ABSTRACT
Since their introduction in the mid-1940s modern synthetic herbicides have revolutionized weed control and quickly became the most cost-effective and efficient means of controlling weeds. Herbicides are still the primary weed control method employed in crop production; however, they face several major challenges. One challenge is the real and perceived risks to people and the environment, which has led to everincreasing stringent regulations necessary to register a new product. Regulations that have increased the cost of bringing new herbicides to market, in combination with the domination of Roundup Ready crops in key market segments, have led to the cessation of registration of herbicides with novel sites of action (Fig. 1). This is a major problem for the future of weed control, as the use of herbicides with new sites of action was the primary way in which growers dealt with the appearance of herbicide-resistant weeds. It is clear that weed scientists have chosen to emphasize finding ways to maintain the utility of existing herbicides until new cost-effective alternatives eventually replace them rather than searching for new sites of action and developing new, novel ways to control weeds (e.g. robotic weeders).
