Purpose. To study the economic and biological characteristics and to reveal the genetic potential of various hybrids of Chinese cabbage depending on the climatic zone of cultivation. Methods. In the experiment, hybrids of Chinese cabbage ‘Pioner F1’ (control), ‘Villi F1’, ‘Manoko F1’, ‘Orient Star F1’, ‘Vitimo F1’, ‘Sprinkin F1’, ‘Summer Highland F1’, ‘Suprin F1’, and ‘Richi F1’ were evaluated. The experiment was laid out in a randomized block design with four replications with a single plot area of 21 m2. The container seedlings (40 days old) were planted in the middle of April according to the scheme 70 cm by 25 cm. Results. Having been planted at the same time, seed germination over the studied hybrids was not simultaneous. The first sprouted seeds (4 days after seeding) belonged to hybrids ‘Villi F1’, ‘Manoko F1’, ‘Orient Star F1’, and‘Summer Highland F1’. Seeds of the other hybrids started active germination on the 5–6 days after seeding. The highest yield of the cabbage heads was obtained from hybrids ‘Villi F1’ (31.7 t/ha) and ‘Sprinkin F1’ (28.7 t/ha), which was 10.0 and 7.0 t/ha more than in the control variant. The yield of ‘Summer Highland F1’ was 24.9 t/ha and ‘Suprin F1’ 24.6 t/ha. Under the conditions of unstable soil moisture, hybrids ‘Villi F1’and ‘Sprinkin F1’ appeared the most productive and ensured yield increase of 10.0 t/ha and 7.0 t/ha, respectively, compared to the control; and crop commercial quality was high. The highest percentage of dry matter (DM) content was in ‘Summer Highland F1’ (6.2%) followed by ‘Sprinkin F1’ (5.9%), which was 1.1% and 0.8% more than in the control. There was no significant difference between the values of the total sugars content over the variants. They ranged between 1.7 and 2.1%, which was similar to the control values. The content of nitrates in the cabbage heads of the studied Chinese cabbage hybrids was within the tolerance limit and amounted to 600 mg/kg (raw mass). Conclusions. Phenological observations of plant development and their biometric indices, depending on the varietal characteristics, indicate that under the conditions of unstable soil moisture, hybrids ‘Villi F1’ and ‘Sprinkin F1’ were more yielding and ensured yield increase of 10.0 t/ha and 7.0 t/ha, respectively, compared to the control. The crop commercial quality was high. The long growing season of ‘Richi F1’ (93 days) did not affect the crop quality and yield and demonstrated the lowest productivity compared to the control and the other experiment variants.

Purpose. Comparative studies of the photosynthetic apparatus of winter wheat varieties of modern and earlier breeding in the relation to their productivity. Methods. Field, pot experiment, biometrical, gas analysis, analytical and statistical ones. Results. It is found that the modern high-yielding winter wheat varieties have a higher rate of flag leaf photosynthesis during generative period of development, particularly at grain filling period, improved ability to store assimilates in stem and effectively use them later for grain growth. The modern varieties form crop canopy with greater leaf area and chlorophyll indexes and larger photosynthetic capacity and maintain functional activity of photosynthetic apparatus longer at the end of the growing season. Conclusions. The superiority for grain productivity of modern high-yielding wheat varieties, originated from the Institute of Plant Physio­logy and Genetics, NAS of Ukraine, over varieties released before the “green revolution”, results from increased capacity and durability of functioning the crop photosynthetic apparatus, higher CO2 assimilation rate and optimization of source-sink relations in whole plant.

Purpose. Determination of optimum dozes of foliar fee­ding for each cultivar that will provide the highest output of standard rootstocks. Methods. Field, analytical and statistical ones. Results. The author presents the results of study of the hazelnut plant foliar feeding in the mother plantation for vegetative propagation with applying different carba­mide concentration combined with 0.1% potassium sulfate (1.50.4 m) in case of horizontal method of growing. Biometric indices of hazelnut layers were analyzed; the influence of each factor on their height and diameter was determined. The rootstocks output per 1 linear meter for each cultivar as well as optimum foliar feeding doze was defined (0.5% carbamide with 0.1% potassium sulfate). Conclusions. The highest output of standard rootstocks in the mother plantation for horizontal vegetative propagation was achieved when applying the foliar feeding with 0.5% carbamide combined with 0.1% potassium sulfate, particularly (thousand rootstocks per 1 ha) for the cultivars: ‘Sviatkovyi’ – 66.7, ‘Dolynskyi’ – 62.1 and ‘Darunok Yunnatam’ – 50.7. For ‘Koronchatyi’ cultivar, the use of 3% carbamide was the most efficient.

