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Zero row spacing could take crop competition to a new level

Grain grower Leigh Bryan doesn’t shy away from an unconventional idea. His crop-guided shielded sprayer is working a treat, he is confident with chaff lining and now he is testing the possible advantages of zero row spacing.

His aim is weed-free paddocks with crops growing at their full potential across the 2400 ha of cultivation within 30 km of Swan Hill in Victoria’s Mallee region.

“Being crop-guided, the shielded sprayer provides precise control over weeds and crop volunteers,” he says. “It makes it possible to suppress medic and other hard-to-kill weeds in lentil crops and take self-sown wheat plants out of barley paddocks. Keeping crops as clean as possible.”


Shielded sprayer used to apply paraquat for control of medic in lentils.

Using the shields strategically over the past seven years, Leigh has drastically reduced weed numbers and can concentrate on preventing seed set in just the odd plant here or there. The shields allow Leigh to use more cost-effective pre and post emergence herbicide options to prevent seed set of grass and broadleaf weeds in cereal crops.

“The shielded sprayer also makes it possible for me to crop top at the optimum time to have maximum impact on weed seed set without damaging the crop, regardless of the crop maturity stage,” he says.

The shielded sprayer has played a significant role in managing herbicide resistant brome grass and annual ryegrass.


Leigh’s crop-guided shielded sprayer in action, controlling brome grass in a barley crop.

As a harvest weed seed control tactic, narrow windrow burning was a good ‘get out of gaol’ tactic but Leigh has been chaff lining now for three years. He says depositing the chaff-only fraction in a narrow line between the harvester wheeltracks is a very effective way to keep weed numbers low.

“Dropping the chaff line between the wheeltracks, rather than into the wheeltracks, minimises disturbance of the seeds, reduces weed seed contact with soil and promotes more rotting down over summer,” says Leigh. “The chaff lining chute is also cheaper to make and install than a chaff deck.”

Last year Leigh used the chaff lining chute in all crops except canola and found there was no problem pulling the tines through at planting this year.

“We first tested the idea in clean paddocks hoping to keep them clean,” he says. “We are now completely confident in the system and will be using the chaff lining chute in all crops across the farm this season. It has proven particularly valuable in lentil crops.”

If weeds become a problem in the chaff line Leigh is prepared to band spray the chaff line with pre-emergent herbicide, but this has not been necessary to date.

For the last three years Leigh has also been trialling zero row spacing in a bid to capture optimal yield from his crops. The planter has been fitted with splash plates that spread 35 per cent of the seed at random while the remaining 65 per cent of the seed is sown conventionally, down the tube.


Leigh uses splash plates fitted to his planter to spread 35% of the seed randomly across the soil surface to achieve ‘zero row’ spacing.


Close-up on the splash plate.

“This will only work in relatively clean paddocks,” he says. “With no trifluralin applied the in-crop weed control is reliant on strong crop competition and very, very low weed seed bank. Next year I will be looking at different pre-emergent herbicide options and how they might fit in this system.”

The seeding operation is faster than normal and this helps throw sufficient soil to enable successful germination and establishment for the seeds spread on the surface. In Leigh’s on-farm side-by-side trials, the zero row spacing strips are showing that the idea has promise.

“There are others playing around with the idea of zero row spacing too and I think it has potential,” he says. “In 2016, a strip-trial in barley resulted in the zero row spacing strip yielding 4.994 t/ha compared to 4.889 t/ha in the conventionally sown crop at 375 mm spacing.”

This result gave Leigh the confidence to sow one-third of the farm using zero row spacing this season. To achieve the best results Leigh sows considerably more seed but says this is cheaper than pre-emergent herbicide and results in potentially higher yielding crops. The results of this large scale trial will be very interesting in terms of both weed management and crop yield.


Leigh takes a weed-point view in zero row spacing (left) and 375 mm spacing (right).

“The random placement of stubble is easier to sow through the next year. It still provides trellising for pulse crops and shades the soil to conserve moisture and reduce soil surface temperatures,” he says. “There can be a 10-day delay in germination between seeds sown on the surface compared to those sown into the soil because the surface seed needs rain to germinate.”

When it comes to growing a competitive crop Leigh emphasises the need to get the crop planted on time, keep it healthy and well-fed.

Leigh’s continuous, no-till cropping system includes wheat, barley, canola, lentil, field pea and lupin brown manure. When planning the crop rotation for paddocks he ranks them according to weed burden and uses a 4-year break crop system to clean up paddocks with high levels of grass weeds.

“In a weedy paddock we start with a pea/lupin brown manure, then plant canola, in year 3 we plant a cereal and use the shielded sprayer in-crop then finish with a lentil crop,” he says. “This gives us a 4-year run at grass weed control and then we can return to ‘normal’ rotation with a low weed seed bank.”

Once weed numbers are low, Leigh says it is relatively easy to keep them low through the consistent use of both herbicide and cultural practices. “When weed numbers are low it is possible to look at ways to improve yields and reduce production costs,” he says. “That’s what I hope to achieve with zero row space planting, supported by crop rotation and chaff lining to manage survivors. If there is evidence that weed numbers are increasing, then we have other tools at the ready to stop a weed blow-out.”

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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.
 

Webinars

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Ryegrass management in the High Rainfall Zone – What have we learnt?

This webinar was hosted by Jana Dixon, WeedSmart’s High Rainfall Zone extension agronomist.

