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Die Bodenkultur - Journal for Land Management, Food and Environment
H.-G. Stock, K. Warnstorff and M. Kazmi:
Yield structure analysis of soya (Glydne max [L.] Merr.) on an eastern German site
Soya, a highly interesting crop thanks to its manifold uses, is still not considered worth cultivating in Central Europe despite of more than 100 years of concentrated endeavours. The present analysis of yield structure is hoped to make a contribution to controlled yield formation. The data were collected in agrotechnical field plot experiments run between 1987 and 1993 on waterlogged sandy loam in the Central German dry region. The partially considerable lasses during combine harvesting were conditioned by the position height of the lowest pods. Losses fell below 0,5 tonnes per hectare only when the pods were positioned higher than 22 CID. Since higher plant densities lifted the position of the lowest pods, yields at harvest correlated positively with the number of plants per unit area, although lower population densities gave rise to higher grain yields as a result of the excellent pod setting potential of soya on the single plant. Both correlation estimates and optimum ranges of the yield components as derived from regression functions showed that the grain yield is not dominated by the expression of a single yield component. Moreover all components may support the formation of high yields by fairly different combinations. The investigations have led to the conclusion that on the test site the following results can be reached: grown average yield - 2.0 to 2.5 tonnes per hectare with approx. 20 to 35 plants/m2, 32 to 39 pods per plant, 1.69 to 1.80 seeds per pod and 142 to 153 g TKW, combine-harvested yield - 1.4 to 1.8 tonnes per hectare from over 60 plants per m2, 8 to 11 pods per plant, 1.67 to 1.80 seeds per pod and 133 to 139 g TKW. All yield components can be more or less influenced by various agronomic measures; this means that the crop grower is able to exert optimal influence on yield formation. Key words: Soybean yield structure, eastern Germany, field plot experiments.