Seed-bone infection level of watermelon with F. oxysporum f. sp. niveum has a significant effect on wilt incidence. When high (23-31.5%) or moderate (8.5-9.5%) seed-borne infection occurred, wilt incidence reached up to 47.5-57.5% and 45-55%, respectively. However, when low (1.5-2.5%) seed borne levels occurred wilt incidence did not increase more than 5-10%. It is recommended to use seeds of free or low infection levels of Fusarium to minimize watermelon wilt incidence.