Echinochloa pyramidalis
(Antelope grass)

A perennial grass, originally from southern Africa, which grows up to 3 meters high, inflorescence up to 30 cm long, racemes purplish, and awnless spikelets. The plant is able to create a dense stand and grows well in swampy areas, but it is a drought resistant plant.  Antelope grass is propagated by cuttings. It is a valuable plant for animal feeding. In Africa It makes useful hay and silage

The plant has been introduced in some countries of the western hemisphere for its use for livestock, but due to mismanagement or misuse antelope grass has spread extraordinarily to several areas where the plant is unwanted.

The plant has become the major weed problem in Guyana. It was introduced as pasture in 1984, and nowadays it is spread along the shores of the rivers and canal banks becoming a serious problem to irrigation and drainage in the country. E. pyramidalis is not found in crop areas. Its stand is so high in some rivers that the canopy from both sides has closed over, preventing the normal water flow of the river and necessitating spraying with glyphosate to arrest its further growth.  The problem affects very seriously the irrigation network of rice areas in the country.
For the control of Echinochloa pyramidalis there is no biological agent to be used. The most feasible solution is to remove the plant mechanically or applying a low-toxic and non residual herbicide, e.g. glyphosate.
The use of the mass of plants removed may also stimulate its control among different stakeholders.