Purpose. To find out the peculiarities of sugar beet productivity formation under the application of plant growth regulators. Methods. Laboratory, field. Results. Seed treatment using growth regulators provided a significant increase in the intensity of germination in the laboratory and in the field, in the plant density and uniformity of crops. The use of the Stoller's growth regulators in seed and crops treatment under the conditions of unstable and sufficient moisture has ensured a significant increase in the weight of root, which contributed to an increase in root yield. Particularly, when sowing treated seeds and treated seeds following by spraying crops, or only for spraying crops with studied growth regulators, a significant increase in root yield and sugar content compared to control was obtained. Conclusions. The newest growth regulators by Stoller, namely Stimulate, Bioforge, Sugar Mover and Nitrate Balancer, are effective for intensification of plant growth and development and increasing sugar beet productivity; therefore they can be effective elements of modern cultivation technologies.

To establish the biological characteristics of growth and development of plants and the formation of planting material of miscanthus under conditions of drip irrigation. Methods. Field, laboratory, visual, measuring, weight, mathematical-statistical. Results. Represented the effectiveness of cultivation of planting material of miscanthus under conditions of drip irrigation without the application of Maxi Marin absorbent and when it is added to the period of planting of the rhizome. High survival of miscanthus plants in transplanting them from growing to open ground is established. In the conditions of drip irrigation it was 4.9% (without absorbent) and 3.3% (for making absorbent) more than without irrigation was. Drip irrigation significantly influenced the plant height and the formation of stems, while the introduction of absorbent was observed only a tendency of increase of these indicators. Introducing absorbent in rainfed conditions has resulted in a substantial increase in the content of free water in the leaves of miscanthus. Drip irrigation has contributed to intensive growth of not only land mass, and the mass of roots that provided a significant increase in the yield of planting material - the rhizome. The average for years of research weight uterine rhizome in drip irrigation was greater in control (without absorbent) by 62.8%, or 917,9 g than the absorbent application, respectively, the 61.8% or 912,7 g compared to irrigated conditions. Conclusions. The use of an absorbent as in rainfed conditions without irrigation, and in drip irrigation did not provide the increase of biometric parameters of the plants, weight of roots and, consequently, the output of planting material - the rhizome. The increase of these indicators was significantly affected only drip irrigation. In drip irrigation without any absorbent and when it is added from one of the ovaries rhizomes obtained mass was 15-20 g in 1.5 and weighing 25-30 g in 1.4 times more compared to the cultivation of ovaries without irrigation.

Purpose. Developing a method for determination of the laboratory seed germination that could reduce the biological dormancy period and, accordingly, increase the intensity of germination. Methods. Laboratory, measuring and weighing, mathematical and statistical. Results. Cooling switchgrass seeds at a temperature of 10°C for 7 days on average for three years did not lead to a decrease in germination energy and germination compared to cooling for 14 days. These indexes were almost the same and amounted to 74 and 76%, 73 and 75%, respectively. There were no significant deviations in germination energy and seed germination over the years of research as affected by duration of the cool period. The production test of the developed method, carried out in the accredited control and measuring laboratory, confirmed the obtained in the laboratory results. Conclusions. Seed germination by an improved method, when pre-cooling is carried out for 7 instead of 14 days and counting of germinated seeds on 15th day instead of 20th, has reduced the time to determine germination by 13 days without reducing the quality of analysis. It is advisable to determine the 1000-seed weight in one of three ways, but the most accurate is the third way, i.e. counting the seeds in 10 repetitions.

