Carbonates for apple scab control

Abstract: Apple scab is caused by Venturia inaequalis. As the fungus developed resistanceagainst demethylation inhibitors and anilinopyrimidines, these curative fungicides cannot be usedanymore in pome fruit production in many regions. As a result, fruit growers can only useprotective agents for apple scab control. We tested different substances in the greenhouse fortheir curative efficacy and some promising substances could be identified. Carbonates in differentformulations reduced the apple scab incidence after curative application clearly, but had noprotective effects. Mixtures of protective fungicides with Omni Protect (a.i. potassium carbonate)sprayed protectively or curatively could achieve a symptom reduction up to 97%. Omni Protectcontrolled apple scab populations resistant to demethylation inhibitors and anilinopyrimidines.