300 CITRUS FRUITS AND THEIR CULTURE. 



FERTILIZER ANALYSIS OF THE FRUIT OF ONE VARIETY OF LEMON. 

 [Computed from Bui. 93. Univ. Cal. Ag. Exp. Station.] 



It will be seen from these analyses that the fruit of 

 all kinds of citrus contain practically the same percent- 

 age of fertilizer ingredients. The averages of the five 

 tables given above are .055 per cent, phosphoric acid, 

 .249 per cent, potash and .149 per cent, nitrogen. 



For purposes of computation it may be assumed 

 that a box of citrus fruit will weigh about eighty pounds. 

 No fixed and definite weight can be given. Much de- 

 pends upon the size of the fruit, the season, the curing, 

 and the methods of cultivation, irrigation and fertili- 

 zation. The weights may vary anywhere between sixty- 

 five and one hundred pounds, but the weight fixed upon, 

 viz., 80 pounds, will not be far from a general average. 

 The weight of ten boxes would then be 800 pounds. This 

 amount of fruit would remove from the soil .440 pounds 

 phosphoric acid, 1.976 pounds of potash and 1.192 pounds 

 of nitrogen. 



That soil depletion may be prevented, these are the 

 losses which must be made good for each crop of ten 

 boxes. In addition, provision should be made for a var- 

 iable and unknown quantity of plant food which leaches 

 from the soil and besides, the tree must have a sufficient 

 food supply to enable it to add new growth in roots, 

 branch and leaf. A fair approximation, covering the 

 fertilizer removed in the fruit and that lost by leaching 

 and required for new growth would be two or three times 



