Straight cutting or swathing: What’s best for your canola?

Producers typically swath canola to decrease shattering, promote even ripening and avoid wind and frost. However, straight cutting or combining is gaining interest because of a possible economic advantage.

In a recent article published in Top Crop Manager (November 2007), researchers are finding that straight combining means lower fuel costs and labour, reduced equipment wear and the potential for higher yields and higher seed quality.

A three-year study funded by the Alberta Canola Producers Commission is being conducted by Dr. Paul Watson of the Alberta Research Council with Dr. Neil Harker from Agriculture and Agri-Food Canada and Stewart Brandt with Bayer CropScience. The study is looking at whether canola crops with higher yield potential would be better straight combined than crops with lower yield potential. The study, which began in 2005, has field plots in Lacombe and Vegreville, AB and Scott, SK.

“As potential yield increases, the branches and pods intertwine with each other, knitting the canopy together so in a high wind situation, the crop canopy will move as a whole,” says Watson.

Results of the study show that straight cutting is a viable option, with some straight cut treatments equal to or better than the best swath treatment at all locations.

Says Watson, “if you use all the best farming practices – good fertility, good plant density and early weed removal – then the chances of being successful with straight cutting are increased.”

According to Canola Council of Canada (CCC) research, yields from straight combined canola were equal to yields of canola swathed at 30- 40% seed colour change at 5 lbs/acre. Straight combined yields were 12% higher at the 3 lb/ac seeding rate. Research also indicated increases in thousand kernel weight, seed size and oil content in the straight combined canola.

When to harvest…that is the question.

But before you trade in your swather, there are several variables that need to be considered to ensure success including time of swathing, crop conditions and shatter resistance characteristics.

For the CCC Time of Swathing Guide visit http://www.canola-council.org/pub_swathing.aspx.

According to Harold Brown, Market Development Specialist with Bayer CropScience, the best time to start harvesting is when there is minimal green seed and overall moisture has fallen to 10 per cent or less.

“To straight combine, the crop must be uniformly mature and relatively free of green weeds,” says Brown.

North Dakota State University Extension researchers agree. According to data from the NDSU web site, “the optimum harvest time is identified as the first time moisture falls below 10 per cent. Research trials indicate that seed loss due to shatter increases significantly approximately 10 days after the optimum harvest time was reached with straight combining.”

According to the CCC, “there’s a big difference in shattering characteristics of varieties. In general, Argentine varieties shatter more than Polish canola and canola quality mustard.”

Growers can reduce shatter loss by:

• Targetting fields that have a thick or interwoven canopy and lodged to slightly lodged.
• Trying to straight combine a small amount of acres first.
• Combining during the cooler part of the day or at night.

One advantage of swathing was the time needed for the crop to fully cure or dry down. David Vanthuyne, the Canola Council of Canada's agronomist for Eastern Saskatchewan, says that while desiccants aren’t a requirement for straight combining, it will take longer for dry down to occur.

However, he warns that a desiccant like “Reglone® applied at an improper stage can actually lock in green seed. Glyphosate produces better results but it needs to be applied when at least 85 – 95 per cent of the seeds have turned from brown to black.”

So if straight combining appeals to you, consider these points:

• Does the variety have inherent shattering characteristics?
• Do you need to accelerate harvest to avoid fall frost or to allow double cropping?
• What’s the variability of the field?
• What weather conditions are expected before and during harvest?
• What are disease and weed conditions?

We’d like to know.

If you straight combine your canola this fall and would like to share your experience with other InVigor growers, please email us at invigornews@adfarmonline.com.