WINNIPEG, MANITOBA, CANADA — Despite dry weather conditions for this year's grain harvest, this spring's wet weather may influence the quality of harvested grain when it goes into storage, said the Canadian Grain Commission (CGC) on Aug. 18.
Weeds may be present at harvest because wet spring weather meant many western Canadian grain producers were unable to apply their usual weed controls. If immature weed seeds are not removed from grain during harvest, their higher moisture content can affect grain's moisture content and temperature in storage, CGC said. This could create favorable conditions for insect infestation and fungi development during storage.
Blaine Timlick, the CGC’s stored products entomologist, advises producers to be diligent about using aeration and other methods to keep grain at optimal temperature and moisture.
"Our staff in our service centers, along with Blaine, are here to help," said Elwin Hermanson, chief commissioner of the CGC. "Before producers begin their harvest, I invite them to contact our grain sanitation experts and to take a look at our recommendations for managing stored grain on our web site, www.grainscanada.gc.ca."
Timlick advises producers to check the temperature and moisture of their stored grain and monitor the grain for signs of infestation.
"In the fall, look for stored grain insect pests by taking samples from the central area on the surface of grain." Timlick said.
The same good storage practices producers use to prevent insect infestations can also prevent the development of fungi. Some fungi produce mycotoxins. For example, ochratoxin A is a mycotoxin produced by some kinds of storage fungi under certain conditions.
Research shows that ochratoxin A develops when grain is improperly stored over long periods of time. Its presence cannot be detected visually. Health Canada is proposing limits on the amount of ochratoxin A that can be present in domestic grain products.
To prevent problems caused by moisture, insect infestation and moulds (including those that cause ochratoxin A), the CGC recommends producers:
- Dry grain before storing it, if necessary, to bring it to the recommended moisture content. The Official Grain Grading Guide's specifications for dry grain are:
- Barley (all except select): 14.8% moisture or less;
- Wheat (all classes): 14.5% moisture or less;
- Oats (all) and Barley (select): 13.5% moisture or less.
- Use aeration to help control the heat and moisture of grain in storage, particularly if grain is stored at a high temperature.
- Bring grain temperature below 15°C as quickly as possible.
- Keep the temperature of grain low and uniform, below 15ºC.
- If using aeration, keep the surface of the grain inside the bin as level as possible to avoid the collection of moisture in the cone.
- Suction aeration, which pulls air from the top of the bin to the bottom, can save time and money as it has been shown to cool grain faster than traditional methods that push air through the grain mass. If producers do not have aeration systems, they should turn their grain frequently and monitor its temperature.