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 create and study genotypes of the secondary triticale of the hexaploid level for their effective use in further breeding and plant growing. Methods. Field study, laboratory analyses, intraspecific hybridization with subsequent individual selection. Results. New genotypes of the secon­dary triticale of the hexaploid level have been created and characterized for economic characters and agroecological traits and properties. Series of short-stem winter triticale was represented by ‘Pshenychne’, ‘Chaian’ to be adapted to the conditions of both intensive and organic farming. They are characterized by high drought resistance and winter hardiness, resistance to lodging, grain shedding, grain germination in the spike and spike fragility as well as by immunity to fungal diseases providing a high level of yield and technological quality of grain. The following new constant forms of triticale as ‘ПС_1-12’, ‘ПС_2-12’, ‘ПС_3-12’, that have an average height of the stem and belong to the Polissia-Forest-Steppe and Forest-Steppe ecotypes, demonstrated high productivity and adaptability in organic farming, particularly in case of the use of biologized elements of agrotechnology. Conclusions. For the creation a new parent material during breeding of hexaploid triticale, the method of intraspecific hybridization is desirable with the use of parent material to be contrasting for eco-geographical origin and adapted local forms, followed by individual selection of genotypes with the desired characteristics and properties in cleavable hybrid populations. New genotypes of the secondary triticale have been created and characterized for breeding, genetic and agroecological traits and properties. In breeding practice, it is advisable to use a whole new approach of agroecological and genetic certification of genotypes for the effective solution of a number of theoretical and practical tasks facing modern ecological and adaptive breeding. New parent material of the secondary winter triticale and scientific support for its cultivation is proposed for further breeding and plant growing.

Purpose. To investigate features of commercial head quality formation in varieties of cutting lettuce (Lactuca sativa var. capitata L.) for different growing methods. To study the influence of growing methods for cutting lettuce plants on the weight of commercial heads, indices of yield and quality of freshly harvested products. Methods. Field study, laboratory testing and statistical evaluation. Results. The results of studying peculiarities of head formation in such cutting lettuce varieties as ‘Godar’ (control), ‘Smuhlianka’, ‘Olzhych’ and ‘Dyvohrai’ were shown. Based on the results of phenological observations, the duration of interstage periods of growth and development of cutting lettuce plants was determined for the different growing methods. The model of cutting lettuce of capitata variety for different growing methods was presented in terms of biochemical parameters (content of dry matter, vitamin C, nitrates, amount of sugars). The influence of growing methods for cutting lettuce plants on the commercial head weight, indices of yield and quality of freshly harvested products was studied. Obtained results confirmed that in early ripening varie­ti­es the heads were smaller (150 g) and not dense, in late ripening varieties they were large and dense, weight was 150–500 g. Freshly harvested commercial products of head lettuce in case of seedling cultivation was characterized by a slight increase in dry matter content by 0.15–0.29%. The corresponding pattern was observed for the total sugar content. Its amount was slightly higher: 1.3–1.9% in case of direct sowing and 1.6–1.9% – for seedlings cultivation. The content of ascorbic acid (vitamin C, mg/100 g) was the highest in the ‘Dyvohrai’ variety despite of the method of growing. The largest quantity of nitrates in lettuce heads was in the inner stem (480 mg/kg), while in the middle of the head it was reduced to 110 mg/kg. Conclusions. Freshly harvested heads of cutting lettuce were analyzed for the content of such basic biochemical indices as dry matter, vitamin C, protein, nitrates, amount of sugars. Biochemical characteristics of freshly harvested products of heading lettuce in case of direct sowing and non-seedling methods of growing were within the error being almost identical with minor deviations. According to the study results, a typical model of capitate lettuce variety was designed which will have practical application in qualification examination of plant varieties.

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.

Purpose. To develop a tobacco variety model with optimal inflorescence traits such as size and shape that will allow to increase seed productivity of the crop. Methods. Statistical and mathematical (correlative, regressive) ones. Results. Basic collection consisting of 282 variety samples registered in the National Genetics Center was evaluated, optimal parameters of inflorescence were defined that can provide a high seed yield. During statistical analysis, correlation matrix was developed with the purpose to highlight traits that correlate with inflorescence productivity. According to the results of correlation analysis, a strong relationship between the width and height of inflorescence (r = 0,773±0,038) was established. Somewhat weaker correlation was observed when modeling regressive relation between inflorescence height and width, where regression showed the medium relationship. Regression equation of these traits is as follows: y = 0,5585x + 8,4649. Inflorescence density (r = 0,646), height (r = 0,556) and width (r = 0,527) also had quite a high positive effect on seed productivity. The results of regression analysis pointed to the fact that there were a linear relationship between inflorescence size and seed productivity. Conclusions. Among 282 samples of basic tobacco collection, 29 varieties with high seed productivity was defined which can be used in the breeding process, and ‘Sobolchskyi 15/21’, ‘Ergo 23’, ‘C-11’, ‘Sygarnyi 99’ varieties were selected for large-scale implementation into the production of raw material of cigar type.

