174 RURAL CALIFORNIA 



tillage is effective for moisture conservation, both in 

 operations by rainfall and by irrigation, as will be 

 outlined in Chapter VIII. To these early concep- 

 tions, the State has recently added the widest dem- 

 onstration that cover-cropping with tillage includes 

 restoration of soil fertility in the act of securing the 

 highest duty of water. 



Second, the relation of form to efficiency of plant 

 performance. Methods and styles of tree and vine 

 pruning have been devised and older systems from 

 other parts of the world modified with such suc- 

 cess that "California style" is recognized horticul- 

 turally and accepted as a model for imitation in 

 more recently developed fruit regions in all parts of 

 the world. "California style" in pruning is, however, 

 progressive and is undergoing modification as the re- 

 sult of improvements demonstrated by research and 

 large operations in practice. 



Third, the relation of plant protection to success 

 in commercial production. California has devised 

 original methods and demonstrated the value of new 

 materials in insect warfare which other fruit-grow- 

 ing countries have accepted as important improve- 

 ments. In addition to her initiative in legislation to 

 control and exclude pests, she first applied high- 

 pressure spraying and invented devices to secure it; 

 first publicly announced through an experiment sta- 

 tion bulletin investigations which made legal control 

 of insecticide manufacture and sale imperative, al- 

 though a few other states preceded in actual enact- 

 ments; first demonstrated the efficiency of lime sul- 



