A SURVEY ON SOYBEAN SEED QUALITY PRODUCED IN THE STATE OF MATO-GROSSO

A survey was conducted at the State of Mate Grosso during the 1983/84; 1984/85 and 1985/86 growing seasons to evaluate the causes responsabl e for the decrease in seed quality under natural environmental conditi on of seed production and storage, The standard germination and the te trazolium test were used for that purpose. From the tetrazolium evalua tion was possible to identify the factors that cause soybean seed dete rioration as follow: field weathering, mechanical damage and stink bug damage. A survey of 361 samples was take with the cultivars: Doko, Cr istalina and IAC-8. The cultivar Doko was the best in seed quality con cerning germination and vigor in comparison with the others ones. Fiel d weathering was very critical for the cultivar Cristalina and IAC-8. The stink bug damage was not so severe for seed quality. The mechanica l damage, for the three cultivars, caused discarded of soybean lots du e to lower germination and vigor. From these three factors, the order of importance to reduce soybean seed quality is: field weathering, mec hanical damage and stink bug damage.