Easter lily bulbs,Lilium longiflorumThumb. “Nellie White,” from Oregon were grown under controlled temperature forcing in a greenhouse to flower at Easter. Various miticide and fungicide treatments were applied to elucidate the relationship between a bulb mite,Rhizoglyphus robiniClaparède, and root rot control as caused byPythium ultimumTrow andFusarium oxysporumSchl. emend. Snyd. and Hans. Dicofol and aldicarb, regardless of time of application, significantly reducedR. robininumbers. Dicofol also significantly reduced root rot. Tests showed that dicofol had fungicidal as well as miticidal activity. The fungicide combination of benomyl and Truban gave significant root rot control only when mite populations were relatively low. It is concluded that a threshold exists forR. robiniin greenhouse-forced Easter lilies above which mite suppression is necessary for adequate root rot control by fungicides.