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Fleabane a bane but control is possible

Flaxleaf fleabane, which is increasingly an issue for Western Australian grain growers, is difficult to kill, particularly when mature, and its germination is favoured by factors including good spring rainfall.
However, if growers use a range of control tactics and monitor paddocks vigilantly, successful control is possible.
Grains Research and Development Corporation (GRDC) plant health technologies program manager Ken Young said research showed that optimum control came from targeting young, small fleabane (seedlings and young rosettes) as herbicide efficacy decreased as the weed matured.
“A double-knock approach is needed for dense infestations, especially if weeds are more than one month old,” he said.
“To reduce the likelihood of resistance developing, use full label rates of herbicides, rotate herbicide groups and prevent seed set of survivors.”
Information about managing fleabane is available in the GRDC Flaxleaf Fleabane Fact Sheet, and was included in the September/October edition of the GRDC magazine Ground Cover.


“Weed Management – It’s a numbers game” national webinar

Managing resistant weeds and prolonging the life of herbicides were hot topics at the national web broadcast coordinated by WeedSmart on Wednesday, 16th October.
The internet broadcast titled “Weed Management – It’s a numbers game”, featured a video discussion with leading weed researchers, farmers and agronomists, and allowed growers to ask questions of the panel from wherever they were sitting at a computer.
Peter Newman, panel facilitator and Leader of Communications at the Australian Herbicide Resistance Initiative (AHRI), said the spread of herbicide resistance in weeds and the threat this poses to farming systems across Australia is the most widely significant issue confronting grain growers.
“When herbicides were working well most growers were not overly worried about the size of the weed seed bank because they could spray the weeds and grow a profitable crop. As herbicide resistance takes hold the only option to continue cropping is to take a long term view and strive for a very low seed bank using a diverse range of tools. Herbicide resistance is not a problem if you have no weeds!” Mr Newman said.
“The discussion addressed the range of options available to help manage the weed seed bank, as well as general strategies to help promote the long term sustainability of herbicides
“We’re keen to hear from growers about their concerns and the panel was there to answer their questions in real time,” he said.
The discussion was held at Wagga Wagga’s Agricultural Institute Conference Facility.


Producers tackling herbicide resistance

Farmers in the Cranbury area are tackling the emergence of herbicide resistance with an innovative project.

Cranbury Landcare group have been successful in the latest round of Caring for Country funding for sustainable agriculture from the Federal Department of Agriculture Fisheries and Forestry.
The project “Measuring and Managing Herbicide Resistance in No Till Cropping” will allow members to have access to subsidized herbicide resistance testing of their weeds through Charles Sturt University, Wagga.
According to chairperson Lawrence Balcomb, weeds are becoming more of an issue for farmers in the district.
“In the last twenty years there has been a massive switch to no till cropping with the majority of crops now sown in one pass,” Mr Balcomb said.
“This has put increased pressure on herbicides to control weeds.
“There has been a few positive resistant tests in the last two years as well as other anecdotal signs of resistance in our area.”
Growers hope to get a better understanding of how resistance happens and the extent of the problem in the district through this project.

Funding has also been allocated to run field days and a bus trip to help locals get some expert advice on integrated weed management.
The idea for the project came from a landcare meeting in February where weeds were a major topic of discussion, Mr Balcomb said.
“Some growers in our area have been experimenting with windrow burning, green and brown manuring.
“These non chemical means of control are widely used in Western Australia and South Australia but are only in their infancy in the eastern states.
“If we want to keep our existing chemical controls working then these practices may help.”
The first of two field days will be held at Cranbury Church Hall on October 30.
Coming up from Charles Sturt University Wagga will be their head of resistant weed testing John Broster.
John is also a member of the Australian Herbicide Resistance Initiative based at the University of W.A.
He will be giving a presentation on the current spread of weed resistance in Australia and explaining the mechanics of testing for resistance.
He will also outline the positives and negatives of different non chemical weed controls.
Following John will be Maurie Thomas, CEO Orana Grain Alliance and Dubbo district farmer.
Maurie, in conjunction with GRDC, has been doing windrow burning trials on his property for the last two seasons.
He will explain how it fits into his weed control program.
After lunch the focus will be growers getting ideas for their own robust weed management plan.


