Keep a close watch on stored grain

Keep a close watch on stored grain

Uneven quality and maturity in this year's crop will mean closely monitoring stored grain for mold and insect infestations.

GOOD grain storage practices should be a priority for farmers and grain handlers this fall, Iowa State University grain storage expert and agricultural engineering professor Charles Hurburgh advised.

The unconventional growing season that started with a delay in planting due to cold and wet conditions and finished with dry, hot weather will cause sharp variations in maturity, test weight and moisture in this year's crops.

"Farmers need to be prepared to manage wide variability in grain properties this fall," Hurburgh said. "You can't cut corners on good grain management practices, or it'll come back to bite you."

The roller-coaster difference in the harvested crop quality means the potential for spoilage in stored grain will be greater than in previous years.

Variation in moisture will be an issue this year. A large difference in maturity is occurring within fields or even within the same rows, Hurburgh said.

Monitoring moisture will be the key to preventing mold from spreading throughout the entire bin, especially as temperatures rise next spring.

As mold spreads through a grain bin, the value of the crop dramatically declines.

Iowa State University recommends the following basic principles to properly manage grain with high variability:

* Immediately cool the grain after harvest and drying.

* Have adequate aeration of 0.1 cfm/bu. or more.

* Run a cooling cycle every time there is a 10-15 degrees F change in the average outside temperature, starting at harvest. A cooling cycle will take about 150 hours at 0.1 cfm/bu. and proportionately less for higher airflows.

* Get the grain temperature below 40 degrees F as quickly as possible.

* Check the accuracy on freshly dried grain. Freshly dried grain normally reads low; test 5-10 sealed samples four to six hours later to establish a rough correction factor.

* Take out the center core of fines. Variable quality and a lower test weight will mean more fines.

* Inspect grain and monitor temperature weekly until December and then every two weeks thereafter. Automated temperature cable systems are very useful. The larger the bin, the less likely a manual check will be adequate.

* Respond to temperature changes; this is as important as the actual temperature. A 3-5 degrees F change between readings, even if from 40 degrees F to 45 degrees F, is indicative of spoilage if the fan was not run in the interim.

"This was a difficult year to predict what the growing season would be like," Hurburgh said. "We had very unpredictable conditions, which is why you have to follow the rules and pay attention as far as grain storage is concerned."


Insect infestation

High grain temperature and moisture can provide the proper environment to accelerate the development of not only mold but also insects.

Insects can reach a high population size in neglected grain bins. According to the University of Minnesota, insect infestation amplifies mold problems in grain by exposing otherwise hidden endosperm surfaces to molds, transferring mold spores to new areas in the grain and encouraging mold germination in micro-habitats made moist by insects' metabolic activity.

It is important to control the insect population size before grain is permanently damaged by insect boring, feeding and mold germination.

The best way to control an insect infestation is to properly sanitize empty bins prior to filling them again in the fall.

Still, four insecticide treatment options are available for stored grain: applying insecticides as an empty bin spray, treating grain as the bin is being filled, top-dressing stored grain and fumigation.

The University of Minnesota recommends inspecting stored grain for insects every 21 days when grain temperature exceeds 60 degrees F.


New web tool

The Canadian Grain Commission launched a new web-based tool for identifying more than 50 species of insects recognized as pests of stored grain.

The new interactive online insect identification key, available at, assists users in properly distinguishing insects found in grain bins by prompting them to select corresponding images and descriptions.

"Our insect keys are an effective, easy-to-use tool for insect identification. Once you know the insect you're dealing with, you can make the appropriate decisions for management," explained Brent Elliott with the Infestation Control & Sanitation Office at the Canadian Grain Commission.

Volume:85 Issue:42

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