FREEZING TEMPERATURES OF FRUITS, VEGETABLES, AND FLOWERS. 3 



work is being continued. It has been found in some cases that 

 the freezing points of some varieties are liable to slight variations 

 from year to year, even though the same strain grown in the same 

 locality is used. These variations, however, are probably of more 

 importance in the study of the exact causes and results of freezing 

 injury than from the point of view of the commercial cold-storage 

 and produce man, for the variation of a fraction of a degree hardly 

 warrants 'any change in the treatment of the produce. It therefore 

 seems advisable to publish the results of these investigations from 

 time to time as obtained, because of the need for such information 

 and because there is no comprehensive publication on the subject. 

 The method of determining freezing points has been described 

 in former papers, 2 and a repetition of this description is not required 

 here. 



FREEZING POINTS OF FRUITS. 



Where several varieties of one kind of fruit were investigated 

 the results are given separately to allow comparisons to be made. 

 All temperatures are expressed in degrees Fahrenheit. 



Apples. — Freezing-point determinations were made for a number 

 of authentic varieties of summer or early apples and of fall and 

 winter varieties, most of which were grown on the Arlington Experi- 

 ment Farm. The tabulated results given by varieties are shown 

 in Table 1. These results show considerable varietal differences 

 among both summer and winter apples. The average of all summer 

 varieties is practically the same as that of winter varieties, the 

 former being 28.44° F. while the latter is 28.51° F. These results 

 show very little difference between the freezing points of eastern- 

 grown and western-grown fruit. 



Cherries. — Freezing-point determinations were made for seven 

 varieties of cherries grown on the Arlington Experiment Farm. 

 The average of all varieties was 27.81° F. (Table 1.) 



Grapes. — -Results were obtained from the freezing of seven varieties 

 of grapes, all of which were grown on the Arlington Experiment 

 Farm. The average freezing point of all the varieties was 28.16° F. 

 (Table 1.) 



Oranges. — The average freezing point of the six varieties of oranges 

 studied was 28.03° F. (Table 1.) 



Peaches.— Freezing-point determinations were made for 11 va- 

 rieties of peaches grown near Leesburg, Va.,inthe Loudoun orchard 

 of the American Fruit Growers (Inc.). Peaches in the hard-ripe 

 sta^e were utilized for these tests. The average freezing point of all 

 varieties when hard ripe was found to be 29.41° F. (Table 1.) 



Plums. — Freezing points were obtained for four varieties of plums 

 that were grown in California and purchased on the market and for 

 one variety (Red June) grown at the Arlington Experiment Farm. 

 The variety with the lowest freezing point is Tragedy, with a freezing 

 temperature of 27.21° F. The average freezing-point of all varieties 

 is 28.53° F. (Table 1.) 



2 Taylor, George F. Some improvements on the needle type thermocouple for low-temperature work. 

 In Jour. Ini. and Eng. Chem., v. 12, p. 797-798, 1 fig. 1920. 



Wright, R. C, and Harvey, R. B. The freezing point of potatoes as determined by the thermoelectric 

 method. U. S. Dept. Agr. Bui. 895, 7 p., 1 fig. 1921. Bibliographical footnotes. 



Wright, R. C, and Taylor, George F. Freezing injury to potatoes when undercooled. U. S. Dept. 

 Agr. Bui. 916, 15 p., 1 fig., 1 pi. 1921. Literature cited, p. 15. 



