Cultural techniques to manage weeds Matt Liebman, Iowa State University, USA

Over the last half-century, herbicides have become the dominant tool for weed management in agricultural systems of industrialized nations (Gianessi 2013), as well as the focus of much of the research in weed science (Harker and O’Donovan 2013). Use of herbicides has, in many cases, increased farm profitability, facilitated the adoption of reduced tillage practices that contribute to soil and water conservation, increased farm labour efficiency, and improved farmers’ quality of life (Gianessi and Reigner 2007; Gianessi 2013; Zimdahl 2013). Concomitantly, heavy reliance on herbicides has also resulted in cases of environmental contamination and widespread problems with herbicide resistance in weed populations (Liebman et al. 2016).