Vinasse is not only effectively used in pest control but also creates a conducive environment for the growth of antagonistic microorganisms. Thus, this study aimed to evaluate the potential of vinasse applied via soil for the management of root-knot nematodes in soybean culture. The experimental design was entirely random, in a factorial scheme (2 × 6), consisting of two species of nematodes, Meloidogyne incognita and M. javanica, under vinasse application at five concentrations (20, 40, 60, 80, and 100%) and one control (water), with five repetitions. Soybean plants Intacta cv. M-Soy 8644 IPRO were inoculated with 4000 eggs/juveniles of each species separately. At 60 days after the first application of vinasse, evaluations of parasitism and agronomic characteristics in soybean were performed. Stillage resulted in the highest average values for root volume and root fresh mass in plants inoculated with M. incognita, showing respective increases of 24.33% and 14.92% compared to plants inoculated with M. javanica. However, concentrations exceeding 60% had a detrimental effect on all agronomic variables of soybean. For parasitism, an interaction among the factors was observed, with a significant effect (p < 0.01) for most of the evaluated variables, except for the number of eggs in the soil. The concentration equivalent to 60% vinasse promoted a sharp reduction in parasitism for the two nematode species, making reproduction on plant roots unfeasible.
