Can You Straight Combine Canola

For the past five years, canola production centers in Canada have been testing how straight cutting canola affects yield and oil content.

Out of eight Polish (B. rapa) varieties tested, only three yielded less under straight combing than by swathing and combining. In all cases, oil content was equal to or higher for straight cutting than for swathing.

Straight combining performed best with heavy crops, where the canopy was leaning or somewhat lodged. One concern was with alternaria leaf spot. The disease causes yield loss from pod shatter and losses appear to increase in infected fields left standing for straight cutting.

Yields of most Argentine (B. napus) varieties suffered under straight combining because of greater shattering, compared to the B. rapa varieties. At a few sites, straight B. napus yielded as good or better than swathed. These were the exceptions and usually were sites where growth was excellent and lodging reduced the risk of wind moving the crop canopy.

Like B. rapa, the straight cut B. napus varieties all showed equal or slightly better oil contents than swathed, but the quality advantages for B. napus did not balance off the yield loss from straight cutting.