A STUDY OF SWEET POTATO VARIETIES. 



tion of attractive and (iesirable canned goods of very great impor- 

 tance. 



The investigations reported upon in this paper were made possible 

 by the presence at the Arlington Experimental Farm, where this 

 work was done, of variety test plats, where upward of 40 varieties 

 and strains of sweet potatoes have been under study for a number of 

 years. J. H. Beattie and C. J. Hunn, of the Office of Horticultural 

 and Pomological Investigations, Bureau of Plant Industry, have 

 these varieties under observation, furnished much of the raw material, 

 and otherwise facilitated the work. No claim is made that all 

 varieties are embraced in this study, but all those generally con- 

 sidered as important are included. There has been much confusion 

 in the variety names of sweet potatoes, and it is hoped that the 

 studies now in progress in the Office of Horticultural and Pomo- 

 logical Investigations will make clear the relationship of the numer- 

 ous strains. 



It is possible that under different climatic and soil conditions the 

 same varieties might have given slightly different results from those 

 here reported. Comparative canning tests upon potatoes from other 

 sections of the country have not been made, though these would have 

 been of interest. The potatoes used were handled under carefully 

 controlled conditions, and the uniform treatment which they received 

 makes possible a direct comparison of the merits of the different 

 varieties. This has been the object of the work, and it is believed 

 that the information presented will be found of service not only to 

 those interested in the canning of this product but also to those fol- 

 lowing other methods of sweet-potato utilization. 



CHEMICAL COMPOSITION OF SWEET POTATOES. 



In entering upon a study of this sort it is necessary to know some- 

 thing of the chemical composition of the material under consideration. 

 Table 1, taken from the work of Atwater and Bryant (i),^ shows 

 the chemical composition of both the fresh sweet potato and the 

 canned product. 



Table 1. — Chennical composition and calorific value of fresh and of canned 



sweet potatoes. 





Constituents (i)er cent). 



Condition. 



Water. 



Protein. 



Fat. 



Total 

 carbo- 

 hydrate 

 (includ- 

 ing fiber). 



Fiber. 



Ash. 



Fuel 

 value per 



pound 

 (calories). 





69.0 

 55.2 



1.8 

 1.9 



0.7 



.4 



27.4 

 41.4 



1.3 



.8 



1.1 

 1.1 



570 



Canned 



820 







1 Serial numbers in parentheses {italic) refer to " Literature cited " at the end of this 

 bulletin. . 



