SECTION II 

 NUTRITION 



Nutrient supply is generally considered the most important of the 

 factors limiting growth and productiveness. Certainly it ranks second 

 to no other in determining the success or failure of the orchard enter- 

 prise within those sections or areas where climatic conditions make 

 possible a fruit industry and where economic conditions make practicable 

 its development. Though there are many single cases in which the 

 water supply, the prevalence of pests or some other factor assumes 

 paramount importance, the most common limiting influence is associated 

 with nutritive conditions. Much of the effort of the careful grower is 

 directed toward relieving his plants from unnecessary competition and 

 struggle for a nutrient supply. 



Few general questions pertaining to fruit growing have been less 

 thoroughly understood than soil productivity as it relates to tree growth. 

 This condition has existed mainly because of the assumption by analogy 

 that the requirements of trees, vines or other fruit producing plants are 

 practically identical with those of annual crops and because until very 

 recently experimental evidence upon which to base reliable interpre- 

 tations and Conclusions has been lacking. Trees, shrubs and vines have 

 life histories, even seasonal life histories, quite different from those of 

 annuals. It is to be expected, therefore, that they possess quite different 

 nutrient requirements or at least, quite different feeding habits. These 

 nutrient requirements and feeding habits must be studied thoroughly 

 before there can be a proper appreciation of the orchard soil productivity 

 problem. 



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