Ascertaining research requirements and prioritising the requirements in conjunction with producers and wine-makers is extremely important to the ARC-Nietvoorbij and WINETECH.
Gatherings where producers and wine-makers were informed about WINETECH and the research cycle were held this year in Stellenbosch, Durbanville/Constantia and Malmesbury.
The most important research priorities identified in the various areas are as follows:
- Mealybug/ants (IPW limits control at a late stage)
- Resistance to downy mildew and powdery mildew (substances and programme)
- Irrigation between veraison and ripening for improved quality
- Leafroll (occurrence, distribution and control)
- Optimal weed control (soils/type of weed)
- Determination of optimum ripeness for red grapes. Further aids in addition to sugar, pH, acid and tasting.
- Acid adjustment – when is the optimal time On the skins before malolactic fermentation, influence on buffer capacity, pH and quality.
- Skin contact: Frequency of pressing or racking, the influence on tannins, anthocyanins, total phenols.
- How temperature should be used as an aid to improve quality.
- Should different cultivars be handled differently
- Can a spectrophotometer be used to good effect
- Volatile acid in red wines: Reasons for increases and removal of excessive volatile acid.
- Phenolic composition of South African red wines. Can manipulations be done in the vineyard to optimalise this How can the so-called green tannins be avoided and a concentration of the so-called ripe tannins be promoted
- Technology transfer (Practical implementation), (Application/Guidelines).
- To reverse negative publicity of South African wines.
- Determining quality parameters of wine (“Green tannins”). Compare countries vs quality per cultivar.
- Determining ripeness – methods.
- Determining quality (Viruses etc.) of grafted material.
- Clone selection for specific wine.
- Controlling ants and mealybug within the IPW guidelines. Disturbing berm areas for ant control.
- Various pruning systems for fertility/Production decrease especially in the cooler areas – Sauvignon blanc (vigorous growth).
- Management of excessive vigour.
- Control of Botrytis (resistance)
- Acid composition of grapes (Malic and tartaric acid) – Instant analysis.
- Volatile acid problem in red wine. Preventive actions/diagnoses/Identification of bacteria.
- Stability tests (egg whites/tartrates).
- “Quality” classification – criteria vs grape price.
- Poor settling of young white wines after fining.
- Resistance to downy mildew/powdery mildew Ant control/mealybug Resistance of weeds to existing weedicides Validity of registration of spraying agents
- Irrigation and production norms for wine quality per area/cultivar/clone. Irrigation system vs soil types and aids for scheduling of irrigation.
- Sunburn/heat waves – adjustments in practices to reduce this, e.g. “Vapour gard” (warm country cultivation management).
- Training of labourers on different levels – training of supervisors, video’s, manuals.
- Determining and remuneration of grape quality.
Feedback to producers and wine-makers regarding progress with projects and the results obtained with experiments are of the utmost importance to provide wine-makers, farmers and consultants with the latest technology.
Feedback sessions were held in three areas, namly Vredendal, Upington and Worcester, at which time researchers were given the opportunity to report back regarding their research. The attendance at all three occasions was satisfactory, but it will be necessary to reconsider the format and the regularity of such meetings.
JAN H BOOYSEN