Studies were carried out in Petri dishes to identify herbicides which could eventually inhibit seed germination of Pennisetum polystachion (L.) Schult. Amongst the pre-emergence herbicides, ametryn was the most effective compared with alachlor, metolachlor,oxyfluorfen, imazethapyr and diuron while amongst the contact herbicides, paraquat and glufosinate ammonium were more effective than monosodium methanearsonate (MSMA) and sodium chlorate. Amongst the post-emergence herbicides, imazapyr was morre effective than glyhosate isopropylamine and glyphosate trimesium while triclopyr was more effective than 2, 4-D dimethylamine, bentazone, fluroxypyr, metsulfuron methyl and dicamba. In field trials, minimum effective rates for the kill of P. polystachion were 1.44 kg ae/ha for glyphosate isopropylammine, 1.08 kg ae/ha for glyphosate trimesium, 0.5 kg ae/ha for imazapyr and 2.0 kg ai/ha for MSMA. Glufosinate ammonium was almost as effective as pre-mixed glyphosate isopropylamine + ammonium sulphate in killing the weed and these herbicides were more effective than paraquat, pre-mixed paraquat + diuron and slashing.