Read time: 4 minutes

Lance Wise, Bowenville, Qld

Herbicide + shallow cultivation double knock

An optical sprayer and disc chain combination has proved to be very effective in keeping weed numbers low on the Wise family farm at Bowenville, on Queensland’s northern Darling Downs.

Lance and Fallon Wise and Lance’s parents, Murray and Janette crop 1600 ha and run cattle on 45 ha of non-arable rocky ridges. The locality and soft black plains enable the Wises to grow a range of crops including sorghum, mungbean, chickpea, barley and wheat, along with the occasional crop of faba bean, millet and canola.

In an effort to reduce their reliance on glyphosate and overcome some of the disadvantages of long-term no-till farming, the Wises have reintroduced light cultivation and are moving toward more targeted application of glyphosate and other herbicide products using an optical sprayer.

“Our usual rotation is a legume followed by a cereal, such as mungbean, to sorghum and chickpea to wheat or barley,” says Lance. “We use either a short fallow or double crop to change from a winter to summer crop program and aim for at least one crop every 12 months from each paddock.”

Having been no-till farming for 25 years the Wises have seen the weeds transition to those species that proliferate in the absence of cultivation; weeds like fleabane, urochloa, feather top Rhodes grass, cow vine and bladder ketmia.

In an effort to reduce their reliance on glyphosate and overcome some of the disadvantages of long-term no-till farming, the Wises have reintroduced light cultivation and are moving toward more targeted application of glyphosate and other herbicide products using an optical sprayer.

Nine years ago they had success using the Kelly disc chain to manage urochloa on their less well-structured red earth soils. More recently they have used this implement to target herbicide tolerant feathertop Rhodes grass and fleabane on their main black clay soils.

“We are using a chemical / tillage double knock to good effect on feathertop Rhodes grass in the fallow,” says Lance. “We apply glyphosate and then follow up five days later with the Kelly chain, which does a terrific job of pulling out sick, dead and small plants at an operation speed of 11 to 12.5 km/hr.”

“The same system works well on fleabane too, pulling up plants with foot-long roots from soft soil, although a higher rate of glyphosate is required. It doesn’t work well for weeds like prairie grass that have deep, fibrous root systems.”

The Wises have found the chemical / tillage double knock to work well on feathertop Rhodes grass and fleabane.

Used in reverse order, Lance has found the light cultivation is an effective way to stimulate germination after a poor sorghum crop to sprout volunteers and then spray out the crop.

Along with the benefits of partial stubble incorporation on soil microbial activity and ease of sowing, Lance says the two short chains in the middle fill in the 3 m wheel track to even out the paddock, avoiding the need to do extra wheeltrack renovation operations.

About the Kelly chain

“We also use the Kelly chain to incorporate pre-emergent herbicide after sowing to a maximum depth of 2 cm. This does not disturb seed, which is all sown at least 4 cm deep with a presswheel, and the soil is moved sideways without destroying the cracks in the soil or drying out the profile,” he says. “Weed seed is not buried deeply so it doesn’t come back to haunt you years later.”

Lance avoids using the Kelly chain more than once in a season on the red soils, which can get very dusty and are prone to hardsetting on the surface.

At the end of harvest Lance and Murray assess the stubble load and weed pressure in each paddock. They usually spray glyphosate after a rain event and either double knock with the Kelly chain or spray paraquat through their Weedseeker optical sprayer.

After using the Kelly chain, Lance follows 30–45 days later with the Weedseeker rig to clean up any survivors.

“The Weedseeker is a new fallow option for us and means that we can treat weeds that we might otherwise ignore, apply higher rates, and use more expensive products to control small areas or patches of weeds,” says Lance. “The 36.6 m boom carries 96 sensors so there are not many weeds that go undetected in the fallow.”

At the end of last year, the Wises started sub-soil ripping to a depth of 35 to 40 cm on 75 cm spacing to increase water capture and break up the sub-soil compaction to improve crop growth.

Six weeks ahead of planting they apply the final glyphosate spray and then add fertiliser, which they incorporate with the Kelly chain, with the added benefit of removing any weeds present. Liquid fertiliser applied at seeding promotes early seedling vigour and growth, which gives the crops a competitive advantage over weeds.

They plant using a Tobin planter that achieves a good even strike in stubble, starting on the red soils as soon after rain as possible, then moving onto the black soils.

Pre-emergent herbicide is applied after sowing legume crops and incorporated using the Kelly chain. Herbicide is applied in crop as well as for desiccation purposes in sorghum, mungbeans and chickpea.

Being a spray contractor, Lance has also invested in an air boom on his sprayer that enables him to have much greater control of droplet size to match the environmental conditions, while also covering a larger area in a day.

He says the elliptical cone delivers spray in both a forward and rear motion to achieve better coverage, even at lower water volumes. The controls in the cab allow the operator to adjust the spray quality from fine to extra course without changing nozzles on the boom and there is no need to have all the different nozzles to suit different conditions and products.

The Wises operate a 12 m controlled traffic system and plant all their crops on 375 mm row spacings. Lance has increased the planting rate in sorghum from plants 40 cm apart in the row to 25–30 cm apart to quickly to shade the interspace and suppress weed growth.

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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.

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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.

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Post emergent herbicides

Resources

Spray resistant radish early for best efficacy and yield (Grant Thompson, Crop Updates paper 2014)
Herbicide resistant wild radish (Peter Newman)
Controlling herbicide resistant Wild Radish in wheat in the Northern Agricultural Region of WA with a two spray strategy (Peter Newman)
Diverse weed control: Left jab, right hook (AHRI insight)

 
Part 2:When is it worth rotating from clethodim (Select®) to butroxydim (Factor®)?
Is there any value in rotating the post-emergent herbicides clethodim (Select®) and butroxydim (Factor®)? The research suggests that Factor® will sometimes kill plants that are moderately-resistant to Select® that could help in driving down the weed seed bank. Dr Peter Boutsalis from the University of Adelaide discusses his latest research and observations using both products with AHRI’s Peter Newman.

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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.

Video
Video

Double breaks – a double shot at annual ryegrass

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?
Or are you a ‘double shot’, throwing in a few break crops in a row for maximum effect?
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. Growing two break crops in sequence (broadleaf crop, hay crop or long fallow) was more effective in reducing resistant ryegrass numbers to manageable levels than a single break crop or continuous wheat over a three-year rotation.
And it can still be profitable.

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.

Want to link to this fact sheet/publication?

Full article can be found here

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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