Guidelines for the preparation of table grapes in SA for export 2025/2026_ND

Just before bud swell Vines are emerging from dormancy to begin a new growth season. Root growth starts as soon as soil temperatures rise above 10 °C, which may be before bud break. When roots become active, positive root pressure causes sap flow that is visible at pruning cuts — the canes bleed. • Monitor soil moisture and irrigate if necessary. • Apply chemical mealy bug control. Pay attention to withdrawal periods. • Control stubborn weeds with systemic herbicides. • Remove scion roots and ensure graft unions are not covered in soil. Bud swell Treat for bud mites, dead arm disease (phomopsis), and anthracnose. 1–2 cm shoot length • Treat for dead arm disease, anthracnose, and bacterial blight. Should copper treatment be considered, be careful to avoid damaging vines when spraying in cold, wet weather. 5 cm shoot length • Follow up on treatments for powdery mildew, dead arm disease, and anthracnose. • Apply the first nitrogen fertilisation if necessary. The recommendation for vineyards with normal vigour is 40 kg/ha. Use a nitrate-containing product that vines can respond to quickly. 10 cm shoot length • Treat for powdery mildew, bacterial blight, dead arm disease, bud mites, and downy mildew. • Control snails. 14 days after 10 cm shoot length • Treat for powdery mildew, downy mildew, bud mites and weevils. Use the softest products for the latter two. • Apply trace elements if necessary. • Remove all shoots and lateral shoots in young vineyards, except for a main shoot growing toward the wire and an extra shoot, which is topped. 40–50 cm shoot length • Start with low concentrations (1.0%) of low-biuret urea to boost vigour in weak growers. Also apply to cultivars with compact bunches and poor vigour, where chemical thinning isn’t successful. Applications are usually weekly, but can be increased to twice per week if necessary. At 1.0% it can be sprayed with other products, but at 1.5% it must be sprayed on its own. • Only remove those leaves that directly touch the bunches. Shoot removal is crucial for determining fertility in the upcoming season. Do this judiciously! • Remove all double shoots, retaining the shoot with the best bunch. Remove all shoots without bunches, inferior shoots, and poorly positioned shoots. • Only remove strongly growing laterals from the base of the green shoot up to the bunch if necessary. • Adapt the shoot-removal programme to the cultivar. • Treat for powdery mildew and downy mildew.

22 SATI GUIDELINES FOR THE PREPARATION OF TABLE GRAPES IN SOUTH AFRICA FOR EXPORT