COVER CROPS in South African Vineyards

COVER CROPS IN SOUTH AFRICAN VINEYARDS

Cover crops were sown annually in the work row. The vineyard was drip- irrigated from December to March. Full-surface chemical weed control was applied from just before bud-break until harvest.The trials were conducted over five seasons.The performance of the cover crops is summarised inTable 3.4. More information on nematode-suppressive ability can be found in Coastal Region in Chapter 9 (p170). TABLE 3.4. The seeding dates, seeding densities and performance of cover crops selected to suppress nematodes. Cover-crops are ranked by dry-matter production. Adapted from Fourie et al (2015).

Dry-matter production in tonnes per hectare Cover crop Weeds

Seeding density in kilogram per hectare

Common name

Seeding date

Scientific name

Pallinup oats Avena sativa ‘Pallinup’ White mustard Sinapis alba ‘Braco’

4–10 May 100

4.55 0.15 3.84 0.33 3.19 0.17 2.70 0.36 2.50 0.53

4–10 May

8

Caliente Nemat Canola

Brassica juncea ‘Caliente 199’ 4–10 May 10 Eruca (sativa) vesicaria ‘Nemat’ 4–10 May 5

Brassica napus ‘AV Jade’

4–10 May

8

Which cover crops were successful? Average annual dry-matter production for all the cover crops in the long-term vineyard trial is illustrated in Figure 3.19.The average dry-matter production of the natural weed stand is given for comparison.

Woogenellup subterranean clover

1,27

Grazing vetch Weeds

1,38

1,83

Kelson snail medic Paraggio bur medic Faba bean Rye Black oats Overberg oats

2,59

2,71

3,01

3,32

3,75

4,87

2,00

3,00

4,00

0,00

1,00

5,00

6,00

Dry matter in tonnes per hectare FIGURE 3.19. Average annual dry-matter production of all cover crops in vineyard trials in the Coastal region. Adapted from Fourie et al (2006).

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