256 ECONOMIC PLANTS 



which are dead and those which have passed usefulness 

 should be removed. There is great danger of cutting 

 away too much. Care should be taken to preserve the 

 natural outline of the crown, as both fruit and leaves 

 are borne at the ends of the branches. The orange is 

 propagated by budding. After two years of growth 

 in the nursery it is set out in the orchard and usually 

 commences to bear five years after planting. 



The navel orange, a seedless variety imported from 

 Brazil, is especially adapted to California conditions, 

 but will not thrive in Florida. 



The ordinary sweet oranges of the markets grow on 

 trees 25 to 30 feet high. Seedlings of this variety are 

 subject to root rot, and on that account it is usually 

 budded on a stock of sour or bitter orange which is 

 not subject to this disease. 



The Satsuma orange grafted on Citrus trifoliata can 

 be grown successfully even in parts of southern states 

 subject to killing frosts. 



The Lemon. --This tree will thrive in a variety of 

 soils, though a sandy loam is preferred. While the 

 lemon does not require the high temperature necessary 

 to produce the best qualities in the orange, it will not, 

 at the same time, bear such low temperatures as the 

 orange. Since the orarige root will thrive in a greater 

 variety of soils than will the root of the lemon, it is 

 quite common to graft the lemon on an orange seed- 

 ling stock. Owing to its spreading habit, the tree must 

 be carefully pruned. If this is not done, the fruit will 

 be borne at the ends of the long, willowy branches and 

 necessary cultivation will be rendered impossible. 



The Grapefruit is now extensively grown in Cali- 

 fornia and Florida. The botanical name is pomelo, but 



