Although salinity inhibits plant growth, the use of a nitric oxide (NO) gasotransmitter can reduce its negative effects. In this study, the influence of 200 μM sodium nitroprusside (SNP) (donor of NO) on wheat plants (Triticum aestivum L., cv. Salavat Yulaev) in conditions of salinization (100 mM NaCl) was analyzed in pot experiments. Seed priming regulated the level of endogenous NO in normal and salinity conditions throughout the entire experiment (30 and 60 days). Salinity led to the strong accumulation of NO and H₂O₂, which is negative for plants, and significantly reduced leaf area and photosynthetic pigments (chlorophyll a and b and carotenoids). In addition, stress caused a drop in the content of reduced glutathione (GSH) and ascorbic acid (ASA), an accumulation of oxidized glutathione (GSSG), and significantly activated glutathione reductase (GR), ascorbate peroxidase (APX), and lipid peroxidation (LPO) in wheat leaves. SNP treatment significantly attenuated the negative effects of salinity on leaf area and photosynthetic pigments. An important indicator of reducing the damaging effect of salinity on treated plants is the stabilization of the content of GSH and ASA throughout the experiment (60 days). This condition has been associated with long-term modulation of GR and APX activity. Such an effect of 200 μM SNP may be related to its ability to reduce stress-induced accumulation of NO. Additional accumulation of proline also mitigated the negative effect of salinity on plants, and this also evidenced decreased LPO and H₂O₂ in them. For the first time, in natural growing conditions (small-scale field experiments), it was found that pre-sowing seed treatment with 200 μM SNP led to an improvement in the main yield indicators and an increase in the content of essential amino acids in wheat grains. Thus, SNP treatment can be used as an effective approach for prolonged protection of wheat plants under salinity and to improve grain yield and its quality.

Salicylic acid (SA) plays a crucial role in regulating plant growth and development and mitigating the negative effects of various stresses, including salinity. In this study, the effect of 50 μM SA on the physiological and biochemical parameters of wheat plants under normal and stress conditions was investigated. The results showed that on the 28th day of the growing season, SA pretreatment continued to stimulate the growth of wheat plants. This was evident through an increase in shoot length and leaf area, with the regulation of leaf blade width playing a significant role in this effect. Additionally, SA improved photosynthesis by increasing the content of chlorophyll a (Chl a) and carotenoids (Car), resulting in an increased TAP (total amount of pigments) index in the leaves. Furthermore, SA treatment led to a balanced increase in the levels of reduced glutathione (GSH) and oxidized glutathione (GSSG) in the leaves, accompanied by a slight but significant accumulation of ascorbic acid (ASA), hydrogen peroxide (H₂O₂), proline, and the activation of glutathione reductase (GR) and ascorbate peroxidase (APX). Exposure to salt stress for 28 days resulted in a reduction in length and leaf area, photosynthetic pigments, and GSH and ASA content in wheat leaves. It also led to the accumulation of H₂O₂ and proline and significant activation of GR and APX. However, SA pretreatment exhibited a long-term growth-stimulating and protective effect under stress conditions. It significantly mitigated the negative impacts of salinity on leaf area, photosynthetic pigments, proline accumulation, lipid peroxidation, and H₂O₂. Furthermore, SA reduced the salinity-induced depletion of GSH and ASA levels, which was associated with the modulation of GR and APX activities. In small-scale field experiments conducted under natural growing conditions, pre-sowing seed treatment with 50 μM SA improved the main indicators of grain yield and increased the content of essential amino acids in wheat grains. Thus, SA pretreatment can be considered an effective approach for providing prolonged protection to wheat plants under salinity and improving grain yield and quality.

The effect of white and additional red and blue LED lighting at night (Blue-NLL, Red-NLL) and during the pre-harvest period (Blue-P-hLL, Red-P-hLL) on morphological and physiological parameters, elemental composition, content of polyphenols, and essential oils of purple basil cultivars ‘Ararat’ and green basil ‘Tonus’ grown in the hydroponic conditions of the climatic chamber was studied. The height of the plants was determined by the variety and the LED irradiation period. The highest purple basil plants were obtained in the variant with Blue-NLL illumination; the highest green basil plants were obtained under Blue-P-hLL and Red-P-hLL. The red spectrum, regardless of the lighting period and variety, increased the area and number of leaves, biomass, and vegetative productivity. Significant changes in the elemental composition of the vegetative mass of basil varieties were determined by the period of exposure to the red spectrum. Red-P-hLL stimulated the absorption and accumulation of Mg, Ca, S, and P from the nutrient solution, and Red-P-hLL reduced the nitrate content by more than 30.00%. Blue-NLL lighting increased the content of quercetin, rosmarinic acid, and essential oil and reduced the nitrate content in the vegetative mass by more than 40.00%. The effectiveness of the white LED was observed in increasing the vegetative mass of ‘Tonus’. The results of this study will be in demand in the real sector of the economy when improving resource-saving technologies for growing environmentally friendly leafy vegetable crops with improved chemical composition and high vegetative productivity.

