Flyspeck prevention, Full-dose Captan or Ziram: August-September spray dates

Background Information for this page
Return to Apple list for Westhampton MA
Weather data for Westhampton MA.  Forecast values begin December 31, 2018
      Continuous protection from roughly 14 days after Petal Fall (May 31) until 30 days before harvest preserves maximum lag between end of protection from the final fungicide application and potential for visible SBFS before harvest. 
      With continuous protection prior to the final fungicide spray, apples harvested by September 20 should be at low risk of visible sooty blotch and flyspeck (SBFS) if the Protection End Date from the final fungicide application is after August 26.  Apples harvested by October 10 (or by  October 31) should be at low risk if the Protection End Date is after September 17 (or September 24).
     These estimates are based on moderate infection pressure and climatic average temperature and rain/wetting hour accumulation.  Block history, local SBFS fungal density, tree size, cultivar, pruning, wind & sun exposure, air drainage, mowing and other site characteristics determine the actual risk of SBFS becoming visible before harvest.
Weather data for Westhampton MA.  Forecast values begin December 31, 2018
Inches Rain Spray Date
Estimates assume that fungicide was applied before rain on spray date
Protection End Date
for full-dose
Captan or Ziram
(deadline for postinfection strobilurin or Topsin M)
Date flyspeck infections could appear
(Left side = rough guess of flyspeck show date if weather beyond end of forecast range is in top 20% of years for both temperature and wet hours.  An "x" means there is no need for this scenario because show date is within forecast range.
    
Right side = rough guess of estimated flyspeck show date for small, open canopy, low-risk trees.)
0.76 Wed, August 1 Aug. 3  (Aug. 5) x August 23 (Sep. 10)
0.52 Thu, August 2 Aug. 4  (Aug. 7) x August 27 (Sep. 11)
0.79 Fri, August 3 Aug. 4  (Aug. 7) x August 27 (Sep. 11)
1.20 Sat, August 4 Aug. 7  (Aug. 10) x September 2 (Sep. 13)
0 Sun, August 5 Aug. 9  (Aug. 11) x September 5 (Sep. 14)
0 Mon, August 6 Aug. 9  (Aug. 11) x September 5 (Sep. 14)
0.79 Tue, August 7 Aug. 9  (Aug. 11) x September 5 (Sep. 14)
0.60 Wed, August 8 Aug. 11  (Aug. 12) x September 7 (Sep. 16)
0.14 Thu, August 9 Aug. 13  (Aug. 16) x September 10 (Sep. 21)
0.05 Fri, August 10 Aug. 13  (Aug. 16) x September 10 (Sep. 21)
0.97 Sat, August 11 Aug. 13  (Aug. 16) x September 10 (Sep. 21)
0.30 Sun, August 12 Aug. 14  (Aug. 17) x September 11 (Sep. 24)
0.59 Mon, August 13 Aug. 14  (Aug. 17) x September 11 (Sep. 24)
1.15 Tue, August 14 Aug. 17  (Aug. 20) x September 13 (Sep. 27)
0 Wed, August 15 Aug. 18  (Aug. 23) x September 15 (Sep. 28)
0 Thu, August 16 Aug. 18  (Aug. 23) x September 15 (Sep. 28)
1.11 Fri, August 17 Aug. 18  (Aug. 23) x September 15 (Sep. 28)
0.70 Sat, August 18 Sep. 1  (Sep. 5) x September 23 (Oct. 6)
0.01 Sun, August 19 Sep. 2  (Sep. 6) x September 24 (Oct. 6)
0 Mon, August 20 Sep. 3  (Sep. 6) x September 25 (Oct. 6)
0 Tue, August 21 Sep. 4  (Sep. 6) x September 25 (Oct. 7)
0.48 Wed, August 22 Sep. 5  (Sep. 7) x September 26 (Oct. 7)
0.01 Thu, August 23 Sep. 6  (Sep. 10) x September 28 (Oct. 8)
0 Fri, August 24 Sep. 7  (Sep. 10) x September 29 (Oct. 9)
0 Sat, August 25 Sep. 8  (Sep. 11) x September 30 (Oct. 10)
0 Sun, August 26 Sep. 9  (Sep. 11) x September 30 (Oct. 10)
0 Mon, August 27 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Tue, August 28 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Wed, August 29 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Thu, August 30 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Fri, August 31 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Sat, September 1 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Sun, September 2 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Mon, September 3 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Tue, September 4 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0 Wed, September 5 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0.50 Thu, September 6 Sep. 10  (Sep. 11) x October 1 (Oct. 10)
0.03 Fri, September 7 Sep. 11  (Sep. 12) x October 2 (Oct. 14)
0 Sat, September 8 Sep. 11  (Sep. 12) x October 2 (Oct. 14)
0 Sun, September 9 Sep. 11  (Sep. 12) x October 2 (Oct. 14)
1.32 Mon, September 10 Sep. 11  (Sep. 12) x October 2 (Oct. 14)
0.26 Tue, September 11 Sep. 18  (Sep. 24) x October 12 (> Oct. 31)
0.87 Wed, September 12 Sep. 18  (Sep. 24) x October 12  
0.28 Thu, September 13 Sep. 18  (Sep. 24) x October 12  
0 Fri, September 14 Sep. 18  (Sep. 24) x October 12  
0 Sat, September 15 Sep. 18  (Sep. 24) x October 12