C leaning stores out thoroughly will give them a good break from last year ’ s crop . Storage pests , insects and mites , do not come in with the new crop but live on residues in store . In the UK the most important grain beetle pests rarely fly and do not infest grain in the field ; they are mostly spread between stores on loads of grain , animal feed , contaminated lorries or equipment . Cleaning out stores is then essential to prevent pest carry over and some timely maintenance can prevent access by both the small and large pests such as rats and pigeons . Eliminating cracks and crevices that can act as pest refuge is also a good idea . Don ’ t forget to clean all grain moving equipment such as augers and conveyors .
Insect or mite traps in the store at every 5 metres will allow you to identify any pests still present and prompt action to remove the persistent infections by further cleaning and good hygiene .
Remove the risk of contamination by foreign bodies such as glass , stones , concrete , etc . by good hygiene and fix shatterproof covers over lights if not already done so .
Ideally crops are cool and dry before they enter the store but the weather does not always play fair .
The ideal moisture content for stored grain is 14.5 % or less , with any grain coming in at over 18 %
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needing priority for drying . Both high moisture content and a high temperature in combination puts the grain at a great risk of fungal development and of mycotoxin formation . Using high temperature drying does need care to make sure the grain is cooled adequately following on to prevent insect and mite infestation . And remember grain for milling and malting is often required not to go above 50oC .
Near ambient air drying will be very slow if harvested grain has a high moisture content of above 20 %. Reducing the depth of the stored grain will help with this if feasible .
Grain should be cooled as soon as possible after harvest to below 15oC to control grain beetles and mites ; ideally within 2 weeks of harvest . Long term cooling to 5oC will kill insect pests surviving in store and prevent mite numbers increasing . However , if you have barley in store aimed at the malting market don ’ t cool below 10oC . Cooling to below 12oC will prevent grain weevils from developing .
Monitoring of the store is then on-going .
Ideally weekly for grain temperature once the grain is at the target storage temperature , weekly with pitfall traps for grain mites and insects , and at least once a month for moisture . Pitfall traps should be positioned on top of the grain and just under the surface at 4-5 metres apart . Ideally blow air up through the grain to
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cool it and using a differential thermostat is a good idea which will only blow ambient air when it is cooler than the grain , preventing |
any dampness being added into the stored grain . |