IOO THE APPLE 



food are taken up from the soil by an average crop of apples than 

 by a similar crop of wheat. 



Mineral constituents. A fairly exact knowledge of the composi- 

 tion of the fruit and vegetative parts of the apple tree is desirable 

 for many reasons. One needs to know how the various plant-food 

 elements are made use of, and how their presence or absence in 

 the soil affects the different parts of the apple. It is also useful 

 to be able to detect by diagnosis malnutrition in the orchard, and 

 to observe and interpret the results of plant-food applications. 

 This knowledge, in connection with the known facts as to the 

 approximate annual weights of fruit, wood, and leaves produced 

 by a mature tree under average conditions, will enable one to 

 determine with a fair degree of accuracy the annual draft on 

 plant food exerted by a single tree or by an acre of trees. 



The following table is obtained from a combination of the 

 results of many investigations. 



By using the above table and the following average weights of 

 the various parts of the tree, just how much of the component 

 parts of a tree are nitrogen, phosphorus, potash, etc. can be 

 easily ascertained. 



Green Weight in Pounds 



Average wood and roots per tree 

 Average leaves per tree . . . 

 Average fruit per tree .... 



108 

 1 1 1 

 700 



From these figures the following table of pounds per acre 

 of the different constituents is obtained. For convenience in 

 figuring, the basis of weight has been made a yearly production, 



