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Agrarian science has faced the problem of is the humanity provision with food, the major part of which is provided by grain crops. Winter wheat the most fully uses the existing bioclimatic potential of the Ukrainian regions. The highest productivity of this crop can be obtained with the use of modern adapted varieties with high genetic potential of productivity taking into account the soil-climatic conditions of the zone, improvement and development of highly effi cient, scientifi cally grounded systems of nutrition and plants protection against harmful organisms. The article presents the results of the research conducted in 2017–2019 on dark brown medium-loam low-saline soils under the conditions of the experimental fi eld of State Enterprise Experimental Farm “Kopani” of the Institute of Irrigated Agriculture of NAAS of Bilozersky district of Kherson region. The infl uence of varietal characteristics, mineral and organic-mineral fertilizer system, biological and chemical methods of disease protection on the productivity of winter wheat plants was investigated. The fi eld, laboratory, mathematical and statistical methods were used in the experiment according to the generally accepted methods and guidelines in Ukraine. It was found out that the highest level of productivity was formed by wheat plants of Maria winter variety on the background of application of pre-sowing cultivation of mineral fertilizers at a N30P30 dose with the use of foliar fertilization with organic-mineral fertilizer ROST, solution (2.0 l/ha) at the beginning of the restoration of spring vegetation and in a stage of the fl ag leaf and chemical protection of plants using fungicide – Colossal, emulsion concentrate (1.0 l/ha). Thus, on average during the years of research, the grain yield in this variant was 4.96 t/ha, the number of productive stems – 411 pieces/m2, the number of grains in the ear – 27.6 pieces, the mass of 1000 grains – 51.5g. When using the chemical method of protection to control dark brown spotting (Drechslera sorociniana Subram) of winter wheat, the rate of development of the disease ranged 2.0–3.1 %, and the eff ectiveness ranged 83.1 – 89.4 %. Key words: fertilizers, biologicals, fungicide, yield, foliar feeding, plant protection.

Apart from making farmers adapt agricultural technologies to new, more arid conditions in order to obtain sustainable and high yields, global climate change is also known to alter the pathogenicity of plant pathogens, the biological cycle of which is tightly associated with environmental factors. One of the most common diseases of winter wheat is brown leaf rust, caused by Puccinia recondita Rob. ex Desm. f. sp. tritici. In terms of its harmfulness and prevalence among other leaf and stem diseases, brown leaf rust is comparable to yellow and stem rust, septoria leaf blotch and other leaves blotches. Under arid conditions of the Southern Steppe of Ukraine, the disease manifests itself once every five years provided that sufficient moisture, indicated by the hydro-thermal index above 1.0, is present during the spring and summer vegetation periods. The main factor influencing the intensity of pathogen development is moisture supply from April to June (ΣTP> 50 mm). In 2019, the amount of precipitation during this period was 194 mm, which led to the disease development at the level of 18.4% with a spread of 27.2%. Productivity of winter wheat varieties such as Antonivka, Blago and Maria was reduced by 10.8-11.3%, when infected in the phase of milk grain stage (stages 73-77 on the BBCH scale), while net photosynthesis productivity decreased by 14.2-14.3%, which translates to lower average yields of 2.3-3.1 t/ha. To maximize the productive potential of varieties and effectively control the development of the causative agent of brown leaf rust in winter wheat under favourable conditions for epiphytic development, the application of systemic fungicides with long-term protective effect imparted by the chemical group of triazoles (Colossal e.c., 1.0 l/ha ) is recommended in stages 69-71 on the BBCH scale. This provides not only reliable crop protection (Eff.: 77.9-82.0%), but also yields at the level of 3.3 - 4.6 t/ha, depending on the variety under non-irrigated conditions.

Introduction. Winter wheat is the main food crop grown in all soil and climatic zones of Ukraine. Harmful organisms are among the many factors that affect its yield. Under the steppe conditions, smut diseases, root rot, powdery mildew, septoriosis, orange leaf rust, various types of weeds, cereal aphids, wheat thrips, chinch bugs and others are hazardous. They lead to a significant loss of crop yield and cause deterioration in its quality [3]. Considering the foregoing, there is a need to study the effectiveness of comprehensive measures for the protection of winter wheat crops against diseases, pests and weeds. Analysis of recent research findings and publications. In many countries of the world, various aspects of winter wheat protection against harmful organisms are being investigated. In Ukraine, in particular, the application of herbicides Estrone, Grantar gold, Esteron + Puma super provided the highest

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