Purpose. To establish the optimal seeding time and depth of ‘Dniprovskyi 39’ and ‘Vinets’ sorghum varieties, to prove their effect on the crop photosynthetic capacity in the Right-Bank Forest-Steppe of Ukraine. Methods. Field, laboratory, comparative, analytical, generalizing, mathematical and statistical. Results. It was proved that the best results of crop photosynthetic capacity of sorghum were obtained by sowing in the first decade of May (the second sowing period) at a seeding depth of 4–6 cm. Accordingly, the leaf surface area in these variants reached its maximum during the “panicle-blooming” period and equated 36.13–38.81 thousand m2/ha for the ‘Dniprovskyi 39’ variety and 34.23–36.91 thousand m2/ha for the ‘Vinets’ variety. By sowing seeds in the third decade of April (the first sowing period) at the seedining depth values described above the leaf surface area of the varieties was slightly smaller and amounted to 29.56–31.20 thousand m2/ha for the ‘Dniprovskyi 39’ variety and 27.76–29.40 thousand m2/ha for the ‘Vinets’ variety. By sowing seeds in the second decade of May (the third sowing period), the leaf surface area was 30.68–32.92 thousand m2/ha for the ‘Dniprovskyi 39’ variety and 29.08–31.32 thousand m2/ha for the ‘Vinets’ variety. The highest photosynthetic potential was obtained for sorghum plants in the second sowing period at the seeding depth of 4–6 cm and was 1.27 and 1.34 million m2/ha for the ‘Dniprovskyi 39’ variety and 1.16 and 1.22 million m2/ha for the variety ‘Vinets’. In the first sowing period, this indicator was slightly lower and amounted to 1.18 and 1.23 million m2/ha for the ‘Dniprovskyi 39’ variety and 0.98 and 1.02 million m2/ha for the ‘Vinets’ variety respectively. In the third sowing period, it was the smallest one and equated 1.09 and 1.13 million m2/ha for the ‘Dniprovskyi 39’ variety, and 0.88 and 0.93 million m2/ha for the ‘Vinets’ variety at the optimal seeding depth. The photosynthetic potential was lower at the seeding depth of 2 and 8 cm, which is explained by the different soil and climatic parameters during a certain period of sorghum plant vegetation. The highest value of the photosynthetic capacity net indicator was obtained by sowing seeds at the optimal time and the optimal seeding depth and it equated 3.84–4.02 g/m2 per day for the ‘Dniprovskyi 39’ variety and 3.79 – 3.98 g/m2 per day for the ‘Vinets’ variety. Conclusions. It has been established that the sorghum plants had better vegetation and formed photosynthetic capacity by sowing seeds in the first decade of May at the planting depth of 4–6 cm, which we recommend for growing this crop in the Right-Bank Forest-Steppe of Ukraine.

Purpose. To analyze the divergence of early maturing source material of corn Zea mays L. in heterosis breeding for the genetic base formation at the State Institution the Institute of Grain Crops of the NAAS of Ukraine. Methods. Field (comprehensive assessment of morphobiological and economically valuable characteristics of the source material and maize hybrids) individual selection, cumulative and recurrent selection, backross and testcrosses bree­ding methods; laboratory; analysis and synthesis; statistical. Results. The results of research on the analysis of the divergence of early maturing corn source material in the conditions of the Steppe of Ukraine has become a developed harmonized working collection of corn breeding samples adapted to the stressful conditions of this region. The gradual cyclical improvement of the lines made it possible to form the core of the genetic diversity of FAO 150–290 early maturing specimens of the southern ecotype, which are competitive in heterosis breeding. The complexity of breeding for early maturity in the steppe conditions is due to the lack of material adapted to the stress factors of the South of Ukraine. The available early maturing lines of the world collection F2, F7, Ер1, Ма21, Ма23, Со125, Со255, См7, PLS61, S72, etc., were distinguished by high cold resistance, good starting plant development, intensive accumulation of dry matter during ripening, but not adapted to the deficiency of moisture in the soil and high summer temperatures. According to the results of the experiment, it was revealed that, in terms of breeding, lines of Lancaster plasma (DK427 and DK633) were the most plastic, due to which a number of new mid-early lines were obtained, for example DK2/427, DK267, DK266/417, DK633/266, DK296, etc., which were included in the registered hybrids. Formation of the genetic base of early maturing maize source material for heterosis breeding and systematization accor­ding to different breeding characteristics provided a balance of samples of alternative components, which will be further used to model heterosis hybrids in the early maturing group. Conclusions. The updated basic collection of lines is represented by the samples of plasma Iodent: DK744SVZM, DK216SVZM, DK4173SVZM, DK235zS, DK257zM, SV, DK365SVZM, DK777ZMSV, DK733-7zM,SV, DK315SVZM; Lancaster: DK296zS,VM, DK633/266zS,VM, DK2965ZSZM, DK2953 ZSZM, DK3023 ZSZM, DK236zS,ZM; Raid (SSS): DK232MV, DK2323MV, DK239MV; Mixed: DK253ZSZM, DK273MV, DK272zS, DK281SV, DK233zM,SV, DK959MV, DK9527 ZSZM, DK247MV, DK2442MV, which is the basis of the genetic diversity of early ripening corn samples included in the State register of plant varie­ties suitable for dissemination in Ukraine.

