Fireblight infection conditions - Cougarblight model

Background Information for this page
Return to radar list for Middletown RI
Weather data for Middletown RI.  Forecast values begin August 3, 2008
     Weather-based RELATIVE daily fireblight blossom infection risk values below are according to criteria of the Cougarblight model developed in Washington state by Dr. Timothy J. Smith.     
      ABSOLUTE risk also depends on cultivar and rootstock susceptibility, and on the number of flowers open. Infection risk may be overstated for first few days of bloom because fire blight bacteria may not have been distributed to open flowers.
      Cougarblight heat units are similar to degree hours base 60 F.
   
NOTICE! - Fireblight infection can occur without rain if there is "heavy" dew.  But "heavy" dew in relation to fireblight is not defined.  As a rough guess, if there is no rain on a day, but leaf wetness is expected to exceed 3 hours for that day, then infection conditions are reported with "if dew" attached.  Infection potential may be overstated on days when the "if dew" tag is attached.
Range of
potential
open-blossom dates
Gray box indicates dates when most trees will have lost open blossoms and susceptibility to blossom infection.  Gray box dates included for late cultivars and late-blooming young trees.
Fire blight risk categories by block history
 I  = No FB in the area during last two seasons
      requires 500+ heat units for HIGH! rating, 800+ for EXTREME!

 
II = FB present in the area, but not within 1 mile of your orchard last
    year requires 400+ heat units for HIGH! rating, 650+ for EXTREME!

 
III = FB in this orchard block or neighboring orchard last year
      requires 300+ heat units for HIGH! rating, 500+ for EXTREME!

 
IV = Active FB strikes or cankers present in this or neighboring block
      requires 200+ heat units for HIGH! rating, 350+ for EXTREME!
 
Inches Rain &
Leaf Wet Hours &
Heat Units
No FB in area for last two years
I
FB in area
last year,
but over 1 mile away
II
FB last year within 1 mile
III
Currently active FB
IV
Wed, May 7    0.'',  0 hrs.,  34 HU 0 0 0 0
Thu, May 8    0.18'',  16 hrs.,  51 HU Low Low Low Low
Fri, May 9    0.51'',  16 hrs.,  51 HU Low Low Low Low
Sat, May 10    0.'',  8 hrs.,  54 HU Low Low Low Low
Sun, May 11    0.'',  0 hrs.,  21 HU 0 0 0 0
Mon, May 12    0.'',  0 hrs.,  4 HU 0 0 0 0
Tue, May 13    0.'',  0 hrs.,  23 HU 0 0 0 0
Wed, May 14    0.'',  0 hrs.,  36 HU 0 0 0 0
Thu, May 15    0.'',  0 hrs.,  35 HU 0 0 0 0
Fri, May 16    0.35'',  10 hrs.,  35 HU Low Low Low Low
Sat, May 17    0.57'',  11 hrs.,  80 HU Low Low Low Low
Sun, May 18    0.01'',  7 hrs.,  82 HU Low Low Low Low
Mon, May 19    0.'',  7 hrs.,  82 HU Low Low Low Low
Tue, May 20    0.39'',  9 hrs.,  82 HU Low Low Low Low
Wed, May 21    0.'',  10 hrs.,  21 HU Low Low Low Low
Thu, May 22    0.03'',  9 hrs.,  3 HU Low Low Low Low
Fri, May 23    0.'',  6 hrs.,  62 HU Low Low Low Low
Sat, May 24    0.'',  0 hrs.,  111 HU 0 0 0 0
Sun, May 25    0.'',  0 hrs.,  193 HU 0 0 0 0
Mon, May 26    0.'',  0 hrs.,  215 HU 0 0 0 0
Tue, May 27    0.14'',  16 hrs.,  172 HU Low Low Marginal Marginal
Wed, May 28    0.'',  3 hrs.,  131 HU Low Low Low Marginal
(if dew)
Thu, May 29    0.'',  0 hrs.,  85 HU 0 0 0 0
Fri, May 30    0.'',  0 hrs.,  158 HU 0 0 0 0
Sat, May 31    0.12'',  16 hrs.,  144 HU Low Low Low Marginal
Sun, June 1    0.'',  13 hrs.,  269 HU Low Low Marginal
(if dew)
HIGH!
(if dew)
Mon, June 2    0.'',  0 hrs.,  409 HU 0 0 0 0
Tue, June 3    0.'',  0 hrs.,  509 HU 0 0 0 0
Wed, June 4    0.54'',  19 hrs.,  516 HU HIGH! HIGH! EXTREME! EXTREME!
Thu, June 5    0.'',  16 hrs.,  384 HU Low Marginal
(if dew)
HIGH!
(if dew)
EXTREME!
(if dew)
Fri, June 6    0.19'',  21 hrs.,  205 HU Low Low Marginal HIGH!
Sat, June 7    0.'',  12 hrs.,  241 HU Low Low Marginal
(if dew)
HIGH!
(if dew)
Sun, June 8    0.'',  0 hrs.,  714 HU 0 0 0 0
Mon, June 9    0.'',  0 hrs.,  1261 HU 0 0 0 0
Tue, June 10    0.'',  0 hrs.,  1737 HU 0 0 0 0
Wed, June 11    0.'',  0 hrs.,  1986 HU 0 0 0 0
Thu, June 12    0.'',  0 hrs.,  1801 HU 0 0 0 0
Fri, June 13    0.'',  0 hrs.,  1405 HU 0 0 0 0
Sat, June 14    0.'',  1 hrs.,  1143 HU 0 0 0 0
Sun, June 15    0.39'',  24 hrs.,  686 HU HIGH! EXTREME! EXTREME! EXTREME!
Mon, June 16    0.75'',  10 hrs.,  406 HU Marginal HIGH! HIGH! EXTREME!
Tue, June 17    0.04'',  11 hrs.,  403 HU Marginal HIGH! HIGH! EXTREME!