Frost provides some natural desiccation that may help dry weeds and green stems in fields left for straight combining. Some growers actually wait for frost before combining, using it as a tool to aid in crop dry down — but this may not be advised if the field is ready and no frost is forecast.
After a frost, do watch the pods for shatter. Straight combining may be best performed shortly after a frost if pod shatter seems likely. Urgency may not be as high for varieties with pod shatter tolerance.
When heavy frost hits a variable crop left for straight combining, seeds still green will have the green locked in by a heavy frost. In this case, growers may want to combine high quality areas first and leave uneven high-green areas for later. Straight combining makes it easy to cut around green areas. This would be better than pushing through the green areas and having these immature seeds in the middle of a bin.
Should you swath instead? If standing canola is within the swath window when frost strikes, swathing is a back-up option. Keep in mind that swathing means you’ll handle these brittle crops twice and may create just as many losses as leaving the field standing.
Further reading:
Swath or straight combine frosted canola?
Frost in the forecast: Swath now or leave canola standing?
Pre-harvest products for use in canola