Economic efficiency of growth regulators application in cultivation technologies of spring barley, winter wheat and winter rape is shown in the article. The net operating income obtained as a result of the use of retardants with different active substances was 32.8–197.9 BYN/ha on spring barley (trinexapac-ethyl, mepiquat chloride+ethephon, Messidor, SC), 53.6–310.9 BYN/ha on winter wheat (trinexapac- ethyl, Messidor, SC), 321.0–625.7 BYN/ha on winter rape (Architect, SE, Setar, SC).

The article presents the results of the research carried out under the conditions of the northern region of the Republic of Belarus on the formation of productivity and qualitative composition of green mass of African millet, depending on sowing time and methods of using herbage. It was established that under the soil and climatic conditions of the northern region of Belarus when sown in late May African millet formed 132.6 dt/ha of dry matter with a single cut, which indicated a real possibility for its cultivation in that zone and use as a raw material for making silage. It was identified that African millet was able to grow and form two cuts per year, providing 442.9–457.0 dt/ha of green mass for green fodder. Late sowing time (late May) makes it a potential crop for spring sowing after harvesting winter intercrops.

The application of mineral fertilizers in the amount of N₆₀P₅₀K₉₀ and copper-, manganeseand molybdenum-containing microfertilizers before sowing perennial grasses, and after the second mowing N₆₀K₅₀, contributed to an increase in the productivity of perennial grasses of the second year of use (the third year of life), represented by a cereal mixture, by 76.2, legumes – cereal – by 34.5 centners per unit compared to the control variant. The use of these doses of fertilizers for perennial grasses of the third year of use (fourth year of life) increased the productivity of perennial grasses by 55.0 and 33.8 c.u., respectively. At the same time, the yield from 1 ha of fodder units increased by 36 centners, of feed-protein ones – by 35.6 centners. The cost of 1 q increased by 4.0 and 3.9 rubles, respectively. The bioenergetic coefficient was 6.9.

The research results on the comprehensive assessment of physical and mechanical properties of stems of winter and spring rapeseed varieties for the period of 2022–2023 are presented in the article. Significant differences between them were established. A positive strong correlation between the stem outer diameter (D) and inner diameter (d) (r = 0.85 and r = 0.74), stem section modulus (W) (r = 0.86 and r = 0.76), and, in winter rapeseed, the axial moment of stem cross-section (I) (r = 0.89) was revealed. A direct strong correlation between stem tissue density (p) and stress index (σ) (r = 0.94) and between stress index (σ) and elastic modulus value (E) (r = 0.81) in spring rapeseed, as well as a functional, i.e. almost perfect correlation between stem section modulus (W) and the axial moment of stem cross- section (I) (r = 0.99) in winter rapeseed was established.

The research results on biological and economic efficiency of new herbicide FEMIDA, OD (2,4-D acid, 320 g/l in the form of 2-ethylhexyl ether + chlorosulfuron, 4.2 g/l) produced by JSC “Schelkovo Agrochim”, Russia, are presented in the article. It was established that when protecting winter wheat, triticale and barley crops in the phase of crop tillering in autumn, the reduction of weed infestation by annual and perennial weeds was more than 85.0 %. The preserved yield was 15.2–15.9 dt/ha in winter wheat crops, 5.0–5.8 dt/ha in winter triticale, and 4.7– 6.5 dt/ha in winter barley crops.

The article presents the results of the studies on the efficiency of immunomodulating agents in cultivating fibre flax. It’s established that treating seeds and vegetating plants with immunomodulating increases the survival rate of plants by 2,3 %. When treating the planting material with these preparations a significant increase in the yield of flax seeds ranges from 1,1 dt/ha to 1,6 dt/ha; for vegetating plants – from 0,7 dt/ha to 1,6 dt/ha.

The article presents the results of the studies on the efficiency of immunomodulating agents. It was established that when processing vegetating plants at the herringbone stage, the preparation № 1 (WSP-3 + GK) with a consumption rate of 1,0 l/ha provided the highest yield of 16,4 dt/ha of total fiber and 11,1 dt/ha of long fiber. The increase to the control was 2,9 dt/ha and 2,4 dt/ha, respectively. The fiber quality corresponded to number 11 and exceeded the control variant by one number.

The paper presents the results of the research on the main fractions of protein compounds of green pea microgreens carried out in a production experiment with an eight variant impact scheme of the spectral composition of LED lighting with varying ratios of red and blue areas (R/B) within 1.3–10.5. A significant influence of the studied factor on quantitative and qualitative characteristics of the protein complex of pea microgreens (Pavlusha variety) was determined. It was identified that the tested spectral lighting combinations contributed to protein compounds depletion of pea microgreens by 9–73 % including albumins and globulins against a background of glutelins and prolamins enrichment by 11–170 %. It is shown that the most favorable conditions for forming total protein reserves and its most valuable water- and salt-soluble part in pea microgreens were provided due to LED lighting with a three and four time excess of red light relatively to blue one in the spectrum.

The article states the results of the research on the effect of applying various doses of organic and mineral fertilizers on the yield and biochemical composition of tomato in a specialized vegetable crop rotation under drip irrigation.

The paper demonstrates the impact of the links of a specialized vegetable crop rotation on soil state cultivation and total productivity of crops. The indicators are presented on changing the degree of state cultivation of sod-podzolic sandy loamy soil, depending on the saturation of crop rotation with vegetable and green manure crops for 7 years.

The paper states the results of the comparative study carried out in a production experiment of the effect of a 600 W High Pressure Sodium Lamp, as well as 112 W Arlight and 127 W Eviyar LEDs on the content of solids, free organic, ascorbic and hydroxycinnamic acids, soluble sugars, pectin substances and sugar-acid index in leaf tissue and fruits of tomato plants (variety Fanto). It’s established that using a sodium lamp is unacceptable for enriching the consumed tomato products with a complex of indicated compounds. The most favorable conditions are identified with the use of Arlight LED lamps.

Based on the results of long-term stationary observations biometric parameters of aerial parts of plants at the main stages of ontogenesis of 15 cultivars of highbush blueberry and 1 cultivar of lowbush blueberry introduced in Belarus are presented. Both the general description of the structure of the aerial part of generative blueberry plants and cultivar features of their architectonics are shown. Genetically determined biometric parameters in most cultivars of highbush blueberries are fully implemented by the age of 15 under the conditions of the point of introduction; only the cultivars Nui, Puru, Bonus and Toro have a weak growth force under new conditions. Under the conditions of the Belarusian Polesie plants of lowbush blueberry Putte are superior in height to the characteristics typical of them under the conditions of their homeland. The average height of highbush blueberry plants, depending on the cultivar, by the age of 15 was 1.20–1.75 m with a crown diameter of 1.07–1.67 m, lowbush blueberry – 0.94 × 1.20 m.