46 BULLETIN 63, U. S. DEPARTMENT OF AGRICULTURE. 
prevent the development of decay. Consequently, deterioration is often far advanced 
before the temperature of the fruit is reduced to the point where these processes are 
checked. Under a system of precooling, the ice of the refrigerator car is relieved of 
the burden of initial cooling and is merely required to keep the fruit cool during 
transit. 
Precooling is accomplished by means of special equipment, the refrigerating medium 
being either ice and salt or special refrigerating machinery. When adequate equip- 
ment is supplied, the initial temperature of the fruit maybe reduced in a comparatively 
short time. The work may be done in refrigerated rooms or chambers before the boxes 
are placed in the cars, or it may be accomplished by circulating cold air around the 
packages after loading. The comparative advantages and limitations of these two 
systems can not be discussed here, but a few important points regarding the applica- 
tion of precooling to the shipment of Florida oranges must be emphasized. 
Precooling may not safely be depended upon to offset decay following mechanical 
injuries due to improper methods of handling the fruit when preparing it for shipment. 
It is, however, a valuable and legitimate means of insuring arrival on the market in 
sound condition after each grower, packer, and shipper has done his share in properly 
handling the fruit. Precooling, in order to be effective, must be accomplished 
promptly and rapidly. A considerable delay in applying the process may nullify all 
possible benefits and defeat the object for which the work is undertaken. 
Icing has been practiced to a limited extent in Florida, but precooling has not as 
yet been attempted. The value of this method of shipment in marketing Florida 
oranges is largely problematical. Its advantages are likely to be overestimated if the 
general distribution and application of the processes are attempted without careful 
and systematic investigation. During the warm and humid weather usually prevalent 
in Florida in December and January, precooling may be of considerable benefit, pro- 
vided always that it is not expected to offset the bad effects of careless or improper 
handling. During warm and humid weather, such as occurred during the months 
of December, January, and part of February of the season of 1912-13, oranges are 
injured more easily than under ordinary conditions and are more subject to decay 
from these injuries. Infection from the ever-present, blue-mold spores is almost 
certain, and stem-end decay or other diseases may gain considerable headway. Rapid 
cooling (precooling) may possibly delay the development of stem-end decay for a 
week or more after the fruit arrives in market. While precooling and refrigeration 
can not do more than to delay for a short time the occurrence and development of 
this disease, such delay may prove of material benefit. 
Precooling may reduce the quantity of ice consumed during the trip to market by 
removing the necessity of cooling fruit at the beginning of the trip. Possibly during 
the winter season, when the weather is cool or cold along the route, fruit which lias 
been precooled may be moved to its destination under the initial icing alone. Pre- 
cooling is expensive, and unless a material advantage can be obtained thereby its 
application can not be justified. If a sum of money equal to the expense of precooling 
is expended in insuring careful handling of the fruit during the course of its prepara- 
tion for shipment, the returns will probably be more certain and more lasting. 
STEM-END ROT. 
In addition to the losses from blue mold, there has been considerable deterioration 
of Florida citrus fruits after arrival in market due to the attacks of the stem-end decay 
fungus. Unlike blue mold, this fungus does not apparently depend upon injuries or 
breaks in the skin through which to gain entrance to the tissues of the fruit. Investi- 
gation during the season of 1910-11, in cooperation with the Florida experiment 
station, proved conclusively that the stem-end rot disease can not be controlled by 
