Pot and laboratory experiments revealed that Chloris gayana Kunth and Panicum antidotale Retz. are potentially allelopathic. The root exudates besides inhibiting their own growth reduced growth of Chloris. Aqueous shoot extracts inhibited radicle growth of Chloris gayana, Panicum antidotale, Pennisetum americanum and Chtysopogon aucheri. Both the species exhibited self-toxicity. The toxicity of each species depended up to the amount of material soaked, soaking duration, freshness of the material assayed and the test species used.