EFFECTS OF FREEZES ON CITRUS IN CALIFORNIA 



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in the same vicinity, for the actual minimum temperature means but 

 little in regard to the resulting effects upon plant life, unless the dura- 

 tion of the low temperature, as well as the actual minimum, is also 

 known. Lemon trees subjected to a temperature of 20 to 22, but 

 of very short duration, were not injured ; while the much more hardy 

 orange trees, experiencing a similar low temperature that continued 

 for nine or ten hours on three successive nights, were entirely 

 defoliated. 



Fig. 2. Badly frozen Eureka lemon grove two months after the freeze. 

 The same trees as those shown in fig. 1, but three months later. Photo 

 by Smith, June 24, 1913. 



The elevation of groves above sea-level does not indicate their 

 liability to frost injury. Citrus fruits in southern California are 

 grown at elevations ranging from sea-level to twenty-seven hundred 

 feet or more; and while in some sections trees at sea-level suffered 

 severely from the January freeze, and groves at 1400 and 1500 feet 

 were unharmed, in other sections the reverse conditions occurred. 



