HORTICULTURE 143 



more rapidly than can be done with ice alone. Precooling may also 

 be done before packing, and when this is practicable it is compara- 

 tively easy, because there is a chance for the circulation of the air 

 around the fruit. The disadvantage of such a system is that the 

 packing has to be done in cool rooms to avoid the condensation of 

 moisture on the cold fruit. 



The best system of precooling, whether in cars or in warehouses, 

 has not been definitely determined, although two of the great trans- 

 portation companies of the Pacific Coast are erecting mammoth plants 

 to precool in the cars all the fruit shipped over their lines. One 

 great disadvantage of this system is the delay which must necessarily 

 ensue in assembling the cars from the different districts. Much of 

 the beneficial effect from precooling will be lost unless the work is 

 done as soon as possible after the fruit is packed. A delay of even 

 twelve hours during warm, weather may very seriously affect the 

 results. 



Another disadvantage in car precooling is the great difficulty 

 or impossibility of so distributing the air that every package will be 

 reached. Under the best conditions some of the packages will be 

 cooled very much more quickly than others, depending upon the 

 method of applying the air. 



Precooling in a warehouse or cool room consists in placing the 

 fruit in a refrigerated room, with sufficient piping to keep the room 

 temperature well below the desired point until all the packages are 

 thoroughly cooled. The packages may be so stacked that a thorough 

 circulation is possible, resulting in greater uniformity in the cooling 

 than is the case in the closely packed car. 



One disadvantage of having the precooling done in warehouses 

 is the expense of building and maintaining the necessary plants, and 

 this must be borne by the shipping companies, growers' associations, 

 or individual growers. Under this system the expense and respon- 

 sibility fall on the shipper, while under the car-precooling system 

 the transportation companies bear the burden. However, the trans- 

 portation companies must require that the fruit be delivered to them 

 in sound condition and fit for shipment, and whether the placing of 

 the packages in proper condition for safe shipment should include the 

 reduction to a proper and safe temperature is an open question. 



The advantages of precooling in the handling of deciduous 

 fruits are manifold. The first and most important of these is the fact 

 that, if precooled, the fruit may be left on the trees to attain a greater 

 degree of maturity, thus assuring a much better quality. It has been 

 shown that the soft fruits, like plums, peaches, and apricots, may be 

 allowed to remain until they reach a hard-ripe condition and may 

 then be shipped long distances without deterioration. In the case 

 of cherries and berries, precooling will enable the crop to be shipped 

 greater distances, thus assuring wider market distribution and more 

 satisfactory condition on arrival. 



Precooling is now recognized as one of the important factors in 

 the safe shipping and handling of highly perishable products, and 

 its use will be extended as its advantages and application are better 



