We’re blowing up our most valuable herbicides on the least productive part of the farm. Fencelines, roadsides, drainage areas, etc. AHRI researchers, Dr Yaseen Khalil and Dr Mike Ashworth and others have confirmed the world’s most recent addition to the growing list of glyphosate resistant weeds: capeweed.
About 35 years ago a ryegrass population that had been sprayed several times with Hoegrass® (Diclofop) became resistant to that herbicide and cross resistant to Glean (chlorsulfuron) before Glean® or any other ALS herbicide had ever been used in Australia. P450 enzymes were suspected to be the cause of this cross resistance but it has taken until now to get the definitive evidence. A very patient group of researchers led by Heping Han from AHRI, including researchers from Bayer and Zheijiang University in China have identified the P450 gene responsible for cross resistance to herbicides of at least five modes…
Despite the challenges 2020 presented, there continued to be excellent research which was published throughout the year. In this post we have collated our top five most read AHRI insights and our top five most listened to podcasts for 2020.
AHRI researcher, Dr Roberto Busi is no philosopher, but he has recently published some significant research that shows that Aristotle knew a thing or two about herbicide resistance despite being born over 2000 years before the first herbicide. Amazing! The message from this research – never assume that a herbicide mixture will fail even if there is resistance to both components of the mix.
Some recent research by a former AHRI researcher Jingbo Li and others shows that glyphosate resistance changes this. They studied two populations of barnyard grass with relatively low-level glyphosate resistance and found that when 2,4-D Amine or Ester was added to the tank with glyphosate, barnyard grass control was greatly reduced. They went on to discover that this is due to an effect on uptake and translocation.
They said it couldn’t be done – climbing Everest, flying to the moon and even deep-frying Mars bars. We were also told that we couldn’t reverse herbicide resistance. In the majority of cases, the experts are right – herbicide resistance is permanent, and we thought that was the case for all resistant weeds. Until now…
This AHRI insight is not for the faint-hearted. This recent AHRI research by Chinese postdoc Hongju Ma and others documents the first case of metabolic resistance to metribuzin in ryegrass in Australia. The ryegrass in this population was only about 3 fold resistant to Atrazine and Metribuzin. The researchers used a P450 inhibitor, PBO, and radiolabelled metribuzin to help determine that the resistance is metabolism-based, likely due to P450 enzyme activity.
Welcome to the highlight reel of AHRI’s recently released blockbuster – ‘Don’t stick to it!’. Set in the labs, glasshouses and fields of this world-leading research powerhouse, and featuring renown giants of the herbicide resistance world – Powles, Busi, Yu and Owen, this latest exposé will have you seriously impressed! ‘Don’t stick to it!’ delves into five years of ground-breaking scientific discovery and its value to Australian farmers in their epic battle against profit-sucking weeds.
This AHRI insight is not for the faint-hearted. It is the work of AHRI researcher, Dr Danica Goggin who has dedicated many years to working out how auxin herbicides such as 2,4-D and Dicamba work, and how plants evolve resistance to them. Danica’s research found that plants with fewer receptors on their cell membranes were resistant to 2,4-D due to reduced perception of the 2,4-D. Putting this molecular biology research into words is challenging, so we have created some videos that explain it.
It’s a quaint tradition that many brides follow – ‘Something old; represents continuity with the past and ‘Something new’ offers optimism for the future. ‘Something borrowed’ passes on another’s secrets for success and ‘Something blue’ represent key features of a solid relationship. Finally, ‘A sixpence in your shoe’ for prosperity. With the release of several new modes of action and chemical formulations, it’s helpful to first consider how these ‘new’ chemicals might revive some ‘old’ chemistry.