COVER CROPS in South African Vineyards

COVER CROPS IN SOUTH AFRICAN VINEYARDS

14,00 12,00 10,00

8,00 6,00 4,00 2,00 0,00

Shoot mass 1995/96 Shoot mass 2002/03 Grape yield 1995/96 Grape yield 2002/03

Mass in tonnes per hectare

Sown annually

Sown annually

Sown annually

Sown two-yearly

Sown two-yearly

Sown two-yearly

Chemical control

Henog rye

Overberg oats Saia black oats No cover crop

ic

FIGURE 8.14. Vegetative growth and grape yield in grass cover-crop treatments compared to a control in the Coastal region. Adapted from Fourie et al (2006). ic

,2

clover

rol

16,00 14,00 12,00 10,00

,8

8,00 6,00 4,00 2,00 0,00

,6

Shoot mass 1995/96 Shoot mass 2002/03 Grape yield 1995/96 Grape yield 2002/03

4

Mass in tonnes per hectare

Mass in tonnes per hectare

2

Sown annually

Sown annually

Sown annually

Sown annually

Sown annually

Sown two-yearly

Kelson snail medic Sown two-yearly

Faba bean Paraggio bur medic Sown two-yearly

Sown two-yearly

Sown two-yearly

Chemical control

No

Grazing

Woogenellup clover

vetch

cover crop

FIGURE 8.15. Vegetative growth and grape yield in legume cover-crop treatments compared to a control in the Coastal region. Adapted from Fourie et al (2006).

Although the growth of the grapevines in the treatments where legumes were sown annually tended to be vigorous, canopy density did not affect grape yield negatively. However, these treatments show the potential to over-stimulate shoot growth on medium-textured soils, especially where the trellising system is smaller than that used in this trial.

153