140 



The Philippine Journal of Science 



The combination of nitrate of soda with superphosphate (plot 

 10) and that of the latter with ammonium sulphate (plot 11) 

 show the lowest purity. The plots with nitrate of soda (plot 

 4) and sulphate of ammonia (plot 6) are below the check plots 

 1 and 9 in purity. Plot 11 gave the lowest percentage of 

 sucrose in the cane, while the two plots with complete fertilizers 

 with nitrogen in the form of nitrate of soda show the highest 

 sucrose content. With the exception of plots 8, 10, and 11, all 

 of the fertilized plots show a higher percentage of sucrose than 

 either check. 



The effect of fertilizers on the purity of the juice and the 

 sucrose content of the cane can be best understood with the aid 

 of fig. 1, in which curve 1 represents purity and curve 2 sucrose 

 content of the cane. It will be noticed with interest that the 

 rise and fall of the purity is accompanied by a similar course 

 of the percentage of sucrose in the cane, with the exception of 







d±zz±\±mEnW\ 



Fu;. 1. Curve 1, effect of fei-tili/.ers on the purity of juice; curve 2, sucrose content of 



tlie cane. 



plot 4, where the increase in purity is not accompanied by any 

 increase in the sucrose content as compared with plot 13. 



The effect of manuring on the saccharine content of the cane 

 is a subject that up to the present time is not satisfactorily 

 known. Eckart,® in Hawaii, found that unmanured cane was 

 higher in purity than manured cane. Harrison and Bovel,'" 

 of Barbados, say that they have no definite information as to 

 the specific effect of the different mineral constituents of fer- 

 tilizers on the saccharine content of the cane. While Geerligs 

 is in the same position, Deerr believes that cane manuring affects 

 the tonnage of the cane rather than its saccharine content. 



Deerr, Noel, Cane Sugar (1911). 



' Ibid. 



