26 September 1997

Dry at a higher moisture content, growers advised

"TRADITIONALLY, farmers have been discouraged from using heat to dry their grain until moisture content falls well below 18%," says Farm Energy Centres, Andrew Kneeshaw.

Mr Kneeshaw is currently advising growers in the north and west, where overloaded on-floor driers struggle to cope with 20% plus grain, not to hesitate to follow a more modern approach to drying problems.

"Air humidity drops by about 5% relative humidity with each degree rise in temperature," he explains. "So a rise as small as 2C can double drying rates in some cases.

Mr Kneeshaw also believes growers should not be deterred by the prospect of grain capping with such small temperature rises, adding that the addition of heat is often nothing to do with capping.

"Normally it is caused by a delay in surface drying which means that the grain starts to mould and break down. Capping often happens to coincide with the late introduction of heat," he says.

Advice from the Farm Energy Centre is that wet grain should be constantly ventilated, day and night, irrespective of weather conditions.

"Trials have shown that very wet grain can be dried with air at more than 90% relative humidity and ambient humidities rarely get this high, even at night," says Mr Kneeshaw.

Mechanical weeding with the Garford inter-row maize cultivator.