The date of harvesting is dependent upon the intended use of the crop. If the crop is destined for fresh market, three of the major considerations determining the timing of the harvest are tuber size, shape, and appearance. Most of the late crop of potatoes in the United States is stored for periods of three to nine months. During storage and marketing of potatoes, disease, sprouting, water loss, sugar buildup, and greening should be prevented. Temperature control is essential for long-term storage of potatoes. Potato storages should be equipped with ventilation systems that provide for the exchange of the entire volume of air frequently enough to maintain adequate oxygen levels and to provide necessary cooling. The higher the storage temperature, the more quickly tubers will sprout. Potatoes held at 7°C for long-term storage should be treated with a sprout inhibitor, but seed potatoes should never be treated.