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

Actions by phenological stage

Dormancy Pruning: Canes (12 buds) with 25 buds per m 2 . Improving bud break: Prune so that bearers are all more or less the same diameter (12–14 mm). Bud break is uneven in bearers that are too thin or too thick. Bud break to flowering 40 cm shoot length: Thin shoots. Remove weak shoots and shoots without bunches. Aim for 18–20 shoots per metre. Weak shoots produce poor-quality bunches with watery berries and berry stem necrosis. Keep one bunch per shoot. Two bunches can be left on vigorous shoots. Remove leaves around bunches for more effective fungicide applications. Flowering to set 2-3 mm berry diameter (set): Thin with 1–1.5 ppm gibberellic acid to abort shot berries. Low concentrations (1.0%) of low-biuret urea can be added during cold weather or for vineyards with poor vigour. Repeat 1 ppm gibberellic acid after three days. Set to véraison 5–6 mm berry diameter: Girdle after set. Correct girdling can improve berry size by 25% and positively affect the following season’s fertility. Shorten bunches to 80–90 berries per bunch. It may sometimes be necessary to use larger bunches on vigorous shoots if there aren’t enough bunches. Leave 49 000 bunches per hectare. 8–10 mm berry diameter: Remove leaves around bunches. Apply 7.5 ppm gibberellic acid plus 2 ppm CPPU (cytokinin) for berry enlargement. High doses of gibberellic acid may negatively affect fertility. Control berry stem necrosis with foliar applications of magnesium every two weeks. Handling bunches after 10–12 mm berry diameter can cause surface browning. Véraison to harvest ± 10% colour: Diffuse light under the canopy is necessary to harden off berries, but the bunches shouldn’t receive direct sunlight. Canes must harden off to a light brown colour. Remove damaged berries and bunches. Control powdery mildew and decay. Harvest to packing Don’t handle turgid grapes on cold mornings after rain or irrigation. This can lead to hair cracks and decay in the carton. Don’t pack bunches after hanging for a long time to develop sugars or bunches from weak shoots. These bunches have an elevated risk of internal browning.

SATI GUIDELINES FOR THE PREPARATION OF TABLE GRAPES IN SOUTH AFRICA FOR EXPORT 47