20 



BULLETIN 331, U. S. DEPARTMENT OF AGRICULTURE. 



Table VI. — Decay in carefully handled nonprecooled prunes immediately 

 loaded and in those delayed two days in the warehouse ■'before loading, Wil- 

 lamette Valley, seasons of 1911 and 1913. 





Time factors and extent of decay (per cent). 





Season of 1911. 



Season of 1913. 



Time of inspection. 



Immediate 

 shipment. 



Delayed 

 shipment. 



Immediate 

 shipment. 



Delayed 

 shipment. 





10-day 

 with- 

 drawal. 



15-day 

 with- 

 drawal. 



10-day 

 with- 

 drawal. 



15-day 

 with- 

 drawal. 



10-day 

 with- 

 drawal. 



15-day 

 with- 

 drawal. 



10-day 

 with- 

 drawal. 



15-day 

 with- 

 drawal. 





0.1 

 1.8 



2.4 



0.1 

 1.1 

 3.6 



0.4 

 2.1 

 2.5 



1.7 



4.9 



4.5 



0.4 

 3.0 



5.8 



1.2 



4.6 

 8.7 



4.0 

 10.0 

 15.6 



6.4 



4 days after withdrawal 



13.8 



6 days after withdrawal 



20.4 







The data for 1913 emphasize even more strongly than the 1911 

 data the necessity for prompt shipment. After a transit period of 

 10 days the immediately loaded fruit showed on arrival 0.4 of 1 

 per cent of decay and 5.8 per cent after a holding period of six days, 

 as compared with 4 per cent of decay on arrival and 15.6 per cent 

 at the end of a holding period of six days in the delayed fruit. The 

 15-day withdrawals are equally consistent and show, of course, in 

 the aggregate, more decay than the figures just given for the 10-day 

 transit period. Where brown-rot is an important factor, as it was 

 during 1913, prompt cooling and shipping is a prime necessity, and 

 any considerable delay before cooling or shipping means the almost 

 certain arrival of the fruit on the market in a very badly decayed 

 condition. 



EFFECT OF PRECOOLING ON CARRYING QUALITY. 



The precooling experiments, as previously mentioned with cherries, 

 were carried on in connection with a small precooling plant of 

 1-carload capacity built by the Salem Fruit Union under the super- 

 vision of the Bureau of Plant Industry. This plant was the first 

 of its kind to be erected, and in it the principle of passing air 

 directly through the mixture of ice and salt was adopted. The 

 tank containing the refrigerating mixture is filled with crushed ice 

 and salt, the air being passed through the bottom of the tank, and 

 as the ice melts a new supply continually drops from the upper 

 part of the tank. In this way the tank can be operated through an 

 entire run without refilling. The precooling room is fitted with a 

 false floor and return ducts, and by means of a fan the cool air is 

 forced below the floor and through holes or openings in the false 

 floor into the room, to circulate between the fruit packages stacked 

 therein. The air is drawn back through the ceiling ducts to the ice 

 tank and again circulated, the same air being used throughout the 

 process. This method was utilized in the precooling experiments 



