A CIKCULAR 2 7 8, U. S. DEPARTMENT OF AGRICULTURE 



in the form of bulletins or textbooks; for many of them only general 

 information exists. 



Fresh fruits, vegetables, cut flowers, etc., intended for storage 

 should be as free as possible from skin breaks, bruises, and decay. 

 They should be neither immature nor overmature, because in either 

 case it may be difficult to keep them from too rapid deterioration, 

 and even if they do not change appreciably in storage, they will not 

 be commercially desirable when removed. The proper degree of 

 maturity in each case can usually be determined by consulting the 

 various sections of this circular or the other publications listed in 

 Literature Cited (p. 40), or on the basis of previous experience. 

 There is a seasonal variation, however, in the storage quality of 

 certain products, particularly fruits; hence care must be taken not 

 to assume too much from one year's experience concerning the prob- 

 able behavior of a given commodity grown the next year. 



Decay and other deterioration in storage is too broad a subject to 

 be discussed in detail in this publication. It is discussed very gener- 

 ally in connection with various fruits and vegetables covered by this 

 circular and in greater detail in other publications {3, 4, 9, 17, 19, 21, 

 24, 84, 36, 37, 38, 39, 40, 45, 48, 54, 56)} 



FACTORS INVOLVED IN COLD STORAGE 



Details of the best conditions for the storage of fresh fruits, vege- 

 tables, and cut flowers are subject to change from time to time as 

 more definite information is gained in the handling of these com- 

 modities. The conditions and requirements given in this circular 

 are derived from the best commercial practice at the present time 

 and from scientific experimentation. 2 All of the temperature require- 

 ments are given in degrees Fahrenheit and represent the average air 

 temperatures that should be maintained. The humidities are relative 

 and are expressed in percentage of saturation; for example, when it 

 is stated that a certain humidity should be 85 percent, this means 

 that the air should be at approximately 85 percent of complete 

 saturation with water vapor at the recommended temperature. 



The term "cold storage" refers to storage where the desired tem- 

 perature is maintained by mechanical means; the term "common 

 storage" is used where the natural outdoor temperature, modified 

 or controlled as far as possible by means of insulated walls and 

 ventilators, is depended upon to maintain the desired storage tem- 

 perature. The storage period given in each case includes the transit 

 period if there is one. Allowance has been made for the fact that 

 the temperature of fruits and vegetables in transit is usually higher 

 than the recommended storage temperature and that, except during 

 winter weather, ripening or other changes are likely to go on more 

 rapidly during a given transit period than during the same length of 

 time in cold storage. 



TEMPERATURE OF STORAGE ROOMS 



If the best results are to be obtained in the cold storage of the 

 products discussed herein it is highly important that the tempera- 



1 Italic numbers in parentheses refer to Literature Cited, p. 40. 



2 The writers have not only included results of their own investigations but have drawr) freely on pub- 

 lished and unpublished results of other staff members, whose assistance and cooperation have done much 

 to make this publication possible. Information is also cited from other sources. 



