Research staff All-Russian Scientific Research Institute of Vegetable Growing – Branch of the Federal State Budgetary Scientific Institution Federal Scientific Vegetable Center in collaboration with Russian state agrarian University – Moscow Timiryazev agricultural Academy conducted research (2014-2016) on the effect of fertilizers and plant growth regulators on changes in the quality of onions of the Pervenets F1, Bennito F1 hybrids and Poisk 012 F1 during storage. As a result of research, the greatest effect was obtained from the complex application of N90P90K90 in combination with trace elements (tenso-cocktail) and a growth regulator Zircon. This system allowed to obtain high biochemical parameters of onions. At the end of the 7 months of storage (October-may), the highest dry matter and sugar content and the minimum nitrate content was observed in Pervenets F1 onions, as well as in hybrid Bennito F1. In the latematuring hybrid onions Poisk 012 F1 at the end of storage, the dry matter content decreased to 6,8-7,3%, sugars to 3,6-4,1%, vitamin "C" to 3,2-4,9 mg%, and nitrates increased to 92,1 mg/kg, which led to a decrease in product quality and large losses of onions from diseases and natural losses (up to 48-59%). The main reason for these losses was the lack of maturity of bulbs,low solids and sugars during harvest. It is obvious that for long-term storage it is necessary to use bulbs with a dry matter content of at least 10%. It was found out that feeding of onions during the beginning of the formation of food organizations with potassium nitrate, treatment with a growth regulator of Zircon and a complex of microelements of tenso-cocktail contributes to better preservation of the quality of onions.

Relevance. Increased demand in Russia for common bean (Phaseolus vulgaris L.) varieties of domestic breeding has stimulated the Federal Scientific Vegetable Center of breeding to intensify research on the creation of new asparagus bean varieties of vegetable direction.Materials and methods. Four vegetable bean varieties – Secunda, Lika, Ulyasha, Si Bemol of the laboratory of selection and seed production of vegetable Legume crops of the Federal Scientific Vegetable Center were used as the material for the study. The counts and observations were made according to the Methodology of the State Variety Trial of Agricultural Crops, 1975. The count of productivity was carried out in the technical stage of ripeness by replications. Harvesting was carried out when the biological stage of ripeness was reached. Biochemical studies of plants were carried out in the laboratoryanalytical department of the FSBSI FSVC. The biochemical composition of vegetable bean (green bean) varieties was studied according to the following indicators: determination of the total content of water-soluble antioxidants, ascorbic acid, dry matter, polyphenols, monosaccharides, total sugar content and starch.Results. Evaluation of samples by aggregate factors contributes to the selection of the most promising and high-quality varieties for their introduction into production. As a result of the research of vegetable bean on the main economically valuable features and biochemical composition for the period from 2018 to 2020, the varieties Lika and Ulyasha were selected. They were distinguished by high productivity of beans and seeds. Green bean variety Lika was noted for the highest total content of water-soluble antioxidants, ascorbic acid and the total of sugars content, the green bean variety "lobio" Ulyasha - high content of polyphenols and the total of antioxidants in the alcohol extract. Stable high yield, adaptive potential and high quality of beans, confirmed by the results of biochemical evaluation, allow us to recommend these varieties for consumption by the population as part of the diet and as an alternative to meat and dairy products.

Relevance. When creating tomato varieties and hybrids, much attention is paid not only to the commercial component (yield, appearance and uniform ripening), but also to the taste qualities of the products. Salad tomato varieties with yellow, tangerine, and pink fruits are increasingly in demand. As a rule, these fruits do not store for a long time, so it is necessary to increase their storability and transportability. Fruits of this group of tomatoes have high antioxidant activity, which is due not only to the significant content of water-soluble antioxidants (such as ascorbic acid), but also carotenoids. The preservation of fruit largely depends on the dry matter content.The aim of investigation is to study biochemical parameters of tangerine tomatoes fruits under different ripening conditions.Materials and methods. Plants were grown in the greenhouse of Federal Scientific Vegetable Center. Biochemical characteristics of tomato fruits were studied during harvesting and after laying for storage in the milky ripeness phase according to the following indicators: dry matter, ascorbic acid, total content of water-soluble antioxidants, titratable acidity, monosaccharides, polyphenols and carotenoids.Results. The percentage of dry matter in tangerine tomato fruits does not change during storage, even increases slightly. The dry matter content of fruits from the open field is slightly higher than that of fruits from the greenhouse. The content of sugars and ascorbic acid in fruits with tangerine fruits after laying for ripening decreases slightly. However, the content of these compounds is higher in mature fruits immediately after picking than in fruits after ripening. The total content of antioxidants during ripening decreases, though not significantly (in 1.1-1.7 times).

Relevance. Tomato occupies a special place among vegetable crops in the world, including in the Republic of Dagestan. The article presents the results of research on the use of biostimulators of growth on the productivity of tomato plants in open ground conditions of the Tersk-Sulak subprovincion of Dagestan. The purpose of the study was to evaluate the effectiveness of the use of the biological product Relict R and Humate+7 on economically valuable indicators in the production of tomatoes of domestic selection in open ground conditions. Tomatoes were grown using conventional technology in open ground conditions.   Material and methodology. The research was carried out on the basis of the Tersko-Sulak subprovince of the Federal Agricultural Research Center of the Republic of Dagestan of the Kizlyar district. The soil of the experimental site is alluvial-meadow, medium-saline, medium loamy in mechanical composition. Agricultural technology is generally accepted in the Republic of Dagestan for tomato culture. The objects of research were tomatoes of the Voskhod VNIISSOKa variety, Relict R, Humate+7.   Results. The use of humic preparations accelerated the duration of the interphase period of germination-maturation, the difference in variants ranged from 6 to 11 days. The yield of tomatoes has shown that the use of biostimulants of growth gives a significant increase. Relict P turned out to be the most effective – the increase was 4.1 t/ha. The effectiveness of Humate+7 also exceeded the control yield and amounted to 2.3 t/ha, respectively. The use of the biopreparation stimulated the accumulation of dry substances in tomato fruits from 5.9 % in the control to 6.4-6.9 % in the experimental versions, the sugar content increased by 0.2 %. The studied preparations had a positive effect on the yield and quality indicators of tomatoes. According to the research results, it is recommended to use the Relict R – liquid humic preparation on tomato to increase yields and quality indicators in the conditions of the south of the country.

Relevance. The soil and climatic conditions of the Lower Trans-Volga region are considered favorable for melon growing and make it possible to obtain high-quality products. The purpose of the research was to create new competitive varieties and hybrids of melon and pumpkin.Materials and methods. The object of the research is new varieties of melon and butternut pumpkin created at the Bykovskaya melon breeding experimental station. Melon cultivar Osen and pumpkin cv. Zhemchuzhina were used as standards. The methods of creation are intervarietal hybridization, individual and mass selection. During the growing season, appropriate observations and counts were carried out.Results. As a result of many years of breeding work at the Bykovskaya cucurbits selection experimental station, a melon cultivar 251 and a pumpkin cultivar 509 have been created. both producers and consumers. Therefore, the obtained varieties were evaluated for taste, yield, resistance to biological and abiofactors of the environment, dry matter content, fruit size, fruit and pulp color. During the comparative assessment of the accessions, it was determined that the new varieties of melon and pumpkin exceed the standards in terms of the main economically valuable traits. The average yield during the study, in the melon cultivar 251, exceeded the standard by 47.8%. In the pumpkin cultivar, the average yield for three years of research exceeded the standard by 69.6%. In terms of taste, the new melon variety was at the level of the standard, the cv. Osen. A variety of butternut pumpkin exceeded the standard in all quality indicators. The susceptibility to powdery mildew in the melon cultivar varied depending on the year of research. The melon sample showed resistance to anthracnose higher than the standard by 16.4 and 18.6%, over the years of study. In the pumpkin cultivar, resistance to powdery mildew and anthracnose was higher than the standard, on average by 34.9% to powdery mildew and by 28.6% to anthracnose. Thus, new varieties of melon and pumpkin meet the modern requirements of the industrial melon industry, are resistant to environmental stress factors, common diseases, and have economically valuable traits.

