ABSTRACT
Agriculture has had a major influence on the evolution of weeds. Most studies of weed ecology have emphasized the growth characteristics and adaptations that enable weeds to exploit the ecological niches left open in croplands, and the adaptive mechanisms that enable weeds to survive under conditions of maximum soil disturbance, such as conventional tillage systems. The central objective of weed management is to manipulate the crop/weed relationship so that growth of the crop is favored over that of the weed. Perhaps the ecological role of weeds can be best visualized by analyzing the possible consequences of a complete eradication of the weed flora from agroecosystems. The environmental simplification that characterizes modern agricultural systems has accelerated plant succession patterns in agriculture, creating specialized habitats that favor the selection of competitive and opportunistic weeds. Weeds have traditionally been considered unwanted plants that reduce yields by competing with crops or by harboring insect pests and plant diseases.
