PKUNIKG 



225 



crown is removed, by cutting off the main branches, this is 

 called pollarding. Poplars and willows are often pollarded, but 

 other trees may be ruined by this process. Heading in may 



Photograph by H. L. Hollister Land Co. 



FIG. 166. Young plum tree, heavily loaded with fruit, grown under irrigation 



be rendered unnecessary by removing the tips of the tender 

 growth with the thumb and finger when it has reached the 

 desired length. This latter operation is called pinching or 



