Vol 8, No 3 (2023)

The purpose of the research is to develop methods for increasing onion productivity and minimizing the content of heavy metals in products by introducing phosphogypsum on chernozem soils of the southern agroclimatic zone of the Samara region. It was revealed that the onion of the Coabo F1 hybrid under conditions of sufficient moisture on chernozem soils produces a sufficiently high yield – 53.0 t/ ha. Due to the application of FG, the sulfur content in the soil increases: at a dose of 2 t/ ha, it increases 1.6 times and grows dynamically with an increase in the dose of FG, the maximum increase (5.5 times) was noted with the application of 10 t/ha – 124.3 mg/kg. With a low availability of movable sulfur in the region and a shortage of the element in the soil, FG can be considered as a source of this element. Regarding the dynamics of the gross content of heavy metals, it was found that when FG is applied, there is practically no increase in the amount of Zn, Ni, Cu in the soil, and the Cd content decreases. The amount of Pb decreases by 1.7 times – from 13.0 to 5.0 mg/kg. The gross content of all heavy metals and the number of their movable forms in all variants does not exceed the established MPC. The application of phosphogypsum in combination with mineral fertilizers helps to increase the onion productivity. The application of phosphogypsum into the soil against the background of the use of mineral fertilizers provides an increase in the yield of onion of the Coaba F1 hybrid in the range of 14.0-19.5% (or 26.9-33.9 t / ha), the highest yield was obtained in the variant with the application of 8 t / ha of phosphogypsum – 57.5 t/ ha. The use of phosphogypsum helps to increase the calcium content, improve the structure of the soil and increase the yield and quality of vegetable crops.

The aim of the research is to increase the yield and resistance to the stress factors of ammi majus with the application of growth regulators and microfertilizers in the conditions of the Middle Volga region. Obtaining stable yields, the value of which corresponds to the biological potential as much as possible, is an urgent task of modern medicinal crop production. The instability of weather conditions and the deterioration of the general environmental situation have a negative impact on the growth and development of medicinal crops, leading to a decrease in the resistance of plants to stress factors and the inability to fully realize their potential in cultivated varieties. In this regard, in medicinal crop production, in the development of progressive growing technologies, great attention is paid to the use of natural bioregulators for the treatment of seeds and vegetative plants with different active substances. On the territory of the collection nursery of the Central Volga branch of the Federal State Budgetary Institution VILAR in 2020-2022 the experiment was conducted to study the influence of Zircon, Albit and Siliplant growth regulators on the resistance of plants to unfavorable growing conditions, and an increase in the yield of ammi majus fruits. The experiment and observations were carried out in accordance with the methodological instructions. During the years of research, weather conditions were extreme with high temperatures and no precipitation. Stimulation of plants with studied preparations increased height of plants by 1.1-6.0%, number of umbrellas by 5%, weight of fruits in one umbrella by 7.1-22.0%, yield by 10-26%. Over three years of studies in raw materials in the Middle Volga region, when laying the generative organs, the most optimal conditions were developed for ammi majus, the large seeds of which were treated with the Albit growth regulator at a dose of 0.03 l/t. The fruit yield in this case was 804 kg/ha, which is 164 kg more than the control group.

The purpose of the study is to improve the quality of embedding of the upper horizon during tier tillage. The work examines the quality of topsoil embedding with tiered plows: a serial PNYa-4-42 plow and a combined plough with a frictionless lower-tier hull. To determine the profile of the furrow at the beginning of the experiment, an even section of the field was selected. In this area of ​ the field, one working stroke of the unit was carried out. Then, to create a coordinate system, four posts were installed on the field, two (furrow posts) on the treated part and two (field posts) on the untreated part of the field. Racks with a scale were laid and fixed on furrow and field posts, forming coordinates in the longitudinal direction. To determine the coordinates of movement of the upper and lower soil layers, a developed private technique for laying numbered chips was used. Chips up to 0.02 m in size were located in two levels the first level on the soil surface, the second at a depth of 0.08...0.10 m. 8 rows of 6 chips in a row were laid. Comparative analysis of soil tillage by tiered plows confirms the effectiveness of tools in weed control due to high-quality filling of weed vegetation seeds with transportation of the topsoil to the furrow to the specified depth of tillage. At the same time, treatment with a plow PNYA-4-42 allows embedding to a depth of more than 0.2 m 86.1% of the seeds of weed vegetation, and experimental tier tillage with a combined plow allows embedding to a depth of more than 0.2 m 96.6% of the seeds which is better in the quality of embedding with a special serial tiered plow. Combined plow makes it possible to provide better embedding of topsoil with contained seeds of weed plants, which can increase efficiency of weed vegetation control, as well as find its application in technologies providing embedding of organic and mineral fertilizers into root layer.

