8 June 2001

Clear up those myths as well as the dust

WITH harvest looming it is worth blowing away common misconceptions about grain storage, as well as last years store dust, says a leading specialist.

"Number one is cooling," says the CSLs Ken Wildey. "People get grain down to 15C and think that will do. You have to keep going.

"Get set up with a differential thermostat so the decision is taken out of human control."

Sensors in the grain and outside in ambient air should trigger fans to run whenever the air is at least 6C cooler than the grain, regardless of weather. For long-term storage target grain temperature is 5C for all but malting barley.

Fears that running fans in wet weather re-introduces moisture are unfounded. Given that 6C temperature differential it is safe to blow, he stresses.

Cleaning stores, while good practice, will not necessarily remove residual pests, even when insecticides are used. Drying and rapidly cooling are doubly important if there have been previous problems. Baiting while stores are empty helps identify risks.

That rat-baits control mice is another misconception. Calciferol is the material for mice, says Dr Wildey.

Lastly, oilseed rape needs drying to 8% moisture to be safe from moulds and mites, not the 9% delivery standard many growers aim for. Fan capacity must be doubled or depth halved for storing oilseed rape compared with wheat or barley.

"Really, good storage comes back to the Boy Scouts motto – be prepared," he concludes. &#42

GRAIN MYTHS EXPLODED

&#8226 15C is not cool enough.

&#8226 5C should be target.

&#8226 Fans on in wet weather is OK.

&#8226 Temperature differential key.

&#8226 Rat-bait will not kill mice.