The introduction of the urea-ammonia mixture together with trace elements of copper and manganese and plant growth regulators Hydrohumate and Epin contributed to an increase in the yield of spring wheat grain by 3,5– 6,9 c/ha, the level of profitability–by 1,2–11,9 p. p., bioenergy coefficient – by 0,3–0,6 unit.. compared to the control option. The best option is where the urea-ammonia mixture was used together with Cu and Mn, an Epin growth regulator against the background of N₁₅P₅₅K₁₂₀. The yield of spring wheat was 63,3 c/ha. At the same time, the level of profitability was 52,5 %, the bioenergy coefficient was 9,4 units.

The article analyzes the possibilities of using magnetic devices to change the properties of water, which can be effectively used in irrigation and irrigation systems of various crops. This technological reception is most appropriate when cultivating plants in the conditions of protected soil, but can also be applied for field irrigation systems. In this case, the parameters and design of water metering devices have a significant impact on the development and yield of cultivated plants. A study of 10 different options for using permanent magnets made it possible to establish advantages in the cultivation of various crops with achievement in the best embodiments of the final indicators with higher parameters of magnetic induction and increasing the zone of the magnetic field to the supplied water.

Нybrids Poisk, Agat, LG-5412 were found to be the most high-yielding as a result of the study in the north-east of Belarus. The largest mass of thousand seeds (64,1 g) was obtained from the hybrid LG-5412. The maximum number of seeds (1012,5 pcs.) was obtained from the hybrid Agat. 34,3 % of heat needs for vegetative growth and 65,7 % of heat needs flowering and ripening of theseeds was established. The growing season of early hybrids and varieties is 113–120 days; for mid-early hybrids and varieties is 120–138 days. The sun of active temperatures is 2160,3–2245,0 °C for early hybrids and varieties and 2345,0–2347,9 °C for mid-early hybrids and varieties.

For the wide use in the production a method of doing the diagnostics of soil provision with the potentially acceptable by plants nitrogen form is proposed. The gradations of sod-podzolic soils provision with the potentially acceptable nitrogen and the agricultural crop needs in nitrogenous fertilizers for the planned yield, correction factors to the rates of fertilizers are developed. The differentiated by fields application of nitrogenous fertilizer rates considering the data of N assimilation content in soils provides with the grain crops yield increase up to 6–0 cwt/ha at losses decrease for17–24 and the nitrogenous fertilizers economy up to 20 kg/ha a. i., poisoning substance (PS) mineralization for 12–26 % and soil humus losses decrease.

The article presents the results of studies on the effectiveness of the use of various herbicides in the cultivation of corn. It was found that the greatest economic effect was provided by the use of the herbicide Adengo, CS (0,3 and 0,4 l/ha) in the phase of 2–3 maize leaves. When using the herbicides Extracorn, SE (4,0 l/ha) and Lumax, SE (4,0 l/ha) on the crops of this crop, net income decreased in comparison with the use of the herbicide Adengo, CS (0,4 l/ha) by 0,52– 23,61 cu/ha, profitability – by 0,18–2,14 %, and the cost of grain increased by 0,01–0,16 cu/c depending on the duration of chemical weeding and the drug used.

It is determined that for the period of 2015–2021 in fodder bean crops the dominant pests have been tubercular weevils (lined and bristle) which in the phytophage structure have made 75,3–76,4 % and also bean aphid – 20,4–21,6 %. Depending on weather conditions by tubercular weevil imago increase for 1 indiv./m² the yield losses have made 0,36–0,97 cwt/ha and by bean aphid increase for one indiv./plant – 0,04–0,48 cwt/ha. Considering the planned yield by insecticides application from different chemical groups, the ETH for tubercular weevils has made 7,0– 14,7 indiv./m², bean aphid – 7,4–16,4 indiv./plant.

The article presents the research on the effect of presowing treatment on the phytopathological state of oil flax seeds. The positive effect of chemical disinfectants and biological preparations on the sowing qualities of seeds, a decrease in the fungal infection, and a limitation of the prevalence and development of anthracnose has been shown. The economic efficiency of the use of preparations for presowing seed treatment has been proved, and an assortment of promising seed disinfectants has been formed.

In the article the results of researches on studying the biological, farming and economic efficiency of the perspective chemical and biological fungicides for oil flax protection against the dominant diseases (anthracnose, wilt of flax and septoria leaf spot) during crop vegetation are presented. It is determined that the fungicide treatment promotes the diseases development for 22,1–100 % and raising the crop yield for 0,3–24,2 cwt/ha.

The article presents the results of a complete factorial experiment (Pareto analysis) in order to study the conditions for obtaining high productivity and oil content in flax lines of oilseed breeding variety testing. It follows from the literature review that the consequences of global climate changes are becoming more and more noticeable in the climate of the republic every year, which require increased study and improvement of plant growth and development conditions in the process of ontogenesis. The description of the climatic conditions of the growing seasons of 2016–2019 of the selection lines of oilseed flax and their influence on the value of yields and oil content is given. It was found that the optimal values of the sum of average daily temperatures and precipitation, at which the oil content of seeds is formed at least 38 % in combination with high productivity, are 270 °C – 285 °C and 340 мм – 450 mm, respectively.

The results of the study of genetic polymorphism of 9 varieties of flax, created in Institute of Flax: Grant, Lada, Mara, Rubin, Mayak, Dukat, Taler, Altyn, Everest using SSR markers are presented. The peaks on the electrophoregram were identified using microsatellite DNA markers, which made it possible to identify genetic diversity by unique loci in new varieties of flax. On the basis of the selected system of markers, including 11 loci with a high level of informativeness, genetic passports of new varieties of flax have been compiled. The obtained research results will further contribute to improving the efficiency of breeding and seed-growing work on flax culture, as well as serve as a mechanism for copyright protection.

The article presents the results of studies on the effect of protective-stimulating compositions of table carrots on germination, yield and marketability of products.