Early planning the key to canola direct harvesting

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Direct harvesting canola is an increasingly appealing option for southern canola growers because of the potential cost saving over windrowing. Provided the crop is harvested on time and the header set up correctly, direct heading allows for maximum yields, but no more than a well-timed windrowing. Researchers agree that oil content is not affected by choosing either direct harvesting or later windrowing.

Kathi Hertel, from the New South Wales Department of Primary Industries, says oil accumulation within the seed ends when it reaches 35 to 40 per cent seed moisture content.

“Seed oil accumulation begins slowly, about three weeks after flowering. By about 35 days after the start of flowering, the oil content of seed then enters a phase of rapid accumulation,” she says.

“By the time it reaches about eight per cent seed moisture when you direct head, oil increases have long since stopped.”

Grain Orana Alliance chief executive officer Maurie Street says yield gains are more likely because crops are windrowed when plants are still green and not mature, but it depends on the finish to the season.


The grower:

Fine-tuning a positive experience

For Victorian grain grower Tom Dunstan, the change from windrowing
to direct harvesting canola “just made economic sense”.

This will be the third year that canola has been direct headed rather
than windrowed on Tom’s family property at Telangatuk East, which he
farms with his wife Amity, his brother James and his wife Penny, and their
parents Tom senior and Sue.

Seven years ago, when their windrower caught fire and burnt out,
it was time to look at the economics of windrowing and buying another
machine. They did their sums and with the price of a new windrower
at that time being up to two-thirds the cost of a new header, they
decided it was not worth it.

A new windrower was going to cost them $37.50 per hectare
(excluding GST), which included owning their own machine, repairs,
cost, maintenance, driver wages and depreciation. The cost was
about the same whether they bought their own machine and employed
a driver, or hired a contractor.

They had direct harvested canola at times in the past, but with the
extra windrowing cost, they decided to give it a go on a larger scale.

Victorian canola grower Tom Dunstan with
his daughter Camilla. Tom says his
experiences with direct heading have all
been positive, and it has helped save
money in their business.

In 2012, the Dunstans direct harvested about 400ha with their own
header – a Claas Lexion 580R, which easily handled 22 tonnes of
canola per hour.

“There was a lot of scaremongering about direct heading
canola; that it will all end up on the ground or if there is a
big wind, it will all be lost,” Tom says.

“All my experiences with direct harvesting have been positive.
Every season, we believe we are better off for it.

“Timing is also a benefit in terms of the fact we are not losing
grain in windrowing late, so we are cancelling out potential crop loss.”

The Dunstans had a specialist pick-up front for windrows
that was only used for canola. It was sold and an upper-cross
auger fitted to their draper front for about $7000. This helps
to channel tall standing crops into the header. But tall crops
bunched into the front’s centre, so rubber paddles were fitted
to help improve flow into the machine. These cost only $100.

“I’m getting more capacity out of the header in direct heading because
I don’t need to take as much residue and put it through the header
as when I was windrowing,” Tom says.

About 600ha of canola has been sown this year, as part of the family’s
2200ha program, and all will be direct harvested.

Tom has found some varieties of canola are better for direct harvesting
than others. His preference is Pioneer® 45Y82 because it is less brittle
and feeds more smoothly into the header. He is growing a range of
Clearfield® and triazine-tolerant varieties.

Tom says direct harvesting must occur on time, but he still prefers it
to windrowing.

He says windrowing only had a 10-day window and the Dunstans always
felt like they were battling the elements with hot weather and northerly winds.

But he realises not everyone has their own header and the decision boils
down to management preferences.

“Everyone’s situation is different, some people employ contractors
because they feel more comfortable with windrows if their contract harvester is late.

“But I still believe you have a reasonable amount of time to leave it
standing before your contractor turns up. If a windrowing contractor
is late, there can be losses too.

“We still see it as an unnecessary spend of $37.50/ha, but I have a large-capacity
header and a chaser bin to get stuck into the crop as soon as they’re ready. To others,
windrowing may be a necessary part of their operation.”

“While windrowing canola is still the mainstay harvesting method for most, it has a lot of advantages, but if you own your own header and have a nice, even crop, direct harvesting is an acceptable alternative,” Mr Street says.

Ms Hertel says there is no yield penalty between direct heading and windrowing at the correct time.

“However, if the windrowing takes place too early, there will be a yield and oil penalty, but the magnitude of such negative effects will be seasonally dependant,” she says.

