Australian Herbicide Resistance Initiative (AHRI)

Blog: AHRI insight

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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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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