The article presents the results of studies on the effectiveness of the use of herbicides in the cultivation of corn for grain. It was established that in the prevailing weather conditions during the research period, the highest yield of corn grain (79,1 c/ha) was ensured by the use of the herbicide Capreno, SC (0,25 l/ha) + Mero, EC (2,0 l/ha). When other studied herbicides were used in this phase, this indicator decreased by 1,3–18,4 q/ha (1,6–29,2 %). When herbicides were applied in the 5-leaf phase of corn, the grain yield decreased, depending on the preparation used, by 2,5– 8,9 c/ha (3,4–15,9 %) compared to their application in the 3-leaf phase.

The article presents the results of many years of research on the effectiveness of plant growth regulators based on trinexapac-ethyl on winter wheat. Correlations have been constructed between the number of stems in the BBCH 31–32 phase and the density of the productive stem with resistance to lodging of winter wheat, between the rate of germination of the growth regulator Moddus, CE and the length of the internodes. The effectiveness of the methods of using retardants based on trinexapac-ethyl on the resistance to lodging of winter wheat and their effect on the elements of productivity and crop yield is shown. The introduction of trinexapac-ethyl into the phase of BBCH 31– 32 (70–105 g/ha d. v.) increases the resistance to lodging by 2,0–4,5 points and retains an average of 6,8 c/ha of grain. The double use of growth regulators in the phases of BBCH 31–32→39–49 by 35–50 g/ha increases the resistance to lodging by 2,0–6,0 points and retains an average of 6,2 c/ha of grain.

The paper presents the results of the studies on the efficiency of morpho regulation of winter wheat with the preparation Messidor, СS (mepiquatchloride + prohexadione-calcium). Its effect on plant growth, resistance to lodging, formation of productivity elements and crop yield is shown. The application of the growth regulator Messidor, СS at the ВВСН 31–32 stage increases the resistance to lodging up to 7,5–9,0 points and saves on average 13,0–14,9 % of grain yield. When it is applied at the BBCH 39–49 stage the resistance to lodging increases up to 6,5–9,0 points and yield – by 3,7–3,9 %. With fractional application of the preparation the resistance to lodging rises up to 8,5–9,0 points and yield – by 5,5–14,0 %.

The results of studying the influence of growing conditions on the variability of elements of the structure of the harvest of soft winter wheat are presented. Genotypes with the most productive parameters and high stability of their manifestation in contrasting growing conditions were determined. The degree of dependence of the elements of the crop structure on the hydrothermal regime during the studied period of plant growth and development is established.

In 2020–2022, the nutritional value and productivity of alfalfa in single-species and mixed crops were studied on connective-sandy soil with an increased content of humus, phosphorus and potassium, on the basis of which it was concluded that the greatest productivity with good quality indicators of green massis provided by the option of itsspring sowing with a seeding rate of 6 million germinating seeds per 1 ha in a pea-barley mixture (0,8 million/ha + 3,0 million/ha) or a single-species early spring sowing (12 million/ha). Joint sowing of alfalfa with festulolium (6 million seeds per 1 ha) forms the smallest collection of protein and energy, and the mixture of a fast-growing cock's-foot grass hedgehog with alfalfa has the lowest nutritional value of the green mass due to the mismatch of the timing of oblique ripeness.

In the field conditions of the breeding experimental field of the Department of Breeding and Genetics of the EE «BSAA» were created, selected against an infectious an- thracnose background and evaluated varieties of yellow lupine for a complex of economically useful traits. As a result, varieties were selected for the fodder use of BGSHA 333, BGSHA 331 with a green mass yield of 704,5–745,7 c/ha, grain – BGSHA 325, BGSHA 330, BGSHA 332 with a grain yield of 26,7–30,9 c/ha and the universal direction of use – BGSHA 323, BGSHA 326, BGSHA 329, BGSHA 338, BGSHA 340 with a yield of green mass 572,4–620,8 c/ha and grain 21,8–26,2 c/ha.

The highest damage to corn plants by the Ostrinia nubilalis Hbn. was noted in the Brest and Gomel regions and reached 97,0–80,0 % respectively. In the analysis of damaged stems, the caterpillar population of plants with damage types of stem breakage above the cob was 14,0–34,0 %, below the cob – 30,0–42,0 %. Sorghum and millet crops were damaged by the pest by 51,0 and 90,0 %, respectively, spring wheat – 5,0 %, oilseed sunflower – 6,8 %. The high damage of stems by phytophagus is a decisive argument in favor of the use of insecticides contact action, systemic and combined actions.

