Avoiding phosphine resistance in stored grain products

Lesser grain borer

Phosphine resistance in stored grain insects is a serious issue which, if not addressed, has the capacity to seriously damage Australia’s ability to maintain its market edge in the export of bulk grain.

With more than 80 per cent of Australian grain treated with phosphine, the Australian grains industry is highly reliant on the continued effectiveness of this fumigant as the cheapest and an efficient pest management method that allows the export of clean and "residue-free" grain.

It is therefore critically important that growers implement best practice when storing grain, particularly in relation to fumigation. Silos must meet the latest gas-tight standards and fumigant application rates and fumigation periods must be sufficient to reduce the incidence of phosphine resistance among grain storage pests. 

Phosphine resistance has increased in the past 10 years because of failed fumigation practices. All recorded levels of resistance found on-farm can be controlled when using label rates in sealed, gas-tight storage.

The insecticide dichlorvos is now out of reach of most grain growers and is more suited to bulk handler use, underlining the importance of phosphine to the industry and the need to respect is availability through proper use.