Einsatz von Folientunneln zur Ertragssicherheit und Qualitäts-verbesserung von Erdbeeren im ökologischen Landbau

Summary

The effect of two different roofing systems in comparison to the open field (closed tunnel, rain shelter - open field) were investigated in a field experiment during the seasons 2009 to 2011 at the Chamber of Agriculture North-Rhine Westfalia, Station Cologne-Auweiler, Germany. Four shortday varieties ('Clery', 'Darselet', 'Elsanta' and 'Sonata') were used. Considered quality features were yield, behaviour of the fruit during storage, fruit quality such as fruit firmness and sugar- and acid contents. The yield of the shortday strawberries was highest in the tunnel for normal and cold temperatures; under hot conditions the yield was reduced. The rain shelter protects against freezing during cold periods and at high temperatures it reduces heat stress, so that the yield under the shelter was high. The lowest yield was found in open field. Fruits from open field decays fastest due to the influence of rain; fruits from rain shelter ranked between tunnel and open field. In closed tunnel fruits trends to result in higher quality. This was found in nearly all analysed parameters.