652 



Journal of Agriculkire, Victoria. [10 Nov., 1917. 



Table XI. 

 Pounds of Plant Food Contained in the Roots, Calculating 12,000 



Plants per Acre. 



• Owing to the advanced state ot decomposition, difficulty was experienced in collecting all the roots 

 at the fourth harvest. Apparently the loss was equal to 30 per cent., and this would make the analytical 

 figures obtained from the fourth harvest of the roots practically equal to those of tlie third harvest. 



Table XIa. 

 Plant Food Ratio in Roots. 



The above tables provide additional proof of the function of th& 

 plant in exerting its energies during the first two months' growth in 

 the ahsorption of the essential plant foods from the soil, particular 

 attention being paid to phosphoric, acid. It will again be remarked 

 after a study of the tables that a definite ratio exists between the alkaline 

 earths, i.e., lime and magnesia, and this agrees almost exactly with the 

 ratio found in the haulm. (Table VIIa.) 



Table XII. 

 Composition of "Whole Plant at Various Stages of Development. 



The graph on i:>age 648 shows the amounts of plant foods, in- 

 eluding lime and magnesia, which, in this experiment, are calculated 

 to be food for the potato plant required or contained in a potato 

 crop at various stages of development, and which ultimately produced 

 approximately 25 tons of green tubei-s per acre. 



The graph explains itself. Computing on the figures of the fourth 

 diagram it is found that approximately one-fifth of the total plant food 



