Two red and three white new fungus-tolerant grape varieties were tested within a period of five years. REGENT, RONDO, JOHANNITER and Gf 48-12 show a better wine quality than PINOT NOIR  or SILVANER and can be recommended for Organic Viticulture as well as for the conventional viticulture to reduce copper and fungicide applications

Knott, R.

Schottdorf, W.

Schwab, A. L.

English

Organic Eprints

Results from new fungus-tolerant grapevine varieties for Organic ViticultureA. L. Schwab, R. Knott and  W. Schottdorf Bayerische Landesanstalt für Weinbau und Gartenbau, Würzburg-VeitshöchheimHerrnstraße 8, D-97209 Veitshöchheim (email: arnold.schwab@lwg.bayern.de)AbstractTwo red and three white new fungus-tolerant grape varieties were tested within a period of fiveyears. REGENT, RONDO, JOHANNITER and Gf 48-12 show a better wine quality than PINOTNOIR  or SILVANER and can be recommended for Organic Viticulture as well as for theconventional viticulture to reduce copper and fungicide applications.Keywords: fungus-tolerant grape varieties, environment protectionIntroductionThe breeding of  fungus-tolerant grape varieties began in France after the introduction of Phylloxeravastatrix at the end of the last century. The first hybrides had a low wine quality and were not suppor-ted because the grafting method showed better results to combat the Phylloxera and delivered furtherwines of higher quality with the traditional varieties. In the last 50 years new varieties were combinedand the tested grape varieties showed acceptable results in fungus tolerance and wine quality.Material and methodsFive new selected varieties were tested in comparision to traditional varieties growing on a shell limesoil in Franconia, Germany. The trial was a split plot design with 3 replicates.  The fungus-tolerantvarieties were not treated with fungicides. Yield, sugar content, acid and the amount of fungus damagewere investigated. The varieties were separately treated and fermented in 100 l steel barrels. Thebottled wines were tested 2-3 times every year in Double-Blind-Tastings by 12-16 expert tasters. Thenew varieties were also tested in open tastings in the last two years by a panel of 248 winegrowers. All Table 1. New red fungus-tolerant varieties for Organic Viticulture (abc: P<0.05)criteriavVarieties Regent Rondo Pinot noiryears 1995-99 1995-99 1995-99yield kg/a 74.7 a 80.8 a 72.9 asugar content (°Oechsle) 93 a 88.6 b 85 bacid (must) 7.2 c 10.7 b 13.7 aquality number  (DLG 1-5) 2.44 a 2.48 a 2.13 b     open wine tasting  (n=248) 2.55 a 2.27 b 1.98 cdominant flavor Blackberry Elder-berry Cherrydominant flavor  Elder-berry Woodberries Strawberry bud break (mean) 01. May 25. Apr 29. Aprdays until flowering 46 46 50days from flowering to harvest 124 a 111 b 121 aDowny mildew – leaf (1-9) 1 1 1Downey mildew - grape (1-9) 1 1 1Powdery mildew – leaf (1-9) 1 2.2 2.6Powdery mildew – grape (1-9) 1 3 1.4Red fire disease – leaf (1-9) 4 2.5 1.5Botrytis infection in % 16 7 10*)1-9 infection index ( 1=very low infection; 9=very strong infection)presented varieties in this study were pre-selected from the bulk of tested varieties and showed goodresults and therefore can be recommended for Organic Viticulture. All presented varieties have a very good winter hardiness and do not suffer from seriouse viticultural problems.Results and discussionTable 1 shows the results of the two new promising fungus-tolerant red varieties REGENT andRONDO in comparision to Pinot Noir in the mean of five years.Both had a higher sugar accumulation than Pinot Noir and a lower content of acid. REGENT needsprofund soils because of a lower vigor and needs more vigorous rootstocks.The expert panels and thewinegrowers in the open tastings rated the wine quality of both fungus-tolerant varieties significantlyhigher than of Pinot Noir. RONDO is a very early variety with early bud break, early flowering andearlier harvest maturity compared to REGENT and Pinot Noir. Only its powdery