Q CIRCULAR 447, U. S. DEPARTMENT OF AGRICULTURE 



GRAPES 



Results were obtained from 11 varieties of American grapes, labrusca 

 type, and 7 varieties of European grapes, vinifera type, all American 

 grown. While the average freezing point of the American grapes 

 grown at Arlington Farm or at the National Agricultural Research 

 Center, Beltsville, Md. 3 was 27.5° F., it will be noted (table 1) that 

 the freezing point of the Delaware variety, 24.6° ; is considerably 

 below that of the other varieties of both American and European types 

 due probably to the greater sugar content. In addition, there were 

 studied two varieties of vinifera- type grapes grown in Argentina and 

 South Africa to compare with the same varieties grown in California, 

 and also five other commercial varieties from South Africa. It will 

 be noted that the American and South African grown Almeria grapes 

 had about the same freezing point, while the same variety from Argen- 

 tina froze at several degrees lower. On the other hand, the Emperor 

 variety from South Africa froze at higher temperatures than those 

 from either California or Argentina. The lowest freezing point wa3 

 22. 7 C in the Almeria from Argentina. 



All the vinifera grapes studied came from commercial shipments on 

 the market and were all American grown and mature except where 

 noted. 



ORANGES 



The average freezing points of oranges grown both in California and 

 Florida were determined. 



PEACHES 



Freezing-point determinations were made on 13 varieties of peaches 

 commercially grown in nearby Virginia or Maryland. Peaches in the 

 hard-ripe stage were utilized for these tests. 



PEARS 



Studies were made on five commercial varieties of pears, all Cali- 

 fornia grown except the Kieffer variety. They were tested both in the 

 hard-ripe or shipping-ripe stage of maturity and in the soft-ripe or 

 eating-ripe stage. 



PLUMS 



Freezing points were obtained for three varieties of plums grown in 

 California and purchased on the market and for two varieties grown 

 at Arlington Farm. The variety with the lowest freezing point is 

 Damson. 



STRAWBERRIES 



Freezing-point determinations were obtained for 16 varieties of 

 strawberries grown at the Maryland Agricultural Experiment Station 

 and at the National Agricultural Research Center. The greatest 

 difference was found between Lupton, which froze at 28.8° F., and 

 Redheart, which froze at 30.3°. 



BLACKBERRIES. RASPBERRIES. AND CRANBERRIES 



Four varieties of blackberries, one of Logan blackberries (eastern 

 grown), and five of raspberries were studied. Four of the varieties of 

 cranberries frozen were grown in Wisconsin and eight in Massachusetts. 

 Considerable differences were found in the freezing points of some of 

 these varieties. While the McFarlin variety, for instance, froze at 

 29°, Shaw's Success froze at 25°. 



