Determination of the biological effectiveness of fungicides to protect oak from powdery mildew

The article discusses the issues of determining the biological effectiveness of fungicides to protect oak seedlings from powdery mildew. This disease is of great importance in nurseries when growing planting material, as well as in natural forests. Currently, there is not a single approved pesticide in the arsenal of oak protection products in nurseries from powdery mildew. Therefore, it is important to test modern fungicides in order to be able to use protective equipment on legitimate terms. When conducting such tests, it is important to evaluate the effectiveness of these pesticides as objectively as possible. In order to evaluate the results as objectively as possible, the possibility of using some formulas for this has been tested. The comparisons made it possible to choose one of the formulas that most objectively assesses the effects of the fungicide.