106 TROPICAL AGRICULTURE 



citric acid, orange juice, orange wine, orange vinegar, lemon oil, 

 bergamot perfume, and various other products. 



In recent years a keen rivalry for the early citrus fruit mar- 

 ket has developed between California, Florida, and Porto Rico. 

 The highest prices are obtained usually for the earliest ship- 

 ments of fruit which the market receives. From a financial 

 standpoint, therefore, it has been a point of great advantage 

 to reach the market first with grapefruit or oranges or other 

 fruit in which the shipper is interested. No one of these com- 

 petitors has any pronounced natural advantage of earliness 

 from climatic conditions over his competitors. The race for 

 the early market has therefore involved certain tricks of the 

 trade, and among these perhaps the most familiar one is the 

 process of artificial ripening. It has been found that by a 

 sweating process under the influence of artificial heat the 

 chlorophyll or green color in the unripe fruit may be made to 

 disappear quickly, thus producing the appearance of ripeness in 

 so far as the bright yellow color of the rind of the fruit is con- 

 cerned. Of course, the development of sugar in the fruit can 

 not keep pace with this change of color, and artificially ripened 

 fruit may therefore be readily detected by the narrow ratio be- 

 tween acid and total solids in the juice, these total solids being 

 chiefly sugar. After numerous tests on ripe oranges it has been 

 determined that the ratio of acid to total solids in the juice 

 should not be closer than i : 8 as a standard requirement. In 

 fruit artificially ripened by sweating the ratio between acids 

 and total solids may be as close as i :S. The United States De- 

 partment of Agriculture is attempting to prevent the use of 

 this process of artificial ripening for the reason that it is 

 essentially a fraud toward the consumer. 



OLIVE 



The olive is one of the oldest of cultivated crops. It is 

 native of Asia Minor and is referred by botanists to the name 



