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CALIFORNIA FRUITS: HOW TO GROW THEM 



BLIGHT OF THE PEAR 



Although California pear growers who came to the State en- 

 dowed with eastern experience have always apprehended the intro- 

 duction of the true pear blight and shivered every time they saw 

 die-back or blackening on a pear branch, the probability is that 

 all early reports of its entrance were misapprehensions until the 

 real scourge appeared in the San Joaquin Valley about a decade 

 ago. The rapidity with which trees began to be destroyed at that 

 time manifested its habit in this State and warrants the conclu- 

 sion that earlier troubles of the tree probably arose from other 

 causes. In 1904, after having nearly wiped out bearing trees in 

 the southern counties of the San Joaquin Valley the disease began 

 to devastate the orchards along the Sacramento River through 

 the vast area of rich valley land which it traverses and on which 

 is situated our most extensive pear acreage. In 1905 resolute 

 warfare was made upon the blight, with a large appropriation of 

 State funds, by the plant disease experts of the United States 

 Department of Agriculture and of the California Agricultural Ex- 

 periment Station, with the assistance of the local horticultural 

 authorities. It was probably the greatest campaign ever made 

 against a single tree disease although some insect warfares have 

 been greater. The outlines of the plans followed and the results 

 attained are to be found in the publications of the institutions 

 engaged.* 



In a later chapter on Diseases of Trees and Vines, an outline 

 of procedure against pear blight will be given. It is apprehended 

 that neither paying crops nor living trees can be counted upon in 

 the future unless the disease is successfully kept under control 

 by successful fighting or by recourse to some form of natural 

 immunity which can be discovered or developed by plant breeding. 

 It is probable that pears can not be grown in the future as cheaply 

 and profitably as in the past and there is a certain amount of 

 bravery or daring in pear investments at the present time. It 

 is encouraging, however, to note that in California the disease 

 shows signs of relaxing the virulence which characterized its first 

 attacks and it is reasonable to believe that here as elsewhere it 

 may be possible to have the blight and pears also. The reader 

 must keep himself continually informed of the various phases of 

 the problem as they will arise, by careful study of our excellent 

 California horticultural journals and of later publications from the 

 official sources which have been indicated. 



* Reports of the California Commissioners of Horticulture, 1901 to 1906, includ- 

 ing Reports on California Fruit Growers' Conventions for 1905-6-7, J. W. Jeffrey, 

 Commissioner, Sacramento. Report of Plant Pathologist, University Experiment 

 Station, Berkeley, 1906 and 1908. 