In the intensive arable farming the productivity of sugar beets depends on many factors: soil-climatic conditions, introduction of highly productive hybrids, quality pre-sowing seed treatment, use of updated machinery and technologies, fertilizers, reliable plant protection, high technological processing at sugar mills and others. All the mentioned factors can reduce the productivity of sugar beets considerably, but it is not possible to reach a maximum potential of crop productivity without the use of good-quality seeds of the latest hybrids. The quality of sugar beet seeds is formed during the growth, and it depends on several factors, and first of all on the quality of mother root crops – their mass, sizes, turgor, disease damage and others. Laboratory trials were carried out at the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS, field trials were carried out in the conditions of Ivanivka research-breeding station in the years of 2016–2018. The trial scheme envisaged the planting of root crops, which were not damaged with root rot and damaged with root rot, a focal point of rot being removed before planting. During vegetation, seed plants were treated with fungicides at a bud stage (one–time treatment) and at a bud stage and the beginning of flowering (two–time treatment). Fungicides were not used in the control. Mother root crops, seed plants and seeds of a sugar beet hybrid, developed on the basis of cytoplasm male sterility Romul, were the object of the research. In the field trials the following was determined: viability of the root crops (the number of the emerged crops as to the number of the panted root crops) and the seed plant density at a full emergence stage and before harvesting. Agro-biological evaluation of the seed plant condition was made before harvesting – the number of non-productive seed plants (dried, infertile ones and others), the number of disease-damaged plants and the degree of their development. A record plot area of one replication was 20 m2 in field trials, a fourfold replication. The technology of seed plant cultivation is conventional, in accordance with the recommendations of the Institute of bio-energy crops and sugar beets of Ukraine’s NAAS. The paper covered some peculiarities of the yield formation and the quality of sugar beet seeds, depending on the quality of mother root crops. It was proved that the use of the root crops, partially damaged with rot during storage, and even when a focal point of rot was removed before harvesting, had an effect on the root crop viability (which was by 4.4 % lower), the formation of more non-productive plants – by 1.6–1.8 times – due to the increase of prematurely dried plants and infertile ones, which resulted in a serious yield decease – by 0.09-0.13 t/ha and seed quality – viability by 4 % and emergence by 6 %, as compared with the variants where health root crops were planted. Two-time spraying of the seed plants with fungicides resulted in the increase of the yield capacity and the seed quality in the variants where only partially rot-damaged root crops were planted. A tendency to the increase of the mentioned indicators, both in the variants with healthy root crops planted and with partially damaged root crops planted, was recorded under one-time spraying of the seed plants with fungicides. The research of the seeds gathered from the seed plants, which were grown from the root crops, disease-damaged and healthy ones, confirmed the results of the field trials. The viability of the seeds, received from the healthy (not disease-damaged) root crops was higher by 9 %, emergence – by 5 %, as compared with the root crops, partially rot-damaged, focal points of which were removed before planting. Key words: mother root crops, rot, productive seed plants, yield capacity, viability, germination.

The article presents the research results on the efficiency of switchgrass seeds sorting by a set of characteristics – specifc gravity and aerodynamic properties in order to reduce the biological state of seeds dormancy and germination increase signifcantly. It is experimentally proved that sequential seeds sorting in two stages by a set of features – specifc weight on the pneumatic table and aerodynamic properties on the aspiration column provided a signifcant increase in its germination energy, germination and 1000 seeds weight. Sorting of Morozko variety seeds on the pneumatic table ensured obtaining seeds with germination energy and similarity in positions 1 and 2, respectively – 16–19 % and 20–22 %, while in positions 3–5 these indicators were, respectively – 5–13 % and 9–17 %. Re-sorting of these seeds by aerodynamic properties provided an increase in germination energy and seed similarity from the position of the pneumatic table "3", respectively – by 12 and 13 %, the intermediate fraction – by 14–16 %, and waste – by 19–21 % compared to these indicators to sorting, due to the selection of the lung and with lower seed similarity. Sorting seeds by a set of characteristics provided not only an increase in its quality, but also an increase in the yield of more similar seeds. The most effective way to prepare switchgrass seeds for sowing is to sort them by a set of features – specifc weight and aerodynamic properties, which reduces the biological dormancy of seeds, signifcantly increases its germination energy, similarity, 1000 seeds weight and quality seeds. But this measure does not provide a complete solution to reduce the biological state of dormancy of seeds. Key words: seeds yield, aerodynamic properties, specifc gravity, germination energy, similarity, 1000 seeds weight.