The article examines the prerequisites for the formation of plant protection organizations in Ukraine in 1917-1930. The process of distinguishing functions between operational and scientific institutions is shown. The history of the creation of the state plant protection service and its areas of activity are revealed. Scientific studies on applied entomology and phytopathology, which were conducted at regional agricultural research stations, were analyzed. Data on the species composition of harmful insects and parasitic microorganisms - pathogens of major agricultural crops and their biology were obtained. The role of plant protection in the development of agriculture is characterized.

The priority direction of research of Ukrainian entomologists has become the development of an agrotechnical method of pest control. The achievement of phytopathologists was the development of a new stage in science, the essence of which is the transition of the experimental study of a diseased plant into its dialectical relationship with the pathogen and living conditions. Knowledge of diagnostic signs of diseases, biological features of their causative agents makes it possible to purposefully and timely carry out effective protective measures on the culture, significantly increase the yield and quality of the obtained products.

The methodological basis of the research is the general scientific principles of historical reliability, scientific objectivity, systematicity and continuity, which ensure a comprehensive coverage of the chosen problem.

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