COVER CROPS in South African Vineyards

CHAPTER 8 EFFECT OF COVER CROPS ON GRAPEVINE NUTRITION AND PERFORMANCE two-yearly rotation fescue

20,00 18,00 16,00 14,00 12,00 10,00 8,00 6,00 4,00 2,00 0,00

Shoot mass 1996/97 Shoot mass 2001/02 Grape yield 1996/97 Grape yield 2001/02

Mass in tonnes per hectare

Triticale Grazing vetch Triticale|vetch Perennial

No cover crop

two-yearly rotation

dwarf fescue

FIGURE 8.6. Vegetative growth and grape yield in treatments with cover crops sown two-yearly, and perennial dwarf fescue, compared to a control in the Breede River valley. Adapted from Fourie (2011). The ratio of grape yield to shoot mass to grape is shown in Figure 8.7. Ratios were within the range that indicate a good balance of vegetative growth and grape yields. er er ation

7,00

6,00

5,00

4,00

3,00

1996/97 2001/02

2,00

1,00

Ratio of grape yield to shoot mass

0,00

Control

Control

Control

Control

Annual Two-yearly Slashed Control

Control

August November August November August rotation rotation

August

Triticale

Grazing vetch Rye|faba Triticale|vetch Perennial No cover bean mix dwarf crop fescue

FIGURE 8.7. Ratio of grape yield to shoot mass in cover-crop treatments compared to a control in the Breede River valley. Values below line would indicate potential for increased grape yield. Adapted from Fourie (2011).

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