Scientists battle glyphosate resistance in Italian ryegrass

Mississippi State University scientists are leading the charge in the fight against glyphosate-resistant Italian ryegrass with a research-based plan of attack.
Jason Bond, a weed scientist at the MSU Delta Research and Extension Center in Stoneville, said Mississippi was the first state to discover Italian ryegrass that cannot be controlled with glyphosate, a common herbicide originally known as Round-up, in a crop situation. The weed has spread quickly since it arrived.
“We have 32 counties that contain glyphosate-resistant Italian ryegrass,” Bond said. “The state with the next highest amount is Arkansas, and they have eight counties with this problem. We’ve been working on this challenge since 2005, and everyone is looking to Mississippi for recommendations.
Bond said he and his colleagues with the Mississippi Agricultural and Forestry Experiment Station and the MSU Extension Service are very confident about the effectiveness of the research-based program they developed to control glyphosate-resistant Italian ryegrass. It is based on the use of other types of herbicide applied at specific times.
“Our program requires a minimum of two herbicide applications to even approach complete control,” he said. “Ideally, growers will use fall, winter and spring herbicide applications for total control.”
Bond said growers should make the first herbicide application in fall, from mid-October to mid-November; the second in winter, from mid-January to early February; and the third in spring, around March 1.
“Many of our Delta growers already use post-harvest herbicides in the fall,” he said. “They do a lot of tillage after harvest and don’t want to disturb the fields before they plant, so they put down an herbicide to control winter vegetation. That practice isn’t typical in other states, so some growers hesitate to invest in that application. But to control glyphosate-resistant Italian ryegrass, they need to put down a residual herbicide to control it before it comes up.”
Bond said growers who do not take steps in the fall to control glyphosate-resistant Italian ryegrass find it more difficult to control later. He and his colleagues have tested a variety of factors to develop their approach.
“We’ve sprayed around 50 residual herbicides to test their effectiveness, and we’ve found five or six that are active against glyphosate-resistant Italian ryegrass,”
he said. “We haven’t kept track of post-emergence herbicides we’ve tried, but I’d guess easily over 100. Basically, at one time or another, we have sprayed every herbicide with any activity on grass species that is labeled for use in corn, rice, cotton or soybean.”
Once Bond and his colleagues developed their recommendations and collected more data to verify their approach worked, they tackled the research from a yield perspective.
They began with test plots: some were free of ryegrass; some had been treated with two to three herbicide applications; and some were not treated at all and were carpeted with ryegrass.
“We applied different levels of our herbicide program and planted corn, cotton or soybeans,” he said.
Then they monitored the yields from each test plot to see how the invasive weed impacted production.
In 2012, MSU researchers found corn was the most susceptible to yield reduction because of uncontrolled glyphosate-resistant Italian ryegrass.
“When we controlled glyphosate-resistant Italian ryegrass in corn, the benefit-to-cost ratio was 13:1,” he said. “For every dollar spent to control glyphosate-resistant Italian ryegrass, we received a $13 return in corn yield. Even if that was only 2:1, the inputs still paid for themselves.”
Unfortunately for growers, Italian ryegrass is not the only glyphosate-resistant weed they have to manage.
Mississippi has the dubious honor of having more documented glyphosate-resistant weed species than any other state. While new control technologies are on the horizon, for now, growers must battle some type of weed year-round.
Darrin Dodds, cotton specialist with the Mississippi State University Extension Service, said each year more weeds are identified as resistant to herbicides.
“Mississippi has had documented resistance to herbicides as far back as 1989, when common cocklebur was identified as being resistant to a certain class of herbicides,” Dodds said. “But beginning in 2003, the number of weeds resistant to glyphosate began steadily increasing: horseweed in 2003; Italian ryegrass in 2005; Palmer amaranth in 2009; johnsongrass, common waterhemp, and giant ragweed in 2010; and goosegrass and spiny amaranth in 2012.
“Mississippi row crop producers need to be as adaptable as the weeds they fight, because herbicide-resistant weeds are here to stay,” he said.
For herbicide program information, visit http:///
or the Mississippi Crop Situation Blog,
To read the original article, click here.


Weed management – it’s a numbers game!

