Fireblight infection conditions - MaryBlyt model logic

Background Information for this page
Return to radar list for Middletown RI
Weather data for Middletown RI.  Forecast values begin August 3, 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 Monday, June 23
   If fire blight blossom infection occurred on June 15, then blossom blight would be noticeable by June 25, and shoot blight by July 1.
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 7 
  0.'',  0 hrs.,  7 DH,  60F No FB infection
Thu, May 8    0.18'',  16 hrs.,  7 DH,  59F No FB infection
Fri, May 9    0.51'',  16 hrs.,  5 DH,  51F No FB infection
Sat, May 10    0.'',  8 hrs.,  4 DH,  51F No FB infection
Sun, May 11    0.'',  0 hrs.,  0 DH,  51F No FB infection
Mon, May 12    0.'',  0 hrs.,  0 DH,  48F No FB infection
Tue, May 13    0.'',  0 hrs.,  1 DH,  55F No FB infection
Wed, May 14    0.'',  0 hrs.,  1 DH,  54F No FB infection
Thu, May 15    0.'',  0 hrs.,  1 DH,  54F No FB infection
Fri, May 16    0.35'',  10 hrs.,  1 DH,  54F No FB infection
Sat, May 17    0.57'',  11 hrs.,  32 DH,  58F No FB infection
Sun, May 18    0.01'',  7 hrs.,  33 DH,  58F No FB infection
Mon, May 19    0.'',  7 hrs.,  21 DH,  54F No FB infection
Tue, May 20    0.39'',  9 hrs.,  16 DH,  51F No FB infection
Wed, May 21    0.'',  10 hrs.,  0 DH,  54F No FB infection
Thu, May 22    0.03'',  9 hrs.,  0 DH,  52F No FB infection
Fri, May 23    0.'',  6 hrs.,  22 DH,  59F No FB infection
Sat, May 24    0.'',  0 hrs.,  34 DH,  59F No FB infection
Sun, May 25    0.'',  0 hrs.,  74 DH,  60F No FB infection
Mon, May 26    0.'',  0 hrs.,  74 DH,  59F No FB infection
Tue, May 27    0.14'',  16 hrs.,  76 DH,  60F No FB infection
Wed, May 28    0.'',  3 hrs.,  54 DH,  56F No FB infection
Thu, May 29    0.'',  0 hrs.,  48 DH,  59F No FB infection
Fri, May 30    0.'',  0 hrs.,  52 DH,  63F No FB infection
Sat, May 31    0.12'',  16 hrs.,  35 DH,  60F No FB infection
Sun, June 1    0.'',  13 hrs.,  98 DH,  65F No FB infection
Mon, June 2    0.'',  0 hrs.,  186 DH,  67F No FB infection
Tue, June 3    0.'',  0 hrs.,  250 DH,  66F No FB infection
Wed, June 4    0.54'',  19 hrs.,  168 DH,  60F No FB infection
Thu, June 5    0.'',  16 hrs.,  125 DH,  58F No FB infection
Fri, June 6    0.19'',  21 hrs.,  0 DH,  56F No FB infection
Sat, June 7    0.'',  12 hrs.,  124 DH,  67F No FB infection
Sun, June 8    0.'',  0 hrs.,  435 DH,  78F No FB infection
Mon, June 9    0.'',  0 hrs.,  830 DH,  82F No FB infection
Tue, June 10    0.'',  0 hrs.,  996 DH,  77F No FB infection
Wed, June 11    0.'',  0 hrs.,  968 DH,  77F No FB infection
Thu, June 12    0.'',  0 hrs.,  723 DH,  71F No FB infection
Fri, June 13    0.'',  0 hrs.,  505 DH,  66F No FB infection
Sat, June 14    0.'',  1 hrs.,  328 DH,  68F No FB infection
Sun, June 15    0.39'',  24 hrs.,  220 DH,  61F INFECTION RISK
Mon, June 16    0.75'',  10 hrs.,  179 DH,  61F No FB infection
Tue, June 17    0.04'',  11 hrs.,  174 DH,  66F No FB infection