Grain growers urged to give silos a ‘health check’ as harvest ramps up across WA

With harvest in full swing across WA, the Grains Research and Development Corporation is urging growers to maintain their storage silos to prevent weevil infestations. GRDC grain storage extension team project lead Chris Warrick said prevention was “always better than the cure”. “Controlling insects once they infest grain requires fumigation or controlled atmosphere, both of which require gas-tight, sealable storage,” he said. “For un-sealable storage, prevention is our only option short of transferring grain into gas-tight sealable storage for batch fumigation.” Mr Warrick said whole farm hygiene should be a priority, including the cleaning of any equipment that handled or held grain. He said waste grain should be fed to stock, buried or spread over the ground thinly to decompose. “A pile or drum of waste grain creates the perfect breeding ground for insects, undoing all our hard work in cleaning up,” he said. To prevent surviving insects from re-infesting grain, Mr Warrick said storage and equipment could be treated with diatomaceous earth once the clean-up was complete. For cereal grain, he said protectants containing Spinosad, Methoprene, or Deltamethrin and Piperonyl butoxide should be rotated every year or two. GRDC has also recommended the use of aeration cooling to prevent the spread of insects. “By cooling grain, insect activity can be slowed or even stopped if low enough grain temperatures are achieved,” Mr Warrick said. He said aeration cooling could also prevent mould growth and reduce the vent time needed to clear gas after fumigation. He said monitoring temperatures and regularly checking for pests were essential parts of grain management. “This can be done with simple probe traps and thermometers inserted into the top of the grain stack,” Mr Warrick said. More information is available on the GRDC website.