You are invited to take part in an interactive web broadcast on Wednesday, 16th October 2013 with leading weed researchers, farmers and agronomists who will answer questions on the latest strategies to manage weed numbers in broadacre crops.
The discussion will address the range of options available to help manage the weed seedbank, as well as general strategies to help promote the long term sustainability of herbicides.
Enabled by the latest technology, the web broadcast will be streamed on the internet and growers from across Australia will be able to ask their own questions of the panel – live!
Panel speakers will be at the Wagga Wagga Agricultural Institute Conference Facility and include:

Peter Newman, Leader of Communications, Australian Herbicide Resistance Initiative
Ray Harrington, Darkan grower (WA) and developer of the Harrington Seed Destructor
Lachlan Caldwell, Agronomist with Delta Agribusiness, at Lachlan Fertilizers Rural, Grenfell.
Prof. Dierdre Lemerle, weed scientist and Director of the Graham Centre for Agricultural Innovation (an alliance between Charles Sturt University and NSW DPI), Wagga Wagga
Murray Scholz, Culcairn grower (NSW) and Nuffield Scholar.
Michael Widderick, Principal Research Scientist (Weeds), Agri-Science Queensland, Department of Agriculture, Fisheries and Forestry, Queensland

Event:     Weed Management – It’s a Numbers Game!: Live Web Broadcast
When:     Wednesday, 16 October 2013
                @ 12pm – 1:30pm (Australian Eastern Daylight Time)
To register and view the broadcast visit:
Login prior to the event on the computer and use the click “test” to ensure the web conferencing software is compatible. You will need the latest Flash player.
During the broadcast questions can be asked via a ‘chat’ window on the webcast page or by tweeting #weedsmart. You can also email questions in advance to Kate Leahy at

For more information about the broadcast please contact Kate Leahy on or phone 02 6020 3247.


Get to know your soil moisture

Understanding the current soil moisture levels within each paddock is paramount leading into summer crop planting and help is at hand for northern region growers facing a dry start to the season.
A new research paper presented at the Grains Research and Development Corporation (GRDC) Updates provides a comprehensive outline of the tools available to cost-effectively measure soil water leading into summer crop planting.
However CSIRO researcher Neal Dalgliesh warns soil water can be effectively monitored to assist managers in crop decision support but given the inherent variability of northern cropping soils and currently available sensor technologies it is difficult to achieve high levels of accuracy.
“Given the vagaries of the system, there are a number of technologies which will provide a level of information useful in decision support that aren’t cost-prohibitive,” Mr Dalgliesh says.
“Devices include in-situ devices that have relatively small zones of measurement and rely on good soil/sensor contact to measure soil water are at a disadvantage in shrink/swell soils where soil movement and cracking are typical.
“In comparison, the use of a portable EMI device to measure bulk electrical conductivity and calculate soil water has a number of advantages.”
He says EMI is quick, allowing for greater replication, measures the soil moisture of a large volume of soil (to 150 centimetres depth), is not affected by cracking or soil movement and does not require installation of an access tube thus making it available for use on multiple paddocks.
The downsides are that it is unsuitable for use in saline soils and does not apportion soil water to particular layers within the soil profile, he says.
To download the GRDC Update paper detailing soil moisture measurement, click here
For more information on GRDC-supported research, visit


Cropping in the digital age – support at growers’ fingertips

Farm dogs beware – digital technology is increasingly proving to be a grain grower’s best friend.
The digital age is providing growers with easy access to resources and support tools in their quest to lift efficiency and productivity, according to the Grains Research and Development Corporation(GRDC).

