178 ANNUAL REPORTS OF DEPARTMENT OF AGRICULTURE. 



vested until they are consumed. The chemical analyses show that 

 grapefruit behaves very much like deciduous fruits when in cold 

 storage so far as chemical changes are concerned. The acids seem 

 to break down, while the sugar content remains about the same. 

 In warm storage, however, the sugar seems to disappear and the 

 acids to increase to some extent. One of the serious problems in 

 the storage of grapefruit is the development of what is commonly 

 called " pitting." This is the breaking down of certain cells in the 

 skin of the fruit, which results in the formation of brown-colored 

 pits that may be very numerous and may increase in size until many 

 of them coalesce. This produces a very unattractive appearance. 

 It has been determined as a result of this line of work that grape- 

 fruit cured at a temperature of 60° to 65° F. in a humidity of about 55 

 per cent, the curing being continued from 10 to 20 days, and then placed 

 in a storage temperature of 32° F, may be kept in good condition 

 for two months, thereby materially extending the marketing period. 

 Fruit so handled does not suffer from pitting and comes from storage 

 in an attractive condition with excellent dessert quality. The results 

 of this work have been published in two papers in tl>e Journal of 

 Agricultural Eesearch. 



Conditioniiig citrus fruits. — The fact is becoming accepted that 

 some citrus fruits reach their highest edible quality before their 

 color changes from a chlorophyll green to the orange or yellow shades 

 which the consumer and the public generally have come to associate 

 with a citrus fruit in good edible condition. If such fruit is allowed 

 to remain on the tree until the desired color appears, it may lose in 

 edible quality, and it may lose the advantage of an earlier market. 

 This is true particularly of Satsuma oranges and one or more early- 

 ripening varieties of oranges grown in Florida. Considerable atten- 

 tion has therefore been given to the working out of practical methods 

 of accelerating the development of a ripe color in such citrus fruits. 

 While this work has been in progress for several years, its commercial 

 application has been given particular attention during the past year. 

 The method of procedure is to confine the fruit in a compartment 

 which can be made practically air-tight and to subject it to the prod- 

 ucts of incomplete combustion of kerosene or gasoline. The effect of 

 these products on the color of the fruit is to change the green shades to 

 the orange or yellow shades which would develop normally at a much 

 later period. This change of color is brought about in three to five 

 days. The work with Satsuma oranges has been carried on in coop- 

 eration with the Gulf Coast Horticultural Society and the Gulf 

 Coast Citrus Exchange. This method of treating Satsuma oranges 

 has been adopted on a somewhat extensive scale. Nine packing houses 

 in Alabama have been equipped with conditioning rooms, and about 

 two-thirds of the crop of 1921 was treated in this way. This has 

 enabled the growers to complete the marketing of their crop about 

 four weeks earlier than would have been the case otherwise. This is 

 of importance commercially, because if left to color naturally some 

 of the fruit would have been overripe and insipid in flavor. The 

 best marketing conditions for this type of orange prevail earlier in 

 the season than can be taken advantage of when the fruit is allowed 

 to color on the tree, and by this accelerated coloring the full advantage 

 of the best marketing period can be realized. 



