10 



BULLETIN 714, U. S. DEPARTMENT OF AGRICULTURE. 



sible, sorting in cool rooms, which will prevent wetting the fruit by 

 condensation from the air, is further considered under the next 

 topic. 



Low Temperature. 



• A study of the temperature relations of many of the fungi which 

 'cause fruit rots of cranberries (14, pp. 524 and 525) has shown that 

 most of them grow very slowly, if at all, below 10° C. (50° F.). 

 The only conspicuous exception is the end-rot fungus, which grows 

 somewhat even at 0° C. (32° F.). The rate of growth of all these 

 fungi, and consequently of the rot which they cause, increases rapidly 

 with rise of temperature above 10° C. (50° F.). As already men- 

 tioned, the ripening processes which result in the death of the cran- 

 berry itself also go on more rapidly as temperature rises. 



As an illustration of the effect of temperature on the keeping 

 quality of cranberries, the results of temperature tests conducted at 

 Washington, D. C, during 1916 and 1917 may be cited (Table IV). 

 Equal quantities of apparently sound cranberries from uniform lots 

 were kept at different temperatures in the refrigeration apparatus 

 described by Brooks and Cooley (1). 



Table IV. — Effect of temperature on the keeping quality of cranherries as shown 

 by tests made at Washington, D. C., in 1916 and 1911. 





Days in 

 storage. 



Percentage of cranberries spoiled in storage at temperatures—' 



Variety. 



0°C. 

 (32° F.). 



5°C. 

 (41° F.). 



10° C 

 (50° F.). 



15° 0. 

 (59° F.). 



20° C. 

 (()8° ¥.). 



Early Black 



2S 

 2S 

 25 

 60 

 60 

 56 

 67 



2 

 1 



2.5 

 16 

 20 

 39 



8 



4 

 1.5 



5 

 27 



27 

 43 

 27 



5 

 3.5 



8 



12 

 9 



15 5 

 48 

 51 

 92 

 48 



19 



Do 



13 



Howe 



19 



Earlv Black . . . . 



72 



t)o 





60 



Do 





99 



Howe . 





76 









» This includes smothering and all forms of fungous rot. 



In the course of the first three tests, the results of which are given in Table IV, it was observed that cran- 

 berries color more rapidly at relatively low temperatures (5° 0., 41" F.). It Is, then, desirable from every 

 point of view for cranberries to be kept as cool as practicable. 



When cranberries are picked they are usually at a temperature 

 considerably warmer than that of the air, and the sooner they are 

 cooled the better. To this end it is desirable that cranberries should 

 be removed from the bog as soon as practicable and placed in the 

 shade. They should be stored in ventilated boxes, never in barrels, 

 and the boxes should be so piled as to permit free circulation of air 

 among the boxes. 



The storehouse in which cranberries are held should be kept as 

 cool as is possible without danger of freezing the fruit. This can 

 be done most economically by having the house provided with ade- 

 quate ventilators to admit air at the bottom of the building. These 



