Einfluß von Beregnung und Stickstoffdüngung auf agronomische Eigenschaften von Topinambur (Helianthus tuberosus L.)

The aim of this study was to determine the effects of irrigation and nitrogen application on agronomically important traits of Jerusalem artichoke (Helianthus tuberosus L.). Early and late maturing genotypes, five in each case, were investigated in 1988 and 1989 under two levels of water supply (unirrigated and irrigated) and two levels of nitrogen supply (70 and 140 kg N ha-1) on a light sandy soil in Braunschweig-Völkenrode. Although the genotypes differed in the magnitude of their responses to higher levels of water and nitrogen supply, the direction of these changes were generally the same. In both years, irrigation resulted in a considerable increase in plant height, tuber number, tuber weight and haulm yield.