Six soybean genotypes were studied with the objective of identifying the relative contribution of the yield components to the final grain production. The experiment was conducted during the 1996/97 growing season in the EEA/UFRGS, Eldorado do Sul, RS, Brazil. Plants were evaluated individually from flowering until maturity. Results obtained demonstrate that the relative importance of each yield component varied according to the cultivar. Cultivars FT-2003 and RS 9-Itaúba were significantly superior to the others with regard to grain production per plant, the exception was RS 7-Jacuí. They were characterized by a high number of fertile nodes in the branches and high production in them, while RS 7-Jacuí had high 100 grains weight and high number of pods with three grains. CEP 20-Guajuvira presented high fixation percentage of legumes. One hundred grains weight is an important component in the production of the cultivar BR 16. In the cultivar OCEPAR 14 the production is the result of a high production of branches and of a high number of fertile nodes in them.
Glycine max; genotypes; developmental stages; crop yield
