f 
7 BULLETIN 1159, U. S. DEPARTMENT OF AGRICULTURE. 
merchandise. In the mind of the consuming public a green-colore 
for decorative purposes as well as for eating, and a well-colore 
orange is much more attractive than one green or partially green 
in color. The green-colored fruit is therefore at a decided di 
advantage in competitive selling. It is evident then that some 
method of treating this fruit so that it would assume a rich orange- 
yellow color early in the season, when it was most desirable for 
food, would be of benefit to the industry and to the consuming 
public alike. Such a process has been developed in California 
for the coloring of lemons. . 
These lemons are usually picked to size, irrespective of color. 
The green fruit is placed in suitable storage where a temperature 
ranging from 55° to 60° F. is maintained with a humidity of about— 
89 per cent. During the winter months or when the demand is” 
hight the fruit may be left under these conditions, and the desired 
yellow color will develop usually in from three to six weeks, § 
When, however, there is sufficient demand, coloring may be resorted 
to and the lemons made ready for market in from three to. Six 
days. Until the result of work by Sievers and True? became a} 
known, the coloring was thought to be due to the heat and humidity 
of the rooms rather than to the fumes from the kerosene stoves 
used to furnish heat. However, it had been noticed that when the § 
old type of kerosene stove was replaced by the more modern odor- } 
less type that was developed about that time, less desirable results } 
were obtained, and careful experiments by the above-mentioned } 
workers showed that the change in color of the fruit from green to. 
yellow was due chiefly to the effect of the gas and not to the heat or 
humidity of the coloring rooms. 5 
This method of coloring citrus fruit should not be confused with — 
the old sweating process, which consisted in holding the fruit ina J 
hot room until it either became yellow or rotted. In the process now | 
employed the change in color is brought about by the destruction of } 
the chlorophyll in the cells of the rind with a consequent appearance 
of the yellow color, which was present but masked by the green. 
Oranges, both navel and Valencia, as well as lemons, are colored | 
by this process in California, and it was considered possible that it 
might be well adapted to the peculiar conditions existing in the Sat- 
suma orange industry in Alabama. 
MATURATION OF SATSUMA ORANGES IN ALABAMA. 
Satsuma orange growing as a commercial industry is confined to 
the two southernmost counties in Alabama, Baldwin and Mobile. 
At present about 15,000 acres are planted, of which about one-fourth 
are In bearing. The fruit is usually fully colored by November 4 ‘ 
but, as has been said, it is physiologically mature and desirable for — 
food some time before this date. This is shown in a series of experl-_ 
ments the results of which are given in Tables 1 to 3. In these ex- 
periments the soluble solids and acidity were determined after the. 
® Sievers, Arthur F., and True, Rodney H. A preliminary study of the forced curing 
Peo ae practiced in California, U.S. Dept. Agr., Bur. Plant Indus, Bul. 232, 38 p., 
ge. 1912; 
