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A Technical Guide for Wine Producers
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RECENT ARTICLES | WYNBOER HOME
WYNBOER WORK PROGRAMME FOR JUNE 1999 1. PLANNING AND PREPARATION 1.1 Short-term Financial
1.2 Long-term Establishing a Vineyard: A "Guide for Establishing a Vineyard" compiled by VinPro (SA) Consultation Service which contains the latest Technical and Financial information on this subject can be ordered from Mrs Gerda Kriel, tel. 021 - 8073027. Irrigation: Producers intending to make use of a subsidy on irrigation systems should preferably start the necessary arrangements a year before the system is to be installed. This includes: analyses of the soil and obtaining a report from the Department of Agriculture and Water Affairs; the design of the system; completing and mailing the application to Engineering Services; the amount of the subsidy; obtaining the approval of the Directorate: Agricultural Engineering. 2. VINEYARD PROGRAMME Installation of irrigation systems and trellising must be completed before pruning starts. Cover crop: If necessary the cover crop should be irrigated and/or given a top dressing. Scion roots: Clear soil around the trunks of the vines to remove scion roots. Snail control: See Wynboer Work Programme for May. Irrigation: If good quality water is available one irrigation can be applied to leach alkaline salts. Winter pruning: (See video titled Wintersnoei.) Pruning is one of the most important practices in viticulture and in the case of wine grapes one of the main ways in which the crop size may be restricted. The following are the four main aims of pruning:
The pruning of untrellised (bush) vines, the development of trellised vines and winter pruning of full bearing vines are discussed in detail in Wingerdbou in Suid-Afrika p. 202 - 233. The following are a few practical hints: Pre-pruning: To spread labour the canes of trellised vines can be cut off 30-40 cm from their base. The time-consuming task of removing canes between the trellising wires can to a large extent now be completed. (Female personnel can be used for this task. This action can also be done mechanically.) This accelerates the removal of the remaining canes after final pruning. Clean pruning: Activities during pruning can be spread over a longer period by clean pruning, that is removing all canes except bearers. Later in the season the bearers are cut to the desired length. For clean pruning well-trained personnel must be used. Clean pruning influences the important aspects of shape and potential bud load should receive special attention. Pre- and clean pruning should preferably be practised only on luxuriant vines and early cultivars. Excessively luxuriant vines which have been pre-pruned in May should not be pruned now, but be clean and spur pruned in one operation towards the end of July. Climate: Do not prune while the soil is dry and the humidity is very low as pruning wounds dry out. Wait until the first rains have fallen, but do not prune while raining. Young vines: The first three years are all-important in shaping young vines. In this case pruning is practised not only to regulate the crop, but also to shape the vines. Young vines should be pruned by the most experienced pruners. Vine development: The speed and method of vine development are determined by growth and the system of trellising. Each vine should be judged individually. See Wynboer Tegnies No 1, October 1982. Groenlootontwikkeling - 'n Metode waarvolgens sterk groeiende wyndruifstokke op 'n prieel ontwikkel word and Wynboer Tegnies No 42, January 1991 - Winsgewende Opleitegnieke vir Geilgroeiende Wingerde. The system of pruning should be adapted to cultivar and topography. Fertile cultivars such as Cinsaut, Chenin blanc and most other wine grape cultivars are pruned with 2-bud bearers or spurs. In the case of less fertile cultivars such as Sultana and on infertile sites long or cane bearers are used. Where frost does not occur, cultivars not prone to shelling (coulure) can be spur pruned towards the end of the month (e g Cinsaut). In areas where frost occurs regularly spur pruning should be done late to retard the budding of fruit buds. Luxuriant Hanepoot which is inclined to shelling, should be pruned very late when the buds on the tips of canes have already started budding. In areas where delayed foliage occurs cultivars sensitive to delayed foliage such as Chardonnay, Colombar and Cape Riesling should be clean and spur pruned in one operation as late as possible. Such cultivars should not be pre-pruned. See: Wynboer Tegnies No 28; September 1988, Die voorkoms van vertraagde bot in 1987 and Wynboer Tegnies No 29; November 1988, Strategie vir bekamping van vertraagde bot by wingerde. The number of spurs per vine remains a problem. A standard recipe can be followed for full bearing vines. That is to allow an increase of one bearer on vigorous growing vines and a decrease of one bearer on poor growth (or 2-bud spurs can be pruned to a 1-bud length). For bud loading per hectare and possible number of bearers per vine under various conditions see: Wynboer Tegnies No 11 April 1985 Wintersnoei van wingerd and Wynboer Tegnies No 27 May 1988 Snoeiprobleme by geilgroeiende wingerde - die gevolg van swak beplanning. When vines are pruned according to the Guyot system (a rejuvenating method), whereby a short bearer or spur must be left for every long cane to prevent the yearly lengthening of the bearer. When long canes are used in addition to spurs on luxuriant vines, the position of the long cane on the cordon (permanent arm) must be changed every year to keep the spurs equally strong. When trellised vines are short or spur pruned, the cordon arm should not be twisted around the wire to prevent the arms being pinched as they become thicker. Only the end of the cordon arm should be tied to the wire. (In windy areas the arm may be twisted lightly round the wire once or twice and tied at the end.) When the cordon arm with spurs becomes too long, an experienced pruner should be sent ahead to cut a suitable water sprout back to a one bud length for a new bearer to develop and eventually replace the old arm. Because of the importance of pruning, supervision is extremely important and the producer himself should oversee the excercise. To simplify control, the name of the employee should be written on a card and attached to the head or end pole of each row he prunes. At a later stage the employee can sucker, top and tie the shoots etc of the rows which he pruned. 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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