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RECENT ARTICLES | WYNBOER HOME
WYNBOER GUIDELINES
FOR JANUARY 2003
1 PLANNING
Short term
- Check all harvesting equipment such as picking crates, knives, scissors, loading trucks or harvesting machines and paint grape bins with leadfree acid-fast paint.
- Ensure that all vineyard blocks are numbered for individual record keeping of harvest details (tonnage, sugar content, acid and pH).
- It must be possible to indicate block numbers on the grape bin or grape trailor.
- Consult your winemaker about grading systems and optimal ripeness requirements for specific cultivars.
- In early regions samples should be taken regularly to monitor ripeness, especially in the early cultivars.
Long term
- Order plant material before the end of March from a registered nursery dealing in certified vineyard plant material.
- Order seed for cover crop to be sown in April.
- Book contractor for soil preparation and order lime and / or phosphate according to the soil analysis requirement.
- Cultivar planning must be done in conjunction with cellar manager and / or viticultural consultant. Vines must be ordered 2 - 3 years in advance.
- Order requirements for maintenance liming and post-harvest fertilisation.
- Order poles and wire for trellis systems.
Financial
Contact VinPro (SA) agricultural economists for information about:
- Purchase of land or farm evaluation
- Feasibility studies and breakeven analyses
- Establishment planning and cost
- Budgets and cash flow statements
Compare the actual cash flow with the budgeted figure and make adjustments if necessary.
2 VINEYARD PROGRAMME
Irrigation
This is the time in the growing season when the water requirement of vines is at its highest.
For optimal ripening, vineyards that receive supplementary irrigation should be irrigated in January.
Intensively cultivated vineyards should still be fully irrigated, except in the case of very vigorous early cultivars, where the amount of water may be gradually reduced towards the end of the month to limit active shoot growth.
Foliage management
Active shoot growth during ripening impairs grape quality. In actively growing vineyards a light topping treatment may be applied from v‚raison onwards. Heavy topping is detrimental to grape quality. Make a note of overprolific blocks in order to adjust fertilisation at a later stage.
Disease control
Downy mildew control should be maintained where the disease occurs after the New Year.
Oïdium should no longer be a problem, provided control programmes have been rigorous. In the case of persistent problems, apply chemical fungicides, bearing in mind the safety periods, instead of sulphur (dust or wettable). Maintain control programmes in late cultivars, especially in late regions.
Botrytis cinerea (grey rot) can be controlled, although the success of the programme is to a degree dependent on preventative measures, such as judicious removal of leaves to improve aeration, as well as reduced application of water on fertile soils.
Where severe botrytis is a regular occurrence, the first chemical application should be given after the flowering stage and followed up every three weeks until the harvest. Otherwise an application should be given at pea berry stage with one or two pre-harvest applications. Efficient foliage management is a prerequisite for direct bunch coverage with fungicide.
Some fungicides, if applied shortly before the harvest, may have a harmful effect on fermentation and wine quality. Adhere strictly to safety periods.
Young vine development
Sucker and top actively growing green shoots regularly in their second growing season, so that by winter the vines will be shaped to a large extent.
Vines that were grafted in November according to the winter bud / green shoot method, must still receive meticulous after-care and the growing shoot must be tied up.
Harvesting of grapes
Vineyards or parts thereof that ripen earlier and tend to suffer from sunburn should be harvested in good time.
Consult the winemaker about the grading requirements for specific cultivars and start berry sampling in good time to monitor ripeness.
Sampling procedure
Sample at least 200 berries / 1000 vines or 10 % of vines distributed well across the vineyard.
Do not sample end vines or rows.
Estimate the percentage of bunches exposed to the sun and determine the sample ratio accordingly.
Vary sampling position e.g. both sides of rows, front and back, bottom, middle and shoulders of bunches.
Select more berries from high yielding vines than from weak vines.
Collect samples at the same time of day, e.g. early morning after the dew has dried.
Keep undamaged samples in closed plastic bags in a cool place and process within 24 hours.
In cool areas and dryland vineyards where stress occurs, as well as vineyards on varying soil types, larger samples should be taken.
In years when grapes ripen unevenly, thorough bunch samples give very good results.
Compiled by: VinPro (SA) Consultation Services
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