COVER CROPS in South African Vineyards

COVER CROPS IN SOUTH AFRICAN VINEYARDS

Reference list Van Huyssteen L, Van Zyl JL and Koen AP. 1984. The effect of cover crop management on soil conditions and weed control in a Colombar vineyard in Oudtshoorn. South African Journal of Enology and Viticulture , 5(1), 7–17. Lower Orange River region Trials in this region were conducted in a vineyard under full-surface micro- sprinkler irrigation near Upington in the Northern Cape. Different cover crops were sown in vineyards as described in Vineyard Trials in Chapter 3 (p62). Dry-matter production was measured for summer- and winter- growing weeds in each of the treatments. Winter-growing weeds Two management strategies were compared for the different cover crops. In the first, annual cover crops were sown each year in autumn, and full-surface chemical weed control was started at grapevine bud-break. In the second, annual cover crops were sown every second year, and full-surface chemical weed control was started at véraison. No cover crop was sown in the control, and it was slashed. The overall average dry-matter production of winter-growing weeds in shown in Figure 5.35, for treatments where cover crops were sown annually. It shows that all the cover crops suppressed weeds.

No cover crop Woogenellup clover

2,03

0,56

Pink Serradella Overberg oats Paraggio medic Henog rye Grazing vetch Saia black oats

0,32

0,20 0,19

0,07 0,07

0,03

0,00

0,50

1,00

1,50

2,00

2,50

Dry matter of weeds in tonnes per hectare FIGURE 5.35. Dry-matter production of winter-growing weeds in cover-crop treatments and a control without a cover crop in the Lower Orange River region. Cover crops were sown annually. Adapted from Fourie (2005).

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