CONTENTS 



CHAPTER I 



CLASSIFICATION, ORIGIN, AND DISTRIBUTION OF FIELD CROPS 1 



Early Culture of Plants Number of Cultivated Plants Classifica- 

 tion by Use Important Botanical Groups The Most Important 

 Crops Factors Affecting the Culture of Crops. 



CHAPTER II 



How PLANTS GROW 5 



The Parts of a Plant The General Functions Elements Required 

 for Growth Plant Food Sources Relative Composition of Plants 

 How Roots and Leaves Perform Their Functions The Root System 

 Root-hairs Osmosis Evaporation of Plant Water Leaves and 

 Their Functions Leaf Structure Assimilation Distribution of 

 Manufactured Products. 



CHAPTER III 



THE PRODUCTION OF SEEDS 13 



Function and Use of Seeds Nature of Seeds Preserving the Vital- 

 ity of Seeds Good Seeds How Germination Takes Place When 

 Seeds Sprout Large and Small Seeds Shrunken Seeds Structure 

 of Seeds. 



CHAPTER IV 



COMPARATIVE STUDY OF CEREALS 21 



Germination -Temporary and Permanent Roots Tillers Tlie 

 Stems of Cereals The Ear or Head The Spikelet The Flower 

 Fertilization Cross- and Self-Fertilization Formation of the Seed 

 Composition of the Seed Composition of Cereals Composition 

 of Hard and Soft Grain Effect of Climate on Composition Moisture 

 in Grain. 



CHAPTER V 



CROPPING SYSTEMS 31 



Productiveness How Rock Minerals Become Soluble Nitrogen 

 Its Fixation by Legumes Importance of Organic Matter Effects 

 of Cropping Single Cropping System Alternating Crops Rota- 

 tion Farming What Rotation Does Rotations Do Not Keep Up 

 Mineral Supply Some Results with Rotation Applying Fertilizers 

 Amount Applied Lime Manure Care of Manure. 



CHAPTER VI 



CORN 41 



Where Corn is Produced The Corn Belt The Origin of Corn 

 Classification of Corn Pop-corn Flint Corn Dent Corn Soft 

 Corn Sweet Corn Number of Varieties Growth and Develop- 

 ment of Parts Fertilization Hybridizing. 



CHAPTER VII 



CLIMATE AND SOIL REQUIRED FOR CORN 55 



Effect of Climate Sunshine Soils for Corn Length of Growing 

 Season Rainfall Importance of Adaptation. 



vii 



