22 CIRCULAR 2 78, U. S. DEPARTMENT OF AGRICULTURE 



pion, Hiley, and Carman are less desirable as storage varieties and 

 cannot be expected to hold up well even under optimum conditions 

 for more than 2 or 3 weeks. 



(See i, 00, £0,53.) 



Pears 



(Temperature: Bartlett pears, 29° to 30° F. ; fall and winter pears, 30° to 31° ; relative 

 humidity for all varieties, 85 to 90 percent) 



BARTLETT PEARS 



The successful storage of Bartlett pears (44, 4$) depends not only 

 on the temperature and humidity in the storage room but also on the 

 condition of the fruit when stored. If the highest quality is to be 

 obtained, Bartlett pears for storage should not be removed from the 

 tree until the ground color begins to lighten and the lenticels have 

 corked over. If picked before reaching that stage, they have a marked 

 tendency to wilt, scald, and break down in storage. They also tend 

 to break down in storage if picked when too ripe. The most desirable 

 temperature for the storage of Bartlett pears is 29° to 30° F. The 

 relative humidity should range from 85 to 90 percent. The maximum 

 period for storage for canning and local fresh markets is about 90 

 days, and for storage at shipping point and at terminal markets, 45 

 to 60 days. 



FALL AND WINTER PEARS 



For fall and winter varieties of pears (57, 58), such as Anjou, Bosc, 

 Clairgeau, Cornice, Easter Beurre, Hardy, Seckel, and Winter Nelis, 

 the most desirable storage temperature is 30° to 31° F. A relative 

 humidity of 85 to 90 percent is most commonly used. However, a 

 relative humidity of 90 to 95 percent is maintained in some pear stor- 

 age rooms in order to prevent shriveling. Such humidities are main- 

 tained in connection with air velocities of 100 to 200 feet per minute. 

 The length of time for which it is safe to store these pears depends 

 on the variety and when it is picked and also on whether the fruit 

 is shipped directly to a consuming center and there stored or is stored 

 at the shipping point for a time and later shipped to market. In- 

 formation on these points is given in table 5. In using the table it 

 should be remembered that wide differences in keeping quality are 

 often found in pears from various producing sections of the country. 

 If Bosc, Flemish Beauty, and Cornice pears are held in cold storage 

 beyond their season they do not ripen satisfactorily or they may not 

 ripen at all (23). For best ripening, these and other varieties of 

 fall and winter pears should be held at a temperature somewhere in 

 the range from 60° to 70°, preferably about 65°. 



The commonest and most serious decays of fall and winter pears 

 in storage are gray mold rot, caused by the fungus Botrytis, and blue 

 mold rot, caused by the fungus Penicillium. Graj^ mold rot is able to 

 spread from decaying to sound healthy fruit and for that reason is 

 frequently called nest rot. Losses from this rot can be reduced by 

 the use of paper wrappers impregnated with copper (15). In the 

 Pacific Northwest blue mold rot, in the form known as pinhole rot, 



