Australian Herbicide Resistance Initiative (AHRI)

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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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Australian Herbicide Resistance Initiative (AHRI)

Microbial degradation of propyzamide – will we have a problem?

Some excellent research conducted by Stephen Hole, under the watchful eye of Professor Steve Powles at the University of Adelaide in the mid-1990’s investigated the microbial degradation of propyzamide and another similar herbicide, carbetamide. Enhanced microbial degradation is where the soil bacteria that can eat a particular herbicide build up to very high levels so when the herbicide is applied it is broken down very quickly, effectively reducing the half-life of the herbicide.

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narrow windrow burning

Australian Herbicide Resistance Initiative (AHRI)

Harvest weed seed control is now mainstream

Australians invented the lawn mower, rotary clothes hoists, plastic bank notes, WiFi, the electric drill, and five of the six harvest weed seed control (HWSC) techniques. And while the Canadians invented the chaff cart (to feed livestock) it was Australian farmers and researchers who started using it for HWSC. So we’re going to claim HWSC as a true blue Aussie invention too! We are the inventors of some of the key tools of HWSC and a recent GRDC grower survey has shown that we are by far the world leaders in the adoption of these practices. Not so long ago…

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stressed weeds

Australian Herbicide Resistance Initiative (AHRI)

Why thirsty weeds are hard to kill

Unfortunately, large parts of Western Australia, South Australia and Queensland are as dry as a London newspaper! This edition of AHRI insight looks to address the issue of spraying stressed weeds. We had to go back to 1995 to find some relevant research, but it was worth it. The GRDC funded research conducted by Dave Minkey and John Moore at DAFWA in the 90s is pure gold! In a dry year, we’re often faced with the whole kit and caboodle – moisture stressed weeds, high temperatures, low relative humidity and long durations between rainfall events.

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HSD

Australian Herbicide Resistance Initiative (AHRI)

Harvest weed seed control tools – they all work

On November 5th, 2010, a truck arrived at Yuna at the northern tip of the Western Australian wheatbelt. Its cargo was a John Deere 9650 harvester with a tow-behind Harrington Seed Destructor attached. Twenty local farmers had arrived to see the new machine that they’d heard about for so long. And what did he find from two years of this GRDC funded, AHRI supported research? One, solitary number: 60%. That’s not the whole story though…read on for more!

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Australian Herbicide Resistance Initiative (AHRI)

Double breaks – a double shot at annual ryegrass

Short black, long black, double shot, double break? Coffee preference is a little like crop sequences. Perhaps you’re a ‘short black’ wheat-canola type, strong on inputs? Or a ‘long black’ type who likes to dilute their rotations a bit more? When it comes to managing annual ryegrass populations, Tony Swan and the research team from CSIRO Plant Industry and FarmLink, have shown that ‘double shots’ are the key.

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Stubble

Australian Herbicide Resistance Initiative (AHRI)

Herbicides and stubble – some wash off, some don’t

Which herbicides wash off wheat stubble? Ask any farmer how hard it is to wash the yellow trifluralin stain out of their clothes and you had better be ready for a tirade of domestic hardship! “I just throw them straight in the bin these days”, commented one irate farmer. “I would sooner try and wash off a tattoo than remove that horrible yellow stuff from my work shirts.” No wonder the urban myth tells us that trifluralin was originally developed as clothes dye. If Yaseen Khalil’s recent research is anything to go by, trifluralin would make a wonderful dye and…

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Gayle Somerville, pre-em

Australian Herbicide Resistance Initiative (AHRI)

Why do pre-em herbicides last so long before resistance bites?

Once in a while, someone comes along and asks a question that you have never given much consideration to. Like, “Why does beer garden beer taste so bad?” or “Why do hotels always give away piles of stuff except for what you actually need, like a toothbrush or a razor?” and “Why do our pre-emergent herbicides last longer than our post-emergent herbicides before resistance bites”? Sure, we had probably considered this question in the past, but many of us would have just assumed that the gene frequency for resistance to our pre-emergent herbicides was low. However, Gayle Somerville, who recently…

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