Fusarium wilt of soybean (causal organism: Fusarium oxysporum Schlecht. emend. Snyd. & Hans.) has become an increasingly severe disease in the breed-ing plots at Gainesville and may be an undiagnosed or misdiagnosed problem in soybean production fields. At Gainesville, severity of Fusarium wilt, or a complex which includes F. oxysporum, has reduced yields in some plots to near-ly zero.