HANDLING DECIDUOUS FRUITS ON PACIFIC COAST 
when the fruit is picked. The develop- 
ment of molds also goes on at a rapid 
rate while the fruit is warm. Reduce: 
ing the temperature retards the ripen- 
ing and prevents the development of the 
molds. The length of time that the fruit 
will remain in good condition depends 
upon the promptness and the thorough- 
ness with which it is cooled. 
Careful records made of many decidu- 
ous-fruit packages show that the tempera- 
tures of the packed fruit during the great- 
er part of the season are extremely high. 
The range runs from 80 degrees to over 
100 degrees F.., and the average of all 
temperature records made is between 90 
degrees and 95 degrees F. At such 
temperatures the fruit ripens very fast 
and decay and deterioration are extreme- 
ly rapid, especially if the fruit has been 
roughly handled and injured to any great 
extent. 
Records made in refrigerator cars show 
that the rate of cooling in the fruit 
packages is very slow when the ice of 
the car is depended upon both to reduce 
the temperature and to hold it low. It 
frequently happens that several days 
elapse before the fruit is cooled sufficient- 
ly to retard ripening and decay. This 
is the main reason why the Pacific-coast 
fruits are picked so long before they 
have acquired full quality. When they 
are not picked green, they become over- 
ripe and soften before the ice of the car 
has a chance to reduce the temperature 
below the danger point. 
Frequently a very distinct advantage 
may be gained by allowing the fruit to 
remain open over night and packing while 
it is cool in the morning. More cooling 
can usually be obtained in this way than 
in one or two days in the refrigerator 
cars after the fruit is packed, especially 
where it is wrapped in paper. This is 
particularly true for grapes, and many 
growers and packers take advantage of 
it. It has been asserted that before a 
system of overnight cooling was adopted 
it was impossible to ship peaches and 
plums in sound condition from some of 
the interior points of the San Joaquin 
valley of California. 
1321 
During the last eight years the Bureau 
of Plant Industry has conducted investiga- 
tions of different methods of quickly cool- 
ing fruits before shipping. This prac- 
tice, which has for its object reducing 
the temperature as quickly as possible, 
has been designated “precooling.” Under 
this system the ice of the refrigerator 
car is not expected to cool the fruit, but 
only to Keep it cool during the trip across 
the continent. 
Precooling is usually done by mechani- 
cal means after the fruit is packed, either 
in a warehouse or a cold-storage plant be- 
fore loading on the cars or after loading 
by forcing large volumes of very cold air 
through the cars, thus reducing the 
temperature of the fruit much more rapid- 
ly than can be done with ice alone. Pre- 
cooling may also be done before packing, 
and when this is practicable it is com- 
paratively easy, because there is a chance 
for the circulation of the air around the 
fruit. The disadvantage of such a sys- 
tem 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 yet been 
definitely determined, although two of the 
great transportation companies of the Pa- 
cific coast are erecting mammoth plants to 
precool in the cars all the fruit shipped 
over their line. 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 de- 
lay of even 12 hours during warm weath- 
er may very seriously affect the results. 
Another disadvantage in car precooling 
is the great difficulty or impossibility of 
so distributing the air that every pack- 
age will be reached. Under the best con- 
ditions some of the packages will be cool- 
ed 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 refrig- 
erated room, with sufficient piping to keep 
