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A Technical Guide for Wine Producers
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RECENT ARTICLES | WYNBOER HOME
WYNBOER WORK PROGRAMME FOR SEPTEMBER 1999
1. PLANNING AND PREPARATION
1.1. Short-term
Financial
1.2 Long-term
Maintenance of irrigation systems: Drip irrigation systems on suitable soils are highly effective if the system maintenance is applied carefully. The regular rinsing of filters and laterals as well as the cleaning of reservoirs diminishes the risk of blockages. Where salts and ironoxide cause blockages, the problem may be solved with acid treatment. Irrigation water may be chlorinated as a preventive measure to suppress microbiological activity and oxidising organic material. The mechanical cleaning of blocked drippers is not recommended as this damages the drippers. Although it is possible in certain instances to clean blocked drippers chemically, it is much better to keep them clean from the start by using the correct filter equipment (Deciduous Fruit Grower, pp. 98 - 102, March 1989).
2. VINEYARD PROGRAMME
Vine planting: Soils which were too wet for planting during August may be planted now. Prevent the drying out of vines. After the vines have been removed from the nursery, cold storage or where they have been laid in, they should be left in water for at least 24 hours. See Wynboer Work Programme for July for practical hints. Dead vines may now be replaced now in the case of early planted vineyards. Competition by weeds can be delayed by a total surface herbicide spray before planting the vines.
Soil cultivation: In areas where frost is common in September the necessary precautionary measures should be taken. Make sure the surface of the soil is fine and as firm as possible. Keep the soil moist during the danger period. Weeds and/or cover crops should be killed off by spraying them whereafter they should be flattened onto the soil surface.
Weed control: To prevent competition for nutrients and water after budding, cover crops and weeds should be controlled chemically and/or mechanically. A chemical pre-emergence herbicide is strongly recommended for bush vines in narrow rows.
Disease and pest control: During spring, the weather is usually favourable for fungal diseases. The occurrence of fungal diseases is closely related to the climate of the area where the vines are grown. Spray programmes should therefore take into consideration the humidity of the area. For effective disease control, preventive spraying is essential.
Pest control is applied only when large scale infestation or damage occurs and only infested vineyards or infested vines should be treated.
Anthracnose and dead arm: These diseases are a greater problem in humid areas than in dry areas. Apply dusting sulphur prior to bud burst or treat chemically on ± 25 cm shoot length with follow up sprays every four days if required.
Bacterial blight: Apply a chemical which contains copper. Bacterial blight can be spread by the sap flowing from pruning wounds, therefore the first treatment should be directly after pruning.
Oïdium: The treatment of oïdium is preventive and although the disease usually occurs later in the season, control should start when shoots are 50 - 100 mm long. A fixed programme may be followed in nearly all areas. The minimum number of applications is three times per season, but in humid areas application should be increased. The applications are applied at intervals of 14 - 21 days after the first application. The most common fungicide used with good effect at a temperature > 18 ° C is dusting sulphur.
Downy mildew: The programme against downy mildew should be adapted to deal with the occurrence of the disease in the area as well as the prevailing weather conditions. Start control when shoots are 100 - 150 mm long.
Vine budmite: Although vine budmite occurs in almost all vineyards it is only necessary to spray when the budmite population becomes too high. Cabernet Sauvignon and Hanepoot are especially susceptible to budmite.
The first spray should be applied 28 days after bud burst, followed by another spray 14 days later. Materials used in an integrated control programme are bromopropilate (50 ml/100 l) and endosulfan (125 ml/100 l), and should be applied at high volume (1 000 l/ha). To determine if a spray programme is necessary, canes should be analysed by a microscopic assessment, as visual symptoms are not reliable for identification of bud mite.
Sampling: 16 canes must be collected randomly from 16 vines, with the first eight buds included on all canes. Samples must be clearly marked with the cultivar, block no, date and contact person, and must be wrapped in plastic. It is up to the producer to bring samples to Nietvoorbij.
Erinose and leaf curl mite: Lime sulphur should be sprayed when the buds are swollen, but before budding. Vines should be dusted with a sulphur formulation when the longest shoots are 100 mm long, during flowering and 3 to 4 weeks later.
