CHAPTER II 



WHY THE CALIFORNIA CLIMATE FAVORS THE 

 GROWTH OF FRUIT 



It was pointed out by the earliest students of meteorology, as 

 related to horticulture, that perfect development of fruits depends 

 upon certain atmospheric conditions, which are included in the 

 term climate : First, temperature ; second, light ; third, humidity 

 or atmospheric moisture, considered wholly apart from soil 

 moisture. It was also shown that temperature and humidity should 

 be equable, or as free as possible from excessive extremes or rapid 

 changes. 



Obviously, the chief characteristics of the California climate are: 

 First, freedom from extremes of low temperature; second, an 

 abundance of sunshine ; and third, an atmosphere with a low per- 

 centage of humidity. It will be interesting to introduce enough 

 statistics to demonstrate these claims, and to cite reasons why these 

 conditions are of special value to the fruit grower. 



THE OFFICE OF HEAT IN FRUIT PRODUCTION 



Temperature conditions may preclude the success of a fruit tree 

 either by destroying it outright, by dwarfing it, or by preventing 

 it from setting or ripening its fruit. .Extremes of temperature 

 accomplish the death of plants, and insufficient or excessive mean 

 temperatures may prevent fruition without killing the plant. The 

 first quality of the California climate to arrest the attention of 

 fruit growers in the states east of the Rocky Mountains is the 

 freedom from the effects of extremely low winter temperatures, 

 to which is due ihe deplorable failure, in the eastern and western 

 states, of many of the fruit varieties from the west of Europe, and 

 to escape which such zealous effort is now being so successfully 

 put forth to secure hardy varieties of native and foreign origin. 



How slight is the injury from low temperatures in all parts of 

 the state where fruit is largely grown may be seen from the fol- 

 lowing compilation of extreme low temperatures at different points 

 approximately at the same latitude on the coast, in the interior 

 valleys, and on the foot-hills. 



These records will show any one familiar with winter killing of 

 the leading orchard fruits that such disasters are not to be feared 

 in the chief fruit regions of California. Local temperature is largely 

 controlled by local conditions, as has been already pointed out, and 



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