Canola storage
Canola seed is more likely than cereals to heat in storage due to its high oil content.
Seed takes up or releases moisture depending on the relative humidity of the air. The moisture equilibrium of canola seed is lower because its large oil component absorbs less moisture than the starch and fibre components in cereals.
The seed and microorganisms on stored seed are alive, meaning respiration occurs. When grain is too warm or moist, respiration increases the temperature. This in turn increases enzyme activity, resulting in mould growth and a loss in grain quality.
Read Also
VIDEO: Green Lightning and Nytro Ag win sustainability innovation award
Nytro Ag Corp and Green Lightning recieved an innovation award at Ag in Motion 2025 for the Green Lightning Nitrogen Machine, which converts atmospheric nitrogen into a plant-usable form.
For marketing purposes, canola is considered dry at 10 percent moisture content. But a moisture content of eight percent at temperatures below 20 C is required for safe, long-term storage. Safe storage depends not only on the moisture content of seed, but also on the temperature.
The moisture content of dockage (which includes weed seeds and broken seeds) can be up to four percent higher than the canola, which can lead to increased respiration and mould growth.
Do regular temperature and moisture tests on probed bin samples and aerate canola bins as required to prevent spoilage.
– Saskatchewan Wheat Pool
Grain insects a problem
“Stored grain insects are more of a problem this winter than they have been in recent years,” said Lloyd Harris, senior pest management specialist with Saskatchewan Agriculture.
Grain was warm when it went in the bin and it has been an abnormally mild fall.
“Normally the grain would have cooled somewhat by now, but that’s not happening this year. The stored grain is still warm enough for insects to reproduce,” said Harris.
Farmers should check stored grain for rusty grain beetles and red flour beetles. Take a coffee can-sized sample from the top centre of the bin or pile, because this is where the insects are most likely to be found.
“The sample should be poured over a screen placed on white paper. The insects, which are 1.5 to three millimetres in length, are reddish brown in color, and will show up clearly on the white paper.”
Kill with cold
If insects are discovered, they can be destroyed by cooling the grain to -6 C for at least six weeks. The colder the grain, the quicker the insects are killed. It will take only two weeks to kill the insects if the grain can be cooled to -15 C or colder, said Harris. The larger the grain volume, the longer it takes to cool.
“If a bin holds 3,000 bushels or more of grain, aeration with cold air is a good idea,” he said. Another alternative is to auger out one or two truckloads – removing the warm, centre grain – cooling it, and augering it back.
Fumigation is not recommended when grain temperatures are below 10 C because it is more dangerous, takes longer and might not be totally effective.
“Farmers don’t need to be reminded that elevators won’t accept grain that is infested with insects. So, if they haven’t already done so, they should be checking their bins for sure this year,” said Harris.
– Saskatchewan Agriculture
