Mandrovska S. Agroecological basics of the introduction of switchgrass (Panicum virgatum L.) in the Forest-Steppe of Ukraine

Object of study: the growth and development of plants, the formation of yield and energy value of switch grass millet depending on genotypic characteristics, weather conditions, stand density of plants and ways to stimulate seed. The aim of research was introdukuvaty culture millet switch grass (Panicum virgatum L.) and establish agri-environment factors shaping its performance and energy values, develop ways of preparing seeds for sowing and elements of technology of cultivation in the steppes of Ukraine. Research methods - conventional. The study is dedicated to the features of growth and development of newly introduced in Ukraine crop switchgrass (Panicum virgatum L.), in particular, new domestic variety Morozko, as well as to the agrophytocenosis productivity and seed quality under the conditions of Forest-Steppe. Based on the developed methods on the difference, uniformity and stability, nine specimens of switchgrass of various eco-geographical origin were differentiated in terms of their uniformity and stability, highland or lowland ecotype, duration of development stages and inter-stages periods. Clustering in terms of complex agronomic characteristics and their adaptive capacity has been carried out. Determined are such characteristics as green and dry biomass yields, solid fuel yield, and energy output as affected by agricultural and environmental factors (i.e. weather conditions, stand density and seeding rate, methods of seed pre-treatment) and determined their share of influence. The collection of switchgrass is suitable for distribution in zones of low and unstable wetting in the Forest-Steppe of Ukraine. The methods of reducing the dormancy period and improving the seed germination of switchgrass have been developed. Soaking seeds in solutions of micronutrients Avatar and Rost-Kontsentrat at the concentrations of 0.7 and 1.0 L/g, respectively, proved to be the most effective treatment, which enhanced seed germination under laboratory and field conditions, regardless of genotype. It was proved that the stratification of seeds for 14 days at the temperature of 10 °C along with subsequent germination at 20 °C shortens the dormancy period of the seeds and increases the intensity of germination. Optimal modes of sorting seeds in terms of their aerodynamic properties and specific weight have been determined. Based on the results of the experiment, criteria of germination vigour (10 days) and seed germination (20 days) have been determined.