CONTENTS 
PAGE 
Summary *> 
Introduction 15 
Economic considerations 16 
Technique of the field plat yield determinations 17 
Adaptation 19 
Variety significance 23 
Home grown versus imported seed corn 27 
Broad fertilization in corn the rule — 
Relation of silking and pollination ' 29 
Amount of self-fertilization occurring normally in a cornfield. ... 36 
Effect upon seed value of preventing the normal amount of self- 
fertilization occurring in a field of corn 37 
Elemental strains in corn and their hybridization — 
Significance of elemental strains 39 
Production of elemental strains 43 
Technique of artificial pollination 43 
Life of pollen 45 
Life of silks 47 
Hogue’s Yellow Dent (Class IX) pure lines and hybrids — 
Pure lines 48 
Hybrids 50 
A comparison of first, second, and third generation pure line 
hybrids 55 
Hogue’s Yellow Dent “leaf area” pure lines and hybrids-^ 
Original stock 59 
Inbred strains 61 
Hybrids between leaf area pure lines 61 
Relation between vigor of pure line parents and productivity of 
first generation hybrids 65 
Rate of growth of first generation hybrids between pure lines. . 67 
Degrees of inbreeding 69 
Degrees of inbreeding, Hogue’s Yellow Dent corn 70 
Degrees of inbreeding, Nebraska White Prize corn 71 
Crossing varieties 74 
Results with first generation variety hybrids 75 
First, second, and third generations of variety hybrids compared 78 
Immediate effect of foreign pollen on kernel weight 80 
Methods of determination 81 
Results with varieties 83 
Results with pure lines and varieties compared 85 
Relative effects of foreign pollen upon embryo and endosperm 
weights of inbred corn 91 
Histological effects of inbreeding 96 
Ear-to-row breeding — 
Tests with Hogue’s Yellow Dent corn 102 
Results from the various methods of ear-to-row breeding with 
Hogue’s Yellow Dent corn. 105 
Ear-to-row breeding of Nebraska White Prize corn 108. 
