Relevance. Many authors note the existence of significant genotypic differences in the assimilation of nitrogen and the accumulation of nitrates by lettuce, point to the additive-dominant nature of the inheritance of the trait. The aim of the work was to evaluate the response of lettuce of various cultivars to mineral nutrition stress created against a nitrogen-deficient background (N0) and with an increased dose of nitrogen (N200).Material and Methods. In a microfield experiment on well-cultivated soddy-podzolic soil, a collection of lettuce varieties belonging to the main cultivated variety types was studied. The varieties differed in geographical origin, early maturity and morphological characteristics.Results. Differences in yield between varieties against the background of N200 were 4.5 times, and against the background of N0 – 5.7 times. Against an increased background of nitrogen nutrition, the highest yield – 2.22-2.64 kg/m2 was formed by the following varieties: All the Year, Quedlinburger Dickkopf, Berlin Yellow, Great lakes. Against a nitrogen-deficient background, Azart and Odessa Kucheryavets varieties stood out in terms of yield, which absorbed soil nitrogen better than others. The content of nitrates in lettuce plants of different varieties varied more strongly when grown on the background of N200 and ranged from 10.7 to 13.6 times (on average over 2 years – 11,2 times), on the control of N0 – 33 times. Varieties accumulating maximum NO3 under conditions of excess nitrogen nutrition were revealed. Lettuce Romaine (Lactuca romana) – 353 mg/kg and White paris cus (198 mg/kg) had a low content of NO3. The period of the maximum increase in biomass also corresponded to the maximum decrease in NO3 in plants. Power function equations were calculated to estimate the rate of change in biomass and NO3 content. The results indicate that there may be some scope for NO3 reduction in lettuce through cultivar selection or breeding.

Relevance. Onions are a traditional vegetable crop that is in demand all year round. To obtain high and stable yields, it is necessary to renew the assortment of herbicides in the fight against weeds, to use compositions of preparations of different spectrum of action, toxic to the most harmful weeds and giving the maximum herbicidal effect with minimal labor and financial resources.Results. The article presents the results of tests of new herbicides Bandura and Boxer, unregistered in the Russian Federation on onions, at optimal rates, which showed high selectivity to the crop, but were inferior in efficiency to the Stomp Professional standard. The tank mixtures of Bandura and Stomp Professional with Dual Gold were more effective, exceeding the level of efficiency of the standard. Due to the action of the mixture Stomp Professional + Dual Gold (2 + 1 L / ha), the weediness of onion crops decreased by 78-89% (by quantity) and by 87 - 95% (by weight), which contributed to a significant increase in the yield of bulbs by 12.2% in comparison with control. The efficiency of Goal 2E 0.5 L/ha (42%) in the phase of 2 leaves of onion was insignificant due to the overgrowth of most annual dicotyledonous weeds by the time of treatment (3-10 leaves). The herbicide completely eliminated weeds at an early stage (up to 5 leaves), as well as older white and smoky grass. The remaining weeds experienced oppression in the form of suspension of growth, twisting and necrosis of leaves. Goal 2 E must be included in the system of protective measures against the background of pre-emergence herbicide treatment to suppress annual dicotyledonous weeds, poorly controlled by soil herbicides.

Relevance. The use of biological preparations in agricultural technology of agricultural crops contributes to the preservation of agrophytocenosis, reduces environmental pollution and has a positive effect on the growth and development of the plants themselves. In this regard, the determination of the effectiveness of the use of biological products in the presowing treatment of common bean seeds is relevant and timely.Materials and methods. In our study, we studied the effect of presowing treatment of common bean seeds with biological products: Polydon Bio Profi, Polydon Amino Mix, Polydon Aminomix, Alfastim on germination energy, germination, seed sprout size, number of roots and length of the root system. Three varieties were taken as objects of study: Athlete, Omichka, Sirenevaya.Results. A different effect of preparations on the time of seed germination was revealed. The average germination time in options 1-4 was higher than the control values for all varieties, i.e. drugs slowed down germination. The seeds of the tested varieties responded positively to treatment with Alfastim (option 5): the average germination time in Fizkulturnitsa and Sirenevaya decreased by 8.5 and 9.8%, in the Omichka variety by 45%, compared with the control. Among the tested varieties, it is necessary to single out the Sirenevaya variety, which has the highest germination energy (ES) from 90% to 100% and seed germination (VS) from 98-100% in all treatment options. The most effective treatment of the Omichka variety was in option 2 (EP-90%, germination rate 90%), the values exceeded the control by 5%. For all options, the germination energy of the Fizkulturnitsa variety ranged from 72 to 90%, germination from 73 to 93%. A positive effect of drugs on the germination of seeds of this variety was established. The defeat of bean seeds by mold fungi was noted. Seed damage is mild to moderate. Seed damage by mold fungi in the variants using Polydon Bio Profi was absent, or it was weak up to 3.3% for all tested varieties. Morphobiometric indicators of seedlings and their root system in all varieties developed more effectively on variants with the use of Polydon Bio Profi and Alfastim preparations, and their mixtures

