Purpose. Determine the effect of plant densities and the use of Organic-balance biological preparation on growth, development of photosynthetic potential and seed yield of maize lines, parental components of perspective hybrids (‘Arabat’, ‘Skadovskyi’, ‘Kakhovskyi’, ‘Azov’, ‘Chonhar’, ‘Hileia’ etc.) under conditions of drip irrigation. Methods. Field, morphometric, statistical. Results. In the flowering phase, the maximum differences in the area of the assimilation surface were observed between the maize lines and between variants using different plant densities and Organic-balance biological preparation. The largest indicator of the area of the assimilation surface was at the mid-late line DK445 for a standing density of 70 thousand plants/ha and the use of organic preparation Organic balance – 0.489 m2/plant. Organic-balance biological preparation had a positive effect on the dynamics of the area of the assimilation surface of the lines, had provide an increase of 0.04 m2/plant or 9.5% over individual phases of development compared to untreated control. The maximum value of the net productivity of photosynthesis – 6.78 g/m2 per day, was obtained from the FAO 420 line at a density of 70 thousand plant/ha, in the FAO 350 line was less by 4.3% with a maximum at a density of 80 thousand. plants/ha. For the FAO 290 line, the optimal plant density was 90,000 plants/ha. It was found that the genotype of the line with a share of influence of 81.2 and 85.2%, respectively, is predominantly influenced by the plant leaf area and the net productivity of photosynthesis. The influence of the organic preparation Organic-balance on these indicators was less and amounted to 13.3 and 12.3% respectively. The least influence on photosynthetic parameters was carried out by the density of phytocoenoses (the proportion of influence of 5.5 and 2.5%). Genotype with 82.2% share had the greatest influence on the seed yield of the lineage-parental components of maize hybrids. Part of the impact of the organic preparation Organic balance was 4.0%, plant density – 5.3%. The maximum seed yield of the FAO 290 line was obtained at a density of 90 thousand. growth./ha and organic drug treatment Organic-balance and amounted to 5.15 t/ha. The FAO 350 line showed the highest yield at a stand density of 80,000. growth/ha and treatment with organic drug Organic-balance – 5.46 t/ha. FAO 420, the highest seed yield, formed at a stand density of 80,000 plants/ha – 6.58 t/ha and treatment with organic drug Organic balance – 7.08 t/ha. Organic Balance treatment increased the seed yield by an average of 8.1%. Conclusions. Photosynthetic indicators of maize lines mainly depend on the genotype. Phytocenosis density and treatment with biopreparation have a much smaller effect. Under irrigation, the maximum seed yield was formed by the FAO 420 parent line of 7.08 t/ha. The results obtained indicate that in order to plan the production of seed material of maize lines, which are the parent components of hybrids, their genotypic features, the response to the density of phytocenoses and biological preparation with growth-stimulating action must be taken into account.

Purpose. To determine morphological and morphometric features of vegetative and generative organs of Persica species and varieties under the conditions of the Forest-Steppe zone of Ukraine for further use in breeding. Methods. Biological (morphological analysis) and statistical (processing of morphometric parameters) ones. Results. It was found that except ternate multiple buds, in peach hybrid ‘Suputnyk’collateral buds were prevalent which was not common to other tested varieties and species. Buds of each species and variety have a certain number of scales. The most scales were observed in ‘Suputnyk’. Pubescence of abaxial side of the leaf in P. davіdiana and ‘Suputnyk’ plants was not revealed. Species of P. vulgaris (‘Pecherskyi’, ‘Antotsianovyi’, ‘Poleskyi’) was characterized by increase in size of leaf blades, flowers and fruits. The distinctive features of P. davidiana and ‘Suputnyk’ are that stamens were accumulated in their flowers while in P. vulgaris they are branched. Raphe of a P. vulgaris stone protrudes above the edges of the bordering creases and consists of a number of narrow plates. Conclusions. For the breeding purposes, plants have an advantage for some basic criteria: the most flower buds that is common to interspecies hybrid ‘Suputnyk’; increase in photosynthetic productivity of the leaf apparatus to be typical for the variety ‘Pecherskyi’; large fruits that ‘Pecherskyi’ variety is noted for; intense red color of fruits that is inherent feature of ‘Antocianovyi’ variety.