Scientifically validated items of growing technology disclosed for cos lettuce marketable products in the conditions of Forest-Steppe of Ukraine. Impact of environmental factors onto growth and development of Lactuca sativa var. longifolia L. plants. Sowing terms established for the seed of cos lettuce at field-seeded growing. Development parameters are quoted for plant productivity indices and marketable product indices for cos lettuce of national and foreign breeding. According to VCU characteristics a  typical model has been designed for the cos lettuce indices of suitability 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.

The article features the results of research on phenological observations, biometric parameters of growth and development of the plants of sugar sorghum Silosnoe 42 variety during the vegetation at different terms of sowing and seeding depth in the Forest-Steppe of Ukraine. In particular, we show data on ground germination capacity of the seeds, the duration of the interphase periods, tillering, plant height and the diameter of the stem. It was established that the planting of sugar sorghum in mid-May (the third sowing date) to the seeding depth of 4...6 cm enabled better plant development, as well as in these conditions the maximum values of plant growth and development were registered compared to the other test editions. Therefore, were would suggest the third term of sowing and seed depth 4...6 cm for growing the crop in this area.

Purpose. To conduct a comprehensive agrobiological assessment of broccoli hybrids Brassica oleracea L. convar. botrytis (L.) Alef. var. сymosa Duch. in terms of the key agronomic traits under the conditions of the Western Forest-Steppe of Ukraine. Methods. The object of the study was the following foreign broccoli hybrids: ‘Lucky F1’ (reference), ‘Batavia F1’, ‘Belstar F1’, ‘Monaco F1’, and ‘Rumba F1’. Phenological observations, biometric measurements, and records were conducted in accordance with the Methodology of Experiments in Vegetable and Melons (2001). Results. On ave­rage over the years of research, the highest yield was obtained from hybrids ‘Monaco F1’ (41.2 t/ha) and ‘Rumba F1’ (38.0 t/ha). A slightly lower yield was in ‘Belstar F1’ (32.3 t/ha) and ‘Batavia F1’ (29.6 t/ha). In general, all hybrids under investigation provided a significant yield increase (6.3–17.9 t/ha) compared to reference ‘Lucky F1’ (23.3 t/ha). The largest diameter of the main head was recorded in the hybrids ‘Rumba F1’ (19.7 cm), ‘Monaco F1’ (20.5 cm) and the smallest in ‘Lucky F1’ (14.3 cm). The weight of the main head of all hybrids was significantly higher than that of reference (295 g): ‘Batavia F1’ 451 g, ‘Belstar F1’ 477 g, ‘Rumba F1’ 514 g, and ‘Monaco F1’ 542 g. The weight of the side heads of the broccoli ranged from 328 g (‘Lucky F1’) to 807 g (‘Monaco F1’). The highest biochemical indicators of commodity product were provided by hybrids ‘Rumba F1’ and ‘Monaco F1’: the total dry matter content was 11.3 and 11.6%, soluble solids 6.4 and 6.7%, sugars 3.5 and 3.8%, and vitamin C 89.3 and 98.7 mg/100 g, respectively. Conclusions. Under the conditions of the Western Forest-Steppe of Ukraine, it is recommended to grow new foreign broccoli hybrids ‘Rumba F1’ and ‘Monaco F1’, which ensure high yield and quali­ty of commodity product. According to the results of the agrobiological assessment, a typical model of broccoli variety is proposed, which may serve as a project for the development of the evaluation form for ability indicators of Brassica oleracea L. convar. botrytis (L.) Alef. var. сymosa Duch. for distribution inUkraine.

