Integrated management of itchgrass (Rottboellia cochinchinensis) in maize in seasonally-dry Central America: facts and perspectives

Itchgrass (Rottboellia cochinchinensis) is a serious and persistent weed problem in many tropical agricultural and conservation areas. In Central America it is one of the most noxious and serious weeds in several upland crops, causing severe yield losses. Experimentally, pre-emergence control with herbicides, weed elimination during the fallow period and zero tillage reduced itchgrass populations in comparison to conventional practices used growers (no fallow management, soil preparation by disc harrowing and limited use of in-crop herbicides. Additional improvement in itchgrass management is brought about by inter-sowing legume cover crops. Of several legumes evaluated, mucuna (Mucuna deeringiana) and Canavalia ensiformis controlled the weed better and covered the soil, especially if planted simultaneously with maize. Itchgrass suppression by mucuna usually corresponded with increased grain yields but competition by the cover crop could reduce yields