Relevance. Foliar feeding when growing vegetables is due to its positive effect on quality and yield indicators. The use of microfertilizers for foliar feeding allows optimizing the absorption of nutrients by plants, which can not only reduce economic costs, but also regulate the accumulation of biologically active substances. Identifying the optimal fertilizing system for different varieties and hybrids of vegetables is especially important in risky farming areas, where the main factor regulating yield indicators is weather.Methodology. The purpose of the work is to conduct a comparative assessment of the effectiveness of foliar feeding of the white cabbage variety Zimovka 1474 different agrochemicals. In a field experiment for three years (2018-2020), the effect of microfertilizers, humate, chelates and a biostimulator on the yield, biochemical and microelement composition of white cabbage variety Zimovka 1434 was studied.Results. It has been shown that the biometric characteristics of cabbage are best influenced by foliar fertilization with microfertilizer Aquarin and the biostimulator BIS-65, and the total and marketable yield is influenced by microfertilizer in chelate form Helaton. The greatest accumulation of dry matter, sugars, and vitamin C was typical for variants using the biological product BIS-65 and chelated fertilizers (Tiaton, Helaton). Chelated fertilizers also contributed to an increase in the accumulation of elements such as potassium, calcium, iron, zinc and manganese in cabbage heads.

Spinach is an economically important vegetable crop widely cultivated and consumed worldwide. This early ripening leafy vegetable is rich in bioactive components, fiber, micro and macro elements, vitamins, and has high antioxidant activity. Results of numerous studies on the effects of spinach on human health confirm its beneficial effect. The species S. oleracea L. is cultivated commercially. The ancestor of cultivated spinach is S. turkestanica Iljin, which has a breeding potential for different economically valuable traits. Its biochemical composition has been studied extremely little. The present article offers a comparative evaluation of the biochemical profile and antioxidant activity of cultivated and wild spinach species. The material for the study was a representative sample of 48 collection accessions of spinach from the N.I. Vavilov All-Russian Institute of Plant Genetic Resources (VIR). The accessions were grown in 2019 and 2020 in the open ground of the Pushkin and Pavlovsk Laboratories of VIR. The antioxidant activity was studied spectrophotometrically by the DPPH assay of free radical scavenging at a wavelength of 515 nm. A significant similarity of the two species in most biochemical parameters was revealed, which confirms their phylogenetic relationship. Significant differences were found in the content of phenolic elements, which determine the elevated values of antioxidant and antiradical activity of S. turkestanica. The article presents correlation matrices of species biochemical composition, describes general trends, negative relationships and conjugated factors. The identified promising accessions of both cultivated and wild spinach are recommended for breeding for increased content of phenolic compounds, ascorbic acid and antioxidant activity. The result of the study helps to reveal the potential of the crop as a valuable source of bioactive components and high antioxidant activity.

The purpose of the study is to determine the growth, development and yield quality of sweet corn varieties and hybrids when grown in different mulching materials in the soil-climatic conditions of Karakalpakstan.Methods. Selected sweet corn Zamin variety and Megaton F1 hybrids were grown in different mulching materials in the fallow season and evaluated for their growth, development and productivity in the conditions of Karakalpakstan in 2018-2020. Mulching materials were selected for growing varieties and hybrids. According to the results of the selection, the varieties and hybrids with a positive conclusion were recommended for use in the production of cultivation in mulching materials.Results. In 2018‒2020, the selected Zamin variety of sweet corn and the Megaton F1 hybrid, when grown on different mulching materials, yield varied from 10.8 t to 13.1 t per hectare. The highest productivity was recorded when mulching with manure and black membrane, it was 11.5-12.2 t per hectare in the Zamin variety, and 12.4-13.1 t in the Megaton F1 hybrid. Cultivation of sweet corn mulched with manure and black membrane has the highest net profit (19509.0 - 21890.8 thousand sums and 22120.5-24150.9 thousand sums) and the highest yield (123,8-138.6% and 134.7-146.8%).Conclusion. It was found that sweet corn varieties Zamin and Megaton F1 hybrids have high productivity indicators when mulched with black membrane and manure in the main term for the soil and climate conditions of Karakalpakstan, and it was recommended for large-scale planting in farms.

Relevance. In the middle zone of Russia, industrial cultivation of pear fruits is almost not produced due to the lack of intensive rootstocks. In regions with a mild climate, this problem has long been solved by grafting pears on common quince, but in more northern regions, quince is not hardy enough. In recent years, as a result of the long-term work of VNIISPK scientists, winter-hardy rootstock forms of common quince have been obtained, capable of restraining the growth of grafts and accelerating their entry into the fruiting season. They have a wide prospect of being used to intensify the production of pear fruits in central Russia. However, the grafting of pears on quince is remote intergenerational and not all varieties can be cultivated on it due to different degrees of compatibility. There is no single methodology for determining compatible and incompatible graft-rootstock combinations of pear varieties with quince, therefore, it is an important and urgent task to identify signs by which non-viable combinations can be identified starting from the nursery.Materials and methods. The research was carried out in the conditions of the VNIISPK production nursery in 2008-2010; 2019-2022. The object of research was graft-rootstock combinations consisting of quince seedlings of ordinary selection of VNIISPK used as rootstocks and various varieties of pear collection of the Institute. Pear seedlings were used as a control. Propagation of varieties was carried out by the method of oculation at a height of 20 cm from the ground in the first decade of August. The repetition of the experiment is 3 times 30 plants in each. Agrotechnics of experience is generally accepted. In order to identify the most common signs characterizing the degree of compatibility of graft-rootstock combinations, starting from the awakening of the eyes of the graft, observations were made every 5-7 days on their development in a nursery.Results. In the course of observations, a number of additional signs were identified that can be indicators of positive or negative accretion of pear varieties with quince and on the basis of which it is possible to determine viable and non-viable graft-rootstock combinations already in the nursery. The conducted studies also made it possible to divide pear varieties into three groups of compatibility with quince: A – well compatible varieties. Their development on the quince rootstock is better than on the pear rootstock. B – satisfactorily compatible varieties. They can grow on common quince, that is, they can be viable graft-rootstock combinations, but there are some signs of their incomplete development. It is advisable to use a compatible insert rootstock, on which such varieties develop better. С – incompatible varieties. It is possible to grow such varieties on quince only with the use of a compatible insert rootstock. With direct grafting on common quince, such graft-rootstock combinations are not viable.

Relevance. Black currant (Ribes nigrum L.) occupies an important place in amateur gardening of the Komi Republic as an economically valuable crop. There is no doubt that it is possible and necessary to develop berry growing in the Komi Republic, to meet the needs of the population in multivitamin products through local production of berries. The purpose of the paper was to study the economically useful traits of varieties cultivated in the North in the conditions of the middle subzone of the taiga. Winter hardiness, phenological phases, productivity, large-fruitedness (berry weight), biochemical composition of berries were analyzed.Methodology. The results of the study of six varieties of black currant in 2020–2022 are presented. Plants are nine to ten years old. The research was carried out according to the "Program and methodology for the study of variety of fruit, berry and nut crops" (1999). Currants are planted in rows according to the scheme 4 x 1.5.Results. As a result of the research, it was revealed that the studied varieties of black currant are promising for cultivation in the middle subzone of the taiga. In all studied varieties, vegetation was observed in the second-third decade of April. The beginning of flowering was observed in the middle of the second – the end of the third decade of May, 25–39 days after the beginning of the growing season. The beginning of fruit ripening was noted in the first-second decades of July, 48-52 days after the start of the flowering. Mass ripening of berries was noted in the middle of the second – the end of the third decade of July, and the middle of the second-first decade of August for “Lazy” variety. During the study period, the vegetation of black currant ended in the second decade of October, with the onset of temperatures below 5°C. The duration of the vegetation period over the years of research was above the norm and equaled 169-185 days. The productivity of black currant varieties was 1.16-1.79 kg per bush. All varieties are characterized by large fruits (berries) weighing 1.02-1.66 g. A biochemical analysis of frozen berries of blackcurrant varieties for 2021-2022 was carried out regarding the content of ascorbic acid, sugars, acidity, solids. The maximum content of ascorbic acid was noted in “Vologda” variety – 97.68 mg%. The highest sugar-acid index was in “Bagira” variety – 3.5. All the varieties have a high content of dry matter in berries: 18.04-20.38%. Overall, the varieties of black currant under study suit for cultivation in the middle subzone of the taiga.

Relevance. Dagestan is a zone of prosperous agriculture, distinguished by the abundance of heat, sun and irrigation in the plain zone. Tomatoes occupy a special place among vegetable crops in the world, including in the Republic of Dagestan. Determinant varieties are now the most common in the production of tomatoes, especially in the open ground. The main areas of specialized cultivation of tomatoes in the open ground are concentrated in the Kizlyar and Derbent districts of plain Dagestan. In these areas, there are high average daily temperatures for the formation and ripening of tomato fruits in excess, which is favorably reflected in the overall productivity of the bushes. Whereas in the foothills of Dagestan, insufficient heat resources do not allow growing tomato varieties with a long growing season. In the foothill part of the republic there is a large labor-resource potential, vegetable growing, as a labor-intensive type of agribusiness, acts as a sphere of employment for a significant part of the rural population. The demand for tomato varieties with a short growing season in this part of the republic is great.Methods. The research was carried out on the basis of the Tersko Sulak subprovincion of the FGBNU of the FANC RD of the Kizlyar district. The soil of the experimental site is alluvial-meadow, medium-saline, medium loamy in mechanical composition. Agrotechnics is generally accepted in the Republic of Dagestan for tomato culture.Results. The method for the study was the new semi-stamp cultivars of FGBNU FNCO (VNIISSOK) selection: Fakel (counter), Blagodatny, Viking, Voskhod VNIISSOKa, Magnat, Severyanka, Sodruzhestvo, Perst, Patrice. According to the maturation dates, the samples were divided into three groups: very early – Severyanka, Blagodatny, Magnat, Voskhod VNIISSOK (97-100 days); early – Patrice, Viking, Perst (102-105 days); middle-early – Sodruzhestvo, Fakel (111-114 days). According to the type of bush, we have identified 5 ordinary and semi-lamb samples with a height of no more than 78 cm. Two samples had a height of 50-53 cm (Patrice, Perst) and an average fetal weight of 72 and 60 g. Three samples had a height of 70, 71, 72 cm (Voskhod VNIISSOKa, Blagodatny, Sodruzhestvo) and an average fetal weight of 107, 110, 130 g. According to the output of gross output, the best indicators were of the following varieties: Blagodatny – 86.3; Voskhod VNIISSOKa – 82.7; Sodruzhestvo – 77.6 t/ha; Patrice – 68.2 t/ha. The following grades had  a high yield of marketable products: Voskhod VNIISSOKa, Patrice – 92%; Blagodatny – 91%; Perst – 90%. The varieties also have a relatively high dry matter index of 5.3-6.4%.

Background. Various plant hormones are used (cytokinins, auxins) to increase the regeneration efficiency and the net reproduction rate of buckwheat in vitro. However, the growth and development rates of plantlets have been noted to be low under these conditions. For this reason, search for the plant extracts that are able to stimulate the regenerative ability of plants is a promising direction of biotechnological research.Materials and methods. Aseptic single-node cuttings of common buckwheat plantlets (varieties Dikul and Izumrud) were grown on MS nutrient media with plant extracts from Fagopyrum esculentum and Reynoutria japonica (0.1, 0.5, and 1%) for 21 days. The following morphobiological paramaters of the plantlets were evaluated: plant height, the number of internodes, the number of leaves, leaf length, and the number and length of roots.Results. Dealcoholized aqueous solutions of the extracts from F. esculentum and R. japonica in the studied concentrations (0.1-1%) significantly stimulated the growth and development of the buckwheat plantlets increasing their net reproduction rate (4.00-6.00) and rhizogenesis. The media with the plant extracts in concentrations of 0.1-0.5% were observed to produce the strongest positive effect. As the result, the morphobiological characteristics of the plantlets and the success rate of the micropropagation were the highest.