Fitness is a big thing amongst the AHRI Comms team. We have bike riders, runners, a kitesurfer, a netballer, a touch footy player – and there’s only seven of us. Fitness is also a big thing in the world of herbicide resistance. Perhaps that’s why we’ve talked so much about herbicide resistance and fitness in past AHRI Insights. In particular, how certain types of glyphosate resistance result in a fitness penalty, where resistant plants are weaker and more susceptible to competition from other plants. Unfortunately, not all types of glyphosate resistance impose a fitness penalty. Click through to learn more.
What sort of person goes to a cocktail party and sticks strictly to beer? A smart one! We all know that mixing drinks can hurt the next day. We can’t say the same for herbicide mixing though. The smart farmers and agronomists are mixing two or more herbicides targeting the same resistant weed to delay resistance and maximise weed control, and the science is supporting this approach. AHRI researcher Roberto Busi is a long-term advocate of herbicide mixing and in his recent paper which describes some computer modelling that he undertook with the help of Michael Renton.
This AHRI Insight is a follow-up on an earlier article ‘Crops are doin’ it for themselves’ to where we investigated the complex interactions of competitive crops and their weed suppression powers. While that paper focused on cereals, in this one we will consider the mechanisms at play in canola, a crop from the mustard family, long known for its allelopathic ability and yet the exact mechanisms are still shrouded in mystery.
‘Trending now’ seems to be everywhere – iTunes, Twitter, the news, so why not herbicide resistance? What have been the #Top5 trends in resistance management over the past decade? As a young agronomist 20-something years ago (clearly before trending was a thing), I remember learning about the threat of herbicide resistance as if it was a kind of apocalypse. Some growers were genuinely concerned that they wouldn’t be able to continue farming. We’ve come a long way in a relatively short time. In this insight, we look closely at what’s trending in the herbicide resistance management space.
The ad in the paper that reads “Horse, free to a good home” seems to be a good deal at first, but what is the true cost of owning a horse? Roughly similar to running a Lamborghini as I understand! The ‘do it yourself’ narrow windrow burning chute seems cheap at the time, but what is the true cost? It depends…
Huan Lu’s been investigating a population of wild radish that has the infamous Ser-264-gly mutation. This is the target-site mutation that is behind TT canola and makes wild radish highly resistant to PSII-inhibiting herbicides like atrazine and, to a lesser extent, metribuzin. But, he wondered if there was more to this resistance than first meets the eye. Does focusing on the strong 264 mutation mean that we could fail to identify other important resistance mechanisms?
We answer a few poignant questions in this insight, including: ‘Can crops do more of the heavy lifting when it comes to weed control than modern farming methods have allowed them?’ or ‘Have we tried so hard to protect crops from weeds that we have forgotten that they have innate mechanisms to ‘stand on their own two feet’ and ‘do it for themselves’?’ A series of important studies into the practical implications of harnessing the crop’s ability to defend itself against weeds are starting to produce important results, leading to improvements in farming practice and the development of new cultivars.
As AHRI and Weedsmart Western region agronomist, Pete recently gave a presentation to a group of high rainfall farmers who were concerned that they hadn’t had a decent knockdown for three years in a row. What he came up with, based on research and experience, was that we definitely should not be waiting for a knockdown, but we need to throw enough weed management at the farming system to make it work. No knockdown, no worries, if… To find out what the “ifs” are, click through to read the insight.
Did you know that rotary hoeing requires less energy than steaming? Or that offset discing requires less energy than microwaving? Well, that’s the case when it comes to controlling weeds. An epic effort to review 170 papers by a team from the University of Sydney (Guy Coleman et al) has shown that mechanical weed control options (eg. tillage) can use significantly less energy than thermal options (eg. heat) to kill weeds. Herbicide energy use sits somewhere in the middle.
Roberto recently completed a project with GRDC investment where he sampled ryegrass from 17 paddocks across eight farms in Western Australia to see if there are benefits of proactively testing for herbicide resistance. Across these tests, he found ryegrass that was resistant to Clethodim (Select) or Butroxydim (Factor) but no ryegrass that was resistant to the mix of the two. The same went for the pre-emergent herbicides as well, no resistance to mixes.