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Strip grazing cattle to manage weeds

As the 2013–2016 drought bit harder in NSW’s Riverina, Ardlethan farmers Lou and Charlie Clemson were thinking about ways to better utilise more of their property, particularly the 200 ha of non-arable country.

Using a NSW State Government drought assistance grant to supplement their own funds they have installed a laneway through the middle of their property, Wongajong, to link the hilly paddocks with the stockyards and provide easy access to all the cropping paddocks between.

Lou Clemson says the laneway allows easy movement of stock through the cropping area and also provides an excellent confinement area with troughed water and creep feeders. The timbered hill paddock is key to the system’s success, providing native pasture for the breeding herd.

Lou says the changes to their business and their weed management have been amazing. “We now have another income stream, and cattle have been very profitable since the drought,” she said. “And we are using less herbicide to manage weeds.”

The re-introduction of livestock to Wongajong started in 2010 when the Clemsons bought 300 steers to make use of a frosted wheat crop. “We fed the steers for 5 months and made good money out of what would have otherwise been a failed crop,” said Lou. “After that we fenced off the hill and added the central laneway and watering points. We are really happy with how well this system is working and see benefits across our whole cropping operation.”

“Growing early varieties is the key to maximising the feed benefit of fodder crops such as Moby barley and Brenan and Naparoo feed wheats, which we plant in February or March,” she said. “In paddocks where we have some annual ryegrass pressure we have sown feed barley in February–March, weaned calves onto it in May and grazed until September. This 73 ha paddock alone turned off 200 prime yearlings.”

With some welcome rain in December, the Clemsons sprayed out the barley and took the opportunity to sow cowpeas over summer. “This year we weaned part of the herd in January and the calves went straight onto the cowpeas where they remained until late April. The cowpeas even podded up and we could have stripped them but decided to just continue grazing. The added nitrogen will also boost the next crop and build soil fertility.”

Cowpeas planted opportunistically on some December rain provided perfect feed for newly weaned calves from January until late April. In addition to the feed value the cowpeas have also provided a boost to soil fertility.

With two back to back seasons of crop competition and sustained grazing pressure, the ryegrass is well under control and the Clemsons have sown Condo grain wheat this winter. After removing the young stock from the cowpeas the Clemsons introduced them to creep feeders offering hay, feed barley and a magnesium calcium supplement in the central laneway.

Lou said their system relies on the 200 ha of hilly country where they run their breeding herd. The cows calve in the hill paddock in July then have access to crop stubbles straight after harvest until January when the cows return to the hill paddocks and the calves are weaned onto feed.

“In this system, Wongajong can carry 200 breeding cows and 50 replacement heifers but no more,” she said. “This is working so well that we are keen to build our herd and will replicate the laneway and fodder cropping system on a second property nearby. We have been expanding our area for both cropping and livestock with additional land purchased and leased.”

Looking across Wongajong, the top paddock grew cowpeas that were grazed over summer, the next paddock down the hill has feed barley ready for grazing and then the laneway where the young cattle are introduced to hay and grain once their rumens are mature. The Lemken speed tiller will be used to prepare the cowpea paddock for sowing the high yielding, short season Condo wheat.

“We identify paddocks that need a spell from cropping and also look at the weed burden,” said Lou. “Grazing barley is our go-to crop for weedy paddocks. It does a good job competing with annual ryegrass and gives us several options such as making hay or grazing and then spraying out.”

Canola has been a mainstay crop for the Clemsons along with barley for grazing, hay and feed grain, and wheat for grazing and feed grain.

The cattle strip graze the fodder crops at a density of 2 head/ha to maximise the feed value and weed control benefits. Electric fencing is used where necessary to manage the grazing intensity and provide fresh feed. Most of the fodder crops will be grazed out and sprayed in spring to clean-up for the following winter. The Clemsons are now planning to extend their fodder cropping program to hay and silage production.

Forage barley has proven to be the most useful crop for livestock production and weed control.

