﻿THE 
  GRAPE-BERKY 
  MOTH. 
  

  

  57 
  

  

  The 
  results 
  of 
  the 
  spraying 
  operations 
  for 
  this 
  season 
  are 
  quite 
  

   indefinite 
  and 
  serve 
  only 
  to 
  bring 
  out 
  the 
  great 
  irregularity 
  in 
  infesta- 
  

   tion, 
  its 
  progress 
  throughout 
  the 
  season, 
  and 
  the 
  difficulty 
  in 
  laying 
  

   out 
  a 
  plat 
  arrangement 
  which 
  will 
  show 
  accurately 
  the 
  effect 
  of 
  spray 
  

   treatment 
  against 
  this 
  pest. 
  That 
  some 
  benefit 
  did 
  result 
  from 
  the 
  

   spray 
  application 
  is 
  indicated 
  by 
  the 
  fact 
  that 
  in 
  a 
  comparison 
  of 
  

   infestation 
  in 
  Plats 
  V, 
  VI, 
  and 
  VII, 
  where 
  the 
  infestation 
  was 
  lighter 
  

   but 
  more 
  uniform 
  than 
  on 
  the 
  opposite 
  side 
  of 
  the 
  vineyard, 
  there 
  was 
  

   throughout 
  the 
  season 
  a 
  greater 
  infestation 
  on 
  the 
  unsprayed 
  plat 
  

   than 
  on 
  the 
  two 
  adjacent 
  sprayed 
  plats. 
  There 
  was 
  not 
  sufficient 
  

   difference 
  in 
  the 
  weight 
  of 
  fruit 
  from 
  the 
  different 
  plats 
  to 
  indicate 
  a 
  

   commercial 
  value 
  resulting 
  from 
  the 
  use 
  of 
  arsenate 
  of 
  lead 
  as 
  against 
  

   arsenite 
  of 
  lime. 
  

  

  VINEYARD 
  EXPERIMENTS 
  WITH 
  POISON 
  SPRAYS 
  IN 
  1908. 
  

  

  The 
  spray 
  work 
  for 
  1908 
  was 
  conducted 
  in 
  the 
  same 
  vineyard 
  as 
  in 
  

   1907. 
  The 
  plat 
  arrangement, 
  however, 
  was 
  changed. 
  The 
  number 
  

  

  Fig. 
  21.— 
  Plat 
  arrangement 
  of 
  poison-spraying 
  experiments 
  against 
  the 
  grape-berry 
  moth 
  in 
  the 
  vineyard 
  

   of 
  Mr. 
  W. 
  S. 
  Wheeler, 
  North 
  East, 
  Pa., 
  1908 
  and 
  1909. 
  (Original.) 
  

  

  of 
  plats 
  was 
  reduced 
  to 
  four. 
  Plat 
  I 
  consisted 
  of 
  5 
  rows, 
  Plat 
  II 
  of 
  

   12 
  rows, 
  Plat 
  III 
  of 
  13 
  rows, 
  and 
  Plat 
  IV 
  of 
  5 
  rows. 
  The 
  position 
  of 
  

   the 
  check 
  or 
  unsprayed 
  plat 
  was 
  also 
  changed. 
  Checks 
  were 
  left 
  in 
  

   two 
  places. 
  In 
  the 
  west 
  section 
  10 
  vines 
  were 
  left 
  unsprayed 
  on 
  the 
  

   east 
  end 
  of 
  all 
  the 
  rows 
  of 
  the 
  four 
  plats; 
  in 
  the 
  east 
  section 
  15 
  vines 
  

   were 
  left 
  unsprayed 
  on 
  the 
  east 
  end 
  of 
  all 
  of 
  the 
  rows 
  of 
  the 
  four 
  plats. 
  

   (See 
  plan 
  of 
  plat 
  arrangement, 
  fig. 
  21.) 
  The 
  dotted 
  line 
  running 
  

   across 
  the 
  plats 
  near 
  the 
  east 
  end 
  of 
  both 
  sections 
  indicates 
  the 
  loca- 
  

   tion 
  of 
  the 
  unsprayed 
  check 
  vines; 
  these 
  portions 
  thus 
  separated 
  are 
  

   numbered 
  Plat 
  Va 
  and 
  Plat 
  V6, 
  respectively. 
  

  

  This 
  rearrangement 
  of 
  plats 
  was 
  adopted 
  in 
  the 
  hope 
  that 
  the 
  

   infestation 
  of 
  the 
  vines 
  in 
  these 
  locations 
  would 
  more 
  nearly 
  represent 
  

   that 
  existing 
  on 
  the 
  sprayed 
  vines. 
  

  

  Arsenite 
  of 
  lime 
  was 
  eliminated 
  from 
  the 
  spray 
  formulas 
  used, 
  on 
  

   account 
  of 
  slight 
  injury 
  to 
  foliage. 
  The 
  spray 
  formula 
  on 
  all 
  four 
  

   plats 
  was 
  the 
  same. 
  (See 
  'Table 
  XXIV.) 
  

  

  