Purpose. To obtain Miscanthus sacchariflorus (Maxim.) Hack and Miscanthus sinensis Andersson in vitro culture by indirect morphogenesis. Methods. Biotechnological procedures, mathematical and statistical analyses. Results. Composition of nutrient medium was developed intended for induction of callusogenesis from Miscanthus seeds with a poor germination and viability of seedlings – Murashige and Skoog (MS) medium was modified for the amount of macroelements (half-dose) that was supplemented with amino acids (300 mg/l of glutamic acid, 50 mg/l of aspartic acid, 5 mg/l of tyrosine, 3 mg/l of arginine, 2 mg/l of hydroxyproline) and plant growth regulators [2,5 mg/l of 2.4D (2.4-Dichlorophenoxyacetic acid), 0,6 mg/l of BAP (6-Benzyl-aminopurine) and 0,3 mg/l of ABA (Abscisic acid)]. Composition of nutrient medium was developed for regeneration of microplants from callus – agar MS medium was modified for the amount of macroelements (half-dose) supplemented with vitamins: 10 mg/l of thiaminum, 1,0 mg/l of pyridoxine, 1,0 mg/l of nicotinic acid (by White), 1,0 mg/l of ascorbic acid, 250 mg/l of glutamic acid, 2,0 mg/l of BAP, 0,3 mg/l of NAA (Naphthaleneacetic acid). On this medium, 100% regeneration of M. sacchariflorus (Maxim.) Hack and 50% regeneration of M. sinensis Andersson was obtained. Due to media modification aimed at initiating callusogenesis and microplants regeneration, reproduction factor of M. sinensis was increased 20 times at the average, M. sacchariflorus – 35–40 times. Conclusions. Plants of M. sacchariflorus (Maxim.) Hack and M. sinensis Andersson were obtained in vitro culture by initiation of callusogenes and microplants regeneration from the Miscanthus seeds with poor germination and viability on nutrient media of certain composition.

Purpose. To assess the demand for sorghum seed material and sufficiency of domestic seeds. Results. The analysis of the State register for the period of 2002–2012 showed that there was the tendency not only towards increasing quantity of sorghum crops in general but their substitution by hybrids of foreign breeding. During the period from 2002 to 2017, 72 sorghum varieties were entered on the State register in total, among them only 12 varieties were of domestic breeding, the rest 60 was presented by foreign breeding institutions. Investigation results allowed to determine that the production of base and prebase seeds of sorghum in 2010 amounted to 1,3 t, in 2016 was 43 t. During the same period the production of sugar sorghum increased from 0,2 to 12,0 t, grass sorghum – from 4,0 to 83 t. In 2017, requirements of acreage of such crops as grass sorghum and broomcorn were completely satisfied by the amount of grown seeds. At the same time, the need for seeds of sorghum and sugar sorghum can not be covered completely at the expense of domestic varieties reproduction. In 2017, general demand for sorghum seeds was 400,5 t, among which only 42,0 t was of domestic production. The rest demand for seeds will be met at the expense of import of foreign breeding seeds into the country to be grown and prepared for sowing abroad. Conclusions. In the Register of plant varieties suitable for dissemination in Ukraine, there are 72 sorghum varieties among them only 12 varieties were of domestic breeding, that is 17%, as compared to 83% of recommended great sorghum varieties of foreign breeding. In Ukraine, the area occupied by sorghum cultivation was 22,8 thou ha in 2005, up to 2017 it increased to 89,0 thou ha, and accordingly the demand for seeds run up from 102,6 to 400,5 t. The area occupied by the sugar sorghum in 2005 amounted to only 2,6 thou ha, in 2017 – 20,0 thou ha, that accordingly determined increase of demand for seed material from 13,0 to 99,9 t. In 2017, the part of the area where domestic hybrids of sorghum are growing was 10%, hybrids of sugar sorghum – 12%, that was indicative of very poor situation with domestic varieties dissemination.