Charlie and Lou use a Lemken Helidor speed tiller to lightly cultivate paddocks that have been sprayed out after grazing. Paddocks are then rested for seven months, from late spring through summer, before they are re-sown. The combination of several non-herbicide weed control tactics such as strip grazing, fodder conservation and the speed tiller have resulted in an overall reduction in herbicide use.

“Sowing early gives us the greatest number of choices,” said Lou. “Some years we would expect about 10 per cent of our crops to be frost affected, but by sowing early we can achieve higher yields and this can make up for losses to frost.”

Lou said there has been a noticeable change in their attitude towards weeds with Charlie being much less stressed. Having the canola and wheat sprayed on time is important while there is more flexibility with spraying times for the grazing crops.

“If there are weeds visible in the paddock we can stay relaxed knowing that once the cattle have finished grazing and been sold, the paddock will be sprayed out before the ryegrass sets seed, and any survivors will be killed with the Lemken Helidor,” she said.

The Clemsons use a Lemken speed tiller straight after harvest to manage stubble and weeds. Provided there is some soil moisture present the cultivation to a depth of up to 10 cm or so causes about 80 per cent of the weed seeds to germinate, allowing a very effective spray opportunity.

Cultivation with the Lemken Helidor machine stimulates weed germination and breaks up the stubble.

Operating at 15–16 km/hr, the 12 m wide cultivator also breaks up and spreads the stubble and throws soil over some of the stubble to aid decomposition. The cattle still have access to valuable feed in paddocks where the Lemken has been used. This light cultivation means there is no need to burn stubble and seeding the next crop is easy.

“Summer cropping opportunities seem to be more common in recent years and we have had success with both cowpeas and sorghum,” said Lou. “The Supa Sudan sorghum we grew this past summer came back three times and provided excellent feed value but it also used too much soil moisture and might limit our immediate cropping choices for that paddock.”

“In winter, forage barley is followed by TT canola then a grazing wheat with the option to graze, make hay or harvest the grain.”

In addition to annual ryegrass incursions the Clemsons have also seen black oats, wild radish and brome grass populations cleaned up through this combination of grazing and cropping.



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What to expect at WeedSmart Week 2021

Big 6 at WeedSmart Week 2021 – Double knock to protect glyphosate
The WeedSmart Forum is set for Tuesday 17 August, 2021 at the Civic Centre in Esperance WA. The program features growers, agronomists and researchers discussing ways to use the BIG 6 to beat crop weeds. You can register for the 3-day WeedSmart Week event here.
Greg Warren from Farm and General in Esperance will be sharing his thoughts on the control of weeds like summer-germinating ryegrass, marshmallow, fleabane and portulaca.
He says the growers around Esperance are tackling glyphosate resistance in annual ryegrass, along with brome and barley grass and other emerging weeds using a range of integrated control tactics. The double knock plays a key role in preserving glyphosate (and soil moisture) and providing a clean seed bed for planting crops.

 
Big 6 at WeedSmart Week 2021 – Increase crop competition
WeedSmart Week 2021 is set for Tuesday 17 to Thursday 19 August, 2021 in and around Esperance WA. The last two days feature local growers hosting visits to their farms and discussing how they use the BIG 6 to beat crop weeds. You can register for the 3-day WeedSmart Week event here.
One of the farms hosting a visit during WeedSmart Week is Warrakirri’s 12,800 cropping operation at Condingup. Farm manager Con Murphy has implemented a variety of tactics to combat their main weeds – annual ryegrass and wild radish. Since 2015 the farm has undergone an intensive soil amelioration program to improve the drainage and ameliorate the sandy soils across the farm.
Con says the benefits have been seen in better germination and establishment that sets their cereal, pulse and canola crops up to compete strongly with weeds. There is also a benefit at the end of the season where rain in August or September enters the soil profile without causing waterlogging, and providing a better finish for their crops.
Since 2016-17 about 80% of the farm has been ripped and a portion has been ripped 2 or 3 times because the sandy soils tend to slump after substantial rainfall events, recreating the hardpan.
Con will be showing the WeedSmart tour group how their ripping, drainage, liming and spading program has helped grow more crop and less weeds!
Listen to the podcast with Warrakirri’s Con Murphy talking about the impact of improved drainage on crop competition

