The red flowered American variant of witchweed, Striga asiatica (L.) Kuntze was germinated with GR 24 [1 mg 1 (to the first less)] and cultured on Murashige and Skoog's (MS) medium. Minimal requirement for stimulation of shoot morphogenesis consisted of mineral salts and sugar only. Supplementation of this medium with a cytokinin, 6-benzylaminopurine, suppressed growth. The plants kept in light became chlorophyllous and flowered after 2 months in culture. In other studies, it was demostrated that urea inhibited Striga seed germination and radicle extension growth, while ammonium sulphate inhibited radicle length. Urea as the sole nitrogen source in MS mineral salts-sugar medium severely inhibited Striga growth and development. The possible use of urea to control Striga infestation of crops is suggested