THE IRRIGATION OF THE CANE 



1-^3 



Table giving Water used in Production of a Cane Crop. 



27-01 



76-5 



The consumption of water per lb. of sugar produced was : — 



Water transpired by Cane. — Maxwell^^ found as the result of experiment 

 that, when cane was grown in tubs, in seven months 79,310 grms., or 174 '5 

 lbs. of water, were transpired by the plant, there being formed 568-9 grms. 

 of water-free material, consisting of 31-8 grms roots, 53-9 grms. stems, 

 and 483-2 grms. leaves, or 147-8 lbs. water per lb. of water-free plant 

 material. The amount of water transpired in each month of growth was 

 found to be as in the annexed table : — 



Time of 



Observation. 



May 



June 



July 



Age of 



Cane. 



[Months. 



Transpiration. 



Grms. 



860 



6,500 



11,000 



Time of 

 Observation. 



Age of 



Cane. 



Months. 



August . . 4 



September 5 



October . . 6 



Transpiration. 

 Grms. 

 19,800 

 20,050 

 21,100 



Experiments due to Kammerling^- in Java showed that on an average 

 one stalk of cane by its leaves transpired over its whole period of growth 

 250 c.c. per day ; this he estimates as equcd to 3,500,000 litres per bouw 

 over the whole vegetative period, or equal to about 1,600 tons per acre. 



During the first month of drought in Java, Kammerling estimates the 

 transpiration per stalk as 500 c.c. per day, and using this as a basis he reckons 

 that the replacing of the soil water thus transpired in a month requires 

 720,000 litres per bouw, or about 330 tons per acre. 



Kammerling also observed that the transpiration of the ]\Ianila, Cheribon 

 and Muntok canes was as 5 : 4 : 3 ; i.e., the latter will remain in vegetative 

 vigour on the soil water longer than the former, and will be drought-resisting. 



Optimum Quantity of Water in Soil. — Water exists in soils in three 

 conditions : as hygroscopic water, as capillary water, and as gravitational 



I 



