Soybean seeds treated with vinasse and cassava wastewater

摘要

ABSTRACT This study aimed at evaluating organic by-products vinasse and cassava wastewater on the sanitary and physiological quality of soybean seeds. Sanity tests, phytoalexin induction and physiological qualities were performed, conducted in a completely randomized design. The sanity test was carried out in a 3 × 5 factorial scheme (two by-products: vinasse – V, cassava wastewater – C and the junction between them – V + C, in five concentrations: 0, 25, 50, 75 and 100), with 8 repetitions/treatment. In the induction of phytoalexin, a factorial scheme (3 × 4) + 1 – two by-products and their junction, was adopted, with 4 concentrations (25, 50, 75 and 100), plus an additional witness – with 5 repetitions/treatment, and for the physiological qualities 3 × 5 factorial scheme, described above, with four replicates/treatment. Cassava wastewater has large amounts of sugars, which may have favored the development of pathogens in this treatment. Vinasse had the highest capacity of inhibiting the genera Aspergillus, Cladosporium, and Penicillium, which was explained by the positive relationship between its concentrations and the induction of phytoalexin, being the most effective by-product in fungus control, at concentrations of 75 and 100 and without changing the physiological quality of seeds.