FRUIT STORAGE 111 



lose weight by evaporation and will also shrivel. On 

 the other hand, if there is too much moisture the fruit 

 will be likely to decay. 



The amount of water vapor that can exist in any 

 given space depends entirely upon the temperature. The 

 higher the temperature the more moisture in a given 

 space. When it reaches its maximum or point of satura- 

 tion, it is then deposited on the fruit or packages and on 

 the walls of the room and furnishes ideal conditions for 

 the growth and spread of decay organisms. 



At one degree Fahrenheit the saturation point for 

 air would be about 0.457 grains to one cubic foot. As 

 the temperature rises, the holding capacity increases 

 until, at 100 degrees, it will hold as high as 19.77 grains 

 to one cubic foot of air space. At a temperature of 31 

 or 32 degrees, the point at which most of the fruit is 

 held in storage houses, the humidity would be about two 

 grains to the cubic foot of air space. 



No very careful figures have ever been worked out 

 for the best humidity for the different fruits, but in a 

 general way they are carried at the same humidity as 

 the percentage of water contained in the fruit. For 

 example, apples will run from 80 to 86% water, and 

 under such conditions the percentage of moisture in the 

 air should be from 80 to 85 in the storage rooms. 



The percent of humidity represents only a relative 

 condition. The exact weight of water in a cubic foot of 

 air when the humidity is 85% and the temperature 31 

 degrees, would be quite different from that for 70 de- 

 grees. For calculating the exact quantity of water in 

 a given space, a chart put out by the United States 

 Weather Bureau should be secured. 



