Vegetation Season Research Articles

Silver fir tree-ring fluctuations decrease from north to south latitude—total solar irradiance and NAO are indicated as the main influencing factors

Silver fir (Abies alba Mill.) is a flexible European tree species, mainly vegetating within the mountainous regions of Europe, but its growth responses across its latitudinal and longitudinal range have not yet been satisfactorily verified under changing environmental conditions. This study describes the tree-ring increment of silver fir in research plots across a latitudinal gradient from the northern range in Czechia (CZ), through Croatia (HR) to the southernmost range in Italy (IT). The research aims to analyze in detail the dynamics and cyclicity of the ring-width index (RWI) and how it relates to climatic factors (temperature and precipitation), the North Atlantic Oscillation (NAO), and total solar irradiance (TSI), including the determination of latitude. The results show that the main drivers affecting fir growth are the seasonal NAO index and TSI. Monthly temperatures affect RWI early in the vegetation season, while lack of precipitation during the summer is a limiting factor for fir growth, especially in July. Seasonal temperatures and temperatures in June and July negatively impact, while seasonal precipitation totals in the same months positively influence the RWI in all research plots across meridian. The longest growth cycles in fir RWI were recorded in the northernmost studied plots in CZ. These cyclical fluctuations recede approaching the south. The cyclic increase in RWI is related to the TSI, which decreases its effect from north to south. The TSI's effects vary, positively impacting CZ but negatively influencing HR while remaining relatively neutral in IT. On the other hand, seasonal NAO tends to negatively affect silver fir growth in HR and CZ but has a mildly positive effect in IT. In conclusion, the TSI and the influence of the seasonal NAO index are prevalent in the fir RWI and are accompanied by a greater cyclicity of RWI in Central Europe (temperature optimum) than in the Italian Mediterranean region, where this tree species is limited by climatic conditions, especially lack of precipitation.

Seasonal Dynamics of Vegetation in the Wetlands of the Lower Dniester NNP Based on Remote Data from the Landsat-8 Satellite

Over the season of 2020, the vegetation dynamics of the wetlands in the Lower Dniester National Nature Park were examined using the indices <i>NDVI </i>(Normalized Difference Vegetation Index) and <i>VCI</i> (Vegetation Condition Index) on the basis of Landsat-8 satellite remote sensing data. The results demonstrated that distribution of values throughout the vegetation season did not correspