PLANT PHYSIOLOGY 



CHAPTER I 

 INTRODUCTION 



THE relation of plant physiology to crop production and 

 vegetation requires no explanation except where physiology 

 and plant production are alike incompletely comprehended. 

 No one may thoroughly understand a modern agricultural 

 problem who has not learned the full significance and 

 scientific relations of the two eminently practical terms 

 "production" and "conservation." The basal field of 

 agriculture is plant production, for upon this animal pro- 

 duction is dependent ; and throughout all agriculture con- 

 servation is necessarily the key to continuous development 

 and success. 



Conservation in the broadest sense implies neither 

 waste of the product grown nor waste of the forces and 

 conditions which make high production possible. These 

 forces are the environment under which the crop is grown 

 and the inherent hereditary possibilities within the seed 

 or seed-material. 



1. Permanent high production. Plants form the nat- 

 ural covering of the surface of the earth, and if there is 

 at present no such covering, where the rock is sufficiently 

 B 1 