Snail control: Apply when required. See Wynboer Work Programme for August.
Ant control: Treatment must be applied when the buds are swollen, but before budding. The trunk of the vine, trellising poles, anchor wires and the soil in the immediate vicinity of each of the above-mentioned must be sprayed thoroughly with coarse spraying (large drops). Special attention must be paid to nest openings.(See Wynboer Tegnies, No 54, Janaury 1993 - Mierbeheer as deel van geïntegreerde plaagbestuur).
Grape mealy bug: The first step is to control ants. Chemical control should be practised only when biological control, after ant control, has not been successful. Successful control of grape mealy bug means that all sections of the vine, especially the trunk are sprayed thoroughly. Spray only infested vines and vines adjacent to infested vines. Mark infested vines to facilitate follow up spraying after 14 days.
Snout beetles: Apply a sticky barrier ± 20 mm wide and 5 mm thick on the trunks of the vines (not on vines up to 3 years without a foundation layer) early in the season as soon as the insects become active, i.e. early October. Leave a shoot at the base of the trunk to serve as indicator for the presence of snout beetles. The shoot should be monitored regularly to determine when and whether to spray.
Eelworm control: In established vineyards chemical control should be applied on a clean berm from time of budding. On sandy soils the treatments should only be applied four to six weeks after bud burst. Stick to the withholding period of 120 days before harvest.
Irrigation: Make use of aids to schedule your irrigation correctly. Unnecessary cost is incurred by starting irrigation too early. The soil probably contains sufficient water and transpiration loss through the leaves is usually minimal. Prior to middle October there is very little root activity and the uptake of water is very restricted. With insufficient winter rain or where the soil has been desiccated by a cover crop, irrigation must be applied to the full water storage capacity of the soil.
Delayed foliage
The agent for release from dormancy should be applied as a directed spray with a spraygun, rucksack pump, brush or sponge. Where bud break is required, complete covering of the buds is essential. Injudicious use is extremely dangerous to humans. Wear a respirator and protective clothing while applying the poisonous chemical.
Summer shoot development: (Study video: Somerlootontwikkeling)
Suckering: Sucker comprises two actions. Start early (50 to 100 mm shoot length) by removing the shoots on the trunks, in fork and between the bearers. Follow up by removing the unfertile and weak shoots on the bearers.
Soil preparation: One of the reasons for poor results with soil preparation is that soils are cultivated at the wrong stage of water content (too dry or too wet). To wet soils should not be prepared while to dry soils can be irrigated up to the required moisture level.
3. VITICULTURE CONSULTANTS IN THE VARIOUS KWV DISTRICTS
For viticulture enquiries consult your nearest KWV Viticulture Consultant.
Paarl/Wellington/Tulbagh: Bennie Liebenberg (021) 8073018, 083 455 5197 or Gavin Taylor (021) 8073418, 083 455 5193.
Malmesbury: Johan Pienaar (021) 8870014, 083 309 7637, Nelius van Huyssteen 083 455 5198 or Bennie Liebenberg (021) 8073018, 083 455 5197.
Robertson/Klein Karoo (02351 - 3017): Francois Viljoen 083 309 7626, Briaan Stipp 083 455 5196, Leon Dippenaar 083 455 5194 or Stephan Joubert 083 650 5590.
Bonnievale: Hendrik Myburgh (02351) 3017 or 083 455 5195.
Orange River: Dirk Malan (054) 4612299, 082 495 7999 or Dricus van der Westhuizen 083 309 7625.
Stellenbosch (021- 8870014): Johan Pienaar, 083 309 7637 or Cobus van Graan 082 650 4404.
Worcester (0231 - 72795): Schalk du Toit 083 303 0530, Pierre Snyman 083 455 5191, Anton Roos 083 629 1735 or Hanno van Schalkwyk 083 455 5192.
Olifants River: Dricus van der Westhuizen 083 309 7625 or Nelius van Huyssteen 083 455 5198.
4. OENOLOGY CONSULTANT
Eugene van Zyl can be contacted at 082 577 2758.
5. WINE GRAPE PLANTING MATERIAL
Enquiries regarding planting material can be obtained from KWV's Plant Improvement Division:
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