Big 6 at WeedSmart Week 2021 – Implement harvest weed seed control
The WeedSmart Week machinery display is set for Wednesday 18 August, 2021 at Dave Campbell’s shed near Esperance WA. The 3-day WeedSmart Week program features growers, agronomists and researchers discussing ways to use the BIG 6 to beat crop weeds. You can register for the 3-day WeedSmart Week event here.
We’ve saved the harvest weed seed control discussion for the machinery session on Wednesday 18 August. Ben White from Kondinin Group will host the machinery session with spray and harvesting gear on display including impact mills from Seed Terminator, Redekop and iHSD (both hydraulic and belt-driven), Emar chaff deck, and spray technologies including Goldacres’ G6 Crop Cruiser series 2, and weed detection technologies using drones and weed identifying cameras (green on green).
Ben White, Kondinin Group (Photo: Melissa Powell, courtesy of GRDC)
Growers doing the WeedSmart Big 6
WeedSmart Week 2021 is set for Tuesday 17 to Thursday 19 August, 2021 in and around Esperance WA. The last two days feature local growers hosting visits to their farms and discussing how they use the BIG 6 to beat crop weeds. You can register for the 3-day WeedSmart Week event here.
One of the growers who will open up their farm for a visit is Adrian Perks who farms at Condingup, 70 km north-east of Esperance. Adrian runs a continuous cropping program on his 4300 ha property, growing canola, wheat, barley, faba beans and lupins. This diverse rotation allows him to mix and rotate both chemical and non-chemical weed control tactics. Over half of Adrian’s farm is sandplain, on which he has implemented a soil amelioration program to address non-wetting to increase the competitiveness of his crops. He currently uses chaff decks for harvest weed seed control and is introducing an impact mill this season. Adrian monitors the tramtracks for weed growth and if he feels the weed pressure is too high, he uses a shielded sprayer to reduce seed set. The bus tour will include four farm visits and a machinery display.
Listen to Adrian on the Regional Update podcast.
Adrian Perkins, Condingup WA
 

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WeedSmart agronomist set to tackle high rainfall zone weeds

