Christa M. Hoffmann
University of Göttingen
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Featured researches published by Christa M. Hoffmann.
European Journal of Agronomy | 2004
Christa M. Hoffmann; Nicol Stockfisch; Heinz-Josef Koch
Abstract In the last 20 years, several crops such as oil seed rape and cereals have developed sulphur deficiency symptoms with subsequent yield reductions due to decreasing S deposition. The study aimed at: (1) defining indicators of the S status of sugar beet; and (2) determining threshold values of internal S concentrations which affect yield and quality. For this purpose, the effect of S supply on S concentration and N/S ratio in leaves and on yield and technical quality of sugar beet was analysed. A field survey with 200 sites was conducted and S treatments were performed in 33 field trials and four pot experiments. In the field survey, the mineral S content of the soil in spring had no impact on the S concentration in sugar beet leaves in July. In accordance, there was no effect of S application on yield and quality of sugar beet in the field trials, indicating that S was available in sufficient amounts. In pot experiments, beet yield and sucrose concentration decreased, while potassium, sodium and amino N concentration in the beet considerably increased with extremely low S supply. With S concentrations above 0.3% (range of: 0.28–0.32%) in young leaf blades, which equalled N/S ratios below 20, no changes in yield or quality occurred as a result of S application, indicating that the plants were adequately supplied with sulphur. Plants from field trials and pot experiments reached maximum yields with the same S concentrations in the leaf blades. This good agreement leads to the conclusion that these threshold values do not depend on growing conditions and are, therefore, a general characteristic for sugar beet. S concentration and N/S ratio in the blades of young sugar beet leaves sampled in July are thus suggested as suitable indicators of the plant’s S status.
Frontiers in Plant Science | 2018
Christa M. Hoffmann; Christine Kenter
The yield of sugar beet has continuously increased in the past decades. The question arises, whether this progress will continue in the future. A key factor for increasing yield potential of the crop is breeding progress. It was related to a shift in assimilate partitioning in the plant toward more storage carbohydrates (sucrose), whereas structural carbohydrates (leaves, cell wall compounds) unintendedly declined. The yield potential of sugar beet was estimated at 24 t sugar ha-1. For maximum yield, sufficient growth factors have to be available and the crop has to be able to fully utilize them. In sugar beet, limitations result from the lacking coincidence of maximum irradiation rates and full canopy cover, sink strength for carbon assimilation and high water demand, which cannot be met by rainfall alone. After harvest, sugar losses during storage occur. The paper discusses options for a further increase in yield potential, like autumn sowing of sugar beet, increasing sink strength and related constraints. It is prospected that yield increase by further widening the ratio of storage and structural carbohydrates will come to its natural limit as a certain cell wall stability is necessary. New challenges caused by climate change and by prolonged processing campaigns will occur. Thus breeding for improved pathogen resistance and storage properties will be even more important for successful sugar beet production than a further increase in yield potential itself.
European Journal of Agronomy | 2006
Dorit Bloch; Christa M. Hoffmann; Bernward Märländer
European Journal of Agronomy | 2006
Christine Kenter; Christa M. Hoffmann; Bernward Märländer
European Journal of Agronomy | 2009
Christa M. Hoffmann; Toon Huijbregts; Noud van Swaaij; Rudolf Jansen
Journal of Plant Nutrition and Soil Science | 1994
Christa M. Hoffmann; Erwin Ladewig; Norbert Claassen; A. Jungk
European Journal of Agronomy | 2011
Christa M. Hoffmann; Sinje Kluge-Severin
European Journal of Agronomy | 2006
Gisela Mäck; Christa M. Hoffmann
International Journal of Food Science and Technology | 2009
Christine Kenter; Christa M. Hoffmann
Journal of Plant Nutrition and Soil Science | 1997
Christa M. Hoffmann; Heidrun Platte; Thomas Lickfett; Heinz-Josef Koch