26 CALIFORNIA FRUITS: HOW TO GROW THEM 



moisture is not from rainstorm, but by irrigation, the same facts 

 remain, for the water reaches the tree without interrupting its 

 aerial activity. Temperature is maintained, light is unobstructed, 

 and the tree is refreshed with moisture without the chill and dark- 

 ness which favor fungoid parasites. Of all the ways by which 

 moisture could come to soils supporting fruit tree or vine, the 

 natural by its time, and the artificial by its method, endow Cali- 

 fornia with the best. 



The characteristics of the California climate which have been 

 especially pointed out in this sketch are not propitious to fruit 

 culture when they exist to excessive degree, as in some interior or 

 continental climates. Local conditions of altitude, distance from 

 the sea, and exposure to the sweep of arctic winds, induce sudden 

 and great weather changes which are serious in their effects. 

 Excessively low percentage of atmospheric humidity, in connection 

 with desiccating wind, often produce greater evaporation from the 

 leaves than the roots can supply. Excessively dry air admits a 

 parching sun heat at one time, and at another facilitates radiation 

 of heat, until the rapid decline in temperature makes killing frosts 

 frequent. It is evident that California has these agencies constantly 

 held in check by her insular situation and protecting environment, 

 and owes her wonderful adaptation to growth of tree and perfec- 

 tion of fruit not more to the possession of certain conditions than 

 to the fact of their existence in moderation. 



