Canola can heat and spoil in the bin, costing growers a lot of lost income.
Here are 10 situations that will increase the storage risk:
10. Can’t remember what’s in the bin. Keep a composite sample for each bin of canola. Record average moisture and grain temperature when canola goes in the bin. Use this information, along with a visual assessment of green count and dockage in the sample, to see which bins may be at higher risk.
9. No cables. Bins with cables make it easy to keep tables on temperature. Bins without cables will need to be probed, or turned over with the truck and auger to check temperature. Even with cables, monitoring is still highly recommended.
8. Inaccurate cables or moisture meter. Calibrate the moisture meter each year to ensure accuracy. Check a few samples at home and at the elevator to see they’re the same. Check cables before filling the bin.
7. Subpar bin space. Not all canola goes into aerated bins. Make sure canola doesn’t go into bins treated with malathion for storage insects. If canola has to go into a ring on the ground, seal the bottom and the top to keep out moisture and make cleanup easier.
6. Larger bins. Bigger bins have greater compaction. Tall and narrow bins have the greatest compaction. More compaction means reduced airflow. Canola is denser than cereals and therefore needs more fan horsepower for proper aeration.
5. Dockage. Insect bodies, plant material, and weed seeds tend to contain more moisture than canola seeds. High-moisture dockage may not elevate overall grain moisture tests, but if it congregates in pockets, it can create localized hot spots. Grain with no dockage can also be at risk.
4. Green canola seeds can increase the storage risk, even if canola is dry and cool.
3. Damp or tough canola. Canola is considered “dry at 10 per cent moisture, but eight per cent is safer for long-term storage. Anything above 10 per cent should be dried. A standard aeration fan should do the trick if the air is warm with low humidity and if canola moisture is just a point or two above 10 per cent. A dryer may be required for canola above 12 per cent. Remember, a bin’s average moisture might be dry, but a couple of tough loads could have gone in, or small areas within each load may have been harvested from weedy slough patches and have higher moisture and higher dockage. These small pockets cause heating. Link: http://www.canolawatch.org/2011/05/02/tips-for-drying-tough-and-damp-canola/.
2. Hot canola. Canola binned hot, even if it has low moisture, low dockage and low green, should still be aerated. Target 15 C at harvest and watch throughout the winter for any rise. External temperatures moving from hot to cool in a few days create perhaps the worst situation for safe canola storage. A wide temperature differential between hot grain inside the bin and cool air outside sets up strong convection patterns in the bin. Moisture will be moving and concentrating at the top of the top middle core of the bin. Cool that grain fast.
1. Neglected bins. Growers are busy enough at harvest just getting the crop off, but take time to check all bins within the first two weeks after filling and again a couple more times until the canola is cool and winter sets in. Canola seed continues to sweat during the first four to six weeks after harvest, making this a critical period to move air through the bin and remove that moist air. It cannot always wait until after harvest. Canola can jump from 30 C to 50 C and beyond in two weeks or less.