Whether you’re storing seed for next season or holding grain and waiting for the right price, it’s essential to reduce the risk of insect damage. Insect-damaged grain can be degraded, and quality can be severely reduced, along with your potential profits. Here are four ways to improve grain storage.
1. Is Your Equipment and Storage Area Clean and Ready? (And Is Your Grain Clean?)
Start by ensuring your grain storage equipment is properly cleaned and sealed.
Note: As of the 15th of August 2026, Fenitrothion will no longer be registered to be used to treat grain storage facilities or equipment (e.g. silos, storage bins). The decision was made in August 2025, and current labels will have a 12-month phase-out. Also, no hand-held spraying will be authorised (but application to the grain itself is still permitted). You can read the APVMA final summary assessment, including supported and non-supported uses, here.
The are only a few products currently registered for treating storage areas and equipment. One is Diplomat 500 by Imtrade, another is CutnDry or Diatomaceous earth, a powder that can be blown into bins, sheds, and machinery to provide a residual insect barrier. Check with your agro on other options.
However, the most efficient pest control practice is to also treat grain with a residual insecticide liquid or aluminium phosphide tablets (phostoxin, i.e., Fumitoxin or QuickPhos). Also, make sure you’re not storing grain with high moisture content; aim for less than 12.5% (the lower the better). If keeping for seed, moisture will affect germination and vigour.
2. Are You Keeping Records? Measure and Dose Correctly, And Don’t Rely On Memory.
It’s essential to keep records for several reasons.
One is to ensure you’re adhering to any withholding periods that may affect grain saleability.
But it’s also crucial to ensure proper timing for treatments such as phostoxin tablets, which need a full exposure period, a ventilation period, and a withholding period. Stickers are available, or use a big black texta and write details on bins, even if it looks a bit untidy.
If you’re not a fan of pocketbooks, try UPL’s SiloKeeper app. It plans, monitors, and tracks your grain fumigation process, including proper timing, and helps you get the Quickphos Dosage right when you fumigate your silos.
3. Why Would You Want To Include A Residual Treatment?
If you’re looking for long-term protection, treat with a knockdown plus a residual or Insect Growth Regulator (IGR). This will knock down immature insects and provide long-term protection against larvae.
Check out our article on Grain Protectant Treatments here.
For a quick summary, a popular product for residual insecticide is Smart Grain Dual. Smart Grain Dual combines 60g/l S-methoprene and 600g/l Fenitrothion to provide a broader range of protection. Fenitrothion will kill any live moths or immature insects in the grain, and S-methoprene will prevent further insect breeding for up to 9 months. The greatest benefit of Smart Grain Dual is that it saves you the time and hassle of buying the two products separately, calculating rates, and mixing them yourself. Smart Grain Dual protects against OP resistant lesser grain borer and a range of other pests. It’s registered in wheat and barley (including malt), and the withholding period is only 24 hours. It’s Available in 500mL (treating 50 tonne) and 2.5L (250 tonne) pack sizes.
However, if there are live mature adult weevils present, the only product for successful control is phostoxin / aluminium phosphine tablets.
4. What Is Your Treatment Target?
Got Fenitrothion in your shed and thought you’d use it to wipe out Lesser Grain Borer’s? Think again. Make sure what you’re targeting matches what you’re treating. Always read labels.
Check the table below to ensure you’re not wasting your time and money (and future profits from that grain!).
5. And Don’t Forget! Check Your MRL’s And Withholdings.
This is the one thing that’s easy for growers to forget. MRL’s and Withholding Periods are important to abide by, so it’s critical that you follow the product label. If not adhered to, you could jeopardise the market that the grain is being sold into.
