The phenological phases of plant development are one of the most important indicators for determining the plant species growth, the disease infestation and for carrying out treatments with plant protection products in regional climatic conditions. In this study the phenological phases, diseases identification and biocontrol measures for apple variety ‘Reinette Simirenko’ were evaluated. Reinette Simirenko apple has good resistance to Phyllosticta, but is very strongly attacked by apple scab and poorly resistant to powdery mildew. Scope of the study - determination of the optimal timing of the use of biological prepara-tions in the control of powdery mildew and scab on the apple tree variety Reinette Simirenko.