WINETECH Technical Yearbook 2020

growth and focuses instead on constantly meeting the needs of the grapevine. It has already been applied in the hedge, as well as sprawling Perold systems with astonishing results in terms of higher productions and quality. CONCLUSION Worcester and Breedekloof are still planting many new vineyards. The decline in plantings since 2015 can be attributed to the drought and wine prices. The new plantings of 2018 indicate that a recovery is underway. In these two areas, hedge systems have increased sharply since 2013 and this trend is likely to continue. The reason for this is that producers have adapted their management actions toward increased productions and income, while still preparing quality wines. For premium wines, however, the Perold systems are still predominantly being used. REFERENCES Burger, J. & Deist, J. (Eds.) 1981. Win­ gerdbou in Suid-Afrika . Maskew Miller Publishers. Stellenbosch University. 2020. Viticulture class notes; trellising of grapevines. Vinpro Cost Guide 2019/20. Sawis. 2020. Statistics supplied on vineyard surface and trellis systems.

can be done by unskilled labour. The main reason for hedge systems’ popularity is probably the increased productions, and that producers have become familiar with the total management actions required by these systems. Only a small percentage of the hedge systems have been planted for mechanical pruning. The Perold systems still have an important place in the bigger picture of Worcester and Breedekloof’s wine industry. Most prime blocks, i.e. vineyards that are earmarked for higher quality wines, are trellised using one of the Perold trellis systems. These vineyards are carefully managed according to a programme and are strictly suckered, with leaf removal actions and crop control also applied. Two important adjustments pertaining to management practices are currently being observed with these two systems. The existing Perold systems with moveable wires are being altered by placing or even fastening wires in a permanent position. The sprawling principle therefore applies in that some shoots are tucked between the wires to grow in an upright position, while the rest are allowed to sprawl. This enables the canopy to utilise sunlight better while not becoming dense. Productions are significantly increased. Some producers have changed their fertilisation practices by increasing the total nitrogen in the growing season and then applying it in weekly instalments. This prevents unnecessary and sudden vigorous

FIGURE 3. Variations of the three-strand Perold trellis system (for a full analysis, study the Vinpro Cost Guide).

FIGURE 4. A diagrammatic representation of the one-, two- and three-strand hedge system.

DISCUSSION Worcester and Breedekloof, with 19 110 hectares (20.5%) collectively under vines, are a major role player and important contributor to the South African industry. Over the past 10 years, 7 154 hectares wine grapes have been planted in these areas. Table 1 suggests that the Perold

(3 295 hectares) and hedge systems (3 249 hectares) are equally popular, but figure 2 clearly shows that hedge systems have increased sharply since 2013 and there are several explanations for this. Less labour is required to manage these systems, as no suckering actions are performed. Add to this that winter pruning

For more information, contact Pierre Snyman at pierre@vinpro.co.za.

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