Below are some example fungicide programs in pecan for highly/moderately susceptible varieties from Dr. Lenny Wells
The important thing to remember is to rotate chemistries and use the fungicides to their strengths. Group 3 + Group 11 materials are excellent on leaf scab when combined and work well on nut scab too. Phosphites make a great leaf scab material and can be used alone at the 2 qt rate. Miravis Top is a superb new material that provides an additional chemistry to throw in the mix and should be focused on nut scab. Elast and Tin both work better on nut scab than on leaf scab and when combined are an excellent choice for nut scab.
Program for Highly Scab Susceptible Varieties
Absolute
Phosphite (2 qt/acre rate)
Absolute
Phosphite (2 qt/acre rate)
Miravis Top (this should be about the time nut sizing begins)
Elast/Tin
Miravis Top
Elast/Tin
Miravis Top
Elast/Tin
(Continue with Elast/Tin or rotate with Absolute if additional sprays needed beyond this point.)
Moderately Susceptible Varieties
Phosphite (2 qt rate)
Absolute
Phosphite (2 qt rate)
Group 3 +Tin
Absolute (or Miravis Top if pressure is high)
Tin (full rate)
Group 3 + Tin (or Elast/Tin if pressure is high)
Tin (full rate)