Our pathologist, Dr. Clemen Oliveira has observed some cases of insensitivity development with Miravis Top and Miravis Prime in 2025 and 2026. It is not occurring everywhere, but it has been found in more than one orchard in different areas of the state. These products have been a game-changer for us in control of nut scab and we desperately need them to remain. That can only happen if we are good stewards of this chemistry. You do not want to over-use these materials. This is why we recommend them ONLY for nut scab season from June-August. They work on leaf scab as well but we have other materials that do a great job on leaf scab. We need the Miravis products for nut scab.
While the label says you should use no more than two sequential applications of Miravis Top, I strongly caution you against using any Miravis products back to back. We feel it is best to rotate Miravis Top or Miravis Prime with Dodine or Dodine/Tin every spray. Miravis Top has two fungicide chemistries, a Group 3 and a Group 7. Miravis Prime also has two chemistries: a Group 7 and a Group 12. Therefore if you spray Miravis Top and then go to Miravis Prime the following spray, you are not rotating chemistries. You are throwing that Group 7 out there two sprays in a row, making it easier for scab to adapt to the seven and develop resistance. For the purposes of rotation, you should treat Miravis Top and Miravis Prime as the same product. The same goes for rotating Miravis Top with something like Custodia or TopGuard or Absolute or anything with a Group 3. The best rotation partners for the Miravis products are Dodine or Dodine/Tin. The Dodine/Tin combo still provides some of the best nut scab protection out there. By the label it is suggested to use the Miravis products only 4 times per season. However, in the interest of protecting the future of this chemistry, I recommend trying to keep your Miravis product applications down to 3 per season if possible, using them at critical times (now through July) and rotating them each time with Dodine or Dodine/Tin until mid August and never use them back to back.