STORAGE OF FRUITS, VEGETABLES, AND FLORISTS' STOCKS 17 



Dates 



(Temperature, 28° to 32° F. ; relative humidity, Go to 75 percent ; or 28° F. and no humidity 



control for cured grades) 



Dates absorb moisture and odors readily from the air. The rate of 

 absorption is much less at temperatures below 32° F. than at those 

 above 32°. Deterioration caused by humidity above 75 percent is 

 slow at storage temperatures below 28°. The dates of commerce are 

 of three grades with respect to storage life — dried, cured, and non- 

 cured. The cured and noncured grades are perishable. A tempera- 

 ture as low as 0° has no deleterious effect upon dates but is actually 

 beneficial to them. 



Dates are of two different types, and fruits of each type are likely 

 to be either dry, cured, or noncured. The "cane sugar" type is usually 

 firm, light-colored, and comparatively dry, whereas the "invert sugar" 

 type is usually softer, darker colored, and inclined to be slightly 

 sticky or sirupy. 



Degiet Noor, the most important variety grown in this country, is 

 of the cane-sugar type. Dates of this variety, cured grade, keep well 

 until March at 28° to 32° F. and for a year at 24° to 26° or lower, 

 whereas the noncured grade requires 18° .or lower for storage until 

 March, and 0° to 10° for a year. In Degiet Noor dates that have 

 become overripe or have been held under .unfavorable storage condi- 

 tions the cane sugar is inverted and the dates become soft, sirupy, and 

 darker in color, Such dates are commonly graded as "dark soft." If 

 they can be dried down somewhat, they can be stored at 28° to 32° 

 until Christmas without becoming objectionably dark and sirupy, 

 although a temperature of 0° to 10° will be needed if they are to be 

 stored until March. If such dates are not cured, a temperature of 

 0° to 10° is necessary for even short-time storage (75). 



Halawy, Khadrawy, Zahidi, and Saidy dates are all of the invert- 

 sugar type, and the cured grades can be kept until Christmas at 28° 

 to 32° F. without forming sugar spots but require a temperature of 

 18° or lower if stored until March. Noncured grades of these varieties 

 require 0° to 10° for even short storage. After Christmas it is well 

 to shift all dates of the invert-sugar type remaining in storage to 

 -'freezers" at 0° to 10° F. (5). 



Dewberries 



Short storage only. See Raspberries. 



Grapefruit 



(Temperature, see text ; relative humidity, 85 to 90 percent) 



Storage rooms for grapefruit should have a relative humidity of 85 

 to 90 percent. Lower humidities are favorable to pitting, and higher 

 ones may increase decay. 



For short-time storage, grapefruit can be held satisfactorily at a 

 temperature of 32° F. For longer periods the temperature to be used 

 will depend on the character of the fruit and the troubles most likely 

 to be encountered. For fruit grown in sections where stem end rot 



324484°— 41 3 



