The most common weed of pastures in Nigeria is spear grass. This weed is a type of grass that is often found growing in grazing areas and can be difficult to control. It can compete with desirable forage species and reduce the quality and quantity of available forage for livestock. In addition, spear grass can be dangerous for livestock to consume as it can cause injury to the mouth and digestive tract. Effective weed control measures, such as mowing, grazing management, and herbicide application, can help to manage spear grass and other weeds in pastures.