THE WASHINGTON NAVEL 



451 



the vigor of leaf action. Dead twigs which appear among good 

 bearing shoots should always be removed. The gourmand shoots 

 or suckers should be repressed, unless, by clipping, one can be 

 turned into a branch where a branch is needed. 



DISEASES OF THE ORANGE 



The orange is thus far subject to few diseases in California. 

 The most grievous is the so called gum disease, which as analo- 

 gous to the gumming of other trees and will be discussed in the 

 chapter treating of tree diseases. Cracking of the fruit is a trouble 

 which has never been fully explained. 



There are several serious insect enemies of the orange, which 

 will be discussed in the chapter on that subject. The "black 

 smut," which makes leaves and fruit unsightly in some parts of 

 the State, is a fungoid growth upon the exudations of insects, and 

 can be prevented by removing its cause. 



VARIETIES OF THE ORANGE 



Though many varieties of the orange have been introduced 

 in California, but few are largely grown. During the last fifteen 

 years there has been a pervading disposition to concentrate upon 

 the Washington Navel, and, except to get other varieties either 

 earlier or later to extend the season, there seems little reason 

 to go beyond the Navel for commercial purposes. Not only have 

 recent plantings been predominantly of this variety, but old trees 

 of other kinds have been very largely budded over to it, and this 

 work is still going on at a rapid rate. 



As already claimed in the opening pages of this chapter, the 

 Washington Navel is the greatest commercial orange in the 

 world. As it goes from California into the world's commerce it 

 is a combined product of grower's skill and climatic conditions 

 operating upon its own natural qualities and characters. Neither 

 of these factors alone could achieve its present position. The 

 navel mark is neither peculiar to it nor determinative of it, for 

 there are other navels which are inferior here and our navel is 

 inferior elsewhere; and even in Bahia, whence it came, it has no 

 such quality and standing, because in coming to California it 

 passed from humid, tropical to arid, semi-tropical environment. 

 As already suggested, the tropical orange is not in the same class 

 with the semi-tropical from the point of view of commerce. Trade 

 in tropical oranges is local or limited ; trade in semi-tropical 

 oranges is world-reaching. The orange produced in an arid, semi- 

 tropical climate is dense and compact, firm and better in keep- 

 ing and carrying characters. It is also of more sprightly flavor 

 and richer composition. Those who are disposed to exalt the 



