Protecting Glyphosate Efficacy on Combinable Crops: Resistance, Residues and Responsible Use

The value of glyphosate in UK and EU agriculture for preplanting or pre-crop emergence, and pre-harvest use for late weed control or crop desiccation was reported by Wynn etal. This paper highlights those key conclusions and outlines some stewardship actions taken since, to ensure its continued availability and responsible use, particularly in the UK. The key uses of glyphosate in arable crop situations in Europe are pre-planting or pre-crop emergence and pre-harvest for late weed control or as a harvest desiccant to reduce moisture content. In France and Germany pre-planting use predominates, whilst in the UK pre-harvest use accounts for approximately 30% of the usage in wheat and barley and 59% in oilseed rape. The area treated with glyphosate pre-planting was quantified as nearly 7m ha at EU25 level. Glyphosate continues to play a vital role in UK and EU agriculture. Re-authorisation was only one step in ensuring its value to farmers and growers is retained. Manufacturers, agronomists, farmers and all other stakeholders have a vital role in ensuring efficacy is maintained and for effective use to continue. This requires pro-active communication of resistance management strategies and new research to fill knowledge gaps. With few guidelines being available there is a wider role these can play in many situations and geographies. Equally better application efficacy is important and there is a key role for authorisation holders in providing users with better information on dose rates and timings by weed species to reduce resistance risks further. Application to reduce food residues, even below the low levels already seen and to minimise drift risks to water further, all require better decision making and attention to detail when applying the herbicide. Only if regulators, manufacturers, advisers, farmers and spray operators work together will this be achieved. The food and water industry also have a key role to play in encouraging changed practices and in communicating through their supply chains why low levels might be appropriate for the wider benefits that could be achieved. There is an increasing role for glyphosate stewardship and it would be appropriate for the Glyphosate Task Force to evolve from its role in regulatory matters into taking a lead in co-ordinating all interested parties in ensuring more focus on preventing resistance and responsible use.