Two storage questions

November 4, 2015 - Issue 29

Here are answers to two storage questions from Canola Watch readers:

1. I have monitor cables in my bins. What temperature will damage canola?

The Canola Encyclopedia chapter on heated drying provides a clue. It says seed canola should be dried at less than 45°C and that canola stored for crushing can be dried at 60-82°C depending on certain conditions. Based on this, we can assume that canola will not be damaged at temperatures up to 45°C.

However, growers are advised to take action on stored canola well before stored canola reaches this uncharacteristically high temperature.

The recommendation is to cool stored canola down to 15°C after harvest, and then cooler that as days get colder. Once at that safe storage temperature, watch the monitor cables. Any sign that temperatures are going up would signal something going on inside the bin. Once the heating reaction has started, it will probably keep building and could reach 45°C and beyond fairly quickly.

2. What is a safe plenum temperature for drying canola?

To prevent seed damage, the maximum seed temperature should not exceed the maximum allowable temperature for the type of seed and its intended purpose. For instance:

—Canola destined for seeding purposes should be dried at less than 45 to 50°C.
—For oil extraction, seeds can be dried at up to 82°C. But use lower temperatures (max 71°C) when canola is damp (over 12.5 % moisture) or when it is to be stored for over six months.
—A non-recirculating batch dryer or a dryer which does not mix or circulate the seed requires a lower operating temperature as seeds next to the hot-air plenum will warm to near the hot-air temperature. For these dryers, use temperatures 5-10°C lower than those listed for commercial use.

Safe drying temperatures table

The Canola Encyclopedia chapter on heated air drying temperatures

Canola Watch