40 THE SWEET POTATO. 



Wiesner states that sweet potatoes may contain as 

 much as 10 per cent, of sugar, l)ut only about 9 

 per cent, of starch in the tropics, while in the sub- 

 tropics they may contain as much as 15 per cent, of 

 starch and only 3-4 per cent, sugar. From the 

 analyses quoted above we can see that the last part 

 of the statement is inaccurate. General statements 

 of persons holding the same or the opposite view 

 may be found now and then, but the writer is not 

 aware that accurate experiments have been made 

 an^^^iere to settle this question. 



it is very likely that the constitution of the fer- 

 tilizer used should have an influence upon the starch 

 contents, and particular attention has been paid to 

 this question by the South Carolina station. It must 

 be borne in mind, however, that the experiment 

 extended only over one season, with only one variety 

 to test. So, while it may suggest certain lines of 

 experimentation, it can in no way be considered con- 

 clusive. 



Below are parts of the table as given in the South 

 Carolina Bulletin, 63, 1901, giving the percentages of 

 water, starch and sugar in diiferent lots of Horton 

 Yam sweet potatoes grown with different fertilizers : 



November 28, 1898 ; Variety, Horton Yam ; Wet Season. 



Water. Starch. Glucose. Sucrose. 



Fertilizer, Per cent. Per cent. Per cent. Per cent. 



ri^';''p""'"'; I 03.81 22.86 .96 5.41 



1,000 lbs. Compost j 



'1?J'?; ''<^""'' f ^"'"'' ^ 63.77 22.21 1.20 6.10 



1,000 lbs. Compost j 



Kolhin.-- 62.07 24.58 1.19 5.28 



JToo'ii ' r'"'*' f ''''"' \ 64.97 21.63 1.51 5.59 



1,000 lbs Compost | 



250 ll)s. Silicate of Potash ) , ^, 



1 AAA n n f - 65.87 20.70 1.27 6.03 



1,000 lbs. Compost j 



1,000 lbs. Compost 65.26 20.80 1.41 6.21 



