Similar work from three years ago found quality of spring harvested canola deteriorated further after going into storage
If you’re a western Canadian grain farmer who still has unharvested canola in the field, then the Canadian Grain Commission wants to hear from you.
For the second time in the past four years, the grain commission is conducting research on spring-harvested oilseeds.
It is asking growers to submit samples of spring harvested canola and flax, which will be analyzed for quality.
Results of each analysis will be returned to producers to assist with management and marketing decisions, said Veronique Barthet, program manager for oilseeds at the commission’s grain research lab in Winnipeg.
Submitted samples will be assigned an unofficial grade and will also be examined for oil and protein content, chlorophyll content in canola, iodine values in flax and free fatty acid content.
“The purpose of the project is first of all to help (producers) to assess what they have in the field and to determine if something can be saved or not,” Barthet said.
“What we saw in 2017 was that there was some (spring harvested) canola that was good quality. That was quite surprising, actually, because we didn’t think there would be any good quality canola (harvested in the spring) but there was some.”
An estimated two million acres of canola were left in the field across Western Canada this winter.
The last time significant acres of canola were left out was in the winter of 2016-17.
Similar research conducted in the spring of 2017 produced interesting results and also raised important questions, Barthet said.
For example, research in 2017 suggested that the quality of spring harvested canola may be prone to further deterioration after it has been combined and placed in storage.
With that in mind, grain commission researchers are trying to learn more about the potential for post-harvest quality losses. Findings of this year’s research could provide guidance on whether farmers should be marketing spring-harvested material within a specified time frame in order to avoid further economic losses.
“We saw (in the spring of 2017) that there was a lot of degradation when we were storing the samples, even in good storage conditions like low moisture and not-too-high temperatures,” Barthet said.
“I think it’s important for people to know that if they have seed like this, they may have to process it right away because the good quality (may not) last.”
Barthet compared spring-harvested canola to food that’s been stored in a freezer.
If the food is thawed out and refrozen too many times, ice crystals can damage the cell structures and lead to quality deterioration.
In canola, repeated freezing and thawing can also stimulate enzymatic activity that releases free fatty acids within the seed and leads to oil oxidization.
Oxidization and elevated free fatty acid levels in canola are often manifested as orange-coloured or rancid-smelling meal when the seeds are crushed.
“That’s probably what’s happening, but we would like to confirm.”
The winter canola project is also hoping to assess whether quality degradation is more common in swathed canola than standing canola.
It is assumed that canola left standing over winter is less prone to quality deterioration because swaths collect snow and are therefore more prone to moisture damage and mould formation.
On the flip side, yield losses may be higher in standing fields.
Barthet said the appearance of intact spring-harvested canola seeds may indicate quality deterioration. However, it should not be assumed that samples containing gray or discoloured seeds will be downgraded at the elevator or crushing plant.
“If the seed is gray, it’s because there was moisture at some point, but the quality of the seed isn’t known,” she said.
In other words, appearance of the hull does not necessarily indicate compromised oilseed quality.
In 2017, the grain commission received 173 samples of spring harvested canola. Twelve samples could not be analyzed because of excessive mould.
Of the 161 samples that were analyzed, 55 samples (34.2 percent) were graded No. 1, 41 samples (25.5 percent) were graded No. 2, and 33 samples (20.5 percent) were graded No. 3.
The remaining 32 samples were graded Sample.
Growers who submit samples this spring should avoid sending seeds in plastic bags because they are conducive to mould formation and spoilage.
Instead, samples should be submitted in a CGC Harvest Sample Program envelope.
Growers can request envelopes by contacting the grain commission in Winnipeg.