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A Technical Guide for Wine Producers
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RECENT ARTICLES | WYNBOER HOME
1 PLANNING • Short term - Plan the scheduling of irrigation for different blocks. Take care not to over-irrigate since the irrigation needs are still low at this stage. - Plan the application of nitrogen in bearing vineyards and take care not to apply excessively in (over) vigorous vineyards. - Make the necessary arrangements and book contractor for soil that must be prepared at the end of the month and in November / December. If soil is too dry, sensible irrigation will help create the correct soil moisture conditions. • Long term - Plan the necessary actions with regard to soil preparation, fumigation, drainage, irrigation and trellis systems according to your long term plan. • Financial Contact VinPro (SA) agricultural economists for information about: On a monthly basis, compare the actual expenditure with both the budgeted expenditure and the actual expenditure of the corresponding month of the previous year. Make adjustments if necessary 2 VINEYARD PROGRAMME • Disease and pest control - This month the emphasis is on controlling downy mildew and oidium. - Downy mildew infections are encouraged by the occurrence of intermittent rainshowers and require additional spraying. Seeing that the flower cluster in particular is very susceptible to downy mildew, a systemic fungicide should preferably be used during flowering. - Initially oidium may be controlled with a sulphur dusting or application of fungicides when shoot lengths measure 5 – 10 cm, followed by applications of fungicide every 14 to 21 days until grapes begin to ripen. If it should rain a few days after the sulphur dusting, the treatment should be repeated. - If Botrytis cinerea occurs regularly in certain blocks, control should be preventative using contact fungicides. Economically chemical control should be justifiable, due to the high costs involved. Efficient chemical control benefits from good foliage management (suckering, tucking in of shoots, tipping and topping, breaking out of leaves) as well as judicious N-fertilisation and irrigation. - To a certain extent erinose is also controlled by sulphur dusting. Dust when shoot length is 5 – 10 cm, during flowering and again after 3 to 4 weeks. - Caterpillars and snails should only be controlled with suitable fungicides when necessary. - Snout beetles are only controlled if economically justified by the damage. Control may be obtained by hand spraying and / or by using barriers tied around the trunks of trellised vines. - In terms of IPW guidelines vine bud mite should preferably only be controlled if high numbers are confirmed by visual analysis of winter shoots, seeing that visual symptoms are not always reliable. The first application should be sprayed 28 days after budding, followed by two applications with 14 day intervals. - The control of mealybug is directly dependent on ant control, since ants protect the mealybug against its natural enemies. Chemical control should only be applied if biological control, after ant control, is not successful. Only spray affected and adjacent vines and ensure that all parts, the trunk in particular, is properly doused. In summer emergency applications only are advised, since this will also kill natural enemies (predators). - IPW records should be kept up to date. • Green shoot development - In vigorous vineyards it is best to develop the entire framework of the vine in one year with a green shoot. - Due to cultivar and area differences, contact your viticultural consultant and the VinPro (SA) Consultation Services publication "Guide for establishing a vineyard" as well as the video entitled "Groenlootontwikkeling". • Canopy management (also see the video entitled "Somerloofbeheer") - Suckering is important to improve fertility and quality and facilitate disease control, especially in vigorous vineyards. Sucker early (5 – 10 cm shoot length) on trunks, in forks and between bearers. Follow up by removing infertile and weak bearers as well as regrowth so that only two shoots per bearer remain. - Tip / top shoots (uitskieterlote??) at approximately 60 cm length, followed by tipping actions 40 – 50 cm higher up. To improve set in problematic cultivars, all shoots must be tipped at the beginning of flowering. - Tucking in of shoots between trellis wires should be done in good time to prevent bunching of shoots at a late stage. Picking up wires facilitate the process. Where vineyards have not been suckered, the shoots should not be tucked in at all. - Crop control is important in all vines, but especially in young vines and vines being developed according to the green shoot method (see video entitled "Oesbeheer"). - Delayed budding or eyes that remained dormant after normal budding, as well as two-year-old eyes that did not bud the previous season, may be treated individually with a budding stimulant to interrupt dormancy. Take care with treatment and follow IPW prescriptions. A more detailed version may be ordered from Mrs Gerda Kriel at 021-8073027. Compiled by: VinPro (SA) Consultation Services
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