310 CITRUS FRUITS AND THEIR CULTURE. 



The greatest difficulty is in securing a uniform mix- 

 ture, but if sufficient care be exercised, this may be over- 

 come. Many growers, however, prefer to have the dealer, 

 from whom he secures his raw materials, mix them for 

 him. If the dealer can be relied upon to do the work 

 right, this plan has much to commend it. But good, uni- 

 form mixtures can be made at home, as has been demon- 

 strated time and again to our own satisfaction. For 

 home mixing of fertilizers a strong box, with smooth 

 sides and bottom, sufficiently large to contain from 500 

 to 1,000 pounds, should be provided, or the mixing may 

 be done on a tight, smooth, board or cement floor. 



Young and old trees differ in their fertilizer require- 

 ments. Young trees use their food supply in the forma- 

 tion of wood and leaves. For the first two or three sea- 

 sons they grow vigorously. When the bearing period is 

 reached, a gradual change comes about; the trees do not 

 grow so rapidly and a large portion of the food supply 

 is diverted to fruit formation. 



The demands on the trees being different, the food 

 supplied should be different in character. Young trees 

 require a large amount of nitrogen, while bearing trees 

 require less nitrogen relatively and more phosphoric acid 

 and potash. 



For young trees the fertilizer should contain about 

 6 per cent, phosphoric acid, 8 per cent, potash, and 4 per 

 cent, nitrogen, while one containing 8 per cent, phosphoric 

 acid, 12 per cent, potash and 3 1-2 per cent, nitrogen should 

 be applied to the grove of bearing trees. 



The following formulas contain approximately the 

 percentage of the three important plant foods given above 

 for young and for bearing trees. It is not possible to 

 make up an exact ton of fertilizer, using the most desira- 



