While it’s always important to condition harvested canola crops down to storage-safe temperature and moisture levels in the fall, it’s even more critical in years such as this when the crop’s oil content is expected to be quite high, according to the Canola Council of Canada.
“We have all heard that oil and water don’t mix and this is the reason canola will spoil at a lower moisture content than cereals,” said Matt Stanford, a council agronomy specialist at Lethbridge, Alta., in a council release Tuesday.
If you harvest canola with a higher oil content, it will be more at risk for spoilage because the seeds can absorb less water, the council said. “The way to manage this risk is to ensure canola is conditioned appropriately.”
That means moving air through the grain mass to prevent spoilage that results from moisture migration and seed respiration. Stanford stressed that canola harvested much above eight to nine per cent moisture must be conditioned, especially if grain temperatures are above 25ºC.
The objective for safe, long-term canola storage is to cool seed below 15ºC and drop its moisture content to eight per cent or lower, he said.
“If canola comes off the field close to dry, aeration and ‘turning’ canola can be effective ways to cool the seed and reduce seed moisture,” Stanford said, “but if it comes off the field with moisture levels of 10 to 12 per cent or higher, you need to consider heated air drying.”
With farmers using bigger and bigger bins, more heat can be generated and trapped in the bin. Even dry canola can be at risk if it goes into the bin at high temperatures, particularly if there are pockets of damp seed or green dockage, which can create hot spots that can quickly spoil an entire bin of canola.
Even after conditioning canola, it’s critical to keep a close eye on bins since freshly harvested seed can maintain a high respiration rate for up to six weeks, the council said. During this unstable “sweating” stage, there is still risk of canola seed heating or becoming mouldy. Regular monitoring at frequent intervals, particularly until cold temperatures set in, is critical for safe canola storage.
“You have invested a lot in your canola crop this past season,” Stanford said, and “you don’t want to lose your crop now. Keep up your monitoring program in the coming months to ensure delivery of a quality product.”