A STUDY OF SWEET POTATO VAMETlES. 17 



in consistency, while others become very soft and moist. Their be- 

 havior in canning is entirely similar. 



The first season in which these studies were carried on the canning 

 of the potatoes was done shortly after digging. All the varieties 

 studied gave a product which was quite firm, though the representa- 

 tives of the Jersey group were somewhat firmer than those of the 

 other groups. The Vineless Pumpkin " Yam " and one or two others 

 were considerably less firm. The following season the potatoes were 

 cured after digging and then placed in storage for a time before 

 the canning tests were made, and the results obtained were very dif- 

 ferent. All were sweeter and somewhat softer in consistency than 

 those canned the preceding year. The Nancy Hall, Dooley, Porto 

 Rico, and Vineless Pumpkin " Yam " yielded a very soft moist prod- 

 uct; many others were of medium consistency, and a few, including 

 the Big-Stem Jersey, Early Eed Carolina, and Gold Skin, remained 

 relatively firm. This matter of firmness or softness of a variety on 

 cooking is held of much importance, because the soft moist type is 

 in greatest favor in the South while the clrj^ firm type has been con- 

 sidered most desirable for the northern market. Since the work of 

 the two preceding years had shown that the varieties differed among 

 themselves with respect to this property and that changes also oc- 

 curred after digging, the extent of which differed with varieties, it 

 was thought advisable to make a somewhat more detailed study, in 

 order to determine the amount and rate of these changes and their 

 effect upon the quality of the canned potatoes. 



It was impracticable to carry on such a detailed study of all of 

 the forty-odd varieties and strains under investigation, so the third 

 season four representatives were chosen from the list for this work. 

 The others were cured, stored, and canned as previously set forth. In 

 addition to their use for comparative-quality judging and for exhibi- 

 tion purposes these were all submitted to consistency tests made ac- 

 cording to the method which will be described presently in the con- 

 sideration of the four selected varieties. The results of these tests 

 will be found in a later table. 



The four varieties used in the detailed studies were Big-Stem 

 Jersey, Southern Queen, Porto Rico, and Nancy Hall. The Big-Stem 

 Jersey was selected as the representative of the dry, firm group, the 

 Porto Rico and Nancy Hall as representatives of the soft, moist 

 varieties, and the Southern Queen as representative of the inter- 

 mediate group. One lot from each of these varieties was canned im- 

 mediately after digging ; another after curing for 10 days at the aver- 

 age temperature of about 85° F. ; a third lot after 10 days in storage 

 at 55° to 60° F. following curing; and a fourth lot after 20 days in 

 storage. Representative cans for each stage in the handling of the 

 78646—22 3 



