3,00

2,00

1,00

1995/96 2002/03

0,00

Ratio of grape yield to shoot mass

Sown annually

Sown annually

Sown annually

Sown annually

Mechanical control Sown annually

Sown annually

Sown annually

Sown two-yearly

Sown two-yearly

Sown two-yearly

Sown two-yearly

Sown two-yearly

Sown two-yearly

Sown two-yearly

Chemical control

Mechanical control

Henog rye Overberg Saia black oats Paraggio Parabinga Pink Grazing vetch No oats bur medic bur medic serradella cover crop

FIGURE 8.26. Ratio of grape yield to shoot mass in cover-crop treatments compared to a control in the Olifants River valley. Values below line indicate potential for increased grape yield. Adapted from Fourie et al (2007). Grape and wine quality No trends were observed in the sugar content, total titratable acid, or pH of the grape juice.Although differences in the concentrations of potassium, calcium and magnesium were detected in the grape juice, the wine quality was not affected. Reference list Conradie WJ. 1994. Vineyard Fertilisation. Proceedings of a workshop on fertilization, Nietvoorbij, 30 September,ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch, 7599. Fourie JC, Louw PJE and Agenbag GA. 2007. Cover crop management in a Sauvignon blanc/Ramsey vineyard in the semi-arid Olifants River valley, South Africa. 2. Effect of different cover crops and cover crop management practices on grapevine performance. South African Journal of Enology and Viticulture , 28(2), 81–91.

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