Make Every Grain Count

Timely grain store preparation will help protect profit

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With rising input costs and continued volatility across the global grain market, it’s vitally important to safeguard precious crops post-harvest. Time invested in grain store preparation can protect profits by minimising the risk of pest damage during storage, helping farm businesses protect margins by making every grain count.


Grain store preparation often overlooked

Farmers have become resilient and proactive in best managing market forces, having navigated Brexit, Covid; and more recently, labour shortages and the cost-of-living crisis. Managing daily challenges like increasing fertiliser prices alongside unpredictable and more extreme weather has become the norm for arable farmers when growing their crops. Yet, as time becomes more precious when harvest season approaches, farmers often overlook the measures needed to ensure that quality (and sale value) is maintained post-harvest once grain is in storage.  

Effective grain store preparation is often the missing piece of the growing season jigsaw, says Ken Black, National Account Manager at Envu Environmental Science. 

“It isn’t a popular job on farm. It’s time consuming and comes at a time which is incredibly busy, but that doesn’t mean it can be overlooked. A proactive approach is needed to ensure that all the work that goes into growing and harvesting grain doesn’t go to waste.” 

The Agriculture and Horticulture Development Board (AHDB) agrees, stating that “good storage practice minimises risk throughout the supply chain and safeguards food safety for consumers. Critically, effective grain storage helps to minimise loss of premiums, through claims and rejections.”

The scale of potential financial loss due to poor storage practice is hard to estimate but one report from the Texas Farm Bureau in 2021 estimated that “in the US, $2.5 billion is lost every year from stored grain insect damage alone”.

It only takes one insect to be found in a one-kilogram sample of grain for it to be rejected.

With end-users becoming increasingly selective when it comes to buying or rejecting grain, it is vital for farmers to take a proactive approach when it comes to dealing with grain store pests. 


Impact of grain store infestations

The AHDB state that “thorough store preparation and hygiene help to eliminate sources of contamination from storage fungi, insects, and mites. This is essential, irrespective of whether grain is held for a temporary or longer period.

Insects and mites are most likely to be introduced from the store structure and equipment. Even small quantities of grain provide a food source, allowing pest problems to build.”

Some infestations can damage grains directly, with insects moving from one grain to the next, creating a snowball effect. The more insects present, the higher the temperature and moisture content within the store, which attracts even more pests and ultimately causes more damage.

Impact of insect infestations

Understanding grain store pests - The difference between primary, secondary, and tertiary pests

Grain stores provide a unique environment for pests and therefore attract particular insect species that are well adapted to grain store conditions.

The pests within a store aren’t always as well understood as those in the field, says Ken. 

“It’s useful to understand that none of the pests enter the store from the field during the harvest, and if they did, they wouldn’t survive as they aren’t adapted to survive in the store environment. Instead, insects lie dormant on ledges or in cracks in the store, they can be brought in on machinery or on people or on transport delivering or collecting from the farm.”

For effective grain store management, an understanding of the different types of pests and the conditions they like is needed. This will enable farmers to be proactive in taking timely preventative action and effective at dealing with any infestation that occurs. 

“In their simplest form primary pests like Grain Weevils and have mouth parts which damage the grain. They bore into it and lay eggs, which eventually become larvae and break through ready to start the process again. Their activity raises the temperature and moisture levels too, making the grain more susceptible to other pests.

Secondary pests like Red Rust Flour Beetles or Saw-Toothed Grain Beetles feed on the already damaged grain. And tertiary pests don’t damage the grain itself but in large numbers, they can cause an allergic response in humans and livestock, which of course is a huge problem with end-users.”  


Grain store preparation planning

To minimise the risk of infestations, grain stores should be cleaned and prepared 6-8 weeks before harvest. 

Ken says: “The earlier you can prepare a store by thoroughly cleaning it out and monitoring for insect activity - the better. It gives you more opportunity to get it right before the grain arrives and to treat as necessary. Thoroughly clean ledges and dispose of any old dust and debris as quickly as possible, well away from the store. Don’t leave vacuums within the store as the pests can easily crawl out.”

Grain store preparation checklist

Insect monitoring traps, which are sticky boards that can be put in every few metres, can help you identify any insect activity. 

“If you haven’t seen any activity after monitoring you may not need to apply any insecticide. But where there is evidence, you might consider something like Envu’s K-Obiol. This should be applied up to two months ahead of harvest. Its residual effect allows you to control any adult insects that come into contact with it,” concludes Ken.


Temperature control important in grain stores

Once the grain is in store, it is important to get the temperature down, cooling the grain to an optimum 15oC or below. Farmers should be looking out for hotspots, which will help to identify where insects might thrive. Pitfall traps placed at regular intervals on the surface of the grain and regular manual sieving of the grain should be carried out to see what’s there. Checking and monitoring is crucial at this stage, allowing you to act if necessary. 

Post harvest considerations