46 BULLETIN 63, V. S. DEPAETMEXT OF AGKICULTUEE. 



prevent the development of decay. Consequently, deterioration is often far advanced 

 before the t-emperature 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 may be 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 slaipment. 

 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 wliich 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- 

 \dded always that it- is' not expected to offset the bad effects of careless or improper 

 handling. During warm and humid weather, such as occurred dm-ing 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 injinies. 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. WMle 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 

 remo^■ing the necessity of coolir^ fruit at the beginning of the trip. Possibly during 

 the winter season, when the weather is cool or cold along the route, fruit which has 

 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 sliipment, the retvurns 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, tliis 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 1010-11, in cooperation with the Florida experiment 

 station, proved conclusively that the stem-end rot disease can not be controlled by 