mildew resistence islower than that of REGENT. The new fungus-tolerant varieties REGENT and RONDO shows highersugar accumulation and creates deep coloured wines with high density. Best results are reached withbarrique seasoning. Based on a higher acid value RONDO delivers a long-lasting wine with goodageing potential. Meanwhily REGENT is classified within five German wine regions.Table 2. New white fungus-tolerant varieties for Organic Viticulture (abc: P<0.05)criteria/varieties Johanniter Bronner Gf 48-12 Silvaneryears 1995-1999 1995-1999 1995-1999 1995-1999yield kg/a 111.7 a 105.9 a 94.7 a 91.5 asugar content (°Oechsle) 86.0 a 85.6 a 83.4 ab 80.8 bacid (must) 9.1 c 10.1 bc 11.1 b 9.5 cquality number  (DLG 1-5) 2.21 a 2.11 a 2.21 a 1.99 a     open wine tasting  (n=248) 2.31 a 1.79 b 2.22 a 1.87 bdominant flavor Citrus Green appel Black currant Citrus, Peardominant flavor  Apple Citrus Maracuja Green appelbud break (mean) 28. Apr 29. Apr 28. Apr 28. Aprdays until flowering 50 45 53 52days from flowering to harvest 121 131 126 122Downy mildew – leaf (1-9*) 1 1 1 1Downey mildew - grape (1-9) 1 1 2 1Powdery mildew – leaf (1-9) 1 1 2.6 1.8Powdery mildew – grape (1-9) 2 2 3 3.4Red fire disease – leaf (1-9) 3 4 3.5 1.5Botrytis infection in % 9 3 12 14.4*)1-9 infection index ( 1=very low infection; 9=very strong infection)In Table 2 three new fungus-tolerant white wine varieties of German breeders from the same fieldexperiment are listed in comparision to the standard franconian variety Silvaner. JOHANNITERobtained a significantly higher yield, increased sugar content and a higher quality ranking thanSilvaner. These result were confirmed by the winegrowers tastings. JOHANNITER has the samevegetation period than Silvaner, shows a high downy mildew resistence and was infected onlyinsignificantly by powdery mildew in some years. The wine is crispy, aromatic and well balanced inacid and shows a higher acceptance than Silvaner. BRONNER, another new fungus-tolerant variety,achieved medium results in wine quality and does not reach the expression like JOHANNITER. Thenew fungus-tolerant variety MERZLING was not tested in this experimental trial but showed signifi-cant lower quality rankings than Silvaner or Müller-Thurgau within three experiments at threedifferent sites and therefore can not be recommended in contrast to JOHANNITER. The new fungus-tolerant variety Gf 48-12 showed higher acid values but remarcable quality results. In winetastings,Gf 48-12 reached excellent high ratings by both the experts and winegrowers. This aromatic variety isnot fully resistent against fungus, but reached the results without spraying. Sometimes powderymildew is a little problem but in Organic Viticulture with less importance due to the possibilities ofsulfur application. The intense aroma of Gf 48-12 is closely related to the traditional varietiesBACCHUS and SCHEUREBE and is caracterized by Maracuja and black currant flavor. A moderatecontent of residual sugar (half-sweet) seems to be recommended concerning the higher amount of acid.Erschienen in:  Proceedings of the 6th International Congress on Organic Viticulture 2000, Basel,Switzerland, SÖL-Sonderausgabe Nr. 77, S. 225-227Bibliographische Angaben zu diesem Dokument: Schwab, A. L. und Knott, R. und Schottdorf, W. (2000) Results from new fungus-tolerant grapevine varieties forOrganic Viticulture. Beitrag präsentiert bei der Konferenz: 6th International Congress on Organic Viticulture,Basel, Switzerland, 25.08. - 26.08.2000; Veröffentlicht in Willer, Helga und Meier, Urs, (Hrsg.) Proceedings 6thInternational Congress on Organic Viticulture, Seite(n) 225-227. SÖL-Sonderausgabe 77. Stiftung Ökologie &Landbau, Bad Dürkheim.Das Dokument ist in der Datenbank „Organic Eprints“ archiviert und kann im Internet unterhttp://orgprints.org/00002067  abgerufen werden.

Results from new fungus-tolerant grapevine varieties for Organic Viticulture

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