THE ORANGE IN CALIFORNIA FROST PROTECTION. 151 



Fertilization as Affecting Disease. Probably the most com- 

 mon cause of injury to orange trees is a lack of fertilization, 

 yet it is not infrequent for disease to be induced or aggravated 

 by excessive or improper fertilization. This may, indeed, be 

 of much more importance than we are at present inclined to 

 believe. One of the forms of die-back, a common and 

 destructive disease of the orange, is quite evidently due to 

 errors in fertilization. In other cases the disease appears to 

 be caused by planting in improper soil. 



FEOST PROTECTION. 



The Riverside Horticultural Club appointed a committee 

 consisting of J. H. Reed, E. W. Holmes, E. L. Koethen, E. A. 

 Zumbro, and J. H. Martin all practical orange-growers to 

 investigate the question of orchard protection against frost. 

 The committee, after a careful investigation of all the methods 

 in use and experimented with, made its report, which was 

 adopted, as follows:* 



With the assistance of some fifteen or twenty citizens inter- 

 ested in the study of the points involved, a most complete test 

 has been made of the many different methods employed to pre- 

 vent frost damage. With such a force of competent and impar- 

 tial observers, it was possible to secure data of much value in 

 forming an estimate of the efficiency of the various plans made 

 use of. Careful comparison was made between those orchards 

 where no work was done, and where no direct effect of the fire 

 was probable, and those where the different methods were being 

 tried. As indicated by our partial report at the last meeting 

 of the club, these tests were in some particulars emkiently satis- 

 factory, as showing the way to definite conclusions. 



The exceptionally long period of cold following gave addi- 

 tional opportunity to verify the first conclusions reached, and 

 subsequent investigations made by ourselves, as well as by other 

 citizens who have awakened to the possibility of protecting their 

 property, strengthened and confirmed the opinion formed as the 

 result of the tests already partially reported upon. 



* Riverside Press, February 19, 1898. 