In the article the authors present the results of the study biometric and qualitative characteristics of berries highbush blueberry varieties (Vaccinium corymbosum L.) in a specific soil and climatic conditions Forest-steppe of Ukraine (Kiev). Investigations were carried out on 11 varieties of American highbush blueberry. Phenological observations, biometric surveys, tasting score and biochemical analysis of the berries have been conducted during the growing season. By results of researches the group of early-ripening varieties includes Bluestar, Earliblue, Patriot, the middle-ripening – Jonne, Atlantis, Bluegold, Bluecrop, Chyk and late-ripening varieties – Amanda, Darrow, Toro. Duration of collecting period of ripe berries was lower (16 days) in varieties Bluestar, Earliblue, Jonne and Darrow. Berries were large sizes in the varieties of Darrow, Amanda, Jonne, in other varieties berries were medium size. By tasting score the berry of varieties Toro, Earliblue, Jonne and Darrow were the best. For biochemical parameters the better varieties were Amanda, Jonne and Earliblue.

208 potato varieties of domestic and foreign breeding have been examined on Ustymivska examination station of V. Yur’eva plant production Institute UAAS to determine their response during planting material use. By experiment research results was established different variety productivity depending on the origin of plant material and growing in different soil and climatic conditions, applying the special term »zone change growing plant material effect”. As a result of the three-year productivity of different reproduction locations the same varieties potato planting material assessment was founded that in most cases, superiority in performance were varieties that were grown from imported seeds. Experimental studies proved the impact on the productivity expression of physiological aging of the tubers used for planting.

The article explains the aim and objectives of parental components of maize hybrids identification in the course of soil varietal control. Scientific background has been provided to methodological aspects of comparative evaluation of morphological characteristics on control plots for the purpose of establishing authenticity of maize hybrids circulated at the market.

The article provides summary of post-registration research on Barley varieties in 2008-2009. Best varieties of Winter and Spring Barley for different climatic and soil conditions of Ukraine are specified, as well as their productivity subject to the influence of environmental factors.

The study of impact of complex application of biological compositions based on fixing nitrogen by microorganisms and plant lectin and nitric fertilizers on productivity and quality of grain of winter wheat on the dark-grey soil in the field terms was conducted. It is shown, that presowing treatment of seed by biological compositions stimulated forming of greater productivity with the best quality.

Purpose. To evaluate Tartary buckwheat variety ‘Kalyna’ according to morphological, productive and quality indicators in the conditions of the Research Center “State Agra­rian and Engineering University in Podilia”. Methods. The studies were carried out in the field crop rotation of the Research Center “Podillia” of the State Agrarian and Engi­neering University in Podilia (SAEU) in 2015–2020. The soil cover of the experimental field is represented mainly by low-humus, weakly leached soils. Experiment setting, material evaluation, analysis of plants, yield and grain quality were carried out in accordance with the generally accepted methods of state variety testing. An assessment of the Tartary buckwheat variety ‘Kalyna’ was carried out in comparison with the common buckwheat variety ‘Victoriia’. Results. The growing season duration of Tartary buckwheat variety ‘Kalyna’ was 87 days (38 days vegetative and 49 days gene­rative). In the studied variety, a larger number of the 1st order branches up to 5.5 pcs was observed. The number of leaves on the plant was 22–28 pcs./plants. In the studied variety, more than 50% of the grains were located on the main stem and the first order branches, while in common buckwheat this indicator was only 30%. Productivity was 2,28 t/ha, the number of grains in inflorescences was 4,4 grains, in common buckwheat – 0,72 t/ha, and 2.2 grains/inflorescence, respectively. The thousand kernel weight in Tartary buckwheat variety ‘Kalyna’ is 10.2 g less than in common buckwheat variety ‘Victoriia’ and is 17.4 g, with hulls – 19.5%, which is 3.2% less then in common buckwheat variety.Assessment of Tartary buckwheat variety ‘Kalyna’ for resistance to the effects of bio- and abiotic factors indicates that it was at the level of common buckwheat variety ‘Victoriia’.In terms of resistance to abiotic factors, ‘Kalyna’ variety is characterized by high resistance to spontaneous fallof grain (5 scores) and has simultaneous grain ripening (5 scores). Conclusions.The morphological and economic-biological indicators of Tartary buckwheat variety ‘Kalyna’ are significantly higher than the common buckwheat varie­ty ‘Victoriia’. It is recommended to grow Tartary buckwheat variety ‘Kalyna’ as a valuable cereal crop in the Western Forest-Steppe zone.

