LUTHER BURBANK 
their appearance. But there is still opportunity 
for improvement through further selection. 
CULTIVATION OF THE ORANGE 
The orange is budded or grafted on roots of 
its own species or on those of the lemon or the 
shaddock, better known as the grapefruit. 
The process of budding is altogether similar to 
the budding of other trees and it presents no diffi- 
culties. Stocks may be grown from seed but, as 
already noted, seedlings cannot be depended upon 
to reproduce the parent forms, and all the best 
varieties of orange are propagated by grafting. 
The chief peculiarity of orange culture is that 
it is necessary to grow the fruit on irrigated soil. 
Water is, of course, essential to all plant life, 
but a tree like the orange, with heavy evergreen 
foliage, makes exceptional demands, and it is 
imperative, if the large juicy fruit is to be brought 
to perfection, that these demands shall be ade- 
quately met. 
It was the recognition of this fact by the old 
Moors more than a thousand years ago that made 
Valencia in Spain, thanks to the Moorish system of 
irrigation, the heart and center of the orange in- 
dustry of the world. The irrigation system estab- 
iished by the Moors is still in successful operation, 
and Valencia remains the largest single shipping 
port for oranges anywhere in the world. 
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