We then drove to a block that Wiese had been experimenting with for the past couple of years, trying to curb these problems. ”All I did here, was to increase the height of the bush vine from the ground and introduce a height-specific three-wire trellis system – unlike the traditional one seen in most trellised vineyards. I used old poles, which would normally have been discarded. The end result is that I can spray easily and, if need be, harvest mechanically,“ he continued.
TERROIR AND CULTIVAR SPECIFIC
“You can’t plant all cultivars as bush vines and expect the same results everywhere. Bush vines are cultivar specific and soil potential is a great determining factor,” Wiese said. The financial feasibility of planting bush vines concerned him greatly. With the rising production costs, he felt it made no financial sense to plant bush vines in soil with high potential, as they have low yields. In this case one should rather opt for trellised vines.
“Chenin, Pinotage, Grenache Noir, Carignan and Cinsaut are some of the cultivars that come to mind when talking of bush vine. Age plays a big role when it comes to quality, but the basics must be done right in the earlier physiological states of the vine,” he said.
VinPro’s viticulture consultant for the Paarl/Swartland area, Hanno van Schalkwyk, confirmed that the number of bush vines is decreasing, but also mentioned some positive attributes of this method of vine growing. ”Soil potential plays a major role in the planting of bush vines. They are low yielding and have been doing well in the Swartland area in terms of the quality of the concentrated fruit, which comes out in the wine,” he said.
With new water scheme projects, especially in the Swartland region, most producers have uprooted bush vines because of the need for higher production, which is made possible by the trellis system. “Producers have water available, which was not the case in the ’80s, where 80 – 90% of wine grapes in Malmesbury were under bush vine as it is a dryland area*,” he pointed out.
Mechanisation provides an alternative for producers to implement most viticultural practices more efficiently and faster. “Mechanical harvesting and pruning are not possible on bush vines, which has a great impact on producers in terms of time management.” He noted that it made financial sense for most producers to go for the trellis system as it increased productivity and made it possible for them to mechanise. The only challenge was striking a balance between uprooting bush vines and the time and costs involved with establishing new vines.
“Small producers are promoting bush vines and the quality associated with them. These producers will have to keep this momentum as it will make the wine produced from bush vines more valued. If the price of wines produced from bush vines filters down to the grape producer in terms of rands per tonne of grapes, we might see less uprooting as it will make financial sense to keep the vine,” he concluded on a positive note. * (Archer, 1991)
FAST FACTS ABOUT BUSH VINES
- Suitable for low-potential dryland soils.
- Cultivar specific.
- Great sunlight interception.
- Beneficial in cool areas where ripening is problematic.
- High-density planting increases competition and may lead to high yields.
- High chance of longevity.