Purpose. To reveal the scientific bases of forming the conveyor production of commercial products of lettuce, Lactuca sativa L., varieties in the conditions of the Western Forest-Steppe of Ukraine. Methods. Field research was conducted during 2015–2017 at the research field of the Department of Horticulture and Vegetable Growing of the Lviv National Agrarian University in accordance with the Methodology on Experimental Techniques in Vegetable and Melon Growing (2001) and Methods of Expertise of lettuce, Lactuca sativa L., varieties. Results. It is revealed that the soil and climatic conditions of the Western Forest-Steppe of Ukraine contri­bute to the optimal growth and development of all lettuce varieties of the corresponding types, as evidenced by the structure of conveyor receipt of fresh commodity products to the consumer (first decade of April – first decade of November). The shortest growing season was provided by lettuce varieties var. secalina ‘Zorepad, ‘Malakhit, ‘Dublianskyi’, which have the shortest period from seedlings to technical ripeness (21–42 days). Therefore, varieties of this variation occupy the lar­gest share in the conveyor production of commercial products, which, with early spring sowing in open ground (April 14–20), comes to the consumer in the first decade of May. Winter sowing (21.11) ensured the receipt of fresh produce in the first decade of April. Commercial products by mass of edible organs, shape of the rosette of leaves (heads, stems), color, consistency and taste qualities corresponds to the technical requirements for Lactuca sativa L. Conclusions. The selection of varieties of lettuce for the conveyor production of commercial products should be carried out taking into account the variety of the corresponding type, ripeness group, and timing of sowing. The receipt of fresh lettuce to the consumer is directly dependent on the timing of seeds sowing (early spring, late spring, summer-autumn and winter).

Purpose. Developing technology for clonal micropropagation of peppermint (Mentha piperita L.) plants of Ukrainian breeding based on the complex of methods of isolated tissue and organ culture in vitro. Methods. During the experiment, such methods as isolated tissue and organ culture in vitro, clonal micropropagation, detached scion grafting, chemotherapy with adding of virucide Ribavirin to the nutrient medium, biometric and statistical ones were used. Results. The stepped procedure of sterilization that we have developed allows to receive 88–100% of sterile explants. For M. piperita L. introduction into culture and clonal micropropagation, Murashige and Skoog (MS) nut­rient medium appeared to be optimal supplemented with 6-benzylaminopurine (0.75 mg/l), adenine (0.05 mg/l), indole-3-acetic acid (IAA) (0.05 mg/l) and gibberellic acid (0.5 mg/l) on which the reproduction ratio on the 28th day ranged between 1:7 and 1:15. For recovery of plants from viral infection, virucide Ribavirin at concentration of 10 mg/l was added to the nutrient medium. The proposed nutrient medium for rhizogenesis, that contained IAA (0.5 mg/l) and indole butyric acid (IBA) (0.5 mg/l), allows to obtain the frequency of rhizogenesis up to 84–100%. Regenerated plants were adapted to the conditions in vivo on substrate peat : universal soil : perlite : sand in the ratio 2:1:1:1. The survival rate for peppermint varieties amounted to 96–100%. Conclusions. Biotechnological scheme was developed that permits to get healthy, purebred planting material and intensively propagate plants for supplying breeding programs of the Experimental Station for Medicinal Plants of the Institute of Agroecology and Environmental Management of the National Academy of Agrarian Sciences of Ukraine, among which such varieties as ‘Lebedyna pisnia’ and ‘Ukrainska pertseva’ were selected as the most promising for clonal micropropagation.