the dry thermal treatment was conducted in a continuous air flux chamber on alfafa (medicago sativa) seeds with relative humidity under 5%. seeds underwent a pre-treatment for 60 °c during three or six hours, followed by a treatment at 90 °c for three or six hours. the wet treatment was conducted in water bath, and consisted of a pre-treatment at 40 °c for 10, 20 or 30 min, and then treatments at 50 °c or 60 °c for 10, 20 or 30 min. the chemicals tested were benomyl, thiabendazole, iprodione and thiram, at the dosages recommended by their manufactures and also at three times these dosages. the wet thermal treatment at 40 °c for 20 min, followed by the treatment at 50 °c for 20 min, were effective in the eradication of fusarium oxysporum, but significantly affected the alfafa seed germination. the dry thermal treatment at 60 °c for 3 h, followed by the treatment of 90 °c for 3 to 6 h, eradicated f. oxysporum without a significant reduction in seed germination. benomyl was the most efficient chemical product in eradicating f. oxysporum without affecting the alfalfa seed germination.