Quality of the late harvest (November 2016) of western Canadian Canola

The 2016 harvest conditions were challenging; timewise it is considered the longest harvest in western Canada, starting early in August and ending, unfinished, in November (Figure 1). In early to mid-October heavy rain and snow stopped the harvest for over 3 weeks in some parts of Alberta and Saskatchewan (Figure 2). At the time 23% and 33% of the canola grown in Saskatchewan and Alberta respectively was not yet harvested. Improved weather conditions allowed a large part of this “snowed-in” canola to be harvested in November. Samples of this “snowed-in” canola were analyzed; this report presents the quality of these samples compared to the “normal” 2016 canola, i.e. harvested before the snow.


Harvest progress in Saskatchewan and Alberta for the 2015 and 2016 growing seasons
Figure 1 – Harvest progress in Saskatchewan and Alberta for the 2015 and 2016 growing seasons. Provincial crop reports were used to estimate the harvest progress in each province.
  • Figure 1 text version
    Harvesting progress in Saskatchewan and Alberta for the 2015 and 2016 growing seasons
    Harvesting date 2016 Saskatchewan, % 2016 Alberta, % 2015 Saskatchewan, % 2015 Alberta, %
    August 10 0.8
    August 15 0
    August 16 1
    August 17 3 1.8
    August 22 2
    August 23 1
    August 24 7 1.8
    August 29 7
    August 30 2.1
    August 31 14 6.6
    September 5 17
    September 6 5.1
    September 8 25 13.2
    September 12 25
    September 13 8.9
    September 15 38 19.2
    September 19 47
    September 20 21.9
    September 22 47.8 28.9
    September 26 61
    September 27 40
    September 29 70 42
    October 3 77
    October 4 61.8
    October 6 81 60.2
    October 10 77
    October 11 67.2
    October 14 89 79.8
    October 18 67.3
    October 20 97 94.2
    October 22 77
    October 25 67.6
    November 1 96 69.5
    November 8 74.9
    November 15 83
    November 29 86.8
Canola harvest progress as of October 21st, 2016.  Provincial crop reports were used to estimate the harvest progress in each province.
Figure 2 – Canola harvest progress as of October 21st, 2016. Provincial crop reports were used to estimate the harvest progress in each province.
  • Figure 2 text version
    Harvest progress % as of October 21, 2016 (Source: Statistics Canada)
    Canola harvest progress (%) Manitoba crop districts Saskatchewan crop districts Alberta crop districts
    > 95% 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 - -
    86.0 - 89.0% - 2A, 2B, 1B, 1A, 3AS 2, 3
    80.0 - 81.5% - 3AN, 3BN, 3BS, 4A, 4B -
    77.0 - 80.0% - 7A, 7B, 6B 7, 6
    73.0 - 74.0% - 5A, 5B, 6A, 8A, 8B, 9A, 9B -
    59.0 - 60.0% - - 1, 2, 3, 4A, 4B, 5, 6
    48.0 - 49.0% - - 3, 5, 4B, 6, 7

Quality and grade

Background information , such as variety, time of seeding, swathing, harvesting and/or method of harvest (i.e. straight cutting) is collected for the canola samples received by the Canadian Grain Commission annual harvest survey program . This year, this additional data helped to assess the effect of the snow on the canola seed quality.

Oil, protein, glucosinolate and chlorophyll contents of the seed and fatty acid composition and the free fatty acid (FFA) content of the oil are some of the parameters that define seed quality. Chlorophyll and free fatty acid are negative factors for quality and they have to be removed during oil processing. Free fatty acid is produced by the oil breaking down by chemical, enzymatic or microbiological activity whereas high chlorophyll is a sign of seed immaturity. High free fatty acid content is an indication of poor seed quality and reflects seed damage.

The results presented in the tables below include all the samples that were provided by producers for the “snowed-in” canola research project and collected/analyzed up to January 20th, 2017. As we received samples during harvest, some are randomly taken and fully analyzed using referenced analytical methods. The results from these samples were also included in Table 1.

To study the effect of the snow on the canola harvest in 2016, all samples analyzed by using reference analytical methods were grouped using the cutting/swathing/harvest dates supplied by the producers on the sample envelopes. The assumption was made that samples harvested in November were harvested after the snow even if this was not clearly indicated on the envelope. Samples identified as “snowed-in” canola by producers, were added to the November samples. The summarized results of the quality analyses are presented in Table 1. To facilitate the comparison, the 2016 canola quality results for Canada and the three western provinces are also included in this report and presented in Table 2.

The results (Table 1) showed no differences in oil content (p = 0.7295), protein content (p = 0.6097) and glucosinolates content (p = 0.9379) for samples graded Canola No. 1 Canada. Some differences were observed for the chlorophyll content averages, with the tested September samples showing slightly higher values as compared to the October or November samples, however these differences were not very significant (p = 0.0850). Free fatty acid content (FFA) averages were statistically very different among the September, October and November samples (p < 0.0001). The November samples had the higher free fatty acid average (0.39 % as oleic acid) when compared to September (0.17%) and October (0.16%). The free fatty acid medians were 0.12%, 0.15% and 0.28% as oleic acid for the samples harvested in September, October and November respectively (data not shown in the table). Comparing the median for free fatty acid has the advantage of not skewing the comparison by lessening the effects of the extreme high or low results on the data; the median differences confirmed the differences observed between the three sets of samples using the averages.

