406 FIELD CROPS FOR THE COTTON-BELT 



Any condition that retards growth tends to decrease also 

 the percentage of juice contained, although the concentra- 

 tion of the juice is usually increased. 



The amount of juice varies in different parts of the same 

 plant and also with the stage of maturity. The juice 

 reaches its maximum near the middle of the stalk and 

 decreases near the ends, the decrease being greatest near 

 the top. The sugar content of the plant is greatest during 

 maturation. 



505. Composition of the juice. The juice of sugar- 

 cane is a solution of certain soluble ingredients, notably 

 sugars, salts, acids, and the like, in the cell-water. As 

 extracted by the mill it contains also some insoluble matter, 

 such as wax, fat, albuminoids, dirt, and particles of fiber. 

 The sugars are the constituents which give the juice its 

 value. The three principal sugars are sucrose (C 12 H 22 

 O u ), dextrose (C 6 H 12 O 6 ) and levulose (C 6 H 12 O 6 ). Su- 

 crose, which crystallizes out as cane-sugar, is the constit- 

 uent of greatest value. In fact, within the sugar-belt, 

 the presence in the cane of saccharine matters other than 

 sucrose is deprecated by planters, as these substances not 

 only fail to crystallize but their presence causes some of 

 the sucrose to fail to make sugar. In commercial work 

 dextrose (often called grape-sugar) and levulose (often 

 called fructose or fruit-sugar) together with certain other 

 saccharine substances of minor importance, are generally 

 spoken of collectively as glucose. Chemically speaking, 

 the term glucose is applicable to dextrose only. 



506. Conditions affecting the composition of the 

 juice. The Louisiana Station has shown that climate, 

 variety, culture, soil and fertilization are factors that have 

 an influence upon the composition of sugar-cane juice. It 

 was noticed that relatively dry weather during the fall 



