Storage of seed potatoes in pallet boxes .2. Causes of tuber surface wetting

In a paper to establish how different store ventilation systems affect the population of tuber borne Erwinia, periodic reductions in tuber skin resistance occurred (Pringle & Robinson, 1996). To help understand these changes, tuber skin resistance data was collected simultaneously from two stores nearby. All reductions were due to condensation when tubers were colder than the dew-point temperature of the surrounding air. Warm humid air from newly harvested or sprouting potatoes below condensed on the cooler surface tubers in naturally, but not periodically forced ventilated? boxes. Condensation occurred in both naturally ventilated and forced ventilated boxes when ambient air, under both fan pressure or wind induced leakage, and with a dew-point temperature above that of the stored tubers, entered the store. Individual tubers in trays, simulating the surface layer of boxes, received condensation when Ventilation stopped. Warmer humid air from the rest of the crop condensed on these preferentially cooled tubers.