Cogongrass,Imperata cylindrica, in the United States

Abstract

Cogongrass [Imperata cylindrica(L.) Beauv. # IMPCY] is an aggressive, pernicious, rhizomatous perennial in the Poaceae (Graminae). It is native to tropical and subtropical areas of the eastern hemisphere. Introductions of cogongrass into the southeastern United States have been tracked to several separate sources, both accidental and intentional, in southern Alabama, southern Mississippi, and Florida. It was found to be unacceptable for use as a forage and in erosion control. Cogongrass is a highly variable species and has adapted to a variety of environmental conditions in its native and introduced range. Today cogongrass infests 200 million ha in Asia, several thousand ha in the Southeastern United States, and over 500 million ha worldwide. It has been reported to be a weed problem in many annual and perennial crops. In addition to competing for light, water and nutrients, cogongrass interference is caused by alleopathy and physical injury when rhizome apices penetrate crop roots, bulbs, and tubers. Holm et al. designated cogongrass as the world's seventh worst weed.