Canola direct heading


  • Potential for cost savings through fewer operations.
  • Reduced risk of high winds moving windrows.
  • In light or short crops, direct heading is the most
    suitable harvest option because of the inability to
    form a decent windrow.
  • Crops up to 1.5 tonnes per hectare can be handled
    by direct heading.
  • Reduced risk of green seed in harvested grain.
  • Standing crops can dry out faster after rain.
  • One-pass harvest for small areas for
    owner/operator requires only one machine,
    reducing capital outlay.
  • Fewer Rutherglen bugs and aphids in harvested
    grain, and hence issues with insect receival
  • Potential to maximise yields by leaving plants
    until maturity, but dependent on seasonal


  • Increased chance of seed losses due to
    shattering if harvest is delayed significantly.
  • Increased exposure to pre-harvest shatter due
    to high winds or hail, although windrowed crops
    are not immune to this risk.
  • Possible slower harvesting speed than windrowing.
  • Harvesting of crops left for direct heading may
    be delayed compared with a windrowed crop,
    potentially clashing with cereal harvest.
  • Windrowing a canola crop also accommodates
    better predictability for harvest, unlike direct-headed
    crops, which may ‘hang on’ longer than expected.
  • Uneven crops and variable maturity – delayed harvest,
    issues with grain moisture levels, poor harvest sample
    and shattering if ripe areas are left – mean it is not
    suited to paddocks with significant variations in soil
    type and/or topography (factors that affect plant-
    available water).
  • Direct heading may need to be suspended in extreme
    weather conditions, such as heat and/or wind.
  • Where desiccation is not used, green weeds could
    contaminate harvest samples or result in potential
    storage issues with greater moisture content.


Seasonal conditions are the largest factor influencing when canola can be direct harvested. While the general rule of thumb is to direct harvest about 16 to 20 days after the optimum windrowing time, a dry season can speed up the time before a crop is windrowed or harvested.

Ted Wythes from Dundee Contracting in Paytens Bridge near Forbes, NSW, says the key to correct timing for direct harvesting is seed moisture percentage. The ideal level is 7.5 to 8 per cent, which means pods are less likely to shatter and there will be a smoother flow of stalks into the header. If growers wait until canola stalks start to turn white in colour – as they would for harvesting windrowed canola – seed losses will be higher.

“If seed is below eight per cent moisture then go and don’t stop. Below five to six per cent moisture is getting too low, you will see shattering and you could lose the benefit of direct harvesting over windrowing,” Mr Wythes says.

“The best thing with direct harvesting canola is that you can harvest with a slightly green stem and harvesting may continue late into the night, with the night air and dew reducing any losses.

“Reaping at 7.5 per cent moisture means canola can be harvested without dew, plants will still be a bit green.”

Mr Street says a common misconception among growers who have not direct headed before is that some of the canola plant can still be green and grain moisture still well within limits.

“Remember you are delivering the grain, not the stubble, and you will be surprised how well the harvester can handle the green straw,” he says.


Mr Street says the perception is that shattering is a trade-off in direct harvesting over windrowing.

“Shattering, in my view, is nowhere near the issue it is perceived it to be. When considering the potential yield loss from plants of windrowing too early, it dwarfs any losses that may be experienced due to shattering when direct heading,” he says.

Pod sealers may reduce potential for shattering by preventing pods from drying out, but their use can negate savings made from direct harvesting rather than windrowing.

Mr Wythes says if a pod sealer is necessary, then it must be applied at least one to two days before optimum windrowing.

He says maximum water coverage ensures maximum effectiveness of pod sealers. Sealers need to be applied using a ground sprayer at 100 litres per hectare. The rate of application by plane is only 30L/ha, which gives inadequate coverage.

“Pod maturity may develop quickly in hot weather so timing is critical. Pod sealers must be considered early and not at the last minute because it may be too late to apply,” he says.

The contractor:

Maximising oil content

The key to direct harvesting canola is forward planning because
a late decision to direct harvest can be costly, says Ted Wythes, from
Dundee Contracting, in Paytens Bridge near Forbes in New South Wales.

“That can even come back to sowing time, because canola will be
harvested at a similar time to wheat, so this could influence what
wheat varieties you would plant,” he says.

“Canola is usually windrowed at 65 to 70 per cent of seed colour change – from
green to any other colour than green, such as yellow, brown, black – on
the middle third of the plant’s stem."

But in his experience, there is potential to maximise oil content when
direct harvesting because of the extra time the plant has to produce
oil, compared with a crop windrowed even just a few days too early.

Mr Wythes says direct harvesting is a good option in heavy crops
that are lodged and unable to be windrowed or where there is
insufficient stubble height and density to lay windrows. But
even-maturing crops are preferred.

He says direct harvesting is ideal for growers who find it difficult
to source contract windrowers for optimum timing when they only
have smaller areas of canola, such as 40 to 80 hectares.

