Post-harvest jobs to protect stored grain from pests

Diatomaceous earth can provide a non-chemical option for a structural treatment and it only requires a very fine layer along the inside surfaces of the silo Image: Chris Warrick

After harvest is the perfect time for three simple on-farm hygiene jobs to protect your stored grain from pests and prepare for the year ahead.

Kym McIntyre from the Grains Farm Biosecurity Program advises that over summer is a good time to clean your unused grain storage and handling equipment and clear piles of grain residues on your farm.

“Hygiene is an essential step to ensure grain on your farm is kept ready for market in a safe, insect free environment,” explained Kym.

“For example, it is important to make sure old grain residues are not left piled up on your farm.”

“Storage pests will breed in these piles and may fly up to 1 km back to stored grain and infest it again.”

“To prevent this, bury, burn or spread out the residues in the paddock to less than 20mm deep.”

When it comes to unused storage facilities, Philip Burrill from the National Stored Grain Extension Program said the first step is to clean out all grain residues.

“You can then apply structural treatments to the empty storage such diatomaceous earth (DE), commonly known as Dryacide™,” said Philip.

“DE can provide a non-chemical option for a structural treatment and it only requires a very fine layer along the inside surfaces of the silo.

“The fine hard particles of the DE get into the joints of the insect, irritating their waxy exoskeleton and causing them to die of dehydration.”

Philip also emphasised that it is important to clean any grain handling equipment as grain left behind in the equipment provides an ideal place for insects to breed between harvests.

A trial done in Queensland found that a header thought to be clean at the end of the previous year had more than 1000 lesser grain borer insects in the first 40 litres of grain to run through it at the beginning of harvest.

“This shows how a small amount of grain residue can allow insects to breed and subsequently infest freshly harvested grain,” said Philip.

As it is impossible to remove all the grain residues from equipment without a major overhaul he recommends putting a small amount of DE into the harvester or handling equipment.

“Run the machine for a few minutes to distribute it through,” Philip explained.

“Ideally, this should be done after harvest and again one month prior to the next harvest.”

For more information please contact Kym McIntyre at kym.mcintyre@daf.qld.gov.au