Desempenho de oito variedades de soja na várzea do rio Solimões, na ilha da Paciência, no período agrícola de 1976-1977

Summary

Eight varieties of soybean obtained from the Tropical Agriculture Institute of Nigeria (IITA) were tested in Amazonas thus increasing this valuable germplasm collection to soybean previously planted in the varzea in other programs. One of the characteristics of these varieties is insensitivity to photoperiod and high productivity in tropical environments. The maximum yield obtained in this experiment was 1145 kg/hectare with variety TGM 256-1-B. Having been planted on the 24^th of November of 1976, these varieties were exposed to extremely disfavorable climatic conditions during the critical stages of development. Many of the lineages presented excellent photoperiod characteristic which will undoubtedly have great use in future bettering programs. Nodulation was relatively poor, and the quality of seeds was, in most cases, greatly reduced. For a just avaliation of these lineages, it is necessary to plant as soon as the water level descends in varzea (August-September).