Purpose. To establish biological features of plants growth and development and the formation of Miscanthus giganteus planting material depending on the cultivation technology elements. Methods. Field, laboratory, visual, weight measu­ring, mathematical and statistical ones. Results. The features of the growth and development of the miscanthus bioenergy crop were investigated including the formation of planting material depending on the combined technology elements application during the planting time, namely: planting time, rhizome mass, the granules and the MaxiMarin absorbent gel. It was established that the increase in plant height and leaf area as well as the miscanthus stems formation was depended on both the rhizome planting time, their size, and the use of the absorbent. During three-year period, increase in plant height was more intensive and leaf area was largest in case of the absorbent application, as compared to the control during all phases of the development for the first and the second planting time regardless of rhizome mass. On the average, the largest leaf area – 1905,9 cm3 – was in the final stage of vegetation in the context of the second planting time for large rhizomes and application of granules and absorbent gel jointly. Increasing the ground mass due to plant height, leaf area and the number of stems benefited the photosynthesis productivity intensity, that influenced the root system increase, and consequently the output of the miscanthus planting material. It was found that there are direct strong correlation between these indices and the rhizome mass. Ground mass growing is contributed to the increase in the rhizome mass, and accordingly the output of the planting material – rhizome. In case of application of granules and absorbent gel jointly, the ground mass of the miscanthus was growing most intensively and accordingly the rhizome mass was the largest, which in the first year of small rhizomes planting was twice as much as compared to the control and was equal to 1090.5 g, for large rhizomes planting this index was respectively 2.4 times more and equal to 1763.9 g. During the second planting time, the application of granules and absorbent gel jointly resulted in the rhizomes mass increase for small rhizomes planting 1.9, large rhizomes – 2.1 times more as compared to the control. Conclusions. Direct strong correlations were established bet­ween the intensity of the ground mass growth – the height of plants, the number of leaves, leaf area, the number of buds and the rhizome mass. The growth of the ground mass of plants was contributed to the increase of the root system, and consequenly the output of planting material. In all sta­ges of plant development, the increase of the rhizome mass was more intensive in case of the absorbent application regardless the time of rhizome planting, as compared to the control. The application of granules and absorbent jointly allowed to form the largest rhizome mass.

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.

Chloropyll fluorescence intensity dependence on biological features of sugar beet hybrids and plant growth stages is described. Accuracy of a method of rapid diagnosis of the photosynthetic apparatus status of sugar beet plants are evaluated.

The example of various varieties and hybrids of sugar sorghum illustrates the summary of study on assessing varying density of plants in crops on phonological cha­racteristics of sugar sorghum plants, carbohydrate composition of sorghum juice and yield of its plants. The completed study established that one hectare of sugar sorghum, subject to varietal characteristics and varying density of plants in crop, may provide the green weight of 40.83 до 106.87 t/ha at stem juice yield of 22,27 to 56,24 t/ha, which would contain 2.31 to 6.09 t/ha of total sugars suitable for bioethanol production in at the rate of 198.25 to 501.19 dal/ha. However, despite of higher estimate of total sugars yield and bioethanol at 300 thousand plants per ha density in crop, industrial plots would preferably have plant density in crops ranging within 200...250 thousand pieces per ha. Since higher density increases dry matter content of plants, consequentially, cellulose and lignin in stems, this may create preconditions for harvest losses due to stem lod­ ging Besides, 200 thousand plants per hectare enables to reach the highest level of photosynthesis net productivity which combines high intensity of the photosynthesis with photosynthetic activity of leaf surface.

In the article, on the example of different sorts and hybrids of sorgo, efficiency of the use of mineral feed is considered in technology of his growing which positively influences on the size of puff surface and it fotosintetichnu activity, promoting the productivity of plants here.

Outlook for selection on increased photosynthetic productivity of winter rye plants is discussed. Donors of short-stem resistant to powdery mildew winter rye were bred with erect and drooping shape of leaf blade. In the erect form the apexes of leaf are oriented at the angle drooping form has 45° inrelation to the stem. Incomplete domination of the drooping leaf shape with ratio 1 : 2 : 1 is established. For the first time symbolic designation of dominating genes is offered with drooping leaf blade - StSt, with transitional heterozygote Stst with recessional heterozygote stst. Higher yield of grain in the comparative variety examination was proved to be received for the erect leaf form, which is predetermined by decrease of plant height, increase of kernel weight from ear, as well as of 100 kernels from plant and by quantity of redicles. Drooping leaf blade rye forms are also promising for selection on increased photosynthetic potential.

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.

In 2011 to 2013 a study was completed for the impact of varying rates of fertilizing onto the indices of productivity for barley agrophytocenosis of Helios and Commandor, in particular, such its components as a number of productive stems, number of seeds per ear, potential biological activity of ear and photosynthetic apparatus. It is found that the level of spring barley agrophytocenosis productivity is subject both to varietal peculiarities and the rate of mineral fertilizer application. When applying N 60P 60K 60 і N 90P 90K 90 the highest potential and biological productivity of Helios and Commandor was recorder as compared against the control. Impact of varying application rates for fertilizers onto the components of ear biological productivity has been scrutinized. The qualitative composition of ear is a clear expression of variety phenotype and identifies the level of biological yield for spring barley. Application of N 60 P 60 K 60 і N 90 P 90 K 90 mineral fertilizers fairly increased the average leaf surface, photosynthetic lead capacity of varieties in 2 to 2.5 times, as well as FAR efficiency coefficient in 1.5 to 2.0 times as against control that thus contributed to the development of highest biological yield of Helios variety phytomass at the level of 14.9 to 15.0, grain – 7.8 to 8.0 ton per ha and, respectively, 12.7 and 7.5 tons per ha for Comandor variety.