SHEAR: DISTRIBUTION OF PERISHABLE PLANT PRODUCTS 417 



soil and climatic conditions under which they are grown, methods of 

 cultivation and fertilization, nature of the variety, condition as to 

 maturity at time of harvesting, methods and care in harvesting, 

 grading, packing, and handling previous to shipment, and methods of 

 loading, stowing, and bracing in the cars. Any or all these factors 

 may be and frequently are involved in the final decay due to parasitic 

 or saprophytic fungi occurring in the field or in transit. Hence it 

 is of the utmost importance to obtain as complete knowledge as 

 possible of the various organisms which attack the particular product, 

 their life histories, the time, mode, and conditions of infection and 

 development and also their relations to methods of handling and their 

 temperature, moisture, and host relations. These problems are 

 primarily pathological. 



Growers and shippers long ago discovered that storing fruits and 

 vegetables at low temperature prolongs their keeping. This observa- 

 tion finally led to the development of commercial cold storage and 

 refrigeration methods and practices. These methods and practices 

 have developed thus far largely along empirical lines. It happens 

 that growth in most of the organisms which destroy perishable plant 

 products is inhibited at from 33° to 36° F. Therefore, if fruit or 

 vegetables, though infected with fungi, are placed under such tempera- 

 ture conditions before development of these organisms is too far 

 advanced, growth of the fungi will be temporarily suspended. In 

 some cases, therefore, refrigeration may simply delay the destruction 

 of the product and shift or render uncertain the responsibility for its 

 loss which may occur before it reaches the consumer. 



It will appear evident, therefore, that in order to devise methods 

 of preventing or avoiding such losses, all the factors involved in any 

 particular case must be accurately determined as well as their relations 

 and relative importance. Because it is known that certain fungi 

 destroy certain fruits and vegetables and that these fungi occur in 

 the orchard or on the farm, it has been inferred by some that the 

 presence of such organisms on decayed products at destination is 

 sufficient evidence that the responsibility for the loss rests with the 

 grower. This may be true in the case of some particular product 

 affected with some particular disease when shipped without refrigera- 

 tion. In the case of refrigerated products, however, our experience 

 and that of others has shown that in order to determine the real cause 

 or causes and the responsibility for loss in any specific case, the whole 

 history of picking, packing, handling and treatment of the product 

 must be known, or at least its history from the field to destination. 

 This has been very strikingly brought out in the investigations of 



