By Mitchell Japp, MSc, PAg, Provincial Specialist, Cereal Crops and John Ippolito, PAg, Crops Extension Specialist, Kindersley
Harvest has been a challenge for many in 2019. Uneven emergence in many fields followed by a number of precipitation events has made for slower harvest progress than normal. Grain has been harvested in a tough state and when the weather improves producers are likely to harvest some more tough grain. Drying by using natural air is a slower process as we enter a period of shorter days and lower daytime temperatures. Storage goals may need to be adjusted to keep the grain cool to prevent spoiling until you have access to a heated air grain dryer.
Grain stored at high moisture is at greater risk of harvest storage pests or fungal growth. Fungi (Penicillium verrucosum) that produce the mycotoxin ochratoxin A require high-moisture conditions. There is no visual damage from this fungus or the mycotoxin. Grain stored at low temperature and low moisture will prevent development of this fungus and mycotoxin. Information on combinations of temperature and moisture content for proper storage can be found on the Canadian Grain Commission website. Proper storage is one of the basic principles of the Keep it Clean campaign.
For producers dealing with tough or damp grain, grain dryers will likely be in demand. It is important to understand that each crop tolerates supplemental heat differently - be sure to follow recommended settings for the crop being dried. It is also recommended to not remove more than six per cent moisture in one pass through a heated air dryer. Maximum safe drying guidelines are based on not drying to more than one per cent below recommended moisture content.
*Summarized from Canadian Grain Commission
Wheat can be damaged when air temperatures are too high. Care should be taken for milling wheat to keep the grain temperature in any part of the dryer from exceeding 60 C. To achieve this, recommendations are that air temperatures in non-circulating batch dryers and cross-flow continuous dryers not exceed 60 C. Air temperature in recirculating batch dryers should not exceed 60-70 C. Parallel flow continuous dryers should not have air temperatures exceeding 70 C.
The Winter Wheat Production Manual, available online, provides some good suggestions for operating grain dryers.
Grain dryers are an excellent tool available to assist producers when harvest conditions are wet, damp or tough. Just like any other tool, following safe operating procedures and guidelines will keep everyone safe and come out with a better product in the end.