314 RURAL CALIFORNIA 



full bearing to produce full crops of merchantable 

 fruit. 



5. Evergreen fruit-trees, like citrus fruits, need 

 summer and fall irrigation (and sometimes winter 

 irrigation also) irrespective of rainfall, although the 

 amount of irrigation required will be influenced to 

 some extent by the rainfall. 



6. Shallow-rooting plants, like most berries and 

 summer-growing vegetables, require irrigation irre- 

 spective of the soil character and the amount of rain- 

 fall and may die outright in the dry season if they 

 do not amply receive it. 



The foregoing generalizations, which may admit of 

 some exceptions in the case of certain plants and 

 natural conditions, justify the conclusion that the 

 desirability of irrigation cannot be determined by 

 the local rainfall. There are places in California 

 where the average annual rainfall is more than forty 

 inches and yet irrigation is essential; there are other 

 places in which the rainfall is even less than half as 

 much and yet irrigation is needed only for citrus 

 fruits, berries and vegetables which start their growth 

 in the early summer, except on naturally moist low 

 lands. These two regions of widely divergent prac- 

 tice may be within sight of each other. 



Experience has shown that it is beyond human wis- 

 dom to prescribe amounts of water desirable to pro- 

 duce best growth of all plants in all places, because: 

 (a) different plants require varying amounts of wa- 

 ter and the same individual may need diverse amounts 

 of water at different times in the growing season; 



