Report  on  Wheat-Mildew. 
G47 
mentions  1867  and  1877—1881  as  years  of  serious  injury  in  Here- 
fordshire. A.  Young  instances  1780, 1781,  1782,  as  years  of  fatal 
mildew  in  Suffolk.  And  in  1804  the  visitation  was  so  remark- 
able as  to  induce  him  to  issue  the  circular  to  which  I have 
referred.  Sir  Joseph  Banks*  mentions  1797  and  1800  as  years 
of  blight.  During  the  last  45  years  the  following  seem  to  have 
been  those  of  mildew  more  or  less  : — 
1840 
1841  ..  .. 
1845 
1839 
1848  1849 
1850 
..  ..  1852 
1853  !! 
1855 
1859 
1800 

....  ,.  ,, 
1865 

• • • • 
1871  ..  .. 
....  .... 
1875 
..  ..  1877  ..  !.  1879 
1880  1881 
It  would  almost 
seem  from 
these 
notices  that  there  is 
tendency  towards  a repetition  of  the  mildew  year  after  year 
until  the  disease  has  spent  its  force — this  tendency  being 
arrested  by  exceptionally  fine  and  favourable  seasons ; and  this 
would  well  agree  with  Mr.  Plowright’s  theory  of  reproduction  of 
Uredo  without  the  aid  of  the  barberry-tree.  But  probably  a closer 
examination  of  the  meteorological  phenomena  of  the  years  in 
question  than  I am  able  to  give,  might  afford  some  clue  to  the 
solution  of  the  problem.  I shall  have  some  further  remarks  to 
make  on  this  point  under  heading  V. 
III.  Conditions  under  which  Mildew  is  developed  to  a great  or 
injurious  degree. — This  heading  really  includes  all  those  which 
follow,  and  must  be  considered  hereafter. 
V.  Climate. — Upon  this  point  the  only  replies  which  I have 
received  refer  to  spring  frosts,  heavy  rain-fall,  and  violent 
changes  of  temperature,  as  encouraging  mildew.  Young’s  cor- 
respondents appear  to  have  attached  great  importance  to  spring 
frosts  ; and  certainly  in  the  Fen  country  popular  opinion  supports 
the  view  that  crops  which  are  cut  by  late  frosts  are  much  more 
susceptible  of  mildew  than  those  which  have,  from  some  cause 
or  other,  withstood  these  frosts.  I remember  that  in  1865  some 
fields  in  my  own  neighbourhood  which  were  cut  down  to  the 
ground  by  a frost  which  occurred  about  the  1st  of  May,  were 
those  which  suffered  most  from  mildew.  Although  the  quantity 
of  rainfall  must  be  considered  an  important  feature  in  the  problem, 
it  does  not  seem  that  the  prevalence  of  mildew  is  consequent 
on  excessive  rainfall  so  much  as  on  rain  after  hot  weather.  In 
1850  I remember  my  father’s  foreman  attributing  the  mildew  to 
hot  rains,  which  he  said  “ scalded  the  wheat.”  In  1852  we  had 
very  hot  weather,  and  frequent  thunder-storms  with  heavy 
showers.  1860  and  1879  were  wet  and  cold  years,  and  mildew 
* ‘ Annals  of  Agriculture,’  vol.  xliii. 