Purpose. Analysis of the process of hexaploid triticale breeding for winter hardiness by intraspecific hybridization method using systemic ecological tests under contrasting conditions. Methods. Dialectical investigation, field experiments, laboratory testing and statistical evaluation. Results. The results of breeding winter and alternate triticale varieties possessing a complex of valuable traits by the method of intraspecific hybridization of forms of different types of development using systemic ecological tests under contrasting conditions (Forest-Steppe – extremely arid Steppe) and at low temperatures were presented. During the years of research (1980–2005), 18 varieties were developed and transferred to the state testing, 17 of them were registered. Conclusions. Thus, the effective selection of highly productive genotypes with increased and high winter hardiness is possible from populations obtained by crossing hexaploid triticale of different types of development (winter triticale with spring and alternate ones) and contrasting level of frost and winter hardiness. During the period of 1980–2015, medium-tall and dwarf varieties of winter (‘Amfidyploid 256’, ‘Garne’, ‘Kharroza’, ‘Rarytet’, ‘Timofey’, etc.) and alternate (‘Nikanor’, ‘Yaroslava’, ‘Plastun Volynskyi’) triticales were developed. They are superior to the standard varieties of soft winter wheat for the critical temperature of freezing by -0.5...- 2.0 °C, characterized by increased (up to 9–12 t/ha) grain yield of various quality depending on the purpose of use.

Purpose. To obtain Miscanthus sacchariflorus (Maxim.) Hack and Miscanthus sinensis Andersson in vitro culture by indirect morphogenesis. Methods. Biotechnological procedures, mathematical and statistical analyses. Results. Composition of nutrient medium was developed intended for induction of callusogenesis from Miscanthus seeds with a poor germination and viability of seedlings – Murashige and Skoog (MS) medium was modified for the amount of macroelements (half-dose) that was supplemented with amino acids (300 mg/l of glutamic acid, 50 mg/l of aspartic acid, 5 mg/l of tyrosine, 3 mg/l of arginine, 2 mg/l of hydroxyproline) and plant growth regulators [2,5 mg/l of 2.4D (2.4-Dichlorophenoxyacetic acid), 0,6 mg/l of BAP (6-Benzyl-aminopurine) and 0,3 mg/l of ABA (Abscisic acid)]. Composition of nutrient medium was developed for regeneration of microplants from callus – agar MS medium was modified for the amount of macroelements (half-dose) supplemented with vitamins: 10 mg/l of thiaminum, 1,0 mg/l of pyridoxine, 1,0 mg/l of nicotinic acid (by White), 1,0 mg/l of ascorbic acid, 250 mg/l of glutamic acid, 2,0 mg/l of BAP, 0,3 mg/l of NAA (Naphthaleneacetic acid). On this medium, 100% regeneration of M. sacchariflorus (Maxim.) Hack and 50% regeneration of M. sinensis Andersson was obtained. Due to media modification aimed at initiating callusogenesis and microplants regeneration, reproduction factor of M. sinensis was increased 20 times at the average, M. sacchariflorus – 35–40 times. Conclusions. Plants of M. sacchariflorus (Maxim.) Hack and M. sinensis Andersson were obtained in vitro culture by initiation of callusogenes and microplants regeneration from the Miscanthus seeds with poor germination and viability on nutrient media of certain composition.

Purpose. To establish correlation dependence of influence of such factors as seeding rate, sowing time and seeding methods on yield indicators, as well as individual response of winter wheat varieties to them in case of the ecological system of seed production, that would allow to form elements of intensive varietal technology and obtain the genetically determined productivity potential of the variety in the future. Methods. Weight measuring was used to determine seed yield; the reliability of the experiment results was identified by statistical evaluation, analysis of variance and regression procedure. Results. During the period of investigation, the weather conditions differed significantly both for the temperature regime and the amount of precipitation, but the stability of grain and seed yield over years was the main requirement to varieties, that allowed to study the intergenotypic correlation relationships of crop yield indices and the dynamics of their changes under the effect of ecological factors. In the course of investigation, winter wheat yield indices were fixed annually from 684 plots, which were grouped and analyzed for factors of influence in order to ensure the complete certainty. Conclusions. Variants of investigation were defined for the certified seed yield and environmental factors (sowing time and seeding method, seeding rate), that had strong positive correlation relationships. Seeding rate and seeding method had the greatest impact on 1000 kernel weight. For tille­ring coefficient, varieties depending on the variant of the investigation had a negative close correlation relationship, which was greatly affected by seeding rate. For correlation relationships, winter wheat varieties ‘Bohdana’ and ‘Slavna’ appeared to be the most stable, ‘Chorniava’ and ‘Astarta’ were the most plastic.