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.

Scientific approaches to formation of national variety sources of spring and winter barley by State Registration of new varieties and their right protection.

Purpose. To establish the level of formation of winter barley yield depending on weather conditions during the gro­wing season in the Forest-Steppe zone of Ukraine. Methods. Field investigations, ANOVA, variance and correlation analysis. Results. Positive correlation was revealed between yield and the duration of the vegetation (r = 0.54) and especially “heading–maturation” period (r = 0.76). Moderate positive correlation was established between yield and mean daily air temperature during the period from termination to resumption of vegetation (r = 0.44), and strong negative one – between yield and mean daily air temperature during hea­ding to maturation period (r = -0.77). Positive correlation was observed between yield and rainfall amount during the period from vegetation resumption to heading (r = 0.30). In general, during the growing season the correlation was weak (r = 0.16). For the period of “heading–maturation” low nega­tive value (r = -0.11) was fixed. This was due to heavy precipitations, especially torrential rains, which in some years have caused lodging of plantings resulted in yield decrease. Conclusions. Under the conditions of Forest-Steppe zone of Ukraine, fluctuations in temperature and water regimes are responsible for significant variability in growing season duration and yield of winter barley. Optimal amount of precipitation (close to long-time annual average) and their uniform distribution throughout growing season is the most favorable for obtaining high yield. “Heading–maturation» period is responsible for the formation of winter barley yield level.

Purpose. To establish the level of formation of winter barley yield depending on weather conditions during the gro­wing season in the Forest-Steppe zone of Ukraine. Methods. Field investigations, ANOVA, variance and correlation analysis. Results. Positive correlation was revealed between yield and the duration of the vegetation (r = 0.54) and especially “heading–maturation” period (r = 0.76). Moderate positive correlation was established between yield and mean daily air temperature during the period from termination to resumption of vegetation (r = 0.44), and strong negative one – between yield and mean daily air temperature during hea­ding to maturation period (r = -0.77). Positive correlation was observed between yield and rainfall amount during the period from vegetation resumption to heading (r = 0.30). In general, during the growing season the correlation was weak (r = 0.16). For the period of “heading–maturation” low nega­tive value (r = -0.11) was fixed. This was due to heavy precipitations, especially torrential rains, which in some years have caused lodging of plantings resulted in yield decrease. Conclusions. Under the conditions of Forest-Steppe zone of Ukraine, fluctuations in temperature and water regimes are responsible for significant variability in growing season duration and yield of winter barley. Optimal amount of precipitation (close to long-time annual average) and their uniform distribution throughout growing season is the most favorable for obtaining high yield. “Heading–maturation» period is responsible for the formation of winter barley yield level.