Notes on the control of foxtail grass (Pennisetum polystachion (L.) cv. Schult).
P. polystachion has become a problem in 8 Sri Lanka tea plantations. It can be controlled by spraying diuron at 2 g/litre on plants <45 cm high before emergence of inflorescence or flowering. The wetter Surfactant 'N' at 2 ml/litre may also be used. Phytotoxic effects are seen within 1 week of spraying and complete kill is observed in 2-3 weeks. The spray will not kill mature plants in flower. Glyphosate can also be used for control but is expensive and paraquat and dalapon are ineffective. Slashing of plants could also act as a control method by preventing the grass from flowering.