Contraste da qualidade física, fisiológica e sanitária de sementes salvas e certificadas de aveia branca

Abstract

White oat (Avena sativa) is a winter cereal widely cultivated in southern Brazil, and one of the key factors for achieving high yields is the use of high-quality seed. However, many farmers still adopt the practice of saving grain for sowing in the following season, known as ―saved seed‖ or ―farm-saved seed,‖ as permitted by legislation. Therefore, the aim of this study was to compare the physical, physiological, and sanitary quality of saved and certified white oat seeds. Three lots of farm-saved seeds and one lot of certified seed, classified as non-certified second-generation seed (S2), were evaluated for purity, determination of other seeds by number, germination, vigor (first germination count, germination speed index, and seedling length), and fungal infection. The experiment was carried out in the laboratory at the Federal University of Fronteira Sul, Erechim Campus. Regarding physical quality, the certified seed lot did not meet the purity standards, and only one saved-seed lot showed compliant values. The seeds most commonly contaminating the lots were ryegrass (Lolium multiflorum) and black oat (Avena strigosa). Concerning physiological performance, lots 1 (certified seed) and 4 (saved seed) reached high germination rates (>93%) and greater vigor. In the seed health test, all lots showed a high incidence of fungi, with infection levels above 71%, particularly by Fusarium spp., Penicillium spp., and Aspergillus spp. Therefore, some farm-saved white oat seed lots may exhibit physical and physiological quality superior to certified seed lots; however, most saved-seed lots show low germination and vigor, which denotes the need for laboratory importance to sowing. Regardless of origin, fungal presence was high, reinforcing the need for seed treatment.