Why glyphosate is a global herbicide: strengths, weaknesses and prospects

After 25 years of sales, glyphosate (N-(phosphonomethyl)glycine) is the world's biggest selling and fastest growing agrochemical. Glyphosate has many strengths, particularly its systemicity and ability to control perennial weeds, which have facilitated its role as an essential tool in modern agriculture. Surveys of recent scientific and patent literature point to several key areas of current and future interest in glyphosate and its use. Biotechnology topics have been the most popular, but there is still much interest in the molecule per se, particularly in manufacturing processes. The mode of action and physiology of glyphosate are common subjects. More applied aspects concern the development of formulations with new adjuvants, or mixtures with other herbicides, to enhance performance. An increasing number of papers are reporting on its environmental fate and on agronomic techniques designed to improve the efficiency of application and minimise its environmental impact. Lack of weed resistance is a key feature of glyphosate despite its widespread use. However, differential levels of tolerance between species have led to changes in weed succession. There is a need to develop integrated weed management systems in which glyphosate still plays a key role. Glyphosate is an exceedingly effective herbicide and presents a considerable challenge to the development of new herbicides for sustainable cropping systems and situations in which cost-effective and environmentally considerate weed control is required.