﻿37 
  

   RECENT 
  WORK 
  ON 
  THE 
  CHESTNUT 
  BLIGHT 
  

  

  Keller 
  E. 
  Rockey 
  

  

  Forester 
  in 
  charge 
  of 
  Demonstration 
  Work, 
  Pennsylvania 
  Chest- 
  

   nut 
  Tree 
  Blight 
  Commission 
  

  

  The 
  history 
  of 
  the 
  blight, 
  briefly 
  outlined, 
  is 
  as 
  follows: 
  

  

  In 
  1904 
  the 
  diseased 
  condition 
  of 
  the 
  chestnut 
  trees 
  around 
  

   New 
  York 
  City 
  was 
  noted 
  and 
  an 
  examination 
  of 
  them 
  showed 
  

   that 
  they 
  were 
  being 
  attacked 
  by 
  a 
  disease 
  at 
  that 
  time 
  un- 
  

   known. 
  Investigations 
  since 
  then 
  have 
  shown 
  that 
  the 
  blight 
  

   had 
  been 
  at 
  work 
  there 
  and 
  elsewhere 
  for 
  a 
  number 
  of 
  years 
  

   before 
  that 
  time, 
  but 
  it 
  has 
  been 
  impossible 
  to 
  determine 
  just 
  

   when 
  it 
  first 
  appeared 
  or 
  where. 
  The 
  disease 
  was 
  studied 
  and 
  

   described 
  at 
  that 
  time. 
  

  

  On 
  display 
  here 
  are 
  specimens 
  and 
  photographs 
  showing 
  the 
  

   appearance 
  of 
  the 
  blight 
  so 
  that 
  I 
  will 
  not 
  go 
  into 
  that 
  part 
  of 
  

   the 
  subject 
  in 
  detail. 
  I 
  hope 
  that 
  you 
  will 
  notice, 
  however, 
  the 
  

   symptoms 
  by 
  which 
  the 
  disease 
  is 
  recognized: 
  1st. 
  The 
  small 
  

   red 
  pustules 
  which 
  produce 
  the 
  spores 
  and, 
  on 
  rough 
  barked 
  

   trees, 
  appear 
  only 
  in 
  the 
  crevices. 
  2nd. 
  The 
  peculiar 
  mottled 
  

   appearance 
  of 
  the 
  inner 
  bark 
  of 
  the 
  canker. 
  3rd. 
  The 
  discolor- 
  

   ation 
  of 
  the 
  outer 
  bark. 
  4th. 
  The 
  danger 
  signals, 
  such 
  as 
  

   withered 
  leaves 
  in 
  summer 
  or 
  persistent 
  leaves 
  or 
  burrs 
  in 
  win- 
  

   ter, 
  suckers 
  which 
  develop 
  at 
  the 
  base 
  of 
  cankers, 
  and 
  the 
  yel- 
  

   lowish 
  cracks 
  which 
  soon 
  appear 
  in 
  the 
  bark 
  over 
  the 
  cankers. 
  

  

  Workers 
  in 
  the 
  Bureau 
  of 
  Plant 
  Industry, 
  Washington, 
  D. 
  C, 
  

   have 
  been 
  studying 
  the 
  blight 
  since 
  1908. 
  In 
  the 
  Spring 
  of 
  1911, 
  

   a 
  bill 
  creating 
  the 
  commission 
  for 
  the 
  investigation 
  and 
  control 
  

   of 
  the 
  blight 
  in 
  Pennsylvania 
  was 
  passed, 
  and 
  the 
  active 
  work 
  

   began 
  in 
  August 
  1911. 
  The 
  method 
  upon 
  which 
  the 
  Commission 
  

   is 
  working 
  is 
  outlined 
  in 
  Farmers' 
  Bulletin 
  No. 
  467, 
  of 
  the 
  De- 
  

   partment 
  of 
  Agriculture, 
  and 
  consists 
  briefly 
  of 
  determining 
  

   the 
  area 
  of 
  blight 
  infection 
  and 
  in 
  removing 
  diseased 
  trees 
  west 
  

   of 
  a 
  certain 
  line, 
  with 
  the 
  purpose 
  of 
  preventing 
  the 
  western 
  

   spread 
  of 
  the 
  blight. 
  

  

  This 
  Commission 
  has 
  ascertained 
  as 
  accurately 
  as 
  possible 
  

   the 
  amount 
  of 
  infection 
  in 
  the 
  various 
  parts 
  of 
  the 
  state 
  and 
  the 
  

   results 
  are 
  given 
  in 
  a 
  map 
  on 
  display 
  here. 
  The 
  state 
  is 
  divided 
  

   into 
  two 
  districts 
  by 
  a 
  line 
  drawn 
  along 
  the 
  western 
  edge 
  of 
  

   Susquehanna, 
  Wyoming, 
  Columbia, 
  Union, 
  Snyder, 
  Juniata 
  

   and 
  Franklin 
  Counties, 
  which 
  is 
  approximately 
  the 
  western 
  line 
  

  

  