Video
Webinar

Considerations for pre-emergent herbicides with dry sowing

In this webinar, we focus on what factors influence the residual control of weeds by pre-emergent herbicides with a focus on Trifluralin, Sakura and new-to-market herbicides.
Join Chris Davey, YPAG and WeedSmart Extension Agronomist and Mark Congreve, ICAN Senior Agronomist as they assess the sowing issues in South Australia and discuss strategies on using pre-emergents.
Factors covered include

Soil type/texture
Rainfall forecast (after application)
Characteristics of the herbicide
Characteristics of the crop
Sowing time (tine vs disc) – sowing depth, speed, soil throw, stubble
Resistance status

GRDC Spray Application Manual
This Spray Application GrowNotes™ manual provides information on how various spraying systems and components work, along with those factors that the operator should consider to ensure the sprayer is operating to its full potential.
This manual focuses on issues that will assist in maintaining the accuracy of the sprayer output while improving the efficiency and safety of spraying operations. It contains many useful tips for your spray operations.

Video
Webinar

Increase pre-em efficacy through a mix and rotate strategy

Part 1: Control summer weeds for yield and profit
Every $1 spent on summer weed control can potentially return up to $8/ha through moisture and nitrogen conservation. The impact on grain yield as a result of various summer weed control treatments is what Colin McMaster (NSW DPI R&D) refers to as “buying a spring”.  Listen to Colin and Pete Newman (AHRI) as they investigate the $$ benefits of controlling summer weeds.
Resources:

Ask an Expert column with Colin McMaster
GRDC Summer Fallow Weed Management Manual

 
Part 2: Increase pre-em efficacy through a mix and rotate strategy
We’ve done a good job of promoting herbicide rotation over the years. And whilst this advice still stands, recent research shows the benefits of mixing herbicides as well.
As American weeds researcher, Pat Tranel, puts it, “rotating buys you time, mixing buys you shots (of herbicide)”. Listen to Pat and Pete as they explore the benefits of the mix and rotate strategy.

Videos

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Video
Webinar

Ryegrass management in the High Rainfall Zone – What have we learnt?

This webinar was hosted by Jana Dixon, WeedSmart’s High Rainfall Zone extension agronomist.

Video
Video

WeedSmart Shorts: What considerations should be made for glyphosate tolerant canola?

 
Jump to a section

Simon’s client experience with RR Canola and decision-making process 00:27
What’s the decision-making process when it comes to growing a glyphosate tolerant variety over conventional/TT canola? 01:36
Herbicide strategy & resistance testing: 02:44
Timing of glyphosate sprays 05:02
Varietal performance 07:06
Broadleaf weeds 09:33
Dealing with survivors, WeedSmart Big 6 11:12
Desiccation & windrowing 13:48
GM canola marketing 14:46
On-farm storage 15:14

In this new segment, WeedSmart Shorts, our expert agronomists around the country interview experts on topics in a ‘Question and Answer’ video format.
Simon was kind enough to be our first guest and Jana covers lots of important points with him throughout the interview. Above, you can find what questions are covered if you’d like to jump to one of the specific topics highlighted.
Simon says there has been uptake by his clients of glyphosate tolerant canola in South Australia, but there has been a varied response.

“We are finding that some are wanting to try a paddock, some are wanting to sit back and see how it goes. So, it is probably very similar to what happened in Victoria when it rolled out there as an option,” he says.
South Australian farmers in the past have been able to control the weeds with the existing canola options they have, says Simon, but what they are finding now is there is an increase in clethodim resistance, particularly at higher rates and so that is what is likely to be driving the decision-making process around what other canola options are available, such as RR canola.
While it is exciting to have another option for SA growers, Simon says it is critical that growers know their ryegrass resistance status before committing to planting glyphosate tolerant canola.
“Testing is the backbone behind the decision making around canola options and so once we’re aware of what herbicides still work effectively, that’s where we’re able to make a good, informed decision.”
Simon said it was important to know what works on ryegrass across the whole spectrum of herbicide groups.
“An example is, I did some testing for a new client recently and one of his populations came back as 80% resistant to glyphosate. Now, had we not done that test and put glyphosate resistant canola into that paddock, we would’ve been facing a disaster, but because we had that information on hand, we knew what our options were and what they weren’t,” Simon says.
 
 

Video
Webinar

Considerations for pre-emergent herbicides with dry sowing

In this webinar, we focus on what factors influence the residual control of weeds by pre-emergent herbicides with a focus on Trifluralin, Sakura and new-to-market herbicides.
Join Chris Davey, YPAG and WeedSmart Extension Agronomist and Mark Congreve, ICAN Senior Agronomist as they assess the sowing issues in South Australia and discuss strategies on using pre-emergents.
Factors covered include

Soil type/texture
Rainfall forecast (after application)
Characteristics of the herbicide
Characteristics of the crop
Sowing time (tine vs disc) – sowing depth, speed, soil throw, stubble
Resistance status

GRDC Spray Application Manual
This Spray Application GrowNotes™ manual provides information on how various spraying systems and components work, along with those factors that the operator should consider to ensure the sprayer is operating to its full potential.
This manual focuses on issues that will assist in maintaining the accuracy of the sprayer output while improving the efficiency and safety of spraying operations. It contains many useful tips for your spray operations.

Factsheets

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Fact Sheet

Farm Business Management Factsheet

Key points

Effective decision-making is at the core of successful farm business management.
Making informed, logical and timely business decisions is crucial to achieving business objectivess.
Understand the different elements that influence how decisions are made and the possible outcomes.
Consider who is responsible for the final decisions in the different areas of your farm business.
Ensure the decision is finalised and implemented in a timely manner.

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Fact Sheet

Stewardship First SprayBest Guide

The application of herbicides late in the season to prevent weeds setting seed or to desiccate crops must be carried out with caution and in line with herbicide label recommendations.
It is essential to check if these practices are acceptable to buyers, as in some situations markets have extremely low or even zero tolerance to some pesticide and herbicide residues.

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