Not really from a storage risk perspective. Canola is “dry” below 10% moisture, and 8% moisture (in combination with temperature below 15°C) is considered safe for long-term storage.
When canola is very dry, one risk is that seed could start to crack if handled aggressively. These cracked seed become dockage, which means you don’t get paid for them. Cracked seeds will also pack more tightly in the bin and could reduce overall airflow if the amount of cracked seed is more than a few percent of the total.
Of course, the drier the seed, the fewer tonnes of seed you deliver to the elevator. This can be a financial “risk” as it eats into the profit margin.
Leave swaths out in the rain. As you know based on moisture testing, seeds will take on moisture in moist conditions. The risk here is that once rains start, we don’t know when they’ll stop. The lower risk option is probably to take advantage of good harvest days and get the crop in the bin. Also note that seeds do not hold re-added surface moisture for long.
Run moist air through the bin. Running fans on days when air has high moisture content (warmer temperatures and high relative humidity) can reintroduce moisture to the air inside the bin, and seeds will take on this moisture.
If moisture drops from 9% down to 5%, what is my yield loss? This calculator from the Grain Commission can help with the math. In this case, if original moisture is 9%, final moisture is 5% and original quantity (yield) was 50 bu./ac., actual harvested yield will be 48 bu./ac. at the lower moisture content.