THE MODERN POTATO PROBLEM 245 



for food. Seed potatoes may be stored at temperatures 

 as low as 33 F. without impairment of seed value if the 

 storage period is not too long. It is probable that the 

 age and condition of the tubers, when placed in storage, 

 are important factors in determining the possible period 

 of cold storage before they are damaged for seed. 



Besides supplying oxygen to the potatoes and dissi- 

 pating the products of respiration, ventilation is also a 

 means of removing excessive moisture trom the storage 

 air and of controlling the temperature of common stor^ 

 age. The necessary amount of ventilation depends 

 upon the temperature and the season of the year. It is 

 quite generally agreed that the humidity in the storage 

 air should not permit condensation of water on the 

 tubers, but it should be high enough to prevent undue 

 shrinkage and wilting of the tubers by evaporation 

 of their water. The relative humidity would vary 

 with the temperature; at 40 F. it would be about 80 

 per cent. 



This discussion has included just a few of the impor- 

 tant modern potato problems. Many others of equal 

 importance are confronting the potato grower and the 

 potato industry in general such as the physiology of 

 tuberization, immunity to disease, various cultural 

 problems, marketing, utilization of culls and surplus 

 crops, chemical composition, and cooking qualities of 

 the tubers as effected by different conditions. 



Many of the modern potato problems are typical of 

 other food crops and rank with the most important 

 problems confronting modern science as they are con- 

 cerned with the world's food supply. 



