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

    Continuous protection from June 15 until 30 days before harvest is recommended.  Flyspeck infections that begin before August 19 are likely to become visible around September 20.  Infections that begin before August 30 are likely to become visible around October 20.  But warm wet weather in September can reduce flyspeck development time resulting in earlier dates of flyspeck appearance before harvest.
     Postinfection control of flyspeck may occur with application a strobilurin or Topsin M fungicide within 50 wet hours after the 'Protection end date' of the previous fungicide application.
Weather data for Greenville RI.  Forecast values begin September 1, 2009
Inches Rain Spray Date
- assumes that fungicide was applied before any rain fell on spray date
Protection End Date
for full-dose
Captan or Ziram
(deadline for postinfection strobilurin or Topsin M)
Date flyspeck infections that started after end of protection could appear
(Left side = rough estimate of flyspeck show date for dense canopy trees if weather beyond forecast range is in top 20% of years for both temperature and wet hours.
x = show date is within forecast range.

Right side = rough estimate of flyspeck show date for small, open canopy, low-risk trees.)
0 Sat, August 1 Aug 15 (Aug 21) (Sep 13) September 17 (Oct 12)
0 Sun, August 2 Aug 16 (Aug 21) (Sep 14) September 18 (Oct 14)
0 Mon, August 3 Aug 17 (Aug 22) (Sep 15) September 19 (Oct 18)
0 Tue, August 4 Aug 18 (Aug 22) (Sep 15) September 19 (Oct 18)
0.26 Wed, August 5 Aug 19 (Aug 23) (Sep 15) September 20 (Oct 20)
0 Thu, August 6 Aug 20 (Aug 23) (Sep 16) September 22 (Oct 23)
0 Fri, August 7 Aug 21 (Aug 24) (Sep 17) September 24 (Oct 28)
0 Sat, August 8 Aug 22 (Aug 25) (Sep 18) September 25 (> Oct. 31)
0 Sun, August 9 Aug 23 (Aug 28) (Sep 20) September 28  
0.09 Mon, August 10 Aug 24 (Aug 28) (Sep 21) October 1  
0.36 Tue, August 11 Aug 25 (Aug 29) (Sep 23) October 3  
0 Wed, August 12 Aug 26 (Aug 29) (Sep 23) October 5  
0.35 Thu, August 13 Aug 27 (Aug 29) (Sep 23) October 5  
0 Fri, August 14 Aug 28 (Aug 30) (Sep 25) October 8  
0 Sat, August 15 Aug 29 (Sep 7) (Sep 28) October 15  
0 Sun, August 16 Aug 29 (Sep 7) (Sep 28) October 15  
0 Mon, August 17 Aug 29 (Sep 7) (Sep 28) October 15  
0 Tue, August 18 Aug 29 (Sep 7) (Sep 28) October 15  
0 Wed, August 19 Aug 29 (Sep 7) (Sep 28) October 15  
0 Thu, August 20 Aug 29 (Sep 7) (Sep 28) October 15  
0 Fri, August 21 Aug 29 (Sep 7) (Sep 28) October 15  
0.14 Sat, August 22 Aug 29 (Sep 7) (Sep 28) October 15  
0.74 Sun, August 23 Aug 29 (Sep 7) (Sep 28) October 15  
0 Mon, August 24 Sep 7 (Oct 3) > Oct. 31  
0 Tue, August 25 Sep 8 (Oct 5)    
0 Wed, August 26 Sep 8 (Oct 5)    
0 Thu, August 27 Sep 8 (Oct 5)    
0.36 Fri, August 28 Sep 8   (Oct 5)    
1.63 Sat, August 29 Sep 11 (Oct 10)    
0 Sun, August 30 Sep 13 (Oct 14)    
0 Mon, August 31 Sep 14 (Oct 16)    
0 Tue, September 1 Sep 15 (Oct 19)    
0 Wed, September 2 Sep 16 (Oct 21)    
0 Thu, September 3 Sep 17 (Oct 24)    
0 Fri, September 4 Sep 18   (Oct 26)    
0 Sat, September 5 Sep 19 (Oct 29)    
0 Sun, September 6 Sep 20 (> Oct. 31)    
0 Mon, September 7 Sep 21      
Tue, September 8 Sep 22      
Wed, September 9 Sep 23      
Thu, September 10 Sep 24      
  Fri, September 11 Sep 25        
Sat, September 12 Sep 26      
Sun, September 13 Sep 27      
Mon, September 14 Sep 28      
Tue, September 15 Sep 29