Australian Herbicide Resistance Initiative (AHRI)

Blog: AHRI insight

Australian Herbicide Resistance Initiative (AHRI)

How trifluralin resistance works

Do you know what a microtubule is? If you could dream up the most complex way to make a tube, microtubules are it! Assembling a microtubule is about as complex as assembling a car, and there are thousands of them in every cell, in every living thing. If you aren’t super interested in the detail, all you need to know is that trifluralin kills plants by binding to microtubules and stopping cell division. AHRI researcher Qin Yu and her team of Chinese PhD students have recently identified the exact mutation in microtubules that stops trifluralin binding to them and causes…

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Australian Herbicide Resistance Initiative (AHRI)

Wild radish random AHRI survey of Western Australia

The most recent AHRI random resistance survey by researcher Mechelle Owen reflects exactly these observations. The survey visited 500 fields in 2015 and found only 65 wild radish populations in crop compared to 96 in the previous survey in 2010. There were fewer populations of wild radish found in the crop in the north, and more populations found throughout the rest of the state. As you may expect, herbicide resistance levels in wild radish have generally increased a little between the 2010 and 2015 surveys. Click through to read more.

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Australian Herbicide Resistance Initiative (AHRI)

Has herbicide resistance in ryegrass in WA plateaued?

“The nice part about being a pessimist is that you are constantly being either proven right or pleasantly surprised.” George Will, American journalist, author and Pulitzer Prize-winner. We are not pessimists at AHRI, but let’s face it, we rarely have good news when it comes to reporting on the level of resistance progression on Australian farms.  We are normally proven right that herbicide resistance levels are continually increasing. The latest results from the AHRI random ryegrass resistance survey of WA led by Dr Mechelle Owen isn’t necessarily good news, but it’s about as good as we could have hoped.  We…

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Australian Herbicide Resistance Initiative (AHRI)

iHSD – encouraging research despite challenges during 2017 harvest

It would be remiss of us to talk about the latest integrated Harrington Seed Destructor (iHSD) research without acknowledging the challenges with this new machinery during the 2017 harvest. It was frustrating for everyone, but the researchers, manufacturers and suppliers are playing the long game, and they are dedicated to succeeding in the long run. Recent research by Michael Walsh commenced at AHRI and was completed at Sydney University with help from John Broster at Charles Sturt University (CSU), shows that despite the problems that have been experienced with the new machines, iHSD mills are passing the research tests with flying…

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Heping Han

Australian Herbicide Resistance Initiative (AHRI)

Glyphosate resistance and plant fitness

Things that affect your fitness: Christmas – go on, have one more serving of trifle, it is only wafer thin! Television – for example, spending five full days watching the Boxing Day test match cricket. Each on their own are not too bad, but put them together and we have a problem. Things that affect plant fitness: The TIPS mutation that causes high-level glyphosate resistance. The TIPS mutation is a double mutation of the glyphosate target site, the 102 and the 106 mutation. The 106 mutation has been found in a number of species and has no fitness penalty associated…

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Australian Herbicide Resistance Initiative (AHRI)

First report of propyzamide resistance

When your job is as an agronomist or weeds expert, it’s important to have a spectacular, weed-free lawn. Any agronomist worth their salt knows that propyzamide applied in autumn, just before the winter rains, is the answer to your winter grass (Poa annua) problems. Greenkeepers from the golf courses of the world also know how good propyzamide is on winter grass, or annual bluegrass as it’s known in the USA, and they liberally apply it at least once a year. It’ll come as no surprise to you that this practice has now resulted in the world’s first documented case of…

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Australian Herbicide Resistance Initiative (AHRI)

Selfish weeds can manipulate the nitrogen cycle to suit themselves

Weeds are selfish, self-centred, narcissistic, manipulative pieces of work that will do whatever it takes to make themselves look good and make the other plants around them look bad. Some weeds are so self-obsessed that they can manipulate the soil nitrogen into a form that is just the way they like it. New research by Cathryn O’Sullivan from CSIRO is showing that some weeds release chemicals from their roots that slow down the bacteria that are essential to the nitrogen cycle, retaining nitrogen in the ammonium form that weeds can potentially take up faster than crop plants. Totally selfish! Click…

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Australian Herbicide Resistance Initiative (AHRI)

Sowthistle – know the enemy, exploit its weakness

Going into the 1932-33 Ashes tour in Australia, Don Bradman was averaging around 100, and he had averaged 139 in the 1930 tour of England. He seemed unbeatable. How then, did he go on to only averaging a paltry 56.57 in 1932-33 Ashes? Simple, the English cricket team had discovered his weakness, short, fast, leg side bowling known as bodyline, and they employed this tactic much to the chagrin of the Australian public. ‘It’s just not cricket!’ When we are faced with a new enemy, that is seemingly unbeatable, we need to investigate its weaknesses and then perhaps we can…

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Australian Herbicide Resistance Initiative (AHRI)

When does a seed become a seed?

When does a fracas become a melee? When does a cake become a soufflé? When does a wild radish seed become a viable seed, after which time spraying with a crop topping herbicide becomes futile? We know that for grass weeds we need to crop top or spray top sometime between flowering and milky dough of the grass seed (depending on the herbicide) to achieve high levels of control, but this timing is not well understood for broadleaf weeds such as wild radish. In the early 2000’s, Dr Aik Cheam from DAFWA did a great job of describing the critical wild…

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Australian Herbicide Resistance Initiative (AHRI)

How a new wheat variety could compete with weeds like Jonah Lomu did on the field

Jonah Lomu stood at 6’5”, weighed 120kg, and ran the 100m in a lazy 10.7 seconds. He could play the power game, the speed game, and he could step. He was the ultimate competitor. Mace wheat, on the other hand, is agile, dependable, and can play the yield game, but its ability to compete with weeds is limited. However, yield is king, and hence Mace has been an extremely successful variety where weeds are under adequate control. What if we could have a wheat variety that could play the yield game and the competition game? What would that look like?

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