How to protect stored grain from insects [Video]

Central Life Science's Johnny Wilson emphasizes the value of a multi-faceted approach to grain pest control.

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Elise Schafer, editor of Feed & Grain: Hi, everyone, and welcome to Feed & Grain Chat. I'm your host Elise Schafer, editor of Feed & Grain. This edition of Feed & Grain Chat is brought to you by WATT Global Media and is your source for the latest news, product and equipment information for the grain handling and feed manufacturing industries. 

Today, I'm joined on zoom by Johnny Wilson, PhD, technical services for Central Life Sciences. He's here today to discuss how to preserve grain quality through proper grain protectant and other pest management strategies. Hi, Johnny, how are you?

Johnny Wilson, PhD, technical services for Central Life Sciences: I'm doing great this morning. How are you?

Schafer: Doing well, thanks for joining me!

Wilson: Absolutely.

Schafer: Now let's get right into it. Can you briefly explain the main function of grain protectants and how they support maintaining stored grain quality?

Wilson: Really we need to think about grain protectants in terms of prevention. And they go in a team of preventive strategies. We like to use the acronym SLAM as this holistic approach to all of the different sanitary methods that you should be doing to grain as it's going into storage. Things like monitoring moisture content of the grain, making sure that sanitary practices are followed, making sure that grain bins are cleaned out prior to grain being added.

And then we need to think about as grain is going in, we're putting this grain inside of storage bins, so we need to make sure that there's not insects present before, or grains are coming and insects are coming along inside the grain stream itself. We're introducing these pests as we're filling the grain, so we need to do the best that we can to eliminate them as they're coming in. That way they don't flourish inside of that bin.

That's the area that we're focused on — making sure that we don't introduce this problem and allow it to be in an environment where it can grow over this storage time, whatever it is — three months, six months, nine months, a year — because it can be very difficult to monitor exactly what's happening inside that bin and what level of damage it is. The way that we approach it, we have both dry and liquid grain protectants and depending on what type of pests you're looking to deal with, you might need to look at using adulticides, which kill the insects, or you can use what are called insect growth regulators, which are essentially birth control for bugs that keep that next generation from maturing and reaching reproductive age and blooming.

Schafer: How are grain protectants properly applied, and when is the ideal time to do this application?

Wilson: The ideal time is right as grain is going into its initial storage phase and there's a couple of different methods that you can do depending on what your application is set up like. Some people like to apply it as they are harvesting the grain. Some people like to install equipment on their conveying machines and augers and drag conveyors before it goes up into the bucket elevator and elevates up into the grain bin itself.

There's also fogging applications, but then depending on the scale that you have, you might look at liquid versus dry. Really on the liquid, we're adding a negligible amount of moisture content. So that added moisture is really not a concern, we're talking .01% to the total grain mass. So really nothing that's going to cause spoilage concerns, but there are also dry options, as well. And you can be as technical as having metering devices as grain is flowing in that can gauge the speed of the auger and match the speed of products being applied, to the tried-and-true hand scoop method of shaking in dry product as it moves past the auger.

Both have been shown to be extremely effective, it just depends on the scale of operation. If you're looking at small on-farm storage, you might opt for the dry. Maybe you've only got 1,000 bushels, whereas maybe you have a half-million-bushel bin and it would be very time prohibitive to have an employee standing there applying dry products, so you might need to look at more of an automated liquid application.

Schafer: Can you tell me about the research being done to quantify the difference in losses between treated and untreated grain?

Wilson: Absolutely. I like to think of it in terms of shrink. And on farm when we talk shrink, everyone's mind instantly goes to moisture content and how much moisture I'm losing and that's what's causing shrink. And coming from the feed mill industry, when we talk shrink it tends to be more accounting shrink, The accountants just see the number on a spreadsheet and that could be moisture, that could be dry matter loss due to insect damage, it could be grain spoilage that had to be tossed out for whatever reason, but it all encompasses that shrink value.

So that's the approach I took in wanting to quantify what insect loss is actually happening and differentiate it from the different types of shrink because we really don't have a great metric of exactly where those losses are coming from. [We know] just that when we drive that truck across the scale, this number is different than the number we first brought in, so loss is there. But what components of it are split up between these various different parts? So what we've done is we've started some small benchtop studies, then we actually have some scaled up studies going all the way up to 5,000-bushel bins that are in the planning phases right now with the USDA and Kansas State University. And we are looking to measure out all of the different components that account for loss looking at the amount of whole grains versus insect damaged kernels versus fines produced versus the actual amount that the bugs consume, and how much of the bugs are present initially. And finally also, moisture loss is certainly a component of that.

As you see pests grow through different growth phases, you might have an increase or decrease in moisture loss depending on where they're at in their growth cycle. Some of the numbers that we've seen initially — and the study is not completely finished yet — but we'll give a little spoiler. Throughout month one alone, we've seen beyond 2% shrink just from the insects when you correct for that moisture content loss, which is enormous when you're talking about $6.50/bushel corn.

Schafer: Excellent! Now, what other pest management strategies can complement the application of grain protectants in stored grain?

Wilson: Well, certainly that sanitation step and everybody likes to be able to go out and buy a silver bullet and just say 'I want to buy this one thing, and it's going to fix all my problems.' Unfortunately, that doesn't exist. We would love it if we could sell that, but it just doesn't happen. So I help out a lot of both on-farm and commercial operations, doing processing audits for them. And a lot of what I see has to do with those initial sanitation steps and the pitfall that everybody runs into — everyone's short on labor, everyone is trying to optimize their time and they might not be doing the best job they could on those initial sanitation steps. 

And it leads to big problems down the line, as you get into the later months of that grain storage where maybe you didn't clean out your sweeps well enough, maybe you didn't clean out your aeration system and fans well enough, maybe you left all the fines at the bottom of your bin. That just breeds an environment for these bugs to really prosper in and they bloom up through that grain mass and become a huge, huge problem. So that's the biggest one I see is that preventive treatment step. And that's a combination of physically cleaning it out and applying products — adulticides. growth regulators — to empty bins, as well, can help tremendously. And if you only did one thing that's going help the most.

Schafer: Wonderful, thank you for your insights into these various strategies, Johnny.

Wilson: Absolutely! Thanks for having me on.

Schafer: My pleasure! That's all for today’s Feed & Grain Chat. If you'd like to see more videos like this, subscribe to our YouTube channel, sign up for the Industry Watch Daily eNewsletter, or go to and search for videos. Thank you again for joining and we hope to see you next time!