The purpose of the research is to improve the quality of sowing grain crops by developing and using a pneumatic seeder coulter, which allows to increase the uniformity of seed distribution over the sowing depth. The well-known designs of foot, single-disc and double-disc coulters have significant traction characteristics, however, they cannot provide a suitable copy of the terrain of the field, forming an extensive furrow that is not easy to close up. All of the above has a negative effect on the uniformity of the distribution of seeds of grain and leguminous crops both along the length of the row and in the depth of the embedding. It has been established that a promising direction for improving the performance of a sowing machine or unit is to equip grain seeders with disc coulters, along the contour of which there are grooves in the form of an epicycloid. The article presents the design of a disc coulter developed at the Department of Mechanization of Technological Processes in the Agro-Industrial Complex of the Penza State Agrarian University, which has a novelty confirmed by an expert examination, in connection with which a decision was made to grant a patent for utility model №215855. The coulter disc has grooves in the form of an epicycloid along the contour for a qualitative process of furrowing and crumbling of soil containing a large number of crop residues and soil elements of large fractions. A graphic image was obtained, according to which it was found that it is advisable to choose a coulter disc with a radius of 225-250 mm – at the same time it is possible to work with soil elements up to 30-32 mm, but if larger soil elements appear on the surface of the field, they will collapse due to the presence of grooves along the contour made in the form of an epicycloid.

The purpose of the research is to substantiate the effect of the estrogen–type drug fulvestrant on the somatometric parameters of the offspring of laboratory mice. To conduct experimental studies, the offspring of laboratory mice was used, whose mothers were injected with an estrogen-type drug fulvestrant at a dose of 100 mcg/kg once intramuscularly on the eleventh day of pregnancy. Two groups were analyzed. The first (n=15) is intact – without exposure. Animals of the second experimental group were administered once intramuscularly fulvestrant 0.4 ml 0.0005% at a dose of 100 mcg / kg (F-100 mcg / kg). Male and female offspring at the age of one month were separated and raised in groups until puberty. Males and females were placed in separate cells with the appropriate labeling of the injected drug. Somatometric studies were carried out on the resulting offspring – body weight (g), body length (mm), head length (mm), tail length (mm), right hind foot length (mm) and anogenital distance (AGR) (mm) were measured. Analysis of somatometric parameters of male offspring of laboratory mice showed that body weight decrease by 21.5% (p <0.05), body length decrease by 13.1% (p<0.05), head length decrease by 8.1%. The anogenital distance increased by 18.1% (p<0.05). Analysis of somatometric parameters of female offspring of laboratory mice showed that there was a decrease in body weight by 21.4% (p <0.05), a decrease in the anogenital distance by 13.4% (p< 0.05). The resulting male and female offspring at the age of one month of postnatal development as a result of injection to pregnant mothers of the estrogen-type drug fulvestrant at a dose of 100 mcg/ kg had changes in somatometric parameters due to the effect of the administered drug. The results of the study make it possible to use the experimental data obtained to search for means of correcting reproductive dysfunction in postnatal development. Limiting the administration of estrogenic drugs during pregnancy will provide an opportunity to avoid adverse effects in postnatal ontogenesis in female and male offspring.

The purpose of the research is to scientifically substantiate the change in the hair cover of bulls of different productivity directions depending on age and season of the year. Performing a heat-protective function, the hair cover of cattle changes with the age of animals, most of all according to the seasons of the year as a result of spring and autumn molting. In this regard, it is necessary to know what factors influence these changes, what changes occur in the morphological structure of the skin and its derivatives. To achieve this goal, three groups of 15 heads each were formed from newborn bulls of black-and-white, Bestuzhev and Kalmyk breeds at the livestock complexes of the Republic of Bashkortostan and the Samara region. Hair quality, histological and morphological structure of the skin were studied in experimental animals aged 8, 12, 18 months. It was found that at the age of 8 months, the thickest wool was in Calmy bulls. At the age of 12 months, after the change of winter hair cover to summer, the density decreased in animals of group I by 480 pcs./ cm² (35.6%), group II – by 671 pcs./ cm² (42.9%), group III – by 537 pcs./ cm² (31.8%). By the age of 18 months, after the autumn molt, the density increased again, respectively, by 601 pcs./ cm² (69.3%); 833 pcs./ cm² (93.3%); 646 pcs. / cm² (56.1%). Histological studies of the skin have shown that the signs characterizing the quality of the hair cover are due to differences in the structure of the skin, as well as the number and location of the glands of the skin. Therefore, when choosing the method of keeping bulls, it is necessary to take into account these features of the skin and hair of the studied breeds.