Relevance. The study of the collection is one of the main sources of replenishing the source material for the breeding process. The presence of the necessary genetic traits can speed up the breeding process. Therefore, at the Bykovskaya melon breeding experimental station, the genetic diversity of melon plants is assessed and promising samples are selected for use in breeding.Materials and methods. The object of research was samples of table watermelon with an unconventional color of the pulp. The aim of the work is to study and isolate the source material of watermelon for use in the breeding process to create new varieties and hybrids of melon crops. In the course of the study, 12 varieties of table watermelon were identified from 33 varieties of the collection nursery, which are sources of economically valuable traits. The selection was carried out according to the yield, the rate of entry into fruiting, taste, color of the pulp.Results. In the course of the research, the obtained samples of table watermelon with an unconventional color of the pulp were evaluated according to a set of economic characteristics in comparison with the standards: Zenith and Sinchevsky. The analysis of the tested samples made it possible to identify 12 samples by economically valuable traits: 3 samples by early maturity and taste: White sugar lump, White wonder, Golden revenge F1; 7 samples with a high dry matter content, in terms of yield and large fruit: Moon and stars yellowflesh, Sweet Siberian, Orangeglo, Daisy, Clay county yellow meat, Mountain sweet yellow, Tendergold; 2 samples for color and pulp consistency: Early moon beane Bakerlneek, Tenderweet orange. The selected samples meet the modern requirements of the industrial melon growing industry, resistant to stress factors of the environment, good taste and consumer properties.Findings. The obtained experimental data will be used to create a genetic collection of watermelon according to the traits that determine the economic value of the gene pool for further use in the breeding process.

One of the most important crops among all types of Alliums is onion, the value of which is determined by the nutritional and medicinal properties. It is used not only as a seasoning for food, but also as a source of a number of biologically active substances. The biochemical composition of the bulbs and its green leaves in different periods of growth and development varies, depending on the variety, environmental conditions and agrotechnical methods of cultivation. Creation on the basis of interspecies hybridization of fundamentally new forms of Allium plants with a unique combination of genetic material allows to expand the possibility of selection of valuable genotypes in practical terms. The study was performed on plants of the inbred progenies I4-5 from BC1-2 bulbous forms of interspecific hybrids of Allium crossing combinations F5(A. cepa xA. vavilovii), F5(A. cepa x A. fistulosum). The biometric assessment was carried out after harvesting and drying the bulbs according to the "test Procedure for distinctiveness, uniformity and stability" according to the main breeding characteristics: the color of the dry cover scales of the bulb, the mass of the bulb, the shape of the bulb. As the standard used plant varieties Odintsovets. The biochemical composition of onion samples was determined by the content of dry matter, monosaccharides, the amount of sugars, ascorbic acid, antioxidants. Based on the biometric assessment of the forms of interspecific hybrids of onions, 5 forms were identified according to the uniformity of such features as the color of dry cover scales and the shape of the bulb weighing 50-60 g, which are a qualitatively new source material for breeding. In determining the biochemical composition of the isolated forms of interspecific hybrids of Alliums on the main breeding grounds found that the plants of these forms of onions indicators of dry matter (15%), monosaccharides (1.15-1.71%), the amount of sugars (11.17%), were at the level of the standard, or exceeded it, but the total content of antioxidants (8.22 mg/g) inferior to the standard.