Purpose. To study the effect of AKM plant growth regulator on growth, development and yield formation of sunflower (Helianthus annuus L.) hybrids in hybridization plots under the conditions of the Southern Steppe zone of Ukraine. Methods. Laboratory tests, field study, statistical evaluation. Results. The results of studies devoted to determining the optimal AKM concentration for the treatment of seeds of the maternal and paternal lines, the effect of AKM on field germination, biometric parameters of sunflower plants, seed quality (F1) and yield are presented. Three hybrids of the Ukrainian selection, such as ‘Alpha’, ‘Logos’ and ‘Persei’ were studied during 2014–2016. Optimal concentration of AKM (0.0015 g/l) was defined. The vigor of seeds processed by AKM was higher than in check variety by 0.8–12.8 р.р. (♂); 0.4–10.7 p.p. (♀), laboratory germination – by 2.3–6.1 p.p. (♂); 3.5–6.2 p.p. (♀). In 2016, the sunflower plant height for all variants exceeded this parameter to be obtained for other years of the study. This could be explained by the fact that HTC in 2016 for the BBCH 00–39 period was 1.4 times higher than in 2015. In general, hybrids as the studied factor considerably influenced sunflower yield, and the share of the hybrid (factor A) influence is 33%. This should be considered when selecting hybrids for sunflower cultivation technologies in the Steppe zone of Ukraine. Conclusions. Hydrothermal conditions of the year had the maximum impact on the formation of seed quality and yield of sunflower plants of the hybrids under study, but when using AKM growth regulator for presowing seed treatment, this negative impact was reduced by an average of 23%.

Purpose. To identify and describe the basic criteria for studying and assessing decorative and economic-and-biological characters of the genus Heuchera L. varieties in the context of introduction. Methods. Introduction procedure, analytical approach, morphological analysis and biometric data evaluation. Results. Aided by the comparative morphological analysis of introduced varieties of the genus Heuchera, significant differences in their characters were revealed, including plant height, height and width of the basal rosette of leaves, generative shoot height. There was a significant variation of such parameters as the number of generative shoots within one plant, the number of flowers on a single generative shoot, flowering abundance. Based on investigation findings, 17 groups of varieties were identified for the dominant color of adaxial surface of the leaf blade and 7 groups – for inflorescence color. According to phenological observations, Heuchera varieties groups were determined and the dates of commencement and duration of plants flowering were registered in the context of introduction. The results of these investigations are the necessary basis for the study and evaluation of this culture assortment, they are important in breeding and landscaping. Conclusions. Based on the results of investigations of morphological features of introduced species of the genus Heuchera, traits and parameters for varieties grouping were defined as well as decorative and economic-and-biological traits that should be evaluated.

Purpose. To investigate the variability of plant biometrics of cutting lettuce (Lactuca sativa L.) varieties depending on the concentration of microfertilizer Avatar-1. Methods. Field study, biometric technique, comparative approach, statistical evaluation, generalization. Results. Dependence of the plant height, the diameter of the leaf rosette, the number of leaves per plant, the leaf area of plants on the concentration of microfertilizer Avatar-1 was defined. Investigations of cutting lettuce ‘Afitsyon’ and ‘Concord’ varieties by Dutch breeding were conducted in 2016–2017 in the collection sites of the department of vegetable growing in the scientific-experimental field “Fruit and vegetable garden” of the National University of Life and Environmental Sciences of Ukraine. In order to determine dependence of plant biometrics of cutting lettuce varieties on the concentration of complex microfertilizer Avatar-1, the following scheme was used for the both varieties: variant 1 – water (control); variant 2 – 0,10% solution; variant 3 – 0,25% solution; variant 4 – 0,50% solution. Plants were treated with microfertilizer three times during the vegetative period. Alterations of plant biometrics of cutting lettuce ‘Afitsyon’ and ‘Concord’ varieties depending on the concentration of complex microfertilizer Avatar-1 was studied. Conclusions. It was found that in case of three-time plant treatment with complex microfertilizer Avatar-1 at the time of harvesting, the best plant biometrics was registered in variant 3 (concentration 0,25%) for the both ‘Afitsyon’ and ‘Concord’ varie­ties of cutting lettuce. The height of plants of the cutting lettuce in ‘Afitsyon’ variety exceeded this figure in ‘Concord variety by 1,1–1,4 cm. The concentration of microfertilizer had no significant effect on the diameter of the leaf rosette of ‘Concord’ variety (25,1–25,9 см). The diame­ter of the leaf rosette of ‘Afitsyon’ variety was 26,0–28,7 cm. In cutting lettuce, the largest leaf area per plant was registered in ‘Afi­tsyon’ variety (3516.5 cm2/plant) in case of plants treatment with 0,25% solution of complex microfertilizer Avatar-1 that exceeded this figure in ‘Concord’ varie­ty by 660 cm2/plant. The best plant biometrics of cutting lettuce of the studied varieties and optimal concentration of complex microfertilizer Avatar-1 (0.25% solution) was defined that is important for improving agricultural cultivation techniques.