﻿4 
  DECIDUOUS 
  FRUIT 
  INSECTS 
  AND 
  INSECTICIDES. 
  

  

  the 
  vines 
  had 
  each 
  season 
  made 
  a 
  weaker 
  growth 
  as 
  a 
  result 
  of 
  injury 
  

   by 
  this 
  pest, 
  and 
  the 
  yield 
  of 
  fruit 
  also 
  was 
  being 
  greatly 
  reduced. 
  

  

  During 
  the 
  season 
  of 
  1910 
  several 
  acres 
  on 
  the 
  east 
  side 
  of 
  this 
  

   vineyard 
  were 
  sprayed 
  with 
  tobacco 
  extract 
  No. 
  I. 
  This 
  treatment 
  

   resulted 
  in 
  preventing 
  serious 
  injury 
  by 
  the 
  insect. 
  The 
  foliage 
  re- 
  

   mained 
  green 
  and 
  healthy 
  throughout 
  the 
  season. 
  There 
  was 
  a 
  

   greatly 
  increased 
  growth 
  of 
  vine 
  and 
  a 
  higher 
  quality 
  of 
  fruit 
  was 
  

   secured. 
  The 
  greatest 
  apparent 
  benefit 
  in 
  1910 
  was 
  in 
  the 
  great 
  

   increase 
  in 
  growth 
  of 
  vine. 
  

  

  During 
  the 
  season 
  of 
  1911 
  the 
  entire 
  vineyard 
  of 
  25 
  acres 
  was 
  

   sprayed 
  against 
  this 
  pest, 
  which 
  was 
  present 
  in 
  fully 
  as 
  large 
  num- 
  

   bers 
  as 
  in 
  1910. 
  

  

  A 
  tractor 
  sprayer 
  was 
  used 
  in 
  making 
  the 
  application. 
  (See 
  PI. 
  I, 
  

   fig. 
  1.) 
  A 
  pressure 
  of 
  100 
  to 
  140 
  pounds 
  was 
  maintained 
  and 
  about 
  

   175 
  gallons 
  of 
  liquid 
  were 
  applied 
  per 
  acre. 
  The 
  application 
  was 
  

   made 
  by 
  the 
  owner 
  of 
  the 
  vineyard, 
  Mr. 
  H. 
  H. 
  Harper. 
  The 
  spray 
  

   was 
  applied 
  by 
  the 
  " 
  trailer" 
  method 
  (see 
  PL 
  I, 
  fig. 
  1), 
  using 
  a 
  single 
  

   large 
  cyclone 
  nozzle. 
  The 
  work 
  was 
  done 
  very 
  carefully 
  and 
  thor- 
  

   oughly. 
  Stops 
  were 
  made 
  at 
  each 
  vine. 
  The 
  pressure 
  was 
  main- 
  

   tained 
  by 
  driving 
  forward 
  the 
  length 
  of 
  the 
  trailer 
  hose. 
  By 
  having 
  

   a 
  20-gallon 
  air-chamber 
  on 
  the 
  tractor 
  sprayer 
  a 
  pressure 
  varying 
  

   from 
  100 
  to 
  140 
  pounds 
  was 
  secured, 
  rarely 
  dropping 
  below 
  the 
  100- 
  

   pound 
  mark. 
  Under 
  favorable 
  working 
  conditions 
  about 
  3 
  acres 
  

   could 
  be 
  covered 
  per 
  day. 
  The 
  tobacco 
  extract 
  No. 
  I 
  was 
  applied 
  

   at 
  a 
  dilution 
  of 
  3 
  quarts 
  to 
  100 
  gallons 
  of 
  water. 
  The 
  application 
  was 
  

   made, 
  on 
  the 
  3 
  acres 
  from 
  which 
  our 
  record 
  of 
  yield 
  was 
  secured, 
  on 
  

   July 
  6 
  and 
  7, 
  when 
  the 
  majority 
  of 
  the 
  nymphs 
  were 
  small 
  but 
  very 
  

   numerous. 
  The 
  application 
  was 
  very 
  effective, 
  and 
  on 
  account 
  of 
  

   the 
  thoroughness 
  with 
  which 
  the 
  work 
  was 
  done 
  only 
  a 
  very 
  small 
  

   percentage 
  of 
  nymphs 
  escaped 
  being 
  killed 
  by 
  the 
  spray. 
  

  

  As 
  a 
  result 
  of 
  this 
  treatment 
  the 
  foliage 
  of 
  the 
  vines 
  remained 
  green 
  

   throughout 
  the 
  entire 
  season, 
  and 
  the 
  vines 
  made 
  a 
  very 
  heavy 
  

   growth 
  of 
  new 
  canes. 
  The 
  berries 
  and 
  clusters 
  of 
  fruit 
  were 
  large 
  

   and 
  of 
  good 
  quality. 
  A 
  record 
  has 
  been 
  kept 
  of 
  the 
  yield 
  for 
  the 
  past 
  

   three 
  years 
  on 
  3 
  acres 
  of 
  this 
  vineyard 
  where 
  the 
  injury 
  by 
  this 
  

   insect 
  was 
  most 
  apparent 
  at 
  the 
  beginning 
  of 
  the 
  experiment. 
  No 
  

   attempt 
  to 
  control 
  this 
  pest 
  on 
  these 
  vines 
  was 
  made 
  previous 
  to 
  1910. 
  

  

  1909 
  Yield 
  of 
  fruit 
  was 
  262 
  8-pound 
  baskets 
  of 
  grapes 
  per 
  acre. 
  

  

  1910 
  Yield 
  of 
  fruit 
  was 
  423 
  8-pound 
  baskets 
  of 
  grapes 
  per 
  acre. 
  

  

  1911 
  Yield 
  of 
  fruit 
  was 
  796 
  8-pound 
  baskets 
  of 
  grapes 
  per 
  acre. 
  

  

  These 
  results 
  show 
  an 
  increase 
  in 
  yield 
  on 
  the 
  first 
  season's 
  treat- 
  

   ment 
  of 
  161 
  baskets 
  per 
  acre, 
  and 
  for 
  the 
  second 
  season's 
  treatment 
  

   an 
  increase 
  of 
  534 
  baskets 
  per 
  acre 
  over 
  the 
  yield 
  of 
  1909. 
  

  

  Since 
  the 
  price 
  received 
  per 
  basket 
  of 
  grapes 
  varies 
  each 
  season, 
  it 
  

   is 
  difficult 
  to 
  compare 
  cash 
  returns 
  one 
  season 
  with 
  another. 
  Prices 
  

  

  