MPENIXG, STORAGE, AND HANDLING OF APPLES 23 



prior to the fruit dropping appreciably; under other conditions the 

 apples may drop badly while the ground color is still quite green. 

 The accumulation of sugars within the fruit apparently is not inti- 

 mately associated with any of the external factors. From the data 

 obtained so far in these investigations, however, it appears that 

 a consideration of the factors of the ground color of the fruit, the 

 tenacity with which it adheres to the tree, and under certain condi- 

 tions at least the firmness of the flesh forms the best basis for deter- 

 mining w T hen apples are ready to remove from the tree. 



SUMMARY OF PART I 



A study has been made of the gross changes in apples as they ap- 

 proach maturity on the tree in order to determine the most depend- 

 able tosts for time of picking and how seasonal conditions influence 

 the ripening changes in the fruit. 



Under a wide range of growing conditions the fruit of a number 

 of varieties of apples has been found to increase greatly in size dur- 

 ing the late growing season. Apparently increase in size continues 

 as long as the fruit and leaves are adhering to the tree. 



The rate of softening of apples as they approach picking maturity 

 varied greatly under different growing conditions. In some 

 instances practically no softening occurred during the month prior 

 to picking time ; whereas in others, even in the same varieties, soften- 

 ing prior to picking proceeded rapidly. 



Apples from regions having a long growing season were, on the 

 whole, softer at picking time than those from the districts having a 

 shorter growing season. Fruit from Virginia and Washington State 

 was softer when in optimum picking condition than similar varieties 

 from Michigan or New York. 



It has not been possible to associate rate of softening prior to 

 picking with climatic conditions prevailing in the different districts. 



The mechanical pressure tester apparently will be of value as a 

 measure of picking maturity for apples mainly to determine when 

 certain varieties are becoming too soft on the trees. 



As apples ripen on the tree, the unblushed portions change from 

 green to yellow or yellowish green. The color attained when the 

 fruit, is in prime picking condition varies greatly in different 

 varieties, and to a limited extent in the same variety grown under 

 varying climatic conditions. 



Evidence obtained indicates that when apples ripen under warm 

 conditions, such as prevail during an early-ripening season, the 

 unblushed portion of the fruit is greener when the fruit is in prime 

 picking condition than during normal seasons. 



The ease of separation of the fruit from the tree is perhaps the 

 most consistent of the changes as the fruit approaches picking 

 maturity. This loosening under certain conditions may occur while 

 the fruit is still very firm and poorly colored. However, it gener- 

 ally affords a very satisfactory index of picking maturity. 



Because there is a wide variation in the time of the browning of the 

 seeds in relation to picking time, their color is not a satisfactory 

 index of maturity in winter apples. 



The length of growing season is closel} 7 associated with maturity 

 in many varieties and does not appear to vary widely with different 



