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

Actions by phenological stage

Dormancy Pruning: Prune late for better flowering conditions and less variation in the physiological age of berries in a bunch. Spurs (2 buds) with 8–10 buds per m 2 . Or half-long bearers (6–8 buds) with 12–15 buds per m 2 . Improving bud break: Apply hydrogen cyanamide before bud break to advance the harvest date or improve bud break. Use according to the product registration. Bud break to flowering 2 cm shoot length: Start with the powdery mildew programme. 10–15 cm shoot length: Top dominant shoots so that shoots with bunches will all be more or less the same length at flowering. Apply nitrogen according to vigour. Apply 20 kg of nitrogen per hectare 1 week before flowering to promote natural thinning. 20 cm shoot length: Thin shoots. Remove weak shoots and shoots without bunches. Retain the bottom bunch on shoots. 60 cm shoot length: This cultivar reacts poorly to thinning with gibberellic acid. Apply low concentrations (1.0%) of low-biuret urea weekly. 80–110 cm shoot length: Optimal shoot length at flowering. Flowering to set During flowering: Apply low concentrations (1.0%) of low-biuret urea twice, three days apart, to assist in natural thinning. Don’t remove any leaves or top shoots, as that will hinder natural thinning. Full bloom: Thin with 1.5–2 ppm gibberellic acid plus low concentrations (1.0%) of low-biuret urea. Set to véraison 50% of berries with 6–7 mm diameter: Remove leaves around bunches. 8–9 mm berry diameter: Apply 5 ppm gibberellic acid for berry enlargement. Shorten bunches to 70–80 berries per bunch. Smaller bunches with less variation in physiological age between berries are less prone to browning. Leave 55 000 bunches per hectare. Don’t leave bunches on weak shoots. Apply nitrogen according to vigour. Nitrogen may be unnecessary given the urea applications for thinning. Snip out berries or clusters to loosen compact bunches. Use the top 4–5 laterals of bunches. Start with a magnesium programme to control berry stem necrosis if necessary. Avoid handling bunches once the berries start to soften, as this can lead to surface browning. Véraison to harvest ± 20% colour: Prune the apex of the trellis to open a gap of approximately 30 cm. Avoid direct sunlight on bunches. ± 75% of berries soft: Remove bunches from vines that have too many. Harvest to packing Harvest as soon as the minimum sugar levels are achieved. The longer the grapes hang, the bigger the risk of browning. Sensitive to browning: Handle bunches carefully. Sensitive to SO 2 -damage: Use paper on the grapes. Use 4–5 mm perforated bags and a MAM sheet. Don’t handle turgid grapes on cold mornings after rain or irrigation. Swollen surface cells can break, leading to browning.

SATI GUIDELINES FOR THE PREPARATION OF TABLE GRAPES IN SOUTH AFRICA FOR EXPORT 51