The article provides an analysis of existing feeding technologies on dairy farms, which are divided into four types and evaluated by the accuracy of dosing concentrated and bulky feeds into a mixer. In the first type of feeding, the feed is prepared by a trailer mixer-distributor, where each component is dosed by a loader, the accuracy of the feed dosage was measured by the onboard weighing system "Dailly TMR Manager". The second type involves the use of a self-propelled feed dispenser mixer with self-loading. The third feeding scheme in a stationary feed mill provides for the use of a stationary mixer-distributor of feed and automated distribution means (a wheeled robot or a feed wagon). The fourth type of feeding technology is presented in the form of a self-propelled chassis, on which the feed mixer capacity and an autonomous dosing system of concentrated feeds for different age and gender technological groups are installed. The high dosage error of concentrated feeds was shown by the first feeding technology, the maximum recorded value of 17 % out of 100 measurements. When dosing bulky feeds, the first and fourth feeding technologies showed a high error of up to 6 %. The technology of feeding in a stationary feed mill has a high accuracy of dosing of all types of feed, but the main disadvantages of this technology are high metal consumption, energy consumption and bulkiness of the structure, which increases the cost of equipment and its maintenance. The specific gravity of concentrates in the feeding diet requires the use of high-precision dosing equipment, eliminating dosage errors associated with the human factor. An overdose of concentrated grains increases the cost of milk, increases the risk of acidosis, and a lack reduces the efficiency of animal nutrient metabolism. Based on the above analysis of existing technologies, a feeding technology is proposed using a self-propelled mixer distributor with an automatic weight control system and a self-loading device for bulky feeds, and for concentrated feeds – a robotic device equipped with an accurate dispenser of concentrated feeds and mineral additives with a maximum error of 2 %.

The aim of the study is to evaluate the effect of nine different spectral lighting regimes at a constant photosynthetically active radiation (PAR, 150 μmol/(m2 • s)) on the formation of aboveground biomass and essential oil content of common thyme. The study subjects were vegetatively propagated common thyme (Thymus vulgaris L.) cultivar Krymrozovets plants grown hydroponically for 190 days on a rack system. The control variant had a spectral composition that was as close as possible to sunlight. The studied modes included monochromatic radiation (blue, red) and their different ratios, as well as combinations of white light with the addition of ultraviolet and far-red light. Analysis of the obtained data showed that the spectral composition had a significant impact on both growth indicators and essential oil biosynthesis. Monochromatic illumination with blue and red light led to significant growth inhibition (a decrease in weight by 41.3 and 37.2 %, respectively) and a significant decrease in essential oil content (by 37.4 and 29.7 %). Conversely, the optimal result was achieved using combined lighting with an equal ratio of blue and red spectra (69 μmol/(m2 • s)) and a small proportion of green (12 μmol/(m2 • s)). This regimen provided the maximum increase in aboveground mass – by 37.2 % and an increase in essential oil content by 19.2 %, which ultimately made it possible to increase the total yield of essential oil per plant by 63.5 % compared to the control. The study demonstrated the high efficiency of targeted control of the spectral composition of LED lighting for intensifying thyme cultivation in hydroponics. A regime with equal proportions of blue and red light was optimal for increasing both biomass and essential oil content in the studied thyme variety. The results of the study have practical value for the development of specialized lighting protocols in the high-tech production of standardized medicinal and essential oil raw materials with desired properties.

A comprehensive assessment of the effect of different light spectra on the growth, development, and nutritional composition of Mentha longifolia L. cv. “Vesenniy Aromat” (mint) and Melissa officinalis L. cv. “Limonnyy Aromat” (lemon balm) grown in hydroponic conditions in closed artificial agroecosystems was conducted. The growing period was 75 days for mint and 87 days for lemon balm. The photon flux density (PFD) in the range of 400–800 nm was ~140 µmol·m⁻²·s⁻¹, and the light period was 16 h. Five lighting options and four spectral color ratios were used in the treatments—blue (B), green (G), red (R), and far red (FR), and 3:66:27:4 (HPL (control)); 16:42:39:3 (White LED); 96:3:1:0 (Blue LED); 1:1:98:0 (Red LED) and 25:3:72:0 (Red + Blue LEDs)—in a growth chamber for cultivation with controlled environmental conditions. Under White LED, M. longifolia L. plants were compact, with a large number of leaves and high plant biomass. The effect of Red + Blue LEDs had a general trend for M. longifolia L. and M. officinalis L. in terms of improving plant morphology (leaf area, number of leaves, and plant biomass), elemental composition (contents of potassium, magnesium, calcium, and phosphorus) and reducing the accumulation of nitrates in the plants. Blue spectrum lighting significantly affected the content of leaf pigments, quercetin, rosmarinic acid, and essential oils of mint and lemon balm. Red spectrum lighting significantly reduced the accumulation of nitrates in the vegetative mass of plants. Precise regulation of metabolic processes, taking into account the spectral quality of light, can contribute to improving the economic efficiency of the growth, development, and productive potential of mint and lemon balm grown under controlled conditions.