Research work is underway to create pumpkin varieties satisfying the requirements of consumers and the processing industry in Bykovskaya Melons and Gourds Experimental Breeding Station. The aim of the research was to develop pumpkin varieties with high content of dry matter and carotene, resistant to stresses and suitable for use in the food processing industry. Romantica is the variety resulted from breeding program, based on comparative characteristics of ‘Romantica’ and standard variety of Volzhskaya Seraya 92. New pumpkin variety ‘Romanctica’ exceeds the standard in contents of dry matter by 1.2%, sugars by 1.34%, sucrose by 1.73%, carotene by 46.44 mg%, yield by 0.5 t/ha. On the resistance to powdery mildew in artificial infection of sort of Romance has surpassed the standard by 11%, score at 0.4.

Dagestan is the largest region with irrigation system of agriculture in Russia. Irrigated lands provide 70% of total plant production. The field cultivation is carried on arable land in plain region of the republic. The drip irrigation as an ecologically safe technology for watering is regarded as major means for vegetable production farming. This approach maintains the propitious level of water and air in the soil without surface and deep drainage of irrigating water. These irrigated lands are expected to be used first of all for valuable and profitable crops such as tomato that is a leading crop in Dagestan. The experimental work was carried out at OOO ‘Dagagrocomplex’, Aleksandro-Nevskoye, in Tarumovskiy region. The aim of the study was to determinate the optimal dose of mineral fertilizers and the way of their application to improve the productivity without quality loss. The complex analysis of the technology for tomato production under drip irrigation through nontransplanting culture showed its high efficiency, because volume and quality of yield directly depended on soil moisture and precise supporting of mineral nutrition rates. The maximal yield of tomato fruits, 88.7-94.5 t/ha was observed with once mineral fertilizer application at a dose of N180P135K60 with soil humidity 70-80% (field moisture capacity), and also at the dose of N180P135K60 with basic application of N100 in nutrition rate. The result of the study showed that the optimization of two factors, namely soil water rate and mineral nutrition, enabled to produce additionally 39.2 t/ha. It was shown the tight connection between yielding and its quality; when yielding 95 t/ha, the increased contents of dry matter to 7.01%, sugar to 3.8% vitamin C to 18.46% were noticed. The high quality of produced output was supported by pre-watering threshold of moisture at 75-80% (field moisture capacity), when once fertilizer application at a dose of N180P135K60.

Relevance. The priority direction in vegetable growing is the scientifically justified use of types and doses of micronutrients that can increase the yield of watermelon fruits and improve their quality. Due to the large number of different types of fertilizers currently appearing on the market, it is necessary to choose the right ones and study them in optimal doses for growing high-quality melon products.Material and methodology. Objects of research: watermelon varieties Meteor, Zemlyanin, Kholodok and preparations: iron chelate, zinc chelate, vegetable Aquarin. Options using these fertilizers for double foliar treatment of plants during the growing season have been studied. The research was carried out during 2019-2021 at the Bykovskaya melon breeding experimental station.Results. During the study, a positive effect of the tested drugs on the quantitative and qualitative indicators of products was established. As a result of foliar treatments of plants in all variants, the yield exceeded the control variant (without treatments). A comparative analysis of biochemical data showed that the dry matter content was at a fairly high level. As a result of the use of zinc chelate in the Meteor and Kholodok cv., the dry matter content increased by 0.4%. A similar increase in the indicator was obtained when using the drug Aquarin vegetable on the Zemlyanin and Kholodok cv. The content of total sugar in the Meteor and Kholodok cv. was higher than the control (without treatments), and in the Zemlyanin cv. it was at the control level. The fructose content in the tested variants of all varieties exceeded the control. As a result of the use of water-soluble fertilizers for plant treatment, the content of ascorbic acid increased in the variants with treatment in the Meteor cv. – by 1-1.5 mg%, in the Zemlyanin cv. – by 0.8-1.1 mg%, in the Kholodok cv. – by 0 .1-0.7 mg% compared to control (without treatments). Nitrate levels in watermelon fruits of different ripening periods did not exceed the maximum permissible concentration (60 mg/kg).