|
|
Plant protection in organic viticulture in New Zealand by Andreas Welte 3 Page Paper for IFOAM 2000 in Basel Introduction In 1860-1870 first grape vines were planted in different areas of New Zealand. In the 1970's a fast growing wine industry established,and since the 1980's New Zealand has seen the first biodynamic/organic wine growers/winemakers. Organic viticulture is happening in both ,the North Island and in the South Island. There were a total of 363 licenced winemakers in New Zealand,of whom 203 are in North Island and 160 are in South Island in January 2000 (1). 10 of these licences are certified organic.That calculates to 2.75% of New Zealand vineyards are certified organic. The organic vineyards spread from 35 to 45 degrees latitude and climatic-and soil conditions vary widely from hot/humid to cold/dry. These regional conditions require locally adapted systems of organic and bio-dynamic management. Plant protection is very important for an optimum quality control. Various aspects of a preventative and curative plant protection are being used in New Zealand.
Materials and methods There are four fully certified Bio-Gro vineyards (2 each in the Nth and Sth Island),two are Transitional Bio-gro (1 Nth,1Sth Isl) and four (1 Nth,3 Sth Isl) have applied for registration with Bio-Gro. Most of the organic grapegrowers are winemakers as well and honour the guideline that wine is made in the vineyard (2). For organic plant protection and pest and disease control, management techniques like shoot thinning, bunch removal,leaf-plucking, hand harvesting, spacing of vines and cordon length (3) are engaged with a sense of regulating the vegetative (leaves) and generative (fruit) growth and to create a healthy environment for the vines to reduce the causes of fungal infection and minimize disease pressure. For example,an open, airy canopy reduces the likelihood of humidity in the bunches and also increases the effectiveness of the sprays which are applied in a preventative or curative way (3). Two growers run trial plots with varieties GM 312/53+GM 322/58 of Geisenheim (4+5) which are bred for resistancy to fungal disease. The use of limited amounts of copper,sulphur and limesulphur is common practice. The growers are aware of the risks involved and some are using sodium silicate to strengthen the berry skin and give the plants natural disease resistance(3+6). Compost teas and liquid seaweed as foliar sprays together with rockdust,ground seaweed and compost as on the ground applications (3) are used for the same purpose. Some growers (2+4+5) use the made up formulations of plant health enhancing preparations Myco-Sin for Downy mildew and Oikomb for Powdery mildew, to induce resistance to the plants and to strengthen the berry skin. Others (6+7) use soft soap+bentonite to protect of powdery mildew. They also use the biodynamic preparations to enhance life and the environmental sytems,and to make the vines more responsive to pest and didease infestation. One biodynamic grower (6) applies Talcum powder for Botrytis prevention,another one (7) is using the liqid valerian preparation 507 to give his grapes a better frost resistance.
Insect Regulation The main insect problems are Spider mite,Leafroller (in Sth Isl) and Mealy Bug (Pseudococcus longispinus in the Nth Isl). For Spider mite control dormancy application of vegetable oil or fishoil,and the use and support of the predatory mites Typhlodromus pyri and Phytoseiulus persimilis are used. One grower (6) uses bentonite,yeast and kieselgur which are also used in the winemaking process as a vine paste to protect against spider mite and mealy bug (6). Herbal leys and a mix of flowering plants (umbelliferae,phacelia,chickory ,buckwheat,wildflowers) are grown in alternate or every 3-5th row to provide a habitat for the beneficials,and allow the populations of all species to live in harmony(6). For leafroller regulation the establishment of braconid wasps is encouraged. With heavy infestation rates which are monitored with Pheromone traps, Bacillus thuringiensis or pyrethrum/garlic are applied. Mealy bug is controlled with pyrethrum/garlic. On trial a mix of Neem formulation,sodium silicate and alcohol is used. A biodynamic grower uses potentised ashes of the Mealy bug.
Results and discussion Considering the effects of the very different climates of an island nation in the South Pacific,the annual changes of weather patterns and of global warming with an increase in temperature and humidity,it is obvious that the infestation pressure of fungal diseases is growing. Organic and biodynamic growers with experience and a fine tuned management system in place have enough tools to regulate fungal diseases and insect pests,and keep them below a treshold level of economic damage. Vineyards which are just starting with the conversion process are more likely to rely on sulphur and copper as a safeguard,as soon as high infestation pressure of pests and diseases is evident. The use of sodium silicate,seaweed,herbal teas,soap,bentonite and other natural ,biological plant health enhancing and plant protection agents shows good results in the conversion and in the more established organic and biodynamic vineyards.The management of the new approach to plant protection and the use of permitted inputs reflects in growing individualisation and finetuning of the plant protection systems in the vineyards themselves. They become more resilient and responsive to harmful fungi and insects while the vineyard as a whole develops to a more balanced organism. The viticulturist is the planner,initiator and executioner of these new management systems. The learning about new skills and techniques,as much as the open exchange and transfer of the information amongst viticulturists and winemakers in New Zealand does support the future of certified organic viticulture. There is progressive development over time in the North and the South Islands of New Zealand and once the pioneering spirits and capital investments settle down there will be greater movement towards an organic approach in these areas(6). Demand increases for organic produce overseas and in the New Zealand market. Organic wine is slow to follow suit,although those who are producing high quality wine, organically , are successful because of the overall quality.General retail is slow in picking up although supermarkets are the most active.Health Food shops and their customers are not wanting to spend more than NZ$ 15.00 per bottle with rather bland taste perceptions. This could well improve (6). To produce the best wine you have to have the best grapes.To really attain the best grapes then they must be grown organically or better still biodynamically,and this has to embrace the three—folding order—environmental, financial and social.
Acknowledgements The author's grateful Thank You goes to the organic and biodynamic wine growers/wine makers of New Zealand who have supported this report with a lot of background data and information so generously and dedicated time and effort to this process. Andreas Welte
References
BIO-GRO: "Bio-Gro" is the official trademark given to produce grown to the strict standards set by the New Zealand Biological Producers Council. These standards are evaluated and audited by IFOAM. Bio-Gro is cleared for EU entry. BIO-GRO New Zealand BIO-DYNAMICS: Bio-Dynamics is based on Rudolf Steiner's spiritual science,which presents a new understanding of agriculture with the capacity to meet the agricultural demands of the present times. The trademark of Bio-Dynamics is Demeter. Bio-Dynamics is not yet cleared for EU entry. Bio Dynamic Association A third certifying organisation called CERTENZ has been recently established by the official Agri Quality administration and tries to enter the organic certification market. Certenz and its organic standards have not yet been approved by a 3rd party in the potential export markets. Initial stages of COWNZ (Certified Organic Winegrowers of NZ) or is it EWNZ (Ecological Winegrowers of NZ ) occured in January 2000,and are still in infancy.
|
|
Also check out Dr Uwe Hofmann's paper on Crop Cover Management in the Vineyard.
Back to Sirocco Wines Organic Papers
Sirocco Wines Main Page