When we talk about the fitness of weeds, it’s not about how fast they can run a marathon. We are talking about how well they grow and how many viable seeds they produce. Weeds with fitness penalties just don’t grow and reproduce as well as they should, even in the absence of herbicides. Are there fitness penalties for Group B (e.g. Glean®; ALS inhibitor) resistant wild radish? Visiting researcher, Mei Li, along with other AHRI researchers, set out to answer this question. Unfortunately, the answer is NO! Wild radish, with four different target-site ALS mutations, were equally as fit as…

Many a late night has been spent over a glass of red at weeds conferences around the world debating whether high or low herbicide rates lead to faster resistance evolution. All weed scientists have an opinion on this issue, some of which are held very tightly. To some extent, the debate is still raging because the answer is not straight forward. The answer is both. As you can imagine, both sides of the debate are claiming victory! What we do know is that low herbicide rates have been documented to lead to rapid resistance evolution to Hoegrass®, Roundup® and Sakura®…