Fireblight infection conditions - MaryBlyt model logic

Background Information for this page
Return to radar list for Sanford ME
Weather data for Sanford ME.  Forecast values begin October 17, 2008
Shoots near overwintered fireblight cankers would start showing obvious symptoms around  Saturday, June 14
 If canker blight infection spreads to other shoots,
symptoms on those shoots would become obvious around Thursday, June 26
   If fire blight blossom infection occurred on June 21, then blossom blight would be noticeable by June 30, and shoot blight by July 7.
Range of potential
open-blossom dates
Gray box indicates dates when most trees will have lost open blossoms and susceptibility to blossom infection, but late blooming cultivars or young trees may still be susceptible.
Inches Rain,
Leaf Wet Hours,
DH65 heat units, &
Avg. Temperature
Daily fireblight risk rating
as per Maryblyt model criteria
by Dr. Paul Steiner and Gary Lightner. 

In absence of rain, 3 or more hours of leaf wetness counted as possible dew conditions for adequate wetting, which may overstate risk on such days.
Infection requirements:
Any rain, or >0.1 inch rain on previous day,
+ 198 cumulative degree hours > 65F,
+ Average temp. on wetting day >= 60F
Mac King Bloom
Wed, May 14 
  0.'',  0 hrs.,  6 DH,  55F No FB infection
Thu, May 15    0.'',  0 hrs.,  6 DH,  56F No FB infection
Fri, May 16    0.04'',  4 hrs.,  4 DH,  55F No FB infection
Sat, May 17    0.12'',  10 hrs.,  16 DH,  58F No FB infection
Sun, May 18    0.'',  0 hrs.,  17 DH,  57F No FB infection
Mon, May 19    0.'',  0 hrs.,  11 DH,  50F No FB infection
Tue, May 20    0.'',  0 hrs.,  11 DH,  54F No FB infection
Wed, May 21    0.'',  0 hrs.,  11 DH,  55F No FB infection
Thu, May 22    0.'',  0 hrs.,  8 DH,  51F No FB infection
Fri, May 23    0.02'',  4 hrs.,  1 DH,  55F No FB infection
Sat, May 24    0.'',  0 hrs.,  0 DH,  56F No FB infection
Sun, May 25    0.'',  0 hrs.,  22 DH,  59F No FB infection
Mon, May 26    0.'',  0 hrs.,  136 DH,  66F No FB infection
Tue, May 27    0.'',  0 hrs.,  233 DH,  67F No FB infection
Wed, May 28    0.'',  0 hrs.,  233 DH,  54F No FB infection
Thu, May 29    0.'',  0 hrs.,  273 DH,  59F No FB infection
Fri, May 30    0.'',  0 hrs.,  283 DH,  60F No FB infection
Sat, May 31    0.45'',  19 hrs.,  171 DH,  60F No FB infection
Sun, June 1    0.'',  11 hrs.,  146 DH,  65F No FB infection
Mon, June 2    0.'',  0 hrs.,  127 DH,  63F No FB infection
Tue, June 3    0.04'',  3 hrs.,  193 DH,  64F No FB infection
Wed, June 4    0.31'',  20 hrs.,  128 DH,  57F No FB infection
Thu, June 5    0.01'',  24 hrs.,  96 DH,  58F No FB infection
Fri, June 6    0.49'',  24 hrs.,  0 DH,  56F No FB infection
Sat, June 7    0.'',  12 hrs.,  183 DH,  70F No FB infection
Sun, June 8    0.'',  0 hrs.,  480 DH,  77F No FB infection
Mon, June 9    0.'',  0 hrs.,  756 DH,  77F No FB infection
Tue, June 10    0.31'',  14 hrs.,  835 DH,  76F SEVERE INFECTION RISK
Wed, June 11    0.36'',  9 hrs.,  699 DH,  72F SEVERE INFECTION RISK
Thu, June 12    0.'',  0 hrs.,  505 DH,  66F SEVERE INFECTION RISK
Fri, June 13    0.'',  0 hrs.,  377 DH,  66F No FB infection
Sat, June 14    0.41'',  4 hrs.,  452 DH,  66F SEVERE INFECTION RISK
Sun, June 15    1.09'',  24 hrs.,  195 DH,  58F No FB infection
Mon, June 16    0.51'',  24 hrs.,  195 DH,  61F No FB infection
Tue, June 17    0.73'',  21 hrs.,  111 DH,  63F No FB infection
Wed, June 18    0.'',  9 hrs.,  71 DH,  63F No FB infection
Thu, June 19    0.'',  0 hrs.,  117 DH,  64F No FB infection
Fri, June 20    0.27'',  15 hrs.,  150 DH,  62F No FB infection
Sat, June 21    0.21'',  21 hrs.,  199 DH,  66F INFECTION RISK
Sun, June 22    0.66'',  21 hrs.,  212 DH,  65F INFECTION RISK
Mon, June 23    0.49'',  24 hrs.,  211 DH,  66F INFECTION RISK
Tue, June 24    0.22'',  21 hrs.,  246 DH,  66F INFECTION RISK