lO 



Journal of Agricultural Research 



Vol. XII, No. 1 



changes in the roots during the latter part of their growth may also 



throw some light. 



PREVIOUS INVESTIGATION 



The only systematic examination heretofore published on the behavior 

 of sweet potatoes in the ground is that made in South Carolina by Keitt/ 

 who investigated the behavior of four varieties during 1908 and 1909. 

 Since his data are not easily summarized his tables recalculated on the 

 basis of dry matter are given here for purposes of comparison with sub- 

 sequent data. 



Table I. — Percentage composition of sweet potatoes in igo8, according to Keitt 



Variety. 



Total 

 carbohy- 

 drates. 



Aug. 28 

 Sept. 7 

 Sept. 18 

 Sept. 29 

 Nov. 18 



Aug. 28 

 Sept. 7 

 Sept. 18 

 Sept. 29 

 Nov. 18 



Aug. 28 

 Sept. 7 

 Sept. 18 

 Sept. 29 

 Nov. 18 



Aug. 28 

 Sept. 7 

 Sept. 18 

 Sept. 29 

 Nov. 18 



Nancy Hall , 



do 



do 



do 



do 



Polo. 



.do. 

 .do. 

 .do. 

 .do. 



Pvirple yam 



do 



do 



do 



do 



Fulleton yam 



do 



do 



do 



do 



73-67 

 68.69 

 69. 21 

 75-56 

 69-44 



69.87 



67-34 



69. 02 



59-04 

 67.78 



77. 66 

 71-85 



68.35 

 76.65 

 66.76 



73-76 

 72.36 



71-43 

 73-46 



70. 06 



' Keitt, T. E. the formation of sugars and starch in the sweet potato. S. C. Agr. Exp. Sta. 

 Bui. 156, 14 p. 1911. 

 SWEET potato investigation. S. C. Agr. Exp. sta. Bui. 165, 43 p. 1912. 



