﻿186 
  INTRODUCTION 
  TO 
  BOTANY 
  

  

  not 
  thoroughly 
  carried 
  out, 
  much 
  self-pollination 
  and 
  self- 
  

   fertilization 
  is 
  sure 
  to 
  occur. 
  Corn 
  which 
  is 
  sclf-i'ertili/ed 
  

   produces 
  smaller 
  and 
  less 
  vigorous 
  plants 
  tlu- 
  next 
  season 
  

   than 
  cross-fertilized 
  corn 
  (fig. 
  159). 
  Detasseling 
  has 
  there- 
  

   fore 
  been 
  found 
  to 
  increase 
  the 
  yield 
  of 
  corn 
  more 
  than 
  ten 
  

   bushels 
  pci 
  1 
  acre. 
  1 
  

  

  175. 
  Williams' 
  s 
  method. 
  The 
  method 
  of 
  corn 
  breeding 
  as 
  

   above 
  outlined 
  has 
  been 
  criticized 
  on 
  the 
  ground 
  that 
  little 
  or 
  

   no 
  attention 
  is 
  paid 
  to 
  the 
  productiveness 
  of 
  the 
  plant 
  used 
  

   as 
  the 
  source 
  of 
  pollen. 
  A 
  new 
  system 
  devised 
  by 
  Professor 
  

   C. 
  G. 
  Williams, 
  of 
  the 
  Ohio 
  Agricultural 
  Experiment 
  Station, 
  

   provides 
  for 
  equally 
  careful 
  selection 
  of 
  the 
  staminate 
  and 
  

   pistillate 
  parents. 
  The 
  sj^stem 
  in 
  its 
  barest 
  outlines, 
  as 
  stated 
  

   by 
  Professor 
  Williams, 
  provides 
  for 
  

  

  1. 
  The 
  usual 
  ear-row 
  test. 
  Only 
  a 
  portion 
  (usually 
  about 
  one 
  half) 
  

   of 
  each 
  ear 
  is 
  planted. 
  The 
  remnant 
  is 
  carefully 
  saved, 
  and 
  when 
  the 
  

   ear-row 
  test 
  has 
  shown 
  which 
  ears 
  are 
  superior, 
  recourse 
  is 
  had 
  to 
  the 
  

   remnants 
  to 
  perpetuate 
  these 
  ears 
  in 
  a 
  later 
  season. 
  

  

  2. 
  An 
  isolated 
  breeding 
  plot 
  in 
  which 
  are 
  planted 
  the 
  four 
  or 
  five 
  

   best 
  ears 
  as 
  demonstrated 
  by 
  1. 
  J\'o( 
  tlie 
  prot/eny 
  of 
  the 
  best 
  ears, 
  but 
  

   the 
  original 
  ears. 
  Usually 
  the 
  best 
  ear 
  is 
  used 
  for 
  staminate 
  plants 
  and 
  

  

  planted 
  on 
  each 
  alternate 
  row 
  in 
  the 
  small 
  br 
  ling 
  plot. 
  All 
  the 
  plants 
  

  

  from 
  the 
  other 
  ears 
  going 
  into 
  the 
  plot, 
  are 
  detasseled. 
  

  

  The 
  pedigreed 
  strains 
  produced 
  in 
  the 
  breeding 
  plot 
  are 
  multiplied 
  

   for 
  general 
  field 
  use 
  and 
  also 
  furnish 
  ears 
  of 
  varying 
  worth 
  for 
  a 
  second 
  

   ear-row 
  test, 
  if 
  it 
  is 
  desired 
  to 
  continue 
  the 
  improvement. 
  

  

  The 
  ear-row 
  test 
  need 
  not 
  be 
  isolated, 
  for 
  no 
  seed 
  is 
  taken 
  from 
  it. 
  

   Neither 
  is 
  there 
  any 
  need 
  for 
  detasseling 
  until 
  the 
  breeding 
  plot 
  is 
  

   reached. 
  

  

  176. 
  Hybridizing. 
  As 
  has 
  already 
  been 
  shown 
  (sects. 
  13 
  

   and 
  127), 
  seed 
  production 
  is 
  the 
  result 
  of 
  fertilization 
  of 
  the 
  

   egg 
  within 
  an 
  ovule 
  by 
  a 
  pollen 
  grain. 
  Usually 
  the 
  pollen 
  

   and 
  the 
  ovule 
  concerned 
  in 
  fertilization 
  are 
  derived 
  from 
  

   plants 
  of 
  the 
  same 
  species. 
  Often 
  pollen 
  of 
  another 
  species 
  is 
  

  

  1 
  For 
  details 
  about 
  corn 
  breeding 
  see 
  De 
  Vries, 
  Plant 
  Breeding. 
  The 
  < 
  >pen 
  

   Court 
  Publishing 
  Company, 
  Chicago 
  ; 
  Bulletin 
  100, 
  Illinois 
  Agricultural 
  Ex- 
  

   periment 
  Station 
  ; 
  and 
  Circular 
  66, 
  Ohio 
  Agricultural 
  Experiment 
  Station. 
  

  

  