VAPvIATIOX IX THE SUCROSE PEECENTAGE IN THE JUICE. 



The chemical analysis of the juice of the seedlings and cane varieties is a 

 heavy tax on the stafi at disposal. Because of tlie incidence of most of this 

 work at one time of the year, it was not thought necessary to attach more 

 than one chemical assistant permanently to the staff of the Sugarcane Expert, 

 but it will easily be gathered, from what follows, that tin's assistant is cjuiti- 

 unable to deal unaided with tlie work during the period of stress. I am 

 indebted to the Govermnent Agricultural Chemist for generously 2:)lacing two 

 of his assistants at my disposal during the whole of the cropping season, thus 

 making three altogether available for the chemical analysis of the canes. 



The data obtained in the analysis of a seedlhig are as follows :^number 

 of canes cut. weight of canes crushed in lbs., weight of juice obtained, per- 

 centage of juice to cane, Brix (corrected) per cent., sucrose ])er cent, in the 

 juice, glucose per cent., glucose ratio and co-efficient of purity. Eor various 

 reasons, in judging the value of a seedling, it has not been considered .sufficient 

 merely to make an analysis of the juice at harvest time. Eor one thing, the 

 season is so long protracted, because of the number of analyses to be got 

 through, that some of the seedlings would be heavily lianchcapped by this 

 method, and, for another, time is available before harvesting connuences to 

 make a series of jjreliminary analyses to gauge the rate of jipening in the 

 plots, so as to be able better to judge the date at which the final analyses 

 should be made. Tlie former series of analyses, made on one or two canes, 

 is termed the '" petty series " and the final analyses the "' bulk,"' dealing as 

 it does with what canes remain in each clump. There is little doubt that the 

 seedlings of different ]3arentage differ very considerably in their order of 

 ripening, and the petty analyses give some idea as to the order in which the 

 plots should be cut for final analysis. 



The total number of analyses made since the foundation of the cane- 

 breeding station (excluding preliminary soil analyses done by the Government 

 Agricultural Chemist) are as follows : — 



1912 Cane Juice 1"2 others o'2 (uiiscellaneous) 



191.S ., 9-2 ,, 4.3 (mainly well water) 



1914 ,, 2909 ,, 33 1 (mainly chlorine determinations 



1915 ,, 40U ,, 38/ in cane juice; 



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