The post-emergence herbicide bentazone is facing deregulation if growers do not start acting to reduce leaching into ground and surface water, BASF has warned.
Bentazone is one of the few post-emergence herbicides for beans and the only post-em available for some especially challenging weeds in pea crops, such as black nightshade.
It is highly soluble in water and mobile in soil and despite industry efforts to reduce levels found in ground and surface water since 2014, records show no serious decline.
Bentazone is due a review for re-approval in 2025. The Environment Agency will be part of the decision panel and has made it very clear that the industry must reduce the levels and numbers of detects in water in order for it to be considered, says BASF.
Paul Goddard, stewardship and value chain manager at BASF, adds: “Last year, we commissioned some work focusing predominantly on groundwater and the likely sources at a number of the most challenged extraction points. At three of the five locations, a point-source is the likely cause. For the other two, point-source cannot be eliminated and therefore is a factor.
“As bentazone can enter the watercourses through both groundwater and surface, there are multiple chances for leaching so we must do everything we can culturally and chemically to reduce the levels."
He adds: “This can be as simple as how and where growers fill their sprayer. Most farms now have a dedicated area of concrete that can easily be cleaned when using the granular formulation. For those using liquid, we have been working with industry partners to develop the new EasyConnect closed transfer system which, after rigorous testing, will be available to the market shortly. During 2022/23 a broad range of containers [IS 63 Industry Standard] will be equipped with the standardised pre-mounted screw cap, compatible with the system.
“Avoiding high risk areas, ensuring the field is suitable before planting crops and keeping the chemistry on the surface are a few other important considerations,” Mr Goddard says.
To find out more about Better Bentazone Together stewardship, click here