CONTENTS xv 



PAGE 



Sorghum ......./..; 178 



Origin . * . . .-'..* 178 



Classification and inheritance 178 



Some results of selection 179 



Methods of breeding sorghum . 179 



CHAPTER XIV 

 MAIZE BREEDING 



Origin and species 181 



Inheritance of characters 183 



Endosperm characters 183 



Plant characters 187 



Colors in plant organs 187 



Podded condition 189 



Auricle and ligule 189 



Chlorophyll inheritance 190 



Some seed and ear characters 192 



Size characters 192 



Chemica composition 193 



Corn improvement by the trained plant breeder 196 



Relation of ear characters to yield 197 



Ear-to-row breeding 198 



Home-grown seed 199 



Relation between heterozygosis and vigor 200 



Immediate effect of crdssing on size of seed 201 



FI varietal crosses 202 



Isolation of homozygous strains . 205 



CHAPTER XV 

 GRASSES, CLOVER AND ALFALFA 



Grasses 207 



Breeding timothy . 210 



Clovers 214 



Red clover 214 



Selection for disease resistant clover 215 



Alfalfa 215 



Grimm alfalfa and winter hardiness . ..'..' . . .216 



CHAPTER XVI 

 POTATO IMPROVEMENT 



Origin and species . . . , ... v . . 219 



Inheritance ...".... 221 



Production of new forms . . . i . 223 



The difficulties of obtaining crossed seed 224 



Improvement through seedling production 226 



Clonal selection . . 228 



