Purpose. To study the stability and plasticity of spring rapeseed varieties, in order to assess their adaptability potential in the Steppe, Forest-Steppe and Polissia zones, and also select the most ecologically plastic varieties among them. Methods. Field, laboratory, analytical and statistical. Results. Seven varieties of spring rapeseed, included in the State Register of Plant Varieties suitable for dissemination in Ukraine, were studied on indicators of plasticity and stability of yield traits, weight of 1000 seeds, protein and oil content. The highly plastic intensive varieties ‘DK 7150 CL’, ‘DK 7160 CL’ and ‘Sunder’ were selected for yield among the studied varieties, which are able to respond appropriately to changing of growing conditions. Varieties ‘DK 7150 CL’ and ‘DK 7160 CL’ belong to intensive varieties for the parameter of weight of 1000 seeds. The variety ‘Sunder’ was also highly plastic for this parameter. The varieties ‘Axana’, ‘Bilder’ and ‘CLICK CL’, according to their protein content, belong to the intensive type varieties that are capable of combining sufficiently high valu­es of the studied parameter with its stability under changing conditions. Variety ‘DK 7150 CL’, which was low-plastic, has a rather low positive value of the average group deviation of the reaction stability coefficient, therefore, it can be attributed to widely adapted genotypes. Varieties ‘DK 7160 CL’, ‘DK 7175 CL’ and ‘Sander’ belong to highly plastic intensive varieties in oil content. Varieties ‘DK 7175 CL’, ‘Builder’ and ‘CLICK CL’ are showed high stability for yield, varieties ‘Axana’, ‘Sunder’ and ‘CLICK CL’ for weight of 1000 seeds. The varie­ties ‘DK 7160 CL’, ‘DK 7175 CL’, ‘DK 7150 CL’ and ‘Sunder’ were highly stable in protein content, in oil content – varieties ‘DK 7150 CL’, ‘Axana’, ‘Builder’ and ‘CLICK CL’. Conclusions. It were established that high-intensity varieties for yield and weight of 1000 seeds in the Steppe, Forest-Steppe and Polissia zones are ‘DC 7160 CL’ and ‘DK 7150 CL’, for protein content – varieties ‘Axana’, ‘Builder’ and ‘CLICK CL’, for oil content – varieties ‘DK 7160 CL’, ‘DK 7175 CL’ and ‘Sunder’. The evaluation of the plasticity and stability of rapeseed varieties, which were included in the State register of plant varieties suitable for dissemination in Ukraine, makes it possible to select varieties that belong to the intensive type. According to the research results, varieties which are able to successfully adapt to the limiting environmental factors and stress in various soil and climatic zones have been selected.

Purpose. To study the morphological features and determine the biometric indices of leaves of English roses. Methods. Field, morphological, descriptive, biometric. Morphological descriptions were carried out in accordance with the Atlas of morphological features of rose varieties (Rosa L.) (2009) and the Illustrated Guide to Flowering Plant Morphology (2004). Results. The morphological features of the leaves of English rose varieties were determined. Quantitative (length of complex leaf, number of leaf plates, area of leaflet, total leaf area) and qualitative (leaflet shape, leaflet edge shape, leaflet base shape, leaflet tip) were studied. Varieties of English roses that have maximum and minimum values for these indicators were highlighted. Conclusions. The morphological features were revealed and the biometric indicators of the leaves of English roses from the collection of the State Dendrological Park “Alexandria” NAS of Ukraine were determined. The amplitude of variability of morphological characters of the studied varieties was determined. Peculiarities of the morphological structure and biometric parameters of leaves of English rose varieties can be diagnostic signs for determining varieties within the boundaries of the species. Plants with increased photosynthetic productivity of the leaf apparatus, which is characteristic of the ‘James Galway’ and ‘A Shropshire Lad’ varieties, have an advantage in landscaping.

Purpose. Identifying the features of the seasonal growth rhythm, development of the plants, morphological and biological differences in monoecious introduced and domestic varieties of Cannabis sativa L. in the North-east region of Ukraine. Methods. The research was conducted from 2014 till 2019. The following research methods were employed: field (phenological observations, sampling for laboratory analysis), microscopic (study of the morphological structure of glandular and cystolithic hairs on vegetative and generative organs, determination of the size and density of hair formation), laboratory and analytical (determination of the content of cannabinoid substances by thin layer and gas-liquid chromatography), biomorphological me­thods (analysis of morphological characteristics of plants). Chemical analysis for the content of cannabinoid substan­ces was carried out in the laboratory of the breeding and seed production department of the Institute of Bast Crops of the NAAS of Ukraine (Glukhiv, 2014–2019). The content of neutral substances [cannabinol (CBN), cannabidiol (CBD), tetrahydrocannabinol (THC)] and acids (CBDA, THCA) was determined by using a thin layer chromatography (TLC) and gas-liquid chromatography (GLC) methods. For the study, 11 monoecious varieties of C. sativa: ‘YuSO 1’, ‘YuSO 31’, ‘Hliana’, ‘Viktoriia’, ‘Hlesiia’, ‘Hlukhivskyi 46’, ‘Hlukhivski 51’, ‘Zoloto­niski 15’ and 3 introduced varieties: ‘Fedora 17’, ‘Felina 32’, ‘Futura 77’ (France) which differed among themselves in morphological, biological, genetic, ecological-geographical and economically valuable characteristics were selected. Results. Biological and morphological characteristics of modern monoecious varieties of C. sativa were investigated depending on the ecological and geographical zones of origin, conditions of the growing season and the stage of ontogenesis. The functional interdependence between the formation of specialized excretory structures and the content of cannabinoid substances in plants of different varieties of C. sa­tiva  was revealed. The following promising varieties of C. sativa in a ration of ((THC + CBN) ≤ CBD) point the possibility to use them as the source material for creating the medicinal varie­ties of plants with a high content of CBD. Conclusions. Nowadays C. sativa is the main source of phyto material for industrial production of natural CBD. In recent years, high-yielding varieties of C. sativa have been created, which, together with high commercially valuable traits, did not contain psychoactive THC and had an insignificant amount of CBD. The results of the research indicated the features of the seasonal growth rhythm, development of the plants and the morphological and biological features of modern monoecious introduced and domestic varieties of C. sativa in the North-east region of Ukraine. The low correlation between the content of cannabinoid substances and their acids in varieties, which are cha­racterized by the low content of cannabinoid compounds was established. According to the developed own classification (THC + KBN): CBD, varieties with a predominant CBD content ‘Hlukhivskyi 46’, ‘Zolotoniski 15’, ‘Hliana’ which are of significant medicinal value were identified.

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.