10 April 1998

Getting storage right initially is a balancing act

COOLING, curing and disease control need balancing to achieve optimum conditions during initial potato crop storage.

Cooling of newly harvested crops should be avoided to minimise weight loss, says SAC engineer Bob Pringle.

The warmth taken on by cooling air flowing through the crop, as field heat is removed and the crop respires, reduces the relative humidity of the air and promotes weight loss.

That is especially so when wounds are healing, he says. Evaporation can then be 100 times the rate from intact skins.

Adrian Cunnington from the Sutton Bridge Experimental Unit agrees. But he warns that there is a tendency for disease levels to increase where longer curing times and slower temperature pull down rates are used.

"Our trials have shown the curing period cannot be by-passed without risk. But a wound-healing period of 7-10 days, rather than 14-20 days, offers under most circumstances, adequate wound healing while minimising sprouting and disease development," he says.

Care at store loading is vital to avoid weight loss, say SAC advisers.