ously to generous treatment by producing fruit of the highest The 



quality and in enormous quantity. Cultivation o 



4, . . . i . Citrus Fruits 



I o manure rationally, it is necessary to take into ac- - 



count the nature of the soil, the composition of the plant^ Z 3 

 its food requirements, the quantity and constituents of the 

 crop and the conditions of vegetation. Acquainted with 

 these, we are able to determine, with an approximation to 

 scientific accuracy, what are the elements that have to be 

 supplied and in what proportion. 



The chemical composition of the orange tree as well 

 as that of citrus fruits generally is complex, and varies 

 somewhat widely, but the following, which represents the 

 mean of a large number of analyses, will serve as a guide 

 in the employment of manures : 



Analysis of Orange Trees. 



In 100 parts. 



Nitrogen. Potash. Lime. 



Fruit .......... 0.32 -38 0-32 0.43 



Leaves ......... . 0.70 o.io 0.32 0.71 



Trunk and branches 0.70 43 0.58 0.80 



These data clearly indicate that no one element dis- 

 tinctly dominates the others; for although lime is present 

 in quantity, that base exists in abundance in most soils and 

 may be disregarded in the preparation of formulae of ma- 

 nures, sufficient of it being applied in combination with 

 phosphoric and sulphuric acids. 



In the case of trees, like those of the citrus group, 

 whose foliage is perennial, and which are of comparatively 

 slow growth and subjected to only limited pruning, the 

 elements of fertility consumed in the formation of leaf and 

 wood are relatively small in quantity, and the greater part 

 of the plant-food assimilated is expended upon the fruit. 

 Thus, in determining the nature and quantity of the manures 

 to be applied, the production of fruit is the principal factor 

 to be taken into account m arriving at the volume of plant- 

 foods abstracted from the soil and consequently having to 

 be replaced. 



Let us suppose that an acre of orange plantation (about 

 100 trees) produces twelve tons of fruit. According to the 

 analysis given above, this crop will contain: 



