406 Peach-Growing 



Precooling. 



One of the difficulties experienced in shipping perishable 

 products such as peaches is due to the slow cooling of the 

 fruit to a temperature sufficiently low to retard ripening 

 when placed in a refrigerator car. As a result of too tardy 

 cooling, it often arrives in an over-ripe condition, or so far 

 advanced in maturity that it does not hold up well when 

 placed on sale. 



In practice, a large quantity of w^arm fruit is commonly 

 placed in the car at one time. The heat in the fruit for a 

 time counteracts the refrigerating effects of the ice in the 

 bunkers, and it is often several days before the temperature 

 in the car again drops low enough to retard effectively the 

 ripening of the fruit. 



To overcome this difficulty the fruit is sometimes pre- 

 cooled or placed in refrigeration — sometimes in a compart- 

 ment built for the purpose where the temperature can be run 

 considerably below the freezing point if desired — and cooled 

 to a temperature of perhaps 40° F. before it is loaded in the 

 car. When thus handled, the full effect of the refrigerator 

 car operates to maintain the fruit at such a temperature that 

 the ripening processes are approximately stationary, or at 

 least much retarded. 



Another means of greatly facilitating the cooling of the 

 fruit and increasing the effectiveness of the refrigeration in 

 the car is by using a certain quantity of salt with the ice in 

 the bunkers. This simple measure, as proved by the Federal 

 Department of Agriculture, results in so promoting the 

 refrigeration that the fruit is very much more quickly cooled 

 than when it is not used. 



