Straight cutting canola versus swathing

canola field swaths
Straight combining canola can save time and labour, but some fields are more suited to the practice than others, says the Canola Council of Canada's Angela Brackenreed.

Farmers can save time and labour parking the swather, but field selection is important

Whether to straight cut or swath canola isn’t an either/or question.

Farmers should consider doing some of both if it means getting more of their canola harvested at the optimum time, a Canola Council of Canada agronomist says.

Farmers can plant a lot of canola in the spring, but often lack the swathers and labour in the fall to swath it all at the ideal time, Angela Brackenreed, Manitoba agronomy specialist, said Aug. 13 during the Westman Crop Talk webinar. As a result, many farmers swath too early and too late. Swathing early reduces yield and quality because not all the seeds are mature; swathing late results in more pod shattering and less yield.

“A combination of swathing and straight cutting can really help get that timing just right, which we’ve seen can definitely increase yield,” Brackenreed said. “I don’t think we’re at the point where we can park the swather and put the “for sale” sign on it, but a good combination of the two can certainly help with harvest management.”

Research shows little difference in yield when each is done at the optimum time.

“The benefits of straight cutting should generally be seen as time management and the yield really should be seen as equal to that of swathing,” Brackenreed said. “There is some potential for quality improvements, but I think that should be secondary to that time management benefit.

“You’re removing a pass from the field, so if it’s done with care I think there is potential that we could actually reduce losses by straight cutting.”

The best time to swath canola is at 60 to 70 per cent seed colour change. Canola should be 10 per cent moisture or less when straight combined. Brackenreed said on her farm straight cutting canola saves labour, but the crop comes off at about the same time whether it’s swathed or straight combined.

Depends on the field

Some fields are better suited to straight cutting than others. That’s why the assessment should be made just before the ideal time to swath. Even crop maturity is important.

“If you have extreme variability in your field I really think the best option is swathing,” Brackenreed said.

When straight cutting, it helps if the crop is thick, well knitted and slightly lodged in one direction, she said.

“A short, severely lodged, or excessively branched canopy, may also be a good candidate as there is going to be minimal stubble left there (to anchor a swath),” Brackenreed said.

Swathing desiccates both the canola and the weeds in it. A desiccant can be applied to aid in straight combining, Brackenreed said. Reglone is the only true desiccant. Glyphosate kills plants, but it takes awhile and should be considered as pre-harvest weed control.

Reglone, a contact herbicide, kills plants but does not hasten crop maturity.

“For this reason you have to be very careful not to apply it too early as you run that risk of locking in green seed,” she said. “So the timing is about 70 per cent seed colour change or later. Then, after it’s sprayed you can harvest in four to seven days. If left standing too long when sprayed with Reglone, you will definitely incur more shattering losses than if it wasn’t sprayed.”

Brackenreed said a desiccant or pre-harvest glyphosate should have been used on her farm last year. The canola seed was dry, but the canola stalks were still green. That, and humid conditions caused the combine to plug frequently.

“And if you have a high population of green weeds, you’ll want to look at a glyphosate product just to dry down those weeds so you’re not creating a storage risk,” she said.

While glyphosate obviously won’t work on Roundup Ready canola, BASF is working to register its herbicide Heat as a harvest aid in canola, Brackenreed said.

She also noted tank mixing Reglone and glyphosate is not registered.

This year excessive moisture delayed canola seeding, so crops are late. Swathing is something to consider to avoid frost damage, but the crop has to be less than 20 per cent moisture to avoid frost damage even in the swath, Brackenreed said. If the moisture is high, knocking the crop down a few hours before a hard frost isn’t going to protect it.

Farmers have swathed canola at 15 to 30 per cent seed colour change to avoid frost damage, but quality and yield suffer.

“On my farm, and what I recommend to most producers, is swathing at 60 to 70 per cent, so (swathing at) 15 per cent (seed colour change) definitely makes me nervous,” Brackenreed said.

COPA Medallion COPA finalist in 2012, 2014 and 2015.
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