Rigid table auger and draper fronts are both suited to direct
harvesting canola. Flex and extendable table fronts both work
well but are less common. For smooth direct harvesting:

  • with all fronts, a tyne reel is the preferred option for direct
    harvesting canola. Run the reel as slow as possible to reduce
    shattering and pod drop;
  • a top-crop auger will help the flow of material along the draper belts;
  • increase the angle of draper to aid feeding;
  • adjust retractable fingers to stop tangling of material around the table auger; and
  • use crop lifters in lodged crops.

For rotor or conventional threshing systems, Mr Wythes recommends
that the reel speed matches the ground speed, while rotor speed should be
about half to two-thirds of wheat speed (450 to 650 revolutions per minute).

“Set the concave as wide as possible so stalks are not mashed up and
overload the sieves,” he says. “Fan speed should be about two-thirds
capacity (550 to 700rpm), the top chaffer/sieve between six to eight
millimetres and bottom sieve between 3 to 6mm depending on sample quality.

“Some shattering and pod loss is acceptable, remembering that some
shattering and pod loss occurs during windrowing as well, but ultimately
you should get off the harvester and have a look behind to then accurately
set loss monitors.”


For growers for whom shattering is a concern, Ms Hertel says there are several considerations.

  • Harvester speed is more critical when direct heading canola compared with other crops. Excessive speed, especially when the crop is dry, can cause significant shattering at the knife and divider. Harvest speeds may need to be gradually reduced as the day approaches late-morning/midday because pods dry and become more fragile. Harvest should stop if conditions are too hot and dry.
  • Reel speeds can have the greatest influence on shattering. Reel speed should be matched very closely to ground speed and adjusted to only lightly engage the crop when harvesting. Failure to get this right sees the reel act as a huge thrasher where grain will be lost forward of the header front.
  • Cool overcast days and nights can be the most suitable times to direct head canola. However, in the case of uneven crops, seed with higher moisture content is difficult to thresh.
  • Ensure the cutter bar is sharp. Match reel speed to ground speed. Run the reel as high and as far back as possible over the grain table.
  • Remove row dividers. Dividing the row shatters pods where plants are pulled apart.


Desiccants help in heavy weed infestations and when maturity is not uniform. Desiccation is usually not required when high temperature and hot winds help drying. Some desiccants have long withholding periods, which could delay harvesting. Mr Wythes says crop desiccation is sometimes done as an alternative to windrowing to prepare an uneven crop for direct heading. It is usually applied by air. It has a similar effect to windrowing, drying-down evenly all green vegetative growth, including weed escapes such as thistles.

Reglone® is registered for desiccation and there is an application with the Australian Pesticides and Veterinary Medicines Authority for Roundup® Attack™ with IQ Inside™.

The grower:

Butterflies in the stomach

When grain grower John Hamilton first started with integrated pest management (IPM),
he admits there were some nerves and he had to resist the urge to fill up the boomspray
every time he spotted in-crop pests on his Inverleigh farm, 35 kilometres west of Geelong in Victoria.

However, he has been using IPM principles for 12 years, after becoming involved
with trials by Dr Paul Horne from IPM Technologies. While he originally expected that
crop losses would be inevitable under IPM, John says this has not been the case.
The change to IPM was spurred by his desire to avoid insecticide resistance, similar
to the way he had been experiencing grass weed resistance to herbicides. The added
benefit of IPM has been cost savings in reduced pesticide use and fewer pest problems experienced.

“For 80 cents a hectare we could kill all the insects while we were spraying our knockdown
of Roundup®, but we didn’t realise we were killing the pest predators as well,” he says.

John farms with his son Stewart, continuously cropping 3000ha mostly to wheat,
barley and canola at Inverleigh and a second property at Wycheproof, Victoria. He
says the idea behind IPM became quite logical when they thought about how it might
work in their cropping system.

John used to spray for redlegged earth mite (RLEM) and lucerne flea twice a
year on average. He says if they spotted a pest, they would have had the
boomspray out straight away.

But with IPM, if a pest is identified, they return in two days’ time to monitor
predator numbers then recheck in another few days to see if their predator
populations are increasing.

He says about 19 times out of 20, the predator population has built up to levels
sufficient to control the pest. But in cases where this does not happen, the Hamiltons
may use an insecticide, such as pirimicarb, to target specific out-of-control pests and
only spray the minimum area to give predator insects maximum chance of survival.

“Just being conscious of the insect populations in a paddock and what they are
doing is the critical thing,” John says. “We used to spray twice a year, but now
about 90 per cent of the cropping area doesn’t get sprayed with an insecticide
at all. If we have to, about 20 per cent of a 50ha or 80ha paddock where the big
issues are will be sprayed.

“After IPM, the outbreaks of RLEM and lucerne flea wouldn’t be 10 per
cent of what we used to get.”

But John says when it comes to slugs in canola, they are still working
on their IPM strategy.




IPM integral to long-term pest control


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