There were noticeable quality differences for the samples in the lower grades; however the sample size (13 samples in total) was too small to allow statistical comparison. The down grading was due to different factors such as immaturity, seed damage, admixture and excreta.

The seeding date reported by the producer on the sample envelopes showed that the canola was seeded in May, suggesting that the crop was fully mature when harvested. This was confirmed by the low chlorophyll contents of all the samples graded as Canola No. 1, Canada.

Canola still in the field when the snow arrived was left in a high moisture environment; leading to endogenous seed enzyme activation. Low temperatures likely slowed the process but the breakdown in oil was still occurring. After harvest the “snowed-in” canola seeds were likely dried down to allow seed storage. Reducing the moisture content of the seeds slowed the enzymatic process and additional free fatty acids were no longer produced and processed by the seeds. In the field, the low temperatures, the amount of time under the snow and the drying timing contributed to the wide range of free fatty acid contents, 0.07% to 1.35%. The internal enzymatic activity is not visually detectable, no visual damage could be associated with ”snowed-in” canola (weathered, sprouting, discolored and/or covered with rime) and were detected in the snowed-in canola samples. As a result most of the canola harvested after the snow, even with high free fatty acid, were graded Canada, No. 1 Canola.

The study had only 40 samples of canola graded Canola No. 1 Canada that were clearly identified as harvested after snow fall, this might be considered a low number compared to the 1827 received for the 2016 harvest program. However, the statistical differences presented in Table 1 suggested that the “snowed-in” canola condition, for reasons mentioned earlier, can lead to high free fatty acid in the oil. These free fatty acids must be removed during oil refining as they reduce the quality of the oil resulting in poor storage stability, bad taste and bad smell. There are international specifications for free fatty acid content in crude oil, the limit being 2%. However, this specification limit is the worse-case scenario and it is considered that seed free fatty acid levels have to be much lower than 0.7% for top quality seed.

Table 1: Summary statistics and sample results (Samples analyzed up to January 20, 2017)
Grade Harvest - combined N Obs Oil content (%, 8.5% moisture) Protein content (%, 8.5% moisture) Chlorophyll content (mg/Kg) Total glucosinolates (µmol/g, 8.5% moisture) Free Fatty Acid content (% as oleic acid in oil)
Mean Min Max Mean Min Max Mean Min Max Mean Min Max Mean Min Max
1 September 32 43.8 38.4 48.8 20.7 15.2 26.0 12 4 37 10 5 15 0.17a 0.03 0.62
1 October 26 44.4 41.6 47.9 20.4 17.5 24.4 13 2 28 10 7 14 0.16a 0.04 0.64
1 November 40 44.5 40.9 48.0 20.9 17.1 23.9 14 8 25 10 7 12 0.39b 0.07 1.35
2 September 2 42.6 42.5 42.6 21.8 21.4 22.1 18 16 19 11 11 11 0.39 0.29 0.50
2 October 3 46.0 45.9 46.0 20.4 19.4 22.3 31 25 35 9 8 11 0.16 0.08 0.31
2 November 1 44.0 20.3 41 10 0.13
Sample October 5 43.1 37.5 49.0 22.6 16.6 28.4 18 14 25 12 8 16 1.08 0.11 2.80
Sample November 1 44.6 20.2 12 8 0.67
a,b. free fatty acid averages with the same letter are not statistically different.
Table 2: Summary results of the 2016 canola harvest
Grade Harvest - combined N Obs Oil content (%, 8.5% moisture) Protein content (%, 8.5% moisture) Chlorophyll content (mg/Kg) Total glucosinolates (µmol/g, 8.5% moisture) Free Fatty Acid content (% as oleic acid in oil)
Mean Min Max Mean Min Max Mean Min Max Mean Min Max Mean
1 Manitoba 417 43.5 37.5 49.5 20.6 16.4 24.8 10 4 27 10 4 15 0.34
1 Saskatchewan 806 44.8 37.1 50.0 19.6 15.6 26.0 11 4 38 10 4 16 0.16
1 Alberta 604 43.9 38.9 49.5 20.5 15.1 26.0 13 4 41 10 6 19 0.21
1 Canada 1827 44.3 37.1 50.0 20.1 15.1 26.0 11 4 41 10 4 19 0.20
2 Manitoba 12 41.4 39.2 43.8 22.4 20.7 24.7 18 8 33 11 10 13 1.22
2 Saskatchewan 15 43.6 40.1 48.2 20.0 16.8 22.7 22 10 54 12 8 14 0.17
2 Alberta 24 42.4 37.4 46.3 21.9 19.1 26.2 25 5 49 10 7 16 0.73
2 Canada 51 42.7 37.4 48.2 21.3 16.8 26.2 23 5 54 11 7 15 0.58
3 Canada 11 43.2 41.7 45.0 19.9 18.0 21.4 18 7 45 10 7 13 0.32
Sample Canada 26 41.8 30.4 46.0 20.0 17.1 25.6 17 4 21 12 8 30 0.32
Date modified: