Weeds of agricultural importance: bridging the gap between evolutionary ecology and crop and weed science.

An undeniable and expensive consequence of agricultural practices is the adaptation of weeds to agricultural systems. Weeds are responsible for significant crop yield losses and for financial losses in agricultural production – in the order of 10% per year worldwide (Oerke, 2006). To address this critical problem, the discipline of weed science has expanded over the past 50 yr into an amalgam of scientists and practitioners who ask a variety of questions and employ a myriad of tools focused on understanding and managing weeds (Holt, 2002). Two predominant foci of this discipline are the fundamental aspects of weed biology and ecology, and the practical aspects of managing these pests (Radosevich et al., 2007). While weeds can infest many types of ecosystems, weed scientists focus on how weed populations affect crop yield and how to best apply this knowledge to prevent, eradicate or control weeds, primarily through the use of herbicides, with the ultimate goal of maximizing crop production (Davis et al., 2009).