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RECENT ARTICLES | WYNBOER HOME
Wynboer guidelines
for September 2000
Compiled by:
VinPro (SA) Consultation Services
1 PLANNING
Short term
- Calibrate spraying pump to ensure that the dosage is correct.
- Order the required pest and disease control products according to IPW guidelines.
- Check and repair irrigation equipment for all systems.
- Book contractor for soil that must be prepared towards the end of the month and in October. Soil that is too wet or too dry should not be prepared. Also order lime/phosphate/gypsum as indicated by soil analyses.
Long term
- For efficient irrigation the maintenance of irrigation systems, especially micro systems, is of the utmost importance. Clean catchment dams, regularly flush the filters and laterals, and rectify salts and iron oxide blockages with acid treatments. Chlorination of the water will suppress microbiological activities and oxidise organic material.
Financial
- Contact VinPro (SA) agricultural economists for information about: Purchase of additional land or farm evaluation; Feasibility studies and breakeven analyses; Establishment planning and cost; Budgets and cash flow statements
- Obtain quotations from various suppliers for capital expansion and production supplies.
- Schedule and distribute production supplies throughout the season, depending on the cash flow position.
- Production Plan participants (an economic study group) must submit questionnaires for analysis by the required deadline.
2 VINEYARD PROGRAMME
Planting of vines
- Soil that was too wet for planting in August can now be planted. Ensure that the vines do not dry out and leave them in water for at least 24 hours prior to planting. Plant replacements where vines that were planted earlier did not take.
Preparation of the soil
- Take the necessary precautons in regions where frost is common by spraying and dragging weeds and/or cover crops. Ensure that the surface of the soil remains undisturbed and moist.
- Cover crops and weeds now have to be managed chemically and/or mechanically to eliminate moisture and nutrient competition after budding. A chemical pre-emergent herbicide is recommended for bush vines in narrow vineyard rows.
Disease and pest control
- Humid conditions in spring favour outbreaks of fungal diseases. For efficient disease control, spraying should be preventative.
- Combat powdery mildew by spraying according to a fixed programme, from the time when shoots reach 5 - 10 cm in length, at intervals of 14 - 21 days. Early sulphur dust applications give good results, provided the temperature remains above 18°C.
- The control programme for downy mildew should be adapted to the occurrence of the disease in the region and reigning weather conditions. Start applications when shoot length is 10 - 15 cm.
- Anthracnose and Phomopsis present a problem, particularly in humid regions. Apply lime sulphur just before budding, or treat chemically when shoot length reaches 25 cm, including the necessary follow-up applications.
- Bacterial blight, which spreads mainly with the bleeding exudate, must be treated with a substance containing copper immediately after pruning.
- Insect control must be applied locally where symptoms of damage or high pest counts occur, following IPW guidelines.
- Bud mite, a common occurrence in vineyards, should preferably only be controlled if high counts are confirmed by winter shoot bud analyses.
- Leaf blister and leaf curl mite may be controlled by applying lime sulphur during bud swelling shortly before budding, or chemically when shoot lengths reach 10 cm, with the necessary follow-up treatments.
- Snail control, if necessary, should take place.
- Ant control should take place during bud swelling and before budding. Use a coarse spray to thoroughly treat the trunk, trellis poles, anchor wires, ant nest openings and the soil in the immediate vicinity of each of the above.
- Mealybug control is directly dependent on successful ant control. Chemical control should be applied only if biological control, after ant control, was unsuccessful. Only spray infested and adjacent vines and make sure that all parts of the vines, the trunk in particular, are properly soaked. Mark infested vines to facilitate the follow-up spray 14 days later.
- Snout-beetles may be controlled in October by using barrier tapes around the trunks (a protective undercoat is required for vines younger than three years). Leave a snout-beetle shoot on the trunk to monitor the damage.
- Chemical treatment of nematodes on berms with no weeds is justifiable in established vineyards during budding. On sandy soils treatment should only take place 4 - 6 weeks after budding.
Irrigation
- Use aids to schedule irrigation correctly. Since moisture retention is still limited early in the season and soil moisture is probably still sufficient, do not incur unnecessary expenses by starting to irrigate too early. Where insufficient winter rains occurred, or the soil has been dried out by the cover crop, irrigate until the full soil water storing capacity is reached.
Delayed budding
- If climatic conditions are problematic and delayed budding is expected in sensitive cultivars, basal buds may be treated with a budding stimulant approximately 3 weeks before normal budding. Budding stimulants may also be applied during vine development in young vineyards. Consult your viticultural consultant about the use of budding stimulants to terminate dormancy.
Development of summer shoots
- Study the VinPro (SA) Consultation Services video "Somerlootontwikkeling" as well as the "Guide for Establishing a Vineyard".
- If the trellis system is already in place, a wire should provisionally be strung 30 cm from the soil so that ropes may be extended from there to the cordon wire.
- To limit wastage of reserves, start thinning out shoots when they reach 30 cm in length.
Suckering (shoot removal)
- The first suckering of trunks and forks and between bearers should be early (5 - 10 cm shoot length). Follow up later by removing infertile and weak shoots from bearers.
A more detailed version may be ordered from Gerda Kriel at (021) 807 3027.
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