|
A Technical Guide for Wine Producers
|
|
RECENT ARTICLES | WYNBOER HOME
WYNBOER WORK PROGRAMME FOR NOVEMBER 1999
1.1. Short-term
Financial
1.2. Long-term
Make the necessary arrangements regarding soil preparation, fumigation, drainage, system of irrigation and trellising according to your long-term plan. See Wynboer Tegnies, No. 10, January 1985 - Netwerk vir die vestiging van wingerd.
2. VINEYARD PROGRAMME
Soil cultivation: If summer weeds start germinating and breaking through, especially in irrigated vineyards, chemical control should be obtained by using a mixture of pre and post emergent weedicides at the end of the month to ensure control of the weeds for the whole season.
Fertilising: Luxuriant vines and vineyards where botrytis occurs annually should not be top dressed with nitrogen. In young vines, where green shoot development takes place regularly (2-3 weekly), light applications of nitrogen may be made until development is complete.
Irrigation must be practised carefully, taking into consideration soil moisture content and climatic conditions, to prevent excessive shoot growth. Irrigation must be monitored regularly to determine whether over-irrigation may be occurring. Aids to be used are: soil sampling by means of a soil drill or profile hole, pan evaporation figures and tensiometers or neutron probes. During the first year the latter must be used in conjunction with one of the other methods.
Oïdium: Conditions for the development of oïdium are usually especially favourable towards the second half of the month. Preventative treatment must be continued througout November (See hints for October).
Downy mildew: During the second half of the month conditions in certain areas may become less favourable for the development of downy mildew due to drier weather and wind. However, if conditions are favourable for downy mildew, producers must adhere strictly to the programme, as the cycle of the fungus is much shorter and spreading is more rapid.
Botrytis: Effective chemical control can be obtained only when good foliage management and other viticultural practices are applied (See October hints).
Mealy Bug: Can be controlled by summer applications. Mark out the infested vines beforehand and do spot spraying with handguns. Take note of the withholding period of the chemical.
Snout beetles: Only combat when damage might become of economic importance. The entire vine as well as the soil around the trunk should be sprayed thoroughly. (See October hints).
The treatment of thrips must be carried out during blooming and if necessary repeated after three weeks.
Foliage management: (See video entitled Somerloofbeheer) Various foliage management actions ensure good aeration, rapid drying and better penetration by sunlight of individual vines during the growing season, as well as the effective coverage of spraying and dusting.
Suckering: This is the most important practice to obtain optimum foliage density. All shoots not on bearers must be removed during suckering. It is easier and quicker to do two suckerings by hand, one early and the other later in the season, rather that a single suckering with pruning shears later in the season. Under conditions of excessive growth the removal of side shoots in the bunch zone is an effective emergency way of ensuring good aeration. During the second suckering all regrowth as well as weak shoots with bunches should be removed.
Shoots: As soon as the shoots are long enough they must be pushed between the trellising wires and spread evenly. The bundling of shoots causes foliage density.
Tipping and topping: Tipping and/or topping must be carried out judiciously, especially with cultivars susceptible to botrytis. In most cases it is better to tip than to top, because topping done too early induces the development of side shoots in the bunch zone, causing foliage density. It is recommended that the first tipping be done when shoots have grown to a length of 70 to 80 cm.
Breaking out of leaves: One third of the leaves in the bunch zone, as well as excessive leaves inside the trellis system, must be removed evenly throughout the foliage to obtain good aeration and ensure better penetration of light and sprays to the bunch zone. Do not remove too many leaves on the northern and western side of rows as this helps to prevent sunburn. The leaves of vineyards which are regularly infected with botrytis should be removed at berry set (immediately after flowering), as the fungus may establish itself early in the bunch where it cannot be reached by fungicides. If futher densening of the foliage occurs, leaves can be removed from pea size or veraison stage of development in the same manner (1/3) up to half of the total foliage.
Green shoot development: Study the video entitled Groenlootontwikkeling and consult your Viticultural Advisor for advice.
Second foliage vines: Remove only the lower shoots (not the leaves) on the main shoot (trunk shoot) leaving only those shoots required to form the cordon arms. Bend these cordon shoots down and tie regularly but lightly to the wire. Apply nitrogen top dressing to vines that grow too slowly.
Third foliage vines: Sucker the arms so that only one shoot per bearer position remains if this was not done in October. Where suckering has already been done, remove unwanted re-growth. Apply crop control by leaving one bunch per shoot. All bunches on shoots with poor growth must be removed. Tip the longest shoots to obtain uniform shoot growth.
Fourth foliage vines: Sucker all extra shoots leaving only one shoot with all its bunches per bearer. Where vines grow luxuriantly two shoots with bunches can be left per bearer. Sucker re-growth and remove bunches from shoots with poor growth.
Fifth foliage vines: Sucker re-growth and break out one third of the leaves in the bunch zone. Thin out bunches which hang in clusters, so that only 30 bunches per vine remain (See video entitled Oesbeheer).
Crop control is especially important during the first few years of a vine's growth. Too heavy crops at the beginning lead to poor quality grapes and may be detrimental to the future performance of the vineyard. (Read: Riglyne vir oeslading op jong stokke - Wynboer Tegnies, No. 35, November 1989, p. 2).
Delayed foliage: After normal budding, buds which remained dormant, as well as two-year-old buds which did not bud the previous season, can be treated individually with Cyanamide. It is very important to note that the injudicious use of this chemical may be detrimental to human health.
Soil preparation: If the soil is too dry for deep preparation, careful irrigation may help to obtain the correct moisture content.
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:
|
|
Wynboer is incorporated in WineLand, magazine of the SA wine producers.
Visit our sister sites:
|
1. PLANNING AND PREPARATION
| UP |
COPYRIGHT (C) 2000 WineLand |