The paper presents the results of the research on the evaluation of the impact of plant protection means on the increase of faba beans grain quality. The application of soil herbicides to this crop provides increasing crude protein yield by 0,21–0,22 t/ha, post-emergence herbicides – by 0,37–0,47 t/ha, fungicides – by 0,49–0,52 t/ha and insecticides – by 0,21–0,31 t/ha. High indicators of biological efficiency were obtained in all the conducted experiments.

In the conditions of 2018–2021 the biological and eco[1]nomic efficiency of Verango, KS (fluopyram, 400 g/l), a new preparation for the Republic of Belarus, as a nematicide for protecting potatoes from golden cyst nematode (PCN, Globodera rostochiensis (Woll.) Behrens) and stem nematode (Ditylenchus destructor Thorne 1945) was studied. It was shown that the use of the nematicide Verango, KS made it possible to reduce the multiplication factor of PCN by 0,4–1,1 compared to the variant without treatment, and the development of the stem nematode at the end of potato storage did not exceed 10,6–21,3 %. Thus, the biological efficiency of the preparation Verango, KS against PCN was 47,8 %, against the stem nematode – 73,2 %. In addition, it was found that the use of the nematicide Verango, KS contributes to a significant increase in potato yield by 9,7 and 25,4 %, respectively, in experiments against PCN and stem nematode. According to the research results, the preparation Verango, KS is included in the «State Register of Plant Protection Products…» as a nematicide.

The article presents the result of a comparative analysis of route surveys of spring grain crops for contamination with perennial weeds in Belarus before harvesting.

The biological and economic efficiency of the drug Eforia, CS (lambda-cyhalothrin, 106 g/l + thiamethoxam, 141 g/l) for the protection of industrial crops of onion Temptation F1 (2021) and Sabroso F1 (2022) from herbivores was evaluated thrips. A high (up to 100 %) protective effect and a prolonged action of the insecticide against adults and larvae of phytophages were established at consumption rates of 0,35 and 0,40 l/ha, respectively, with two-time treatment of plants. The influence of weather conditions and the stage of plant development on the population density of sucking phytophages and the level of biological effectiveness of the preparation was noted.

The results of studies on the study of the effect of desiccation on the yield and sowing qualities of seeds of Sudanese grass in the soil and climatic conditions of the southwestern part of the republic are presented. The use of desiccant of Reglon super, AS (2 l/ha) for pre-harvest desiccation of seed plants of Sudan grass reduces the moisture content of the leafy mass by 40 % and the grain in the panicle to a moisture content of 18–20  %, thereby increasing the manufacturability of harvesting by direct combining. At the same time, the use of desiccant does not adversely affect the yield and sowing qualities of Sudanese grass seeds.

The adaptive parameters of new varieties of linseed were assessed in terms of seed yield in 2017–2019. The average values of this indicator for the Vizir variety were 15.3 c/ha, Alliance – 14,2 c/ha, Dar – 15,6 c/ha, control variety Salyut –15,4 c/ha. The highest stress resistance ((y_min – y_max) = –1,9), the higheststability in terms of homeostaticity (Hom =120,5), high values of the selection value parameter (Sc = 13,8) and low stability factors (S.F. = 1,13) were noted in variety Dar. The maximum ratio between growing conditions and genotype was found in varieties Dar ((y_min – y_max)/2) = 15,8) and Salyut ((y_min – y_max)/2) = 15,1). Thus, the most promising of all the varieties studied, based on all the indicators calculated above, is the variety Dar.

The results of assessment of influence of micronutrients Nutrivant Pluspotato, Lifdrip rost, Lifdrip universal, Lifdrip bor and Ecohum Complex on the reproduction coefficient, seed fraction yield, productivity and yield of potato varieties of different ripeness groupsare present. The research results showed that it is necessary to take account the responsiveness of the variety to the composition of the proposed micro-fertilizer, as well as to the targeted cultivation of potatoes, when choosing a drug.

The article presents the results of studies on the study of doses of mineral fertilizers in the cultivation of Jerusalem artichoke on productivity, the chemical composition of the main and by-products, the removal of nutrients and the utilization rates of nitrogen, phosphorus and potassium by plants from fertilizers. The most effective was the application of a dose of N₁₂₀P₉₀K₁₄₀Mg₅, which provided a tuber yield of 29, t/ha, an increase of 16,2 t/ha or 121 %, and the highest payback of 85,8 kg of products per 1 kg of applied fertilizers.