Every locality has its own spectrum of weeds, and growers face different opportunities and challenges regarding the control tactics they can employ.
The WeedSmart Big 6 approach is a practical way to ensure that an integrated weed management program is put in place that disrupts weed seed production and the evolution of herbicide resistance.
Commencing in January 2021, Jana Dixon has joined the WeedSmart team of extension agronomists, with a focus on applying the Big 6 to manage weeds in the high rainfall cropping systems of southern Australia – from Esperance in WA to south-eastern SA, Tasmania and south-western Victoria.
Jana will add to the dedicated and experienced extension agronomists on the WeedSmart team with Peter Newman in the Western region, Chris Davey in the South, Greg and Kirrily Condon in the East and Paul McIntosh in the North.
Jana Dixon has joined the WeedSmart team of extension agronomists, with a focus on applying the Big 6 to manage weeds in the high rainfall cropping systems of southern Australia – from Esperance in WA to south-eastern SA, Tasmania and south-western Victoria.
Jana hails from the Mid North of SA, and began working at Pinion Advisory (previously Rural Directions) while she was studying agriculture at the University of Adelaide. She has been employed full-time at Pinion Advisory since January 2019 as an agribusiness consultant, based in Clare, and spends most of her time delivering agronomy and farm business advice to clients from a wide range of cropping regions in South Australia.
Pinion Advisory is a foundation WeedSmart sponsor and Jana has been involved in two WeedSmart Week events already – the first as a participant and grower group organiser at the Horsham event in 2019 and then as the local organiser for WeedSmart Week 2020 in Clare.
In welcoming her to the WeedSmart team, program manager Lisa Mayer says Jana brings energy, commitment and insight to deliver communications focussed on the southern region’s high rainfall regions.
“Growers in the southern high rainfall zones are facing some serious issues with herbicide resistance influencing their farming decisions,” says Ms Mayer. “Jana will be engaging with agronomists, growers and researchers in each of the distinct high rainfall zones to understand the complexities and look for practical ways to apply the WeedSmart Big 6 in various cropping scenarios.”
“We plan to deliver WeedSmart Week in Esperance, part of Western Australia’s high rainfall cropping zone, in August 2021 and Jana will play a key role in the planning and delivering of our annual 3-day flagship event.”
Jana says her experience with the WeedSmart program has been very positive and she has been particularly impressed with the support the program has from all sectors of the grains industry.
Newly appointed WeedSmart extension agronomist, Jana Dixon (green cap) leading discussions with farm visit host, Ben Marshman, Owen SA, and growers and agronomists attending WeedSmart Week 2020 in Clare.
“I have spoken to many growers and agronomists who have found real value in the information that the WeedSmart program delivers,” she says. “For many it is as much about considering another operator’s philosophy on dealing with weeds, and taking a fresh look at their own systems, rather than just learning about a new tactic or the traits of a new herbicide in isolation from the big picture.”
She says the high calibre of industry people who contribute their time and expertise to the program is testament to the value WeedSmart has to agribusiness, growers, agronomists and researchers alike.
In taking on the responsibility for delivering information tailored for the high rainfall zones Jana says she is pleased to have an extensive network of contacts through Pinion Advisory, with offices in a number of high rainfall areas to provide easy access to local agronomists and growers. She is also aware that there are major differences in weed spectrums and farming systems in each high rainfall zone and plans to take full advantage of the opportunity this role presents to expand her understanding of different approaches to weed management.
“The long and favourable growing season and the associated prolonged periods of weed germination, is a key factor that I see potentially impacting on a grower’s weed management strategies in these regions,” she says. “On the other hand, access to highly diverse rotations and a focus on crop competition are two strategies that can play an important role in achieving excellent weed management in these regions.”
“I am keen to engage with anyone working and farming in the high rainfall zones to build my knowledge and understanding,” she says. “And to create opportunities to develop and extend the WeedSmart Big 6 strategies, both herbicide and non-herbicide, that work in each area and in different situations.”
WeedSmart is the industry voice delivering science-backed weed control solutions with support from the Grains Research and Development Corporation (GRDC), major herbicide, machinery and seed companies, and university and government research partners, all of whom have a stake in sustainable farming systems.
You an follow Jana on Twitter and keep up to date with the HRZ here.

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Never cut the herbicide application rate

Scientific studies have demonstrated that resistance can rapidly evolve in weeds subjected to low doses of herbicide. Some weeds can develop resistance within a few generations.
Full rates when mixing herbicides too!
When mixing herbicides it is important that each product is still applied at the full label rate to ensure high mortality.
Applying different chemicals in one mix can provide an additive advantage. It is important to understand the mode of action of each herbicide on the plant when preparing a herbicide mix. This is just as important for pre-emergent grass weed mixes as it is for post-emergent mixes aimed at broadleaf weed control. ALWAYS READ THE LABEL.
Surrounding weed seeds with a combination of pre-emergent herbicides with different modes of action can give a high level of control and help extend the useful life of all the chemicals used. The high level of control must be supported with additional control measures for all survivors. All products with different modes of action must be applied at full label rates for this to be an effective strategy.

 
Mixing two chemicals with the same mode of action can achieve some additional efficacy, however, the mix should deliver the combined full rate to ensure a lethal dose. The amount of stubble present and crop safety are all important considerations when mixing chemicals. For example, when using a tank mix of Avadex® and trifluralin to control ryegrass in wheat, the rates used will vary depending on the sowing system and level of stubble retention. Be sure to get good advice.
Many herbicides on the market are a combination of two or more modes of action within the one product. These products must be applied at the full label rate to be effective. Having dual action does not negate the need to change herbicide products and rotate modes of action. Repeated use of any single strategy will reduce the effectiveness of that strategy over time.
 

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