34 CIRCULAR 2 7 8, U. S. DEPARTMENT OF AGRICULTURE 



SQUASHES 



See Pumpkins. 



SWEETPOTATOES 



(Temperature, 50° to 55° F.; relative humidity, 80 to 90 percent) 



The requirements for the successful storage of sweetpotatoes differ 

 from those recommended for most other vegetable crops. When 

 freshly dug sweetpotatoes are to be stored for any length of time 

 they should be given a preliminary curing treatment to permit the 

 healing of all wounds or abrasions incident to harvesting and handling, 

 in order to prevent the entrance of decay organisms. 



The curing and storing are done in the same house so that the 

 potatoes do not have to be moved after the curing treatment. When 

 commercial lots are handled, the storage house is generally of special 

 construction with sufficient insulation to maintain a uniform tem- 

 perature and some means of ventilation that will insure the desired 

 humidity. Provision should be made for heating the building during 

 the curing process and for holding the proper storage temperature 

 afterward. The curing process ordinarily takes from 10 to 14 days, 

 during which the house is kept at a temperature of 80° to 85° F., with 

 a relative humidity of 85 to 90 percent. After the curing period the 

 storage temperature is allowed to drop to from 50° to 55°, with a 

 humidity of 80 to 85 percent. Short periods of a few hours at tem- 

 peratures somewhat lower than 50° need not cause alarm, but pro- 

 longed periods of low temperature should be avoided because of the 

 danger from certain types of decay which are more likely to develop 

 at temperatures below the range given (19, 4-6). 



Only well-matured stock that is practically free from mechanical 

 injury or decay should be used for storage. Sweetpotatoes are usually 

 stored in slat crates of about a bushel capacity or in bushel baskets. 

 Shallow bins are sometimes used. The roots should be handled as 

 little as possible during storage. 



TOMATOES 



(Temperature, ripe, 40° to 50° F.; mature green, 55° to 70°; relative humidity, 8.5 to 90 percent) 



Ripe tomatoes are held in storage only temporarily and should not 

 be stored at temperatures lower than 40° F. At 40° to 50°, if not 

 already soft ripe, they will keep in good condition for a week to 10 

 days ; at temperatures lower than this they sometimes show a tendency 

 to break down. 



Green tomatoes are best kept at a temperature not lower than 55°. 

 At this temperature ripening progresses slowly but satisfactorily, and 

 mature green tomatoes can be kept for 1 to 6 weeks before becoming 

 overripe. At temperatures below 55° green tomatoes do not ripen 

 well and, if kept there more than 5 to 8 days and then moved to a 

 warmer place, usually do not ripen satisfactorily. Exposures up to 

 5 to 8 days to a temperature of 40° or even somewhat less do not 

 usually prevent mature green tomatoes from ripening satisfactorily, 

 when later removed to a favorable temperature. If fairly rapid ripen- 

 ing is desired, temperatures from 60° to 70° should be used. At 70° 

 or above, ripening is accelerated, but so also is the development of 

 decay, which it will be found difficult to control. The relative hu- 

 midity of tomato storage or ripening rooms should be from 80 to 85 

 percent (61). 



