Technical Yearbook 2024

NOVEMBER

Mechanical pruning in the Orange River – a viable alternative By Hanno van Schalkwyk

Mechanical harvesting has become well-established in the Orange River region over the past decade and this has also presented the opportunity to apply mechanical pruning. The correct application of this practice is important to achieve satisfactory long-term results. Wine grape cultivation in the Orange River region has traditionally been done using the large gable, slanting and T-trellis systems (Photo 1). Over the past decade, there has, however, been a greater emphasis on mechanical harvesting, and the high-wire hedge systems are increasingly used. The reason for this is that producers require a lot of manual labour during harvest time for the drying of raisins. In fact, there has been a major increase in raisin production in this area. The other consideration is that labour costs in the Orange River area have risen substantially. According to the latest Vinpro Cost Guide figures, labour costs in the Orange River are calculated at R25 893 per hectare compared to R13 493 for the Olifants River, which is much more mechanised. In the Olifants River, 97% of grapes are mechanically harvested, compared to 28% in the Orange River (2024/2025 Vinpro Cost Guide). Mechanical pruning started to take off in South Africa in the 1990s after the trend flew over from Australia, where labour costs are astronomically high and mechanical pruning was developed in certain areas (mostly interior irrigation areas) as an affordable option. It is currently used successfully in parts of the Olifants

River, Robertson and the Breedekloof. According to SAWIS statistics, the past decade has also seen the emergence of vineyards in the (mechanically-pruned) two-strand hedge category in the Orange River (Figure 1).

Robertson is a region that has already been applying mechanical pruning for some time, and a lot has been learned from trials under local conditions. Briaan Stipp, viticulturist at Robertson Winery, says that mechanical pruning became a consideration after the serious

PHOTO 1. Colombar cultivated with a gable system where the long bearers have been pruned.

FIGURE 1. Surface (hectares) of the different trellis systems in the Orange River region. The total wine grape area was 4 447 ha in 2013 and 2 405 ha in 2023.

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TECHNICAL YEARBOOK 2024