AGRICULTURE KNOWLEDGE CENTRE BULLETIN: INSECT AND MOLD CONTROL IN STORED GRAIN

With the poor conditions for harvest this fall, farmers may encounter problems with damp grain that is unsuitable for long-term storage. In addition to spoiling grain, moisture will promote fungal growth and the associated insects that feed on the fungus. A good aeration system, that will dry and lower grain temperatures in storage, is usually sufficient to manage both insects and fungus. It is important to take action to preserve the quality of stored grain.

Mold or fungal organisms get into grain masses from soil particles and organic matter. They are present in farm machinery, and as spores on stored seeds. Fungal organisms are usually inactive in low moisture environments (below 12-14 per cent). Under wetter conditions, the spores will germinate and develop into different types of mold. Mold growth will stop in grain temperatures of -8°C.

Storage facilities and aeration systems are factors in maintaining appropriate temperature and moisture levels. For example, smaller quantities of grain cool and dry quicker than larger masses.

General recommendations to manage insect infestations include:

1. Prevention: For long-term storage, start with a clean bin. As well, producers should lower the grain temperature below 15°C as soon as possible after the grain is placed in storage. Aeration systems used during the night immediately after harvest should have the grain below 15°C in about two weeks.

2. Monitoring: Regularly monitor the grain to determine the presence and potential for serious infestations. The presence of insects or insect damaged kernels will indicate a problem. The best way to detect insects in stored grain is by using probe traps. Often the first sign of an infestation will be found near the top centre of a storage bin.

3. Control: The Canada Grain Act states there is a zero tolerance for any primary insects (those that feed on whole, sound grain) in grain delivered to elevators. It is possible to kill insects with cold temperatures. The following grain temperatures may kill insects, found in stored grains, that feed on the grain or on the fungus:

Grain Temperature Time required to kill insects
-5°C 12 weeks
-10°C 8 weeks
-15°C 4 weeks
-20°C 1 week

For more information on insect and mold infestation, and control in stored grain, contact the Agriculture Knowledge Centre at 1-866-457-2377, or check the Guide to Crop Protection 2004 starting on page 349. The guide is also online at www.agr.gov.sk.ca under Crops/Related Information.

Additional information:

Guide to Crop Protection 2004 - http://www.agr.gov.sk.ca/Docs/crops/cropguide00.asp

Canadian Grain Commission - http://www.grainscanada.gc.ca/

Agriculture and Agri-Food Canada - http://res2.agr.ca/winnipeg/storage/pages/princ_e.htm

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For More Information, Contact:

Dale Risula Agriculture Knowledge Centre, SAFRR Moose Jaw Phone: 1-866-457-2377