Reacting to resistance

By James Clarke

Weeds developing resistance to herbicides pose a significant threat to profitability, and undermine our ability to produce food and fuel crops and to meet many environmental objectives.

In general, the more effective a herbicide is, the greater the risk of resistance.

The more herbicides that are used, the lower overall crop profitability will be, and the more likely it is that they will be found in water and that control will be so broad-spectrum that too few desirable plant species survive.

Spring cropping, to counter severe grassweed resistance, may be good for biodiversity and reduce herbicide use, but it reduces production and leaves little profit.

So how can we move forward?

We must develop our understanding of resistance based on weed biology and herbicides’ impact.

We can’t rely on new products becoming available, so we must strive to hold on to a wide range of useful ones. Mixtures and sequences only delay resistance, so we must use them effectively and efficiently alongside cost-effective cultural control.

We should also use all herbicides in a way that reduces risks to water quality.Information is available to achieve both resistance and water quality objectives, but it must be readily accessible.

Ben says: “This is 100% correct. We all know this. We have to look after what we have and use it in a responsible manner alongside the many forms of cultural control available.”