Swath timing: Have enough seeds turned?

Canola fields cut at or after 60 per cent seed colour change (SCC) on the main stem are more likely to maximize both yield and quality.

Once canola plants are swathed, the seed does not continue to fill. Seed that is swathed before accumulating its full complement of oil and protein will not accumulate any more after swathing, resulting in potential yield loss. Increases in thousand kernel weight, seed size and oil content were also observed for later swathed and straight cut canola.

Pod colour is not an accurate indicator of seed colour change. In some cases, green pods can contain colour-changed seeds and, vice versa, turned pods can contain green seeds. Sun scald adds to the confusion. See this helpful tweet.

Early, hot swathing can increase green counts. The combination of swathing canola too early and swathing during a stretch of hot weather can lead to rapid curing that elevates harvest green counts. In a heatwave, leaving crop standing is extra important as rapid curing of swathed crop may not give the green-clearing enzymes enough time to reduce chlorophyll levels. Leaving the crop standing through a heatwave can give the crop a chance to keep these biological processes going for longer.

Dig deeper

Swath timing for higher yield – with VIDEOs
CCC Canola Harvest Guide with photos and decriptions of seed colour change