52 BULLETIN 1406, V. S. DEPARTMENT OF AGRICULTURE 



outside when inadequate ventilation openings are used or where the 

 storage is not properly handled. 



If ventilation openings are sufficiently large and the storage rooms- 

 are opened as much as possible whenever outdoor temperatures are 

 below those existing in the storage room and closed when outdoor 

 temperatures rise above those prevailing inside, it is possible to ob- 

 tain approximately the mean of the outdoor temperatures in the 

 storage room. Basement-type storages, partially underground types 

 (such as hillside storages), or entirely aboveground types of storage 

 have been found to hold about the same temperature if properly 

 handled. 



It is not the purpose in this report to discuss common-storage con- 

 struction and handling but rather to deal with the handling of fruit 

 intended for common-storage holding. The investigations reported 

 in Parts I and II, dealing with the ripening of apples on the tree 

 and in the storage rooms at various temperatures, give a background 

 for recommendations in regard to the actual handling of fruit in 

 common storage. 



The mean prevailing outdoor temperatures, available from the 

 United States Weather Bureau in many sections of every State, give 

 an accurate index of the temperatures which may be expected in an 

 air-cooled storage house and are of great value in determining the 

 adaptability of common storage to any locality. With this fact in 

 mind a map has been prepared (fig. 27) showing* the average mean 

 prevailing temperatures for November for various sections of the 

 United States. November was chosen as the first full month in which 

 apples are generally held in common storage. It is also a particu- 

 larly critical month for common-storage holdings, as it is during- 

 this period that the fruit should be cooled from temperatures pre- 

 vailing at picking time to near the optimum temperature for hold- 

 ing the fruit. The mean October temperatures prevailing over the 

 country are, according to isotherm maps prepared by Ward (18), 

 approximately 10° above the temperatures given for November. 

 In the northern sections October temperatures are somewhat more 

 than 10° above those prevailing in November, while in the warmer 

 sections .there is a difference of slightly less than 10°. December 

 temperatures, on the other hand, will average fully 10° below those 

 prevailing in November in most of the apple-growing sections of the 

 United States. The prevailing temperatures for late October, No- 

 vember, and early December largely determine the adaptability of 

 any district for holding apples in common, or air-cooled, storage. 

 By the latter part of December common-storage temperatures in most 

 apple-growing districts will approximate those for cold storage if 

 the storages are carefully managed. Consequently, the prevailing 

 temperatures during the cooling period from the time of picking 

 to December largely determine the efficiency of common storage for 

 apples. 



• Figure 27 requires little comment. It is apparent that in nearly all 

 of the northern apple districts, including most of New England, New 

 York, northern Pennsylvania, northern Ohio, Illinois, and westward, 

 the mean November temperatures average under 40° F. The southern 

 parts of Missouri, Illinois. Indiana, and Ohio, on the other hand, 

 have a mean November temperature above 44°. Thus there is a dif- 



