COMMERCIAL STORAGE OF ERUITS AND VEGETABLES 27 



expected to extend for 3 to 4 weeks. These melons also tend to show 

 some pitting at storage temperatures of 32° to 36° F. and show the 

 pitting more plainly because of their smooth, light-colored surfaces. 



CASABA AND PERSIAN MELONS 



Casaba and Persian melons are relatively good keepers. They will 

 remain in good condition in storage for at least 4 weeks and have 

 been reported to keep as long as 6 weeks. 



ONIONS AND ONION SETS 

 (Temperature, 32° F. ; relative humidity, 70 to 75 percent) 



Onions are held either in common or in cold storage. In the 

 northern onion-growing States, strongly flavored varieties mostly of 

 the globe type are generally held in common or dry storage. The 

 principal northern onion-producing States have a sufficiently low 

 average winter temperature so that onions can be successfully held in 

 common storage there during the winter months. About one third 

 of the onion crop of these States, however, is put into cold storage for 

 consumption late in the spring. About the first of March is con- 

 sidered as late as onions should be held in common storage, because 

 after this time there is danger of sprouting. The mild or Bermuda 

 types, such as those produced in Washington, southern California, 

 Texas, and other States where the climate is not suitable for common 

 storage, are usually consumed 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 



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 " (29). 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 

 chaw out slowly and without rough handling. In cold storage they 

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

 pairs laid crosswise in stacks 5 or 6 sacks high. The stacks should 

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

 vidual 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. 



