A lot of canola is coming off very dry this year. The safe storage graph in the Canola Growers Manual would suggest that canola at 6% moisture is at very low risk of spoilage, even if binned at 30-40C. So does that mean it doesn’t need to be cooled?
Canola storage experts still recommend that hot canola be put on aeration for cooling. There will still be convection currents and some moisture movement within the bin, which can concentrate moisture at the bottom of the central core — creating a possible start point for heating.
Aeration will also even out the temperature and moisture throughout the bin, preventing these hot spots from occurring.
The risk is even higher with larger bins. With larger bins, there is generally less surface area relative to the volume, meaning natural cooling takes longer. The core will hold that heat longer if not aerated, and larger bins take more loads to fill them so there is a greater chance a load or two might be over 8%. These spots would not necessarily be safe if temperatures are over 25 C.
When using aeration to cool canola that is very dry, fans can be shut off during the day and turned on at night when air is cooler.
If growers feel conditioning is unnecessary, then monitoring frequently is even more critical, especially during the first few weeks when warm seed may be respiring rapidly. They need to ensure that temperatures throughout the bin are at least stable or hopefully falling over time.
Check your moisture meter. Moisture meters can lose accuracy. Test a few samples each year on your home tester and then on the elevator’s tester to see how they compare.
Storage podcast: Derwyn Hammond gives tips for bag storage of canola