Vititec’s main focus is on clonal selection, virus elimination, grafting, establishing and maintaining clean mother blocks, and supplying grafting material to the local nursery industry. Since 2007 Vititec has imported 60 new clones and 15 new cultivars from ENTAV, France, as part of our ongoing process to introduce new cultivars to the South African Wine industry. Some of these varieties, mainly from the Mediterranean area, can be the South African wine producers answer to adapting to climate change. New cultivars include Marselan, Macabeu, Piquepoul Blanc, Sauvignon Gris and Vermentino.
Virus elimination via heat therapy and tissue culture
Vititec annually puts 50 cultivars through heat therapy for virus elimination. Nineteen cultivars are currently undergoing heat therapy which is the first step in the virus elimination process. There are no known chemicals to kill viruses in plants, but viruses can be eliminated from individual plants by heat therapy and meristem tip culture. The process takes between 18-24 months to complete.
These new plants are then maintained in the nuclear greenhouses and are the new nuclear cultivar/clone material. Various virus tests will be performed on these material to ensure that it is free from all known harmful viruses and become registered nuclear material. However the small amount of planting material obtainable from these nuclear vines is insufficient to meet the needs of the industry. Further mass production of material from these vines is therefore done within the certification scheme, first in foundation blocks and then in mother-blocks.
We finished grafting our last order for the 2017 season last week. The trend in cultivars is towards white grapes with Sauvignon Blanc and Chardonnay our top contenders followed by Shiraz and Cabernet Sauvignon. These vines are currently being planted in our 6 nurseries which are allocated in Vredendal, Graafwater, Clanwilliam and the Piketberg area.
Supplier of plant material
Vititec annually supplies 95% of all wine grape scion material to the local nursery industry. This season was one of the worst experienced as only 12.2 million buds were sold compared to the 18 million of the previous year (67% decrease). The top five cultivars sold were Chenin blanc (52% decrease), Sauvignon blanc (3.8% increase), Colombar (59% decrease), Chardonnay (3.7% increase) and Cabernet Sauvignon (4% less). Vititec’s main focus is on clonal selection, virus elimination, grafting, establishing and maintaining clean mother-blocks, and supplying grafting material to the local nursery industry. – Nico Spreeth, VinPro