Agricultural consultant and GRDC Southern Regional Panel member Bill Long  (left), of Ardossan, SA, demonstrates the Yield Prophet® online crop-production model to Barry Mudge of Port Germein, SA. The benefits of using the Yield Prophet® model are outlined in the GRDC’s Cropping In The Digital Cover supplement.
GRDC’s Manager of Delivery Platforms, Tom McCue, says technology is rapidly changing and making it possible for growers and advisers to capture farm information in real time and share this information immediately with a wide network.
“Data can be captured in cloud-based systems, enabling it to be viewed and analysed across multiple platforms,” Mr McCue said.
“Growers and advisers can access large volumes of information almost immediately upon its capture – making on-farm decision-making quicker and more efficient.”
Mr McCue said the GRDC was converting some of its research, development and extension outputs into easy-to-use and accessible applications – such as Weed ID and Insect ID apps – and more decision-support tools are planned for the future.
For further details, go to


Herbicide resistance is manageable, says Australian expert

GREENSBORO, N.C. — Long before herbicide-resistant weeds were making headlines in the U.S., Australian wheat producers were taking steps to solve the problem.
Stephen Powles, weed expert and professor of plant biology at the University of Western Australia and the director of the Australian Herbicide Resistance Initiative, recently spoke at Syngenta’s headquarters on diverse weed management options.
“Basically what’s playing out here in the U.S. is similar to what played out with in Australia some time ago,” he said. “It wasn’t glyphosate. It was a different set of circumstances, but big-time resistance occurred in Australia from 1990 or so on.”
The herbicide resistance in Australia came about when the country was transitioning land from primarily large sheep farms to crop production.
“Wool was the big industry. There were a lot of sheep, and the profitability went out of that when people stopped wearing wool,” Powles said. “We planted ryegrass coast to coast when the sheep was king.”
As the wool industry declined, wheat became the major crop and high densities of ryegrass had to be removed.
Powles said to transform the pastures to cropland, one herbicide chemical was used “with no diversity in the system — and, of course, you get an evolution of resistance in the ryegrass.”
“As you contrast that to the U.S., it’s where the whole south and the Midwest got covered in one great big glyphosate field,” he said.
“So we got big-time resistance in the 1990s onward, and it has multiple resistances across several herbicides, so you couldn’t just reach for another jug to fix the problem. We just had to change our ways, and the U.S. farmer hasn’t learned that yet.”
In an interview with AgriNews , Powles said there were multiple strategies Australian farmers used to control resistant weeds.
“The first thing is the herbicides remain the single-best tool. The herbicide is the bit of crucial technology, but you can’t just rely on it, so we had to diversify our system,” he said.
“We had to never keep using the same chemical. We had to rotate crops. And we had to put some non-chemical tools in there that made sense.”
Diversity and not relying on any one herbicide are recommended, but make sure the strategies are within an economic reality.
“You might like to do something, but if you can’t do it profitably, you can’t do it,” Powles said. “As an example, we always use a pre-emergent residual herbicide — those that still work. We always use a burndown, but we wouldn’t rely just on glyphosate. We’d rotate it.
“The big thing that we do is at the end of the season we have some techniques to kill weed seeds during harvest time. That’s something no one does here.”
Harvest weed seed control provides an opportunity to target future weed populations. Problematic weed species are prolific seed producers capable of establishing a large viable seed bank in just one season.
However, very high proportions of weed seed are retained in upright stems and tillers of the weeds at crop maturity. This creates the potential to target these seed during harvest, thus restricting the inputs to the weed seed bank.
One method of weed seed control is with a chaff cart towed behind the headers during harvest to collect the material as it exits the harvester. The material is then either burned after harvest or used as a feed source for livestock.
Another option used in Australia is the Harrington Seed Destructor that collects the chaff behind the combine and destroys any weed seeds present. The nonviable weed seeds the exits the harvester.
“There are a range of techniques that we do to try to stop the weeds from producing seed,” Powles said.
Another option would be returning to the days of walking fields with hoes. During his recent visit to central Illinois, Powles said he heard of hand crews performing their own harvest weed seed control by chopping weeds at a cost of between $30 and $100 an acre.
“We have a range of mechanical ways of doing that,” he said.“I’m sure U.S. farmers are going to become much more familiar with all those sorts of things over the next few years.”
The key to all weed management is multiple modes of action and more.
“Don’t get me wrong. I love herbicides. I think herbicides are the absolute best way to control weeds. But they’re not much good when they don’t work,” Powles said.
“So the only way to insure they continue working is to use as much diversity as makes economic sense. I find that here in the U.S. pretty much the creativity is confined to one herbicide can I fix this problem with.
“‘Oh, I’ve got a problem. I have glyphosate resistance.’Well, what herbicide can I use to fix the problem when in fact the better question is how can I make my herbicide use sustainable in the long term.
“That just involves thinking about all of the possibilities. What good agronomy can you do? We keep seeing these very wide row soybeans. I bet the weeds love that.
“Some agronomic things will have a big impact. One of the problems right now is that the U.S. farmers don’t fear the weeds. They don’t have much respect for them. Well, a couple million years of evolution and they’re a pretty formidable opponent.
“I’ve learned to respect these weeds. You get something like waterhemp or pigweed, it’s a formidable opponent. You better be using all the control tools at your disposal if you want to get on top of plants like that.
“You should fear them and respect them because if you use any single tool against them, they’ll overcome it.
“I just spent a week in Illinois. What fabulous crops. What fabulous cropping country. What fabulous soils. They’re not going to stop farming, but they’re going to have to be more creative than they have been. And they can do it. That’s the main thing.
“Resistance is entirely a manageable problem. No need to get depressed. Just get on it and start handling it and don’t just rely on the next chemical.”
The original article was published by Agrinews.


Putting herbicides to the test

Relying on herbicide resistance test results from a neighbour or neighbouring paddock can be a waste of time, according to weed testing specialist, Dr Peter Boutsalis.
“Every paddock is different and testing each paddock for herbicide resistance gives growers a baseline to know whether a particularly herbicide will work – before the investment is made,” Dr Boutsalis says. “Guessing or ‘borrowing’ a resistance profile from another paddock can be inaccurate.”

Dr Peter Boutsalis says the main plants being sent in from the southern grains area include ryegrass, brome grass, wild oats, barley grass, phalaris and some broadleaf weeds (Source: Chris Minehan).
Dr Boutsalis is a GRDC funded researcher with the University of Adelaide in weed control and also operates Plant Science Consulting, which provides a commercial plant and seed testing service for growers Australia-wide.
A second herbicide resistance testing service operates out of Charles Sturt University (CSU), Wagga Wagga, NSW and predominately tests weed seed samples.
“One of the most important times to test is during the growing season,” Dr Boutsalis says.
“The weed plant test is called a QuickTest and it involves removing 50 to 100 plants from the field, packaging and dispatching to our Adelaide site.
“This can be done before or after herbicide application but the plants need to remain almost dry during transport to avoid rotting.
“If the soil has been washed off, the plants need to be blotted dry and placed in a waterproof, sealed plastic bag (eg. Ziplock bag) and sent via Express Post. More importantly, leaves must not be wet”
Once the package is received, the plants are trimmed and potted until new growth occurs.
“Within a week we get new leaves emerging, it is a young plant again. Once that happens we spray them in an accurate spray cabinet according to the herbicides the grower wishes to test,” he says.
“We get a result – alive or dead.”
All grasses can be tested effectively, along with young broadleaf weeds including wild radish and mustards.
Dr Boutsalis says the advantage of the QuickTest compared to seed testing is that it saves several months, rather than waiting for results from seed testing.
Nevertheless, sometimes it’s more convenient for seed testing, especially if a trifluralin test is important.
The main plants being sent in from the southern grains area include ryegrass, brome grass, wild oats, barley grass, phalaris and some broadleaf weeds including wild radish.
“The beauty of the QuickTest is that if the plants are still green and in the vegetative stage you can test for resistance – even if they’ve multi-tillered.,” Dr Boutsalis says.
“For grass weeds, the QuickTest takes four weeks from the time the plants are received until the results are conveyed to the farmer. Broadleaf species require more time”
“You know you are testing the actual weeds that have caused the problem in the paddock at that time.”
Testing seed gives growers another opportunity in determining the resistance profile of their properties and southern region growers send seed to Plant Science Consulting between October to January for testing.
Samples are cleaned and dried but the hurdle is dormancy until March-April.
“We have a dilemma in that the seed is dormant during summer but the farmers want their results so they can make decisions for the next growing season,” Dr Boutsalis says
“We have to try to break dormancy and ‘convince’ the seeds to germinate by using various chemicals or manipulating light and temperature. Each species has different conditions required to break dormancy.”
Packaging seed for dispatch is best done in two layers of paper bags and sent via Express Post.
“This is important, particularly in the early part of the season when the seeds are still actively respiring and can rot if placed in plastic bags.”
For more information on testing services, visit or


War on weeds won at harvest

Controlling weed seeds at harvest is the best strategy to prolong the life of herbicides threatened by resistant weed populations.
Michael Walsh, of the Australian Herbicide Resistance Initiative, said harvest weed seed control played an important supporting role to other strategies that focused on early season weed control.

Battleground: Michael Walsh in a wheat paddock, with a Destructor in the background
“If there is one message we want to deliver, it is to control weed seeds at harvest – whether that is using the Harrington Seed Destructor or a chaff cart behind your header, baling harvest residues, or narrow windrow burning, the key is to capture and destroy seeds from weeds,” Dr Walsh said.
The Harrington Seed Destructor, built by De Bruin Engineering in South Australia, has been entered in the Australian Machine of the Year Award at this year’s Elmore Field Days.
Research supported by the Grains Research and Development Corporation shows seedbanks of annual weeds can be rapidly depleted when weed seed control systems are used to capture or destroy weed seeds at harvest.
“Our weed control efforts are aimed at driving these seedbanks towards zero,” Dr Walsh said.
“Harvest weed seed control systems play an important role in that they are the last opportunity during the cropping season to attack weeds by preventing seedbank inputs. The key is: control the seedbank to control the weed.”
Dr Walsh said annual weeds such as ryegrass, wild radish, brome grass and wild oats had adapted to cropping systems, growing to similar heights as cereals and maturing at the same time as annual crops.
“For this reason, some growers may be sceptical about how much seed is captured at harvest, but AHRI research shows a very high percentage of total weed seed production is retained on plants at a height that ensures collection during the harvest operation.
“However, the best time to target these weed species is at the start of harvest as weed seed shedding occurs over the harvest period, reducing the amount of seed that can be collected and subsequently destroyed.”
Research showed that at the start of harvest high proportions of weed seeds were retained at least 15cm above the soil surface.
By harvesting at this height weed seeds were captured by the header.
Read the original article here.


Launch tactical assault on late season weeds

The Grains Research and Development Corporation (GRDC) encourages growers to consider harvest weed seed control (HWSC) tactics in addition to late season herbicide options to minimise weed numbers in subsequent crops.
Due to this year’s seasonal conditions, many Western Australian growers are dealing with higher-than-usual weed burdens in their paddocks in the lead-up to harvest.
GRDC plant health technologies program manager Ken Young said capturing and destroying weed seeds at harvest was vital in managing weed and herbicide resistance issues, and HWSC systems were the last opportunity during the cropping season to prevent weed seedbank inputs.
“GRDC-supported trials in WA have demonstrated that HWSC strategies – used in combination with herbicides – reduce weed populations to very low levels,” Dr Young said.
“HWSC options available to growers include chaff carts, narrow windrow burning, baling chaff and Harrington Seed Destructor (HSD) technology.
“It may be too late to make the necessary machinery modifications for some of these options prior to this harvest, but the GRDC strongly encourages growers to consider employing these techniques during future harvests.”
HWSC is the key strategy of the industry-led WeedSmart initiative which advocates 10 ways Australian farmers can fight herbicide resistance.
Dr Young said growers planning to apply herbicides to crops late in the season must follow product labels and adhere to withholding periods.
“Late applications to crops increase the risk of detectable herbicide residues in harvested grain, potentially leading to breaches of maximum residue limits,” he said.
Information about stewardship is available in the GRDC Pre-Harvest Herbicide Use Fact Sheet.


Knowing your farm business’s risk profile

The Grains Research and Development Corporation (GRDC) has produced a Fact Sheet to enable grain growers to develop a better understanding of their farm business’s risk profile.
A risk profile describes the combination of a business’s ability to incur risk and an individual’s personal risk attitude.
Understanding the business’s risk profile can improve communication and result in better decision making.
The Fact Sheet, produced as part of the GRDC’s Farm Business Management initiative that was instigated by the GRDC Southern Regional Panel, offers information on risk capacity and attitude to risk, illustrates a risk profile through a case study and advises growers on how they can use the information contained in the Fact Sheet.
The Farm Business Risk Profiles Fact Sheet can be viewed and downloaded here
For further details go to

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