40 CIRCULAR 2 78, U. S. DEPARTMENT OF AGRICULTURE 



(laced iii Washington, southern California. Texas, and other States 

 where the climate is not suitable for common storage, are usually con- 

 sumed shortly after being harvested. These onions can be, and limited 

 quantities are, held in cold storage, but usually for much shorter 

 periods than the globe varieties because of their poorer keeping 

 qualities. The Spanish, or Valencia, type of onions grown in this 

 country are often stored and, if well-matured, are considered capable 

 of storage for practically as long as the globe type. 



A comparatively low relative humidity (TO to 75 percent) is very 

 desirable for the successful storage of onions. At higher humidities, 

 in which many other vegetables keep best in storage, onions are dis- 

 posed to root growth and decay. The commonest form of the latter 

 is gray mold rot occurring at the top of the bulb, whence its name 

 "neck rot" (98). The fungus causing it can develop to some extent 

 even at 32° F.; hence onions intended for storage should be carefully 

 sorted over to remove all diseased bulbs. A uniform temperature of 

 32° is found to be sufficiently low to keep onions dormant and reason- 

 ably free from decay provided they are in good sound condition and 

 well-cured when stored. 



Onions are not perceptibly injured by slight freezing if allowed to 

 thaw out slowty and without rough handling. In cold storage they 

 are usually held in bags of 50 or 100 pounds each, which are best piled 

 in pairs laid crosswise in stacks five or six sacks high. The stacks 

 should be set a few inches off the floor on 2- by 4-inch strips and the 

 individual stacks separated by a few inches of space to allow for air 

 circulation. When kept in common storage, onions are best stored 

 in slat field crates holding about 1 bushel, rather than in bags. Be- 

 fore being placed in storage onions should be well dried or cured in 

 the field for a period of 4: to 6 weeks, and all decayed specimens or 

 those showing thick, or ''bottle," necks should be sorted out. 



Onion sets are usually held in common storage. The}' require 

 nearly the same conditions as large onions and are best stored in 

 shallow slat-bottom crates or trays not over -± inches deep and about 

 5 by 5 feet in some districts or 2 by 3 feet in others. The corner posts 

 of the crates should project about an inch above the side pieces in 

 order to prevent the crates from resting tightly on each other when 

 stacked and to allow air circulation between them. Because of their 

 size, onion sets tend to pack closely in the crates : hence it is essential 

 to allow as much air circulation as possible and to maintain a com- 

 paratively low humidity. If good stock is provided and is held under 

 proper storage conditions, it should keep 6 to 8 months. 



(See 57.) 



Parsnips 



(Temperature, 32° F. ; relative humidity. 90 to 95 percent) 



Parsnips have nearly the same storage requirements as topped car- 

 rots and should keep for 2 to 4 months. They are not injured by slight 

 freezing while in storage but should be protected from hard freezing 

 and should be very carefully handled while in a frozen condition. 

 Parsnips dry out readily in storage; hence it is essential that the 

 humidity of the storage place be kept relatively high. Parsnips are 

 sometimes stored in sand or clean soil to prevent wilting, but they 

 will keep in good condition when held in barrels or crates if the 

 proper humidity is maintained. 



