Part 3 - European research institutes - report on visits
During three weeks in August 1996, I visited seven horticultural and/or viticultural research institutes in three European countries. The primary purpose of these visits was to get an insight into the current state of the development of sustainable systems in Europe. The development of sustainable production systems in horticulture and viticulture in Europe is of great interest for similar developments in New Zealand. The following comments taken from my travel report may be of interest to HortNET subscribers :
1. Forschungsanstalt Geisenheim, Geisenheim, Germany
Hosts: Dr Steinberg, Institute for Viticulture and Dr Bäcker, Institute for Horticultural and Viticultural Engineering
The Forschungsanstalt Geisenheim is Germany’s most important teaching and research facility for viticulture and oenology. Geisenheim is located near Rüdesheim in the Rhein Valley, approximately one hour’s drive from Frankfurt. The area around Rüdesheim is called the Rheingau and has approximately 4,000 ha of grapegrowing area. The area produces some of Germany’s most prestigious Riesling wines. A large proportion of the producing area is on slopes.
Institute for Viticulture
Following a general introduction of the Forschungsanstalt Geisenheim, we visited a number of research sites in the vineyards surrounding Geisenheim. A large area of vineyards is owned by the various institutes of the Forschungsanstalt. We concentrated on visiting trials addressing soil management in vineyards. Some observations relevant for New Zealand viticulture were:
• The Poa and Festuca grass species have lower water use than other grass species or herbaceous plants and are therefore preferred for cover crops in vineyards (Note: there is no irrigation in German vineyards).
• Agrostis species are preferred on steep slopes and on skeleton soils. These stoloniferous grasses are better suited to control erosion in steep slopes.
• In spring, mineralised nitrogen concentration in the soil might be as high as 254 kg NO3--N per ha under clover cover crops. In contrast, nitrogen concentration under annual grasses are at 90 kg NO3--N per ha. The current recommendation for nitrate concentration in the soil in spring (the so-called Nmin) is 75 kg NO3--N per ha.
• Dr Steinberg recommended a leaf area index of 2 to 2.5 for Riesling and Pinot noir. Under Geisenheim conditions, this equates to a leaf area height of 1.3 m starting 0.7 m above the ground and equates to 12-15 main leaves. This is sufficient to produce 80-90 hectolitres of wine at the appropriate quality.
Institute for Horticultural and Viticultural Engineering, Geisenheim
Dr Bäcker presented some of the new sprayer technology now available in Germany.
• Injector nozzle. This low cost device allows the modification of standard nozzles to modify the droplet size. In the injector nozzle, air is sucked into the liquid stream and mixed in a mixing chamber thereby leading to an increase in the droplet size. These larger droplets are less prone to spray drift. The larger air-filled droplets disintegarte on impact so that a spray coverage equivalent to standard nozzles is achieved. Good spray coverage is particularly important for fungicide application.
• The use of the collector technique can save about 40% up to 50% of spray chemicals on a yearly average. The additional cost to fit collectors is around 5,000 German marks (~ $5,000).
• Dr Bäcker presented a sprayer fitted with gap sensors. These infra-red gap sensors identify foliage gaps in the canopy. When an individual gap sensor identifies a canopy gap, a valve is switched which closes the corresponding nozzle when the sprayer reaches the position of the gap. Using this technology, up to 30% of spray can be saved. The additional cost for fitting gap sensors to a standard sprayer are around 10,000 German marks.
2. South Tyrol, Italy
South Tyrol is the northernmost area of Italy directly bordering Austria. It is a mountainous region on the southern slopes of the alps with intensive horticulture located on the valley floors and the lower part of the slopes. South Tyrol is a very important horticultural region producing about 33% of the total apple production for Italy, equivalent to 7-10% of the total apple production in Europe. There are about 18,000 ha of horticulture, almost exclusively apple production, plus a further 5,000 ha of viticulture. There are about 6,000 horticultural farms, giving an average horticultural production area of 3 ha per farm. The major apple variety in South Tyrol is Golden Delicious, accounting for about 45% of the total area, followed by Red Delicious and Morgenduft, each accounting for a further 13%.
Visit South Tyrolean orchards and vineyards and regional offices of the Südtiroler Beratungsring für Obst- und Weinbau (South Tyrolean consultancy firm for horticulture and viticulture)
Host: Mr Markus Bradlwarter, Terlan
Mr Bradlwarter is a consultant working for the Beratungsring. The Beratungsring has about 35 employees, 30 of whom work as consultants with the remainder working in administration. The Beratungsring works in seven areas in South Tyrol. In each area there is a local area office. The Beratungsring is funded to 50% from the regional government of South Tyrol and to 50% from the subscription of voluntary members. There is a total of about 8,000 viticultural or horticultural farms in South Tyrol. Of these, about 6,500 are voluntary members of the Beratungsring. Growers pay about 100,000 lira (about $100 NZ) for the first ha of horticultural area, about 95,000 lira for the second and third producing ha, and about 90,000 lira for the fourth and fifth producing ha. The average orchard size is about 3 ha.
The Beratungsring is a registered association with a Chairman and a Board of Directors. The Chairman and the members of the Board of Directors have to be growers themselves. Each of the seven areas has its own regional committee comprising about 20-30 members of which 2-3 are delegated to the Board of Directors.
Mr Bradlwarter commented that the high percentage of Golden Delicious in South Tyrol was a reflection of the still-high demand for this variety. The various marketing organisations require that 40-50% of the produce mix is made up of Golden Delicious.
There are about 40 horticultural co-operatives in South Tyrol and only a few independent marketers. In addition to the horticultural co-operatives, there are about 20 viticultural co-operatives in South Tyrol. Each co-operative is independent and markets its fruit independently. However, in recent years there have been attempts to combine some of the co-operatives and co-ordinate the marketing of South Tyrolean fruit. About 40% of South Tyrolean pome fruit is marketed within Italy. About 40% are exported mainly to countries of the European Union, about 18% are processed, and the remaining are put into intervention for export. Germany is the most important single country taking between two thirds and three quarters of the total exported crop. In most recent years the Scandinavian countries have increased their importance for taking export crop, mainly the apple cultivar, Idared.
For new plantings, the main cultivars used today are Golden Delicious, Gala, Fuji, and Braeburn. Mr Bradlwarter was very positive about the potential and future of the cultivar Braeburn in South Tyrol. He also commented that the cultivar Golden Delicious was planted mainly on the slopes up to an altitude of 1000 m. The performance of the cultivar was not so good at lower altitudes and on the valley floors.
Land und Forstwirtschaftliches Versuchzentrum Laimburg, South Tyrol
Hosts: Dr Mantinger and Dr Raifer
The Laimburg is the main research facility for agriculture, horticulture, and viticulture in South Tyrol. Dr Mantinger is the director. The Laimburg has 15 farms with a total of 530 ha. Of the total, 300 ha are forest, about 120 ha are horticulture, about 30 ha viticulture, and the remainder is pasture and fields. The Laimburg has a total of 60 staff (scientific and administrative) plus a further 70 staff for the farms plus a further 40-80 casual staff. The Laimburg has seven sections: Section - Horticulture, Section - Viticulture, Section - Oenology, Section - Vegetable Production and Floriculture, Section - Field Crops, Pasture and Animal Production, Section - Forestry, and Section - Agro-chemical Laboratry.
Dr Mantinger gave an overview of the main research projects currently underway: apple planting systems (up to 13,000 trees per ha) concentrating on light interception and light distribution; evaluation of cultivars and rootstocks (Note: currently 85-90% of apple in South Tyrol is on the rootstock M9); and soil management and fertilisation. Dr Mantinger also mentioned that there was increasing pressure from growers towards the research institute to conduct their own breeding work. So far there is no apple breeding done at the institute.
• Results from a long term trial on soil management in apple orchards showed the use of cover crops under the tree row, ie no herbicide strip at all, reduced tree growth in the first 5 years but differences were only minor in following years compared to the standard herbicide treatment.
Dr Raifer, Section Viticulture
Dr Raifer is the head of the Section - Viticulture. Excluding the staff working in plant pathology there are currently six staff working in the section Viticulture.
There are about 5,000 viticultural enterprises in South Tyrol. The total grape growing area in South Tyrol is about 5,000 ha, and has declined in most recent years. There are about 15-16 premium varieties grown in South Tyrol. The major varieties are: Vernatsch (40-45%), Lagrein (8%), Blauburgunder (6-7%), Weissburgunder (10%), Ruländer (5%), and Chardonnay (5%). Other varieties grown on about 50-100 ha include Gewürztraminer, Sauvignon Blanc, Riesling, Müller-Thurgau, Sylvaner, and Gold Muskateller. The main variety Vernatsch is marketed as a branded wine called "Kalterer See" or "Sankt Magdalena". The variety Lagrein is often used to blend with Vernatsch. About 80% of the grapevines grown in South Tyrol are grown on a pergola system. However, there is a tendency for more use of espalier systems similar to the ones common in New Zealand. Distance between rows is rarely below 2 m. About 70% of the grapes produced are sold to co-operatives, with 25-27% sold to private trading businesses, and only 3-5% remain on site within the farm unit and are used to make wine in small wineries.
Dr Raifer and her staff are working in four main areas. (I) evaluation of cultivars, clones, and rootstocks; (II) agronomic research including canopy management, fertilisation of grapes, and irrigation; (III) the so-called cultivar-site project; and (IV) mechanisation in vineyards (Note: there are currently no experiments on mechanisation in vineyards. There is no mechanical harvesting in South Tyrol).
• In the so-called cultivar-site project, soils are mapped on an area of 2,000 ha. Eight sites located at varying altitude have been selected and the cultivars Riesling, Sauvignon Blanc, Weissburgunder, Gewürztraminer, Blauburgunder, and Cabernet Sauvignon have been planted. It is hoped that the results from this trial can give further insight into the suitability of certain cultivars to be planted at certain sites. Generally, grapes are grown in South Tyrol from altitudes of about 200 m up to 700 m.
• Dr Raifer commented that there were little problems with fungicide resistance in South Tyrol.
• In contrast to the apple industry, there is little interest in the development of integrated production for viticulture in South Tyrol. The main obstacle to the introduction of integrated productions appeared to be the marketing organisations who are unwilling to have two different product lines, ie IP wine and standard wine. Currently about 30% of the South Tyrolean vineyards use Bacillus thuringiensis products while the rest uses standard insecticides, ie organophosphates.
• Blauburgunder is grown mainly at medium altitude as it is maturing too early at low altitude. In contrast, Cabernet Sauvignon and Merlot are grown at the low altitude. Similarly, Chardonnay is preferred at lower altitudes, while Weissburgunder is preferred at the higher altitudes.
• At low altitudes and also in warmer than average years, white wine varieties are harvested based on their acidity. When the acidity falls to 7.0 grams per litre, these white wine varieties are harvested. By that stage they have normally reached 85-87 °Öchsle (~20.5 °Brix).
• The so-called untypical aging note was not such a big problem in South Tyrol as it is currently in Germany.
3. Staatliches Weinbauinstitut Freiburg, Freiburg, Germany
Hosts: Dr Schruft and Dr Becker
The Staatliche Weinbauinstitut was founded in 1920. It is the major research institute for viticulture of the Federal State of Baden-Württemberg. The main objectives are to conduct applied research in all areas of viticulture and oenology, to provide guidelines for the extension services, and to contribute towards the education of vineyard owners and winemakers. The Institute has around 75 staff and controls an area of around 56 ha of vineyards, located at a number of research vineyards near Freiburg. The Institute is structured into four divisions being: (1) the administration section; (2) Section - Biology; (3) Section - Chemistry; and (4) Section - Viticulture. Dr Schruft is the director of the Institute and Dr Becker the head of Section - Biology.
Following a guided tour of the Institute by Dr Schruft, I met with Dr Riedel, Scientist in charge of the Subsection Soil Science and Grapevine Nutrition. Dr Riedel is evaluating low growing plant species such as Poa pratensis, cress, and lamb’s lettuce for their suitability for cover crops in vineyards.
• Dr Riedel commented that there has been increased problems with nitrogen deficiency in vineyards with permanent cover crops appearing in the last years, particularly where cover crops are used on steeper slopes (Note: these steep slopes are generally low fertility soils). There are suggestions that the so-called untypical aging note found in wines are related to the nitrogen nutrition of grapevines.
Visit to the Research Vineyard Blankenhornsberg with Dr Becker
The Blankenhornsberg is a 35 ha research vineyard with an associated winery, located at the designated area Kaiserstuhl. The Kaiserstuhl is Germany’s sunniest and warmest grapegrowing location.
Dr Becker also is the head of the Sub-section "Grapevine Breeding" at the research institute. He has been crossing and selecting so-called interspecific hybrids or French hybrids for many years. In the last two years, a major breakthrough in the legal classification of these interspecific hybrids has been achieved. Some of these crosses are no longer referred to as "hybrids" or "interspecific crosses", but the term "disease resistant variety" is used instead. In 1995, the German Bundessortenamt, which is the Plant Variety Rights Office, classified the cultivar Merzling (Seyve-Villard 5-276 x (Riesling x Ruländer)) as belonging to the botanical species Vitis vinifera ssp. sativa, ie as an European grapevine. In the meantime, this cultivar has also been registered in the cultivar list. In the European Union, the so-called French hybrids can only be planted for research purposes. The wine produced from such hybrids has to be labelled as wine "originating from research vineyards" and cannot be labelled as "quality wine of designated area" or entered for official judging of quality wines. However, the classification of the cultivar Merzling as belonging to the botanical species Vitis vinifera ssp. sativa opens the way for wider use of these disease resistant varieties in European viticulture. Indeed, the disease resistant variety "Regent", bred by the Federal Institute for Grapevine Breeding at Geilweilerhof has passed all legal hurdles, and is now classified as Vitis vinifera ssp. sativa. Further, the approval has been given for wider planting of "Regent" in the Federal State of Rheinland-Pfalz. Another variety called "Rondo", bred by the Research Institute at Geisenheim, is expected to pass all legal hurdles and be registered for planting within the next year. So for the first time, these disease resistant varieties can now be planted on a large scale and the resulting wine can be classified as quality wine.
Dr Becker has conducted a clonal evaluation of 21 clones of Pinot noir originating from Germany, Switzerland, and France. The German and Swiss clones could be clearly differentiated from the French clones. The clones from Germany and Switzerland have been selected for their success to set fruit as the weather over flowering in these countries is often detrimental for fruit set. However, this leads to rather high fruit set if the weather is good during flowering and subsequently to very high yields. These yields are often too high for Pinot noir thereby reducing wine quality. In contrast, the French clones were selected mainly for their quality in the absence of viral infection as the weather during flowering is most often good and there is a high fruit set. While the French clones have a high fruit quality, producing good wine quality, in years with bad weather conditions during flowering, their fruit set is very low under the conditions in Germany.
Dr Kassemeyer, head of the Sub-section Botany
As Dr Kassemeyer was on leave during my visit, I contacted him by phone several weeks later to discuss his research into the identification of grapevine viruses.
• According to Dr Kassemeyer the grapevine leafroll virus type III (GLRaV III) is easy to identify using the current Elisa technique. However, type I (GLRaV I) is strongly dependent on season and is not always giving a clear result.
• Green propagation has been used to identify several grapevine virus but the method needs to be improved for a good identification of grapevine leafroll virus.
• Grapevine leafroll virus type III, Grapevine virus A (GVA) and Grapevine Virus B (GVB) are transmitted by mealy bugs. Dr Kassemeyer excluded nematodes as possible vectors for these virus. However, Dr Kassemeyer noted that the vector for GLRaV I has not been clearly identified.
Badischer Winzerkeller, Breisach, Germany
This winery, founded in 1952, is a producer co-operative. Today it is the largest winery in Europe. In the area Baden there are 120 vineyard co-operatives of which 90 deliver to this winery, 45 co-operatives all of their grapes. In total, 8,000 vineyard owners are associated with this co-operative winery. During a guided tour of the winery, the dimension of the winery became apparent. The bottling line is able to have an output of 200,000 bottles per day. The wine storage area covers an area of 2 ha holding up to 15 million bottles. In the tasting and sales room, there are over 500 wines on offer.
4. Swiss Federal Research Station for Fruit Growing, Viticulture and Horticulture, Wädenswil, Switzerland
Hosts: Dr Peter Perret and Mr Martin Wiederkehr
There is a total of about 14,000 ha of vineyards in Switzerland. In the eastern part of Switzerland, about 80% of the vineyard area (~ 4,000 ha) are managed according to IP guidelines (the so-called Wädenswil model). In contrast, IP is hardly used in the western part of Switzerland. The use of biological or organic production systems is still increasing. The Wädenswil research station has been essential for the introduction of integrated production systems in viticulture in Switzerland. Every year the research station publishes a booklet on pest and disease control for the integrated and biological viticulture. Besides guidelines for pest and disease control, this booklet also covers areas such as soil management and cover crops, mineral nutrition and mineral deficiencies, application techniques, and safety aspects when dealing with pesticides. It also contains a comprehensive list of pesticides registered for use in the integrated or biological production system.
The choice of the right cultivar and the use of disease resistant varieties is seen as an essential part in the development of integrated fruit production in Switzerland, as already mentioned by Dr Basler during the Cool Climate Symposim. Extensive tests have shown that the consumer acceptance of wines made from these disease resistant varieties is at least on par with the wines made from traditional varieties.
• During a guided tour of the research vineyard, Dr Perret presented a new tractor-mounted machine for the removal of leaves in the fruit zone. This new machine uses compressed air rather than rotating blades for the removal of leaves. This method doesn’t necessarily remove the entire leaf, but rather the air blows away the leaf blade or part thereof, leaving behind the petiole and some of the major leaf veins (it gives the appearance as if the leaves have been hit with a shotgun). Small leaf particles may thereby act as projectiles and damage the grape berries when the removal is done at a later stage and the berry skin has begun to soften. However, a good leaf removal is achieved if done at the correct time.
• Dr Perret is currently concentrating on researching the accumulation and leaching of heavy metals from vineyard soils. Municipal compost has been used in the early 1970s as organic fertiliser for vineyards in Switzerland. These composts have been found to have a high heavy metal concentration. Uptake of these heavy metals within the plant, its re-distribution in the plant, and the leaching of heavy metals from the soil is currently being investigated. Dr Perret has built and installed a large number of suction cups within the vineyard and has automated the process of taking samples. He has previously used this array of sampling cups for evaluating movement of nitrogen out of vineyard soils. This technique could be useful for future research in New Zealand looking at the movement of nitrates and minerals in the soil.
Mr Wiederkehr is the winemaker at the research centre. He gave a guided tour through the research winery.
• Wines made for research purposes are mainly done in 20-50 litre lots.
• All wine bottles, regardless whether destined for the research cellar for further evaluation or for immediate sale to customers, are closed using screw caps (Note: screw cap tops are more widely used now also by commercial wineries. They are also used in the research wineries of Freiburg, Geisenheim, and Geilweilerhof. Given the problems sometimes associated with natural cork, HortResearch should also consider the use of screw caps for their own microvinification unit). Mr Wiederkehr mentioned that the use of screw caps was no more expensive than the use of natural cork, without the disadvantages associated with cork like oxidised or corky taste of wines.
5. Bundesanstalt für Züchtungsforschung an Kulturpflanzen, Institut für Rebenzüchtung Geilweilerhof, Germany
Hosts: Dr Düring, Dr Eibach
The research institute for grapevine breeding at Geilweilerhof has a long tradition. It was founded in 1926. In recent years there have been major restructurings following the reunification of Germany. Following reunification, three previously west German research institutes whose core business was breeding of cultured plants, have been joined with nine research institutes from the former Eastern part of Germany. A new, very large institute, called Bundesanstalt für Züchtungsforschung an Kulturpflanzen (Federal Research Institute for Breeding of Cultured Plants) has been established. The Head Office is in Quedlinburg, formerly East Germany. With the clear dominance of the East German Institute there is a big push to move all the research on breeding towards the East. In the course of restructuring, two of the three former West German Institutes have already been closed, and the research at the Geilweilerhof has been scaled down. Subsequently, there is a lot of unused laboratory space currently at Geilweilerhof. However, it is unlikely that the grapevine breeding programme is going to be shifted to the East as the winter temperatures in the Eastern part of Germany are more severe, thus risking frost damage to the breeding programme. There appears to be lots of political bickering going on between the former East and former West German scientists, not helping staff morale.
Dr Düring is a specialist researcher in the area of water relations of grapevines. He is principally responsible for evaluating new breeding material for their drought tolerance.
• Recent research has focused on trying to understand the movement of opening and closing of stomata as affected by the environment and diurnal rhythm, studying in great detail the opening and closing of a patch of stomata on a grapevine leaf. These observations confirm earlier results by Downton, Grant, and Loveys (New Phytol. 110:503-509) about the non-uniform stomata reaction. From Düring’s work it appears that individual stomata can open or close completely independent of neighbouring stomata. It also appeared that individual stomata follow their own diurnal rhythm.
Dr Düring commented that he had been asked by the institute’s new director to change his current research away from the more traditional approach towards biochemistry, trying to identify key enzymes or proteins involved in drought and cold tolerance. At the time of my visit, Dr Düring was still considering which direction his work would take.
Dr Eibach, plant breeder
Dr Eibach is the scientist in charge of the grapevine breeding programme at Geilweilerhof. He has followed in this position, Profesor Alleweldt who had been the institute’s director at Geilweilerhof for 25 years (from 1970-1995).
• Over the last few years, several very promising new grape varieties have been released by the institute. These varieties are disease resistant to both powdery and downy mildew (Note: this is not a true resistance, but rather a tolerance).
• The white wine varieties Orion, Phoenix, Staufer, and Sirius have all been registered with the Plant Varieties Rights Office, and so has the red wine variety, Regent.
• The current demand for the variety Regent is several times higher than the bud wood supply.
• A tasting of the Regent wine made it obvious why this wine cultivar has become so popular. The wine had a dark red colour, full body, and a fresh yet harmonic acidity. Overall, the wine reminded very strongly of the classical Bordeaux wines of France. Red wines of such colour and body are relatively unusual for wine growing regions of Germany.
6. Staaliche Weinbaudomäne Marienthal/Ahr, Germany
Hosts: Dr Böll and Mr Jacoby
Until the German reunification, the winegrowing region Ahr was Germany’s most northern winegrowing region. The total vineyard area is approximately 500 ha. The Ahr is a traditional red wine growing area with 80% of the area planted in red wine varieties. Pinot noir is the dominant variety, accounting for 53% of the planted area. The vineyards along the Ahr River are located on steep slopes facing south.
The majority of the research conducted at the Weinbaudomäne is of an applied nature, consisting of clonal evaluation and the evaluation of new varieties. Associated with the vineyard is a commercial winery which also has the facility to make wine on a small scale.
• The grape moth Lobesia botrana is the major problem in the winegrowing region, Ahr. Pheromones have been used for mating disruption and these have been partly successful. However, as not all vineyards participated in using pheromones, there was strong reinfestation from untreated vineyards causing economic losses. Growers have now reversed to the traditional insecticide applications. Pheromones for mating disruption are, however, still used successfully on the research vineyard of the Weinbaudomäne.
• Dr Böll commented that the new cultivar Regent was very susceptible to the fungal disease Roter Brenner (Pseudopezicula tracheiphila), and also susceptible to magnesium deficiency. The variety matured about 10 days later than the variety Portugieser. Compared to the variety Rondo, another new disease-resistant variety released by the Institute for Grapevine Breeding at Geisenheim, Regent matured a few days later but had about 1.5 °Brix lower total soluble solids. Rondo has a more compact cluster than Regent and is therefore more susceptible to Botrytis bunch rot.
• Following an extensive trial with Pinot noir clones selected from various German research institutes, the clones L12 and L13 form the Staatliche Weinbauinstitut in Freiburg, have now been classified for the wine region Ahr.
Visit wine region Ahr
A day was spent visiting various wineries and vineyards in the wine region Ahr. There is a large number of small family wineries and a number of larger co-operative wineries in the Ahr region. The wine co-operative Mayschoss, founded in 1868, is the oldest German wine co-operative. The winery receives grapes from about 280 different vineyards and produces about 900,000 litres of wine per year.
7. Fachgebiet für Rebenzüchtung und Rebenveredlung, Forschungsanstalt Geisenheim, Geisenheim, Germany
Hosts: Mr Schmidt, Professor Rühl
Mr Schmidt has been successfully using the Granier technique for measuring sap flow in grapevines. Currently, Mr Schmidt and Dr Braun from the University of Bonn are evaluating the heat balance system built by Dr Braun for use on grapevines. They are measuring sap flow in the stem of grapevines growing outside in the vineyard as well as in the glasshouse. In the glasshouse experiments, sap flow measured by the heat balance system is compared to the weight loss from potted plants as measured by scales. Through the use of a computer system, the change of weight of two potted grapevine plants sitting on scales and the sap flow by the heat balance system are measured continuously.
• The rootstock Börner, selected and bred by the institute, is thought to be the only rootstock truly resistant to phylloxera. It also appears to carry some resistance to transmission of virus by Xiphinema index nematodes (See comments on Rühl’s presentation at the Cool Climate Symposium).
• The Institute has been concentrating on the breeding of disease resistant varieties. The new cultivar Rondo, a disease-resistant red wine variety, will probably be classified in 1997. Once classified, this variety can then be planted without any restrictions.
• Of the many disease resistant varieties currently growing in the breeding vineyard, Mr Schmidt preferred the variety Gm 8221-3 which produces a wine with a good red colour and a good wine quality.
• Discussions with Professor Rühl centred around the evaluation of Geisenheim clones and rootstocks in New Zealand. Professor Rühl was very interested in having the rootstock Börner evaluated in as many countries as possible. As this rootstock is currently being held in collections both in Canada and Australia, an introduction of this rootstock to New Zealand should not pose a problem. With respect to Geisenheim clones, many of the older clones have been introduced into New Zealand, however none of the new clones, and particularly none of the disease-resistant varieties, are available in New Zealand. Disease resistant varieties could play a central part in the development of sustainable viticulture in New Zealand and the import of such disease resistant varieties from Geisenheim, Geilweilerhof, Freiburg and other sources should be seriously considered.
Acknowledgements
I am very grateful to the following organisations for funding the useful and interesting visits of European research institutes and the participation at the international symposium:
HortResearch,
Marlborough Research Centre Trust,
Marlborough Grape Growers Association,
New Zealand Horticultural Science Advancement Trust.
I am also very grateful to my scientific colleagues in the USA and Europe for their time and hospitality.
Edited for HortNET by Helen Percy from HortResearch Internal Report 96/84 (Overseas Travel Report - USA, Germany, Italy, Switzerland. H.W. Caspari. November 1996).
Copyright © 1997 The Horticulture and Food Research Institute of New Zealand Ltd. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of The Horticulture and Food Research Institute of New Zealand Ltd is prohibited.
