Bogach E. Professor S. І. Lebedev (1902 - 1989) – scientist, teacher, organizer of research in physiology and biochemistry of plants in Ukraine.

The thesis is the first scientific and historical work, which highlights life and activity of Professor S. I. Lebedev in Ukraine.The numerous archival documents and published materials and memoirs of contemporaries are used in the study. The conditions of forming scientific outlook of scientist have been found, the main periods of life and creative way have been described. Unknown and little-known facts of S. I. Lebedev’s biography have been collected, summarized and introduced. The basic directions of scientific and scientific organizational activity of scientist, especially the study of hemp plant morphology and introduction of new agricultural techniques of their cultivation, study of the Black Sea algae, pigment system of photosynthetic apparatus and mechanisms to improve the level оf assimilation of photosynthetically active radiation to obtain high yields of crops have been generalized. The thesis highlights the diversity of talent and S. I. Lebedev contribution to the development of the sectoral higher school, educational, social and promotional activity in Ukraine. The historical role of S. I. Lebedev as one of the most talented organizers of national agricultural science in forming Plant Physiology and Biochemistry, which is the theoretical basis of crop growing and farming has been shown. Scientific achievements of S. I. Lebedev in Plant Physiology and Biochemistry, development of agricultural higher school and training of scientific staff of Ukraine have been revealed.