Australian Herbicide Resistance Initiative (AHRI)

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Australian Herbicide Resistance Initiative (AHRI)

Low dose phenoxy resistance

Once upon a time we used to argue about whether smoking was bad for your health. We don’t argue about that anymore. In the world of weeds, we used to argue whether low herbicide rates cause herbicide resistance. We don’t argue about this anymore. Both low rates and high rates of herbicide can cause herbicide resistance, but it seems that low rates are the fast track to herbicide resistance. Dr Mike Ashworth from AHRI, evolved resistance to 2,4-D in wild radish. Mike started with only a few hundred plants of a known herbicide susceptible wild radish population, and in just…

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Australian Herbicide Resistance Initiative (AHRI)

Mungbeans, you will never guess which row spacing is best!

If you have ever tried to use a Philips head screwdriver on a slotted head screw, or hammer in a nail with the back of a spanner, you know how important it is to have the right tool for the job. Mungbeans are often sown with a planter on 1m row spacing that was designed for cotton, maize or sorghum because this is what the grower has and it is hard to have a different planter for every crop. But is it the right tool for the job? We have previously reported on the benefits of narrow row spacing of…

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Australian Herbicide Resistance Initiative (AHRI)

Narrow row spacing – more crop, fewer weeds

It would be really nice if research told us that fast food, chocolate and lollies were better for us than a balanced diet. We could eat what we want without a care in the world. There are those who believe that junk food is good for you, but the science doesn’t support this belief. It would also be nice if research told us that wide row spacing increased grain yield while improving weed control. Wide row spacing is cheap and convenient. Fewer tines or discs to pull, easier stubble handling, good herbicide safety, less fuel and horsepower required, cheaper machinery,…

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Palmer pigweed

Australian Herbicide Resistance Initiative (AHRI)

Warm water

Some things in life are best served warm. It’s just the way it is. The evening meal, toast, custard, hollandaise sauce, herbicide spray water… New research by Devkota and colleagues from Purdue University in the USA tells us that cold water may not be as good as warm water when spraying weeds. They found that when they sprayed giant ragweed and morningglory with a glyphosate + dicamba mix, weed control was improved anywhere from 6% to 26% by using spray water that was 18°C to 39°C compared to 5°C. This response didn’t hold true for all of the weeds in…

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Australian Herbicide Resistance Initiative (AHRI)

Wild oat resistance takes effort

Many young people don’t like the taste of beer, but they know if they work hard, endure the awful bitter taste and hideous hangovers for a few years, they will eventually like the stuff. It takes effort, but if they stick at it long enough they can get there. And, believe it or not, you have to work pretty hard to evolve resistance in wild oats. But if you stick at the same practice long enough (it takes effort), you can get there! We have previously reported AHRI research showing that wild oats evolve resistance slowly because they are both…

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Australian Herbicide Resistance Initiative (AHRI)

Stay native to the (communication) platform

You can’t have your cake and eat it. But what’s the point of cake if you don’t eat it? Ok, we’ve (deliberately) misinterpreted the saying here, but you get the drift. What is the point of doing research if you don’t tell anyone about it? A lot of money is spent on agricultural research, and we need this research to reach the farmer (otherwise, what’s the point?). Everyone’s time poor and, these days, we’re all bombarded with more info than ever. This means that good communication of this info is more important than ever. There’s more to communication than scientific…

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Australian Herbicide Resistance Initiative (AHRI)

Clean seed – most improved

The Carlton football club have improved out of sight this year. The mighty Blues have already won more games than they did last year and the season isn’t even half done! But they still have room for improvement. The Fremantle Dockers on the other hand… Grain growers in WA get the most improved award for seed cleaning this year. A study by AHRI researcher Mechelle Owen in 2015 found that 41% of grower seed samples were completely weed free compared to 27% when the survey was first conducted in 2008. Gold star to these growers! The 2008 study concluded that…

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Australian Herbicide Resistance Initiative (AHRI)

Harvest Weed Seed Control in the North (it’s possible)

Two English shoe salesmen were sent to Africa in the late 1800’s to see if there was a market for their product. The first salesman reported back, “Situation hopeless, no-one wears shoes, returning home immediately.” The second salesman reported back, “Glorious opportunity, no-one wears shoes.” Salesman two is the real entrepreneur, the person who sees opportunity where others do not. Very few grain growers in Queensland or northern NSW use harvest weed seed control. Many feel that most weed seeds shed before harvest so there is little point. Funnily enough, this is what the Americans said, and it turns out…

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Australian Herbicide Resistance Initiative (AHRI)

How stuff works: 2,4-D, free radicals and monkeys

It’s pretty amazing that 2,4-D is our oldest herbicide, yet scientists have only just worked out how it actually kills weeds. This has taken years of research by many researchers to understand. So, like the monkey Curious George, we set out to understand how 2,4-D works (trust us, click through to the full post and the monkey analogy will make sense!) 2,4-D works in three stages: first, it over-stimulates plant growth; second it closes the stomata and shuts down photosynthesis. And finally, the plant eventually starves to death as it works hard to detoxify the free radicals. In a nutshell:…

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Australian Herbicide Resistance Initiative (AHRI)

2,4-D Gridlock

Picture yourself as a city slicker driving to work. Between your house and the freeway there are four sets of traffic lights. On this particular day all of the traffic lights are stuck on red. The city is in chaos with no-one able to get to work. You then spend the rest of your life, in your car, at a red traffic light. Perish the thought! This is how 2,4-D resistance works in wild radish. The traffic lights are transporters that allow 2,4-D to move from cell to cell, and the freeway is the phloem – the plant veins that…

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