Will storage of infected grain for over 1 year reduce Fusarium spp. infection and DON levels?

The viability of various Fusarium spp. during storage is dependent on the storage conditions, with temperature playing a key role. Scientific studies have demonstrated that Fusarium infection levels will be reduced when infected grain is stored for at least 6-9 months at a constant temperature of 25 °C and where either relative humidity is >62% or seed moisture content is at least 10-14%. One study demonstrated elimination of Fusarium graminearum when corn seed was stored in sealed containers at 30°C and a seed moisture content of 14%. However, the same is not true for infected grain stored at cooler temperatures (less than 15°C) which are more consistent with the recommendations for grain storage on the Canadian Prairies. At temperatures below 15C the viability of the pathogen (Fusarium spp.) is unchanged, unchanged, especially under drier conditions, making long term storage of infected grain a poor strategy for reducing Fusarium infection levels. Also, if the grain is to be used for seed, prolonged storage of infected grain at higher temperatures and moisture levels may result in reduced vigour and germination rates.

The mycotoxin deoxynivalenol (DON) in Fusarium infected grain is also unaffected by long-term storage, regardless of the temperature. Under safe storage conditions changes in DON levels would be unlikely.

Submitted by

Holly Derksen, Field Crop Pathologist, Manitoba Agriculture

Barbara Ziesman, Provincial Specialist, Plant Disease, Saskatchewan Ministry of Agriculture

Michael Harding, Research Scientist, Plant Pathology, Alberta Agriculture & Forestry

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Preventing Stored Grain Insects at Harvest Time

#Harvest16 is here and a below is a quick review (from the most recent Manitoba Disease & Insect Update – August 10, 2016) of preventing stored grain insects from John Gavloski, Provincial Entomologist with Manitoba Agriculture.

Preventing stored grain insects: A reminder before moving and storing new grain to clean old grain out of bins, augers, combines, truck beds, and other areas where grain or grain debris may be. Infestations of stored grain insects such as rusty grain beetles usually do not get started by harvesting the insects along with the grain. They are often the result of insects already being present in bins or equipment used to move grain, or insects being able to get into the stored grain through openings in bins or storage structures. Figure 1 (below) is a picture of a sawtoothed grain beetle (top right), red flour beetle (bottom left), and rusty grain beetle (bottom right) with a grain of wheat (top left) to give perspective on size.

faa06s00b

Figure 1. Some beetles that may occur in stored grain.

Some insects in stored grain, such as the rusty grain beetle, will feed primarily on the grain, while others, such as foreign grain beetle, may be feeding primarily on molds growing on grain that is too moist. So it is good to know the species you are dealing with as management options may differ. Additional information on identifying and managing insects on stored grain can be found at: http://www.gov.mb.ca/agriculture/crops/insects/prevention-and-management-of-insects-and-mites-in-farm-stored-grain.html

For long-term storage of grain, lowering the grain temperature below 15C as soon as possible after the grain is placed in storage can help minimize the risk of stored grain insects. Below 15C potential insect pests of stored grain stop laying eggs and development stops. Grain that is not aerated or moved after harvest can often remain warm enough for insects to survive the winter.

Following proper storage recommendations is also a key component in Cereals Canada’s Keep It Clean initiative. More information is available at http://www.cerealscanada.ca/keep-it-clean/

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, Manitoba Agriculture

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Preventing Stored Grain Insects

A reminder before moving and storing new grain to clean old grain out of bins, augers, combines, truck beds, and other areas where grain or grain debris may be. Infestations of stored grain insects such as rusty grain beetles do not get started by harvesting the insects along with the grain. They are the result of insects already being present in bins or equipment used to move grain, or insects being able to get into the stored grain through openings in bins or storage structures.

In Figure 1 below, there is a picture of a sawtoothed grain beetle (top right), red flour beetle (bottom left), and rusty grain beetle (bottom right) with a grain of wheat (top left) to give perspective on size.

grain-feeding-beetles

Figure 1. Some beetles that may occur in stored grain.

Some insects in stored grain, such as the rusty grain beetle, will feed primarily on the grain, while others, such as foreign grain beetle, may be feeding primarily on molds growing on grain that is too moist. So it is good to know the species you are dealing with as management options may differ. Although both are very small beetles, when placed in a glass jar foreign grain beetles can climb up the sides, while rusty grain beetles cannot.
For long-term storage of grain, lowering the grain temperature below 15C as soon as possible after the grain is placed in storage can help minimize the risk of stored grain insects. Below 15C potential insect pests of stored grain stop laying eggs and development stops. Grain that is not aerated or moved after harvest can often remain warm enough for insects to survive the winter.
The above information was submitted by John Gavloski, MAFRD Entomologist.  It is available in the last issue of the Manitoba Insect and Disease Update which is posted at: http://www.gov.mb.ca/agriculture/crops/seasonal-reports/insect-report-archive/insect-update-2015-08-24.html
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Can Hot, but Dry Canola Still Spoil in the Bin?

With the extreme temperatures in the past week, harvested canola is coming off hot, hot, HOT!  Reports of canola measuring in the mid to high 30s are common, as well as the canola being dry at 8% and very dry <6%.

Canola in the above situation, even though moisture is low, needs to be conditioned as soon as it is in the bin.  Conditioning the seed, by turning on aeration fans will help move cooler air through the seeds, cooling in down.  If grain if left hot and unattended at temperatures over 15C, there is a greater risk of spoilage.  Using air movement will also help dry out any green weed material in the harvested seed, which will again help reduce spoilage in the canola, from the moisture in the weeds increasing moisture in pockets in your bin.

If you do not have aeration in your bin, leave the bin hatches on the top of the bin propped open, so hot air can escape.  Close the hatches if it starts raining though.  Also consider taking a truck load of canola out of the bin from the bottom and then auger back into the bin through the top hatch.  This can ‘turn’ the grain and the act of augering will introduce cooler air into the canola and help cool it down.

In all situations, monitor the temperature and moisture of the canola in the bins closely.  Canola keeps longer term if it is cooler than 15C and less than 8% moisture.

Canola Watch has more information in their September 2, 2015 post that can be could at http://www.canolawatch.org/2015/09/02/condition-canola-immediately-after-harvest/

Opposite situation – storing damp grain?  Here is some information on steps to take.  The article also has a good explanation on what is going on in the bin with air movement and how spoilage zones can occur: http://www.gov.mb.ca/agriculture/crops/production/drying-and-storage-of-damp-grain.html

Submitted by: Anastasia Kubinec, MAFRD Oilseed Specialist

 

 

 

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What Moisture/Temperature is Recommended Grain Storage?

Submitted by Anastasia Kubinec, MAFRD Oilseed Crop Specialist

Within the first 6 weeks of harvesting grain, bins should be checked regularly for change in temperature, moisture and watching out for spoilage.  After the 6 week mark, sampling and monitoring should still be occurring to ensure grain is at the appropriate temperature/moisture to store long-term over the winter. 

The Canadian Grain Commission has charts available on their website that indicated the proper temperature and moisture of each type of grain.  http://www.grainscanada.gc.ca/storage-entrepose/ssg-de-eng.htm

Continue to monitor your grain over the winter months, until it is shipped to the buyer, to ensure that the quality put into the bin is the quality coming out of the bin!

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Check Your Grain Bins Before the New Year to Reduce Spoilage Issues

Most of the grain/oilseeds harvested in Manitoba in 2012 went into the bin very dry, but also very hot (>28C).  Good news for not having to dry the grain in fall, but that doesn’t mean you can forget about the potential risk of spoilage.  There are reports of grain deliveries in December 2012 being slightly heated, or having some other spoilage issues or insect damage.

 As we get colder, a convection cycle starts in the bin, moving the humidity from the  cooling grain downward, into the bin centre and then up to the top of the bin.  During the process, two things can happen that causes spoilage issues. First, at the top of the bin, moisture can condense and accumulate, creating an ideal zone for spoilage and crusting. Second, grain is an insulator and the ‘bin heart’ that is warm with moist air moving in, can continue to heat, forming ‘hotspots’ of heated grain and/or creating ideal conditions for insects.

To avoid this unpleasant discovery, go check the bins before the New Year.  Routine monitoring for symptoms of spoilage (smell, visual signs), checking grain temperature and moisture will help manage the stored grain quality. 

  • Watch for bins that the snow has melted off.
  • Open hatch to check inside. Grain/oilseeds should not smell musty, mouldy or sour and should not have any white or greyish crusting. 
  • Probe the core of the bin and the probe should penetrate the grain easily.  If not, a crust could be forming underneath the top layer of grain or a heated/dense spot may have occurred.

 The practise of taking ‘a load’ out of the bottom of the bin and putting it on top or ‘turning’ the bin is also helpful in moving the layers of grain around in the bin and fracturing the heart to reduce pockets of hot and moist grain.

 

More information on preventing and managing stored grain insects: http://www.gov.mb.ca/agriculture/crops/cropproduction/faa06s00.html

Grain Drying and Storage of Damp Grain: http://www.gov.mb.ca/agriculture/crops/cropproduction/faa05s00.html

Manitoba Listing of Grain Handling, Storage and Process Technology: http://www.gov.mb.ca/trade/globaltrade/oem/english/grain.html

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