Ginkgo biloba L. drought resistance assessment in the conditions of introduction in the National Dendrological Park “Sofiyivka” of NAS of Ukraine

Introduction of an important importance acquires issues of drought resistance of plants that are closely linked to the problems of studying the water regime. The main negative consequence of modern warming is drought. Therefore, we have been conducted by drought resistance to G. biloba and its varieties of G. biloba 'Mariken' and 'Troll', which were compared with the indicators of the water mode of the aboriginal leaves for the Right-Bank of Forest-Steppe of Ukraine species Carpinuз betuluз L. and Acer platanoideз L. Determination of the actual and potential drought resistance of the plant studied was carried out with the help of field and laboratory techniques. It is found that all G. biloba plants are characterized by high actual drought resistance. G. biloba plants by most of the water regime exceeds the value of aboriginal species C. betuluз and A. platanoideз. This indicates a high degree of acclimatization and wide plasticity G. biloba to the conditions of introduction.

How Does the pH of Tree Bark Change with the Presence of the Epiphytic Bryophytes from the Family Orthotrichaceae in the Interaction with Trunk Inclination?

The pH of tree bark is affected by many factors, amongst them epiphytic bryophytes changing in their active state environment. Thus, we hypothesized that bryophytes can change bark acidity, dependently of the inclination of the branches, as inclination affect the water regime and particle deposition. We measured the pH under bryophyte cushions and compared it to nearby naked bark. Additionally, we compared results with experimental bark covering with neutral cover. We found that the pH of naked bark declines with decreasing inclination of trunks. Although bryophyte cover did not generally change the pH of the bark, there was a significant interaction with inclination: with higher inclination, bryophytes decrease the pH reaction of bark, while with lower inclination they increase it. One possible explanation may lie in changes to alkaline particle deposition, or conversely in the acidification of the bark by leaching. In addition, an experiment with a neutral cover showed that naked bark covering would substantially increase pH. As, on average, bryophytes do not change the pH of bark, there can be mutual interference between the alkalizing effect of the bark cover itself and the acidifying biological effect of bryophytes.

Aspects of formation of soil water regime and water consumption of corn under subsurface drip irrigation

The results of experimental researches on studying of features of formation of a water mode of soils, water consumption processes, and corn yield under different schemes of irrigation pipelines (IP) under subsurface drip irrigation (SDI) in the Steppe of Ukraine. The wetting zone of dark-chestnut residual-saline sandy soil (SI "SF "Brylivske") changed. There is a shift of the center relative to the drip water outlet into deeper horizons of the soil profile (up to 52 cm) with the increasing norm; soil layer 0-15 cm is almost not moistened, regardless of watering rate. At a distance of IP 1,0 m closing of wetting zones, occur at irrigation rates of 2,7 m3/100 running meter (r. m), and at a distance of IP 1,4 m does not occur even at irrigation rates of 3,7 m3/100 r. m, while the depth of wetting reaches 90 cm. The wetting zone of chernozem sandy loam on the loess species (SI "SF "Velyki Klyny") with irrigation rates of 2,7 m3/100 r. m was observed on the soil surface. The maximum depth of wetting, with irrigation norms of 3,7 m3/100 r. m, reached 70 cm with a maximum diameter of 79 cm at a depth of 25 cm. Closing of wetting zones was not observed. Studies at SI "SF "Brylivske" have confirmed that the depth of IP placement (on the soil surface or at a depth of 30 cm) influenced the formation of the soil water regime and the corn yield. The minimum total water consumption was 6271 m3/ha under drip irrigation (DI) (IP 1,4 m), 17 % more than SDI (IP 1,4 m), and 29% more than SDI (IP 1,0 m). The highest yield was obtained in the case of DI (IP 1,4 m) of 15,72 t/ha. SDI (IP 1,0 m) received 13,93 t/ha, and SDI (IP 1,4 m) received 13,50 t/ha. The distance between the IP in 1,0 m and 1.4 m of the SDI system did not significantly affect corn yield (13.93 and 13.50 t/ha, respectively), but at a distance of IP 1.4 m, the water consumption ratio was 6.8% less compared to IP 1,0 m. The value of the irrigation rate in the variants SDI (IP 1.0 m) was higher than SDI (IP 1,4 m) by 13,6 %. Therefore, in terms of irrigation water consumption and capital expenditures, the SDI (IP 1,4 m) is more economical. Experimental studies conducted in the SI "SF "Velyki Klyny" show that the depth of placement of IP (on the soil surface or at a depth of 20 cm) did not affect the corn yield. For DI (IP 1,0 m) the yield was 12,00 t/ha and for SDI (IP 1.0 m) was 12,10 t/ha, with a water consumption ratio of 533,8 m3/t, and for DI (IP 1,0 m) by 3,6 % more. The research results confirm the importance of the parameters of SDI system for the formation of soil water regime and, accordingly, the realization of the potential of varieties and hybrids of crops for their cultivation by SDI.

The Optical Characterization and Distribution of Dissolved Organic Matter in Water Regimes of Qilian Mountains Watershed

The constituents and content of dissolved organic matter (DOM) in the Qilian Mountain watershed were characterized with a spectroscopic technique, especially 3-DEEM fluorescence assisted by parallel factor (PARAFAC) analysis. The level of DOM in the surrounding area of Qinghai lake (thereafter the lake in this article specifically refers to Qinghai Lake)was highest at 9.45 mg C·L−1 and about 3 times less (3.09 mg C·L−1) in a cropland aquatic regime (the lowest value). In general, DOM was freshly autochthonously generated by plankton and plant debris, microorganisms and diagenetic effects in the aquatic environment (FI > 1.8). Component 1 (humic acid-like) and 3 (fulvic acid-like) determined the humification degree of chromophoric dissolved organic matter (CDOM). The spatial variation of sulfate and nitrate in the surrounding water regime of the lake revealed that organic molecules were mainly influenced by bacterial mediation. Mineral disintegration was an important and necessary process for fluorescent fraction formation in the cropland water regime. Exceptionally, organic moiety in the unused land area was affected by anespecially aridclimate in addition to microbial metabolic experience. Salinity became the critical factor determining the distribution of DOM, and the total normalized fluorescent intensity and CDOM level were lower in low-salinity circumstances (0.2–0.5 g·L−1) with 32.06 QSU and 1.38 m−1 in the grassland area, and higher salinity (0.6~0.8 g·L−1) resulted in abnormally high fluorescence of 150.62 QSU and absorption of 7.83 m−1 in the cropland water regime. Climatic conditions and microbial reactivity controlled by salinity were found to induce the above results. Our findings demonstrated that autochthonous inputs regulated DOM dynamics in the Qilian Mountains watershed of high altitude.

Agrobiological assessment of adaptive plum varieties in the conditions of the Orenburg Urals

The article presents data of agrobiological evaluation (2018-2021) of plum collection samples of Orenburg branch of Federal Horticultural Research Center for Breeding, Agrotechnology and Nursery. The research was aimed at identifying varieties and forms with the best characteristics of winter hardiness, drought resistance, productivity. In the Orenburg Urals, breeding development measures aimed at increasing the adaptability and productivity of plum plantations are appropriate. According to the results of a comprehensive assessment of productivity and adaptability, promising plum varieties have been identified. The best adaptability to adverse weather and climatic conditions of the winter period was characteristic of plum varieties Kuyashskaya and Vega. According to the weight of the fruit, Antonina and Kuyashskaya varieties (24,26 g and 23,19 g) stood out as promising plum varieties. The highest productivity index was found in the plum varieties Svetlana (12,46 kg) and Nadezhda (11,48 kg), the yield of these varieties was 5 and 5,4 t/ha, respectively. The Khabarovsk early and Svetlana varieties were characterized by the greatest accumulation of dry soluble substances –17,93 and 16,72 %. The highest total acidity (1,78 %) and the ascorbic acid content (9,46 mg%) were marked in the Svetlana variety. Characteristics of the water regime were the best in forms 12-7, 11-10 and varieties Antonina, Kuyashskaya. The identified adaptive plum varieties can be recommended for the expansion of the zoned assortment on the territory of the Orenburg Urals.

VARIABILITY AND HERITAGE OF MORPHOPHYSOLOGICAL SYMPTOMS IN BIOLOGICAL PLANTS IN THE PROCESS OF SELECTION OF SUNBULL PLANTS

The total water content, dominance and flexibility coefficients in the leaves of F1- F2- F3 plants of hybrid combinations obtained from simple and complex hybridization to create a water-resistant selection material of sunflower from oilseeds were studied. This study showed that this trait is inherited differently in simple and complex F1, F2 and F3 hybrids under different water regime conditions, with F2 hybrid combinations varying depending on the dominance coefficients and water supply conditions in hp as well as the composition of the parent forms of hybrids. The plants showed that the total amount of water in the leaves depends not only on the conditions of water supply but also on the genotypic composition KEYWORDS: Sunflower, morphophysiological, heredity, hybrid, drought tolerance, yield, seed core, ripening, cohesion, variability, hybridological analysis.

Analysis of the condition of karst springs included in the National Groundwater Monitoring Network

Approximately 20% of the monitored points in the National Groundwater Monitoring Network (NGMN) of Bulgaria are karst springs. The number of monitored karst springs is changing over time for various reasons and currently there are 33 springs monitored continuously and 53 on monthly basis. The monitoring points are distributed over 39 karst basins around the whole country. There are between 1 and 5 monitored springs per karst basin and no monitoring points in 23 karst basins. The present analysis includes the determination of some of the main statistical characteristics of karst springs and it is based on the monitoring data series. The obtained data allow us to make some conclusions of the nature of their water regime. Based on the analysis, some suggestions and recommendations are made with regard to improvements in the monitoring of karst springs in Bulgaria.