418 BROOKLYN BOTANIC GARDEN MEMOIRS 



citrus fruits and also in recent investigations of raspberry, strawberry, 

 and cranberry losses. 



The practice of refrigeration of fruits and vegetables in transit 

 is for two purposes, viz. : to retard the natural ripening processes which 

 continue after the crop is harvested and to prevent the development 

 of destructive fungi which are assumed to be present and are likely 

 to develop unless a constant low temperature is maintained. In 

 many cases it is practically impossible to eliminate the organisms 

 which cause decay and all the handling in such cases must be with the 

 presumption of their presence and the possibility of their rapid develop- 

 ment under favorable conditions. 



Each product and each fungus has its own peculiarities and reac- 

 tions under various conditions and treatment. This may be illustrated 

 by citing a few specific cases. 



Stem-End Rot and Anthracnose of Watermelon 



Meier^ has given an account of a decay of watermelons in the 

 field and in transit, caused by a species of Diplodia. It has been 

 found that this organism is a wound parasite, and infection takes 

 place through the stem end of a melon after it has been cut from the 

 vine. A practical method of preventing this infection by the appli- 

 cation of a fungicide before shipment has been found to be the simplest 

 means of preventing decay from this cause. The anthracnose of 

 watermelons can also be largely controlled by proper field treatment. 



Leak of Potatoes 



This trouble, which is most prevalent on the Pacific coast, has 

 .been found by Hawkins^ to be due chiefly to Pythium deharyanum. 

 It has been shown that infection occurs in the field and through wounds 

 only; hence, the most practical means of prevention is to avoid as 

 much as possible injury in digging and handling and to sort out all 

 wounded potatoes before shipping. This is a case in which trans- 

 portation methods and facilities are not the controlling factor in deter- 

 mining the condition of the product upon its arrival in the market, but 

 are of minor importance. 



Potatoes, watermelons, and similar products which are not usually 

 shipped under refrigeration can fortunately be more or less satis- 

 factorily insured against loss by proper treatment previous to ship- 

 ment. The temperature, ventilation and handling of such products 



' Meier, F. C. Watermelon stem-end rot. Journal of Agricultural Research 

 6: 149-152. Ap. 24, 1916. 



^ Hawkins, Lon A. The disease of potatoes known as "Leak." In Jour. Agri. 

 Res. 6: 627-640. i fig. pi. XV. 1916. 



