38 CIRCULAR 2 7 8, U. S. DEPARTMENT OF AGRICULTURE 



Investigations have indicated that potatoes stored at 50° to 60° F. 

 have better texture, color, and flavor when cooked or made into chips 

 than the same stock stored at lower temperatures (&£, 10^) although 

 the higher temperatures are not suitable for long-time storage. When 

 potatoes are stored at these higher temperatures, sprouting will occur 

 more quickly. A limited amount of sprouting does not injure potatoes 

 for food purposes, but it makes the stock difficult to market because 

 usually only dormant potatoes are wanted. If sprouting has started 

 it can be checked by lowering the storage temperature. 



The relative humidity of a potato-storage house should be 85 to 90 

 percent, to prevent undue shrinkage through loss of water. In cold 

 storage potatoes are generally kept in sacks holding from 100 to 150 

 pounds net; in common storage they are usually placed in bins holding 

 from 150 to as much as 1,000 bushels or more. In Maine and northern 

 New York, where the average temperature is sufficiently low, the 

 large-bin storage is used with success, but in the milder climate of 

 States in the latitude of Pennsylvania potatoes should not be stored 

 in such large units. Potatoes are readily injured by even slight freez- 

 ing, which takes place at about 29° F. or slightly below ; hence common- 

 storage buildings should be sufficiently insulated to prevent freezing. 

 Insulation will also prevent the condensation of moisture on the walls 

 and ceilings, and the consequent undesirable wetting of stored stock, 

 which favors the development of decay. Common storages should be 

 provided with sufficient ventilation to take advantage of the cool 

 night air in mild weather ; this will aid in removing excess moisture, 

 accumulating especially soon after potatoes are stored in the fall, 

 and will maintain a lower average temperature. Ventilators should 

 never be opened, however, when the outside temperature is higher 

 than that inside the storage house. In addition to damage to potatoes, 

 condensed moisture caused by improper ventilation or inadequate 

 insulation may also cause serious impairment to the building struc- 

 ture (19) 



Potatoes intended for storage should be handled carefully to avoid 

 bruises and cuts ; otherwise they are likely to be damaged by various 

 forms of decay before the end of the storage period. 



Pumpkins and Squashes 



(Temperature, 50° to 55° F. ; relative humidity, 70 to 75 percent) 



In general most varieties of pumpkins will not keep in storage as 

 long as the usual storage varieties of squash. Such varieties as Con- 

 necticut Field and Cushaw are relatively poor keepers and cannot be 

 expected to hold in good condition more than 2 or 3 months. Varieties 

 like Large Cheese and Table Queen will keep 3 to 6 months. 



Hard-shell squashes, such as the Hubbards, can be successfully stored 

 for 6 months or longer. 



All stock should be well-matured, carefully handled, and free from 

 injury or decay when put in storage. The best storage temperature 

 appears to be from 50° to 55° F. with a relatively low humidity of 

 about 70 to 75 percent. Investigations have shown that a preliminary 

 curing at 80° to 85° for about 2 weeks is of benefit in ripening immature 

 specimens and in healing mechanical injuries incident to harvesting. 



