The objective of this study was to evaluate physiological seeds quality of four soybean cultivars during storage, under controlled and uncontrolled conditions. Seeds of Brasmax Lança IPRO, Brasmax Raio IPRO (está diferente do Material e Médtodos), Pioneer 95y52 and TMG 7062 IPRO cultivars were stored in controlled (20 ± 1.2 °C) and uncontrolled (producer's warehouse) environments and the following traits were assessed: percentage of germination (GERM), germination speed index (GSI), germination speed (GS) and accelerated aging (AA) at 0, 60, 120 and 180 days of storage. Covariance matrices structure of storage time was tested through repeated measures analysis, adopting a bifactorial model. Data were submitted to ANOVA (α=5%) and when the means presented significant differences, regression analysis and Scott-Knott test (α=5%) were performed. Differences in soybean seeds physiological quality are not related to storage environment. Lança cultivar was the most tolerant to storage, while Ray and TMG 7062 cultivars were more sensitive.

O Centro-Oeste brasileiro representa a região brasileira com maior área e produção de sementes de Megathyrsus maximus, uma gramínea muito utilizada para a formação de pastagens em regiões tropicais do Brasil e outros países da América. Objetivou-se no presente estudo diagnosticar a qualidade física e fisiológica de sementes de três cultivares da espécie M. maximus (Mombaça, BRS Tamani e BRS Zuri) comercializadas por diferentes empresas de Campo Grande (MS). Os experimentos foram conduzidos utilizando-se sementes da safra 2017-2018 em um delineamento inteiramente casualizado, em esquema fatorial 3 x 6, avaliando-se três cultivares e seis procedências. As variáveis analisadas foram: pureza física, peso de mil sementes, primeira contagem do teste de germinação, germinação, valor cultural e teste de tetrazólio. Os resultados encontrados demonstram que, com exceção de um lote da cultivar Mombaça, os demais lotes das três cultivares da espécie Megathyrsus maximus (Mombaça, BRS Tamani e BRS Zuri), de todas as procedências avaliadas, apresentaram qualidade física e fisiológica compatível com a comercialização em função da legislação vigente. No entanto, é possível encontrar lotes com qualidade distinta no mercado de Campo Grande. Assim, a escolha adequada da procedência (empresa) vai garantir a expressão máxima do potencial genético, subsidiada por processos adequados de produção e pós-colheita. Palavras-chave: Megathyrsus Mombaça. Gramíneas Tropicais. Teste de Germinação. Teste de Tetrazólio. Valor Cultural.   Abstract Brazilian's Midwest represents the region with the largest area and production of Megathyrsus maximus seeds, a grass widely used for the pastures formation in tropical regions of Brazil and other countries in America.The objective of this study was to diagnose the physical and physiological quality of seeds of three cultivars of the species Megathyrsus maximus (Mombaça, BRS Tamani and BRS Zuri) commercialized by different companies of Campo Grande (MS). The experiments were conducted using seeds of the 2017-2018 harvest, in a completely randomized design, using a factorial scheme 3 x 6, with three species and six sources, totaling 18 treatments. The variables analyzed were: physical purity, weight of one thousand seeds, first count of germination test, germination, cultural value and tetrazolium. The results showed that with the exception of one lot of cultivar Mombaça, the other lots of the three cultivars of species Megathyrsus maximus (Mombasa, BRS Tamani and BRS Zuri), of all provenances, have compatible physical and physiological quality with marketing in accordance with current legislation. However, it is possible to find lots of different quality in the Campo Grande market. Thus, the appropriate choice of source (company) will guarantee the maximum expression of genetic potential, subsidized by adequate production and post-harvest processes. Keywords: Megathyrsus mombaça. Tropical Grasses. Germination Test. Tetrazolium Test. Cultural Value.