The success of species implantation depends on the quality of seeds used initially. It is therefore important to ascertain that the seed is in an excellent physical, physiological, sanitary and nutritional condition as this will determine the genetic cultivars’ potential. Thus, this research work studied the relationships between physical and physiological variables in the seed. Samples were analysed and grouped according to their similarities. A total of 2,586 black oat seed samples were studied, 2,229 were samples of the seed production process and 357 were samples of their own use, and analyzed in the laboratory of the Agronomy Course of Unijuí, Ijuí, RS. Pearson's linear correlation coefficients, multicollinearity analysis, track and cluster analysis was determined by the agglomerative method of the most distant neighbor. The normal seedlings showed the highest correlation of negative signs, and direct effect with dead seeds. The multicollinearity analysis indicated a severe condition number, influenced by the percentage of pure seeds and number of other seeds per number. Three groups of samples were identified in the seeds produced according to the national seed system and four groups in seeds for their own use. The most representative groups presented the highest physical and physiological qualities. The variable, dead seeds, was the one that influenced the germination of normal seedlings most.
Key words: Avena strigosa (Schreb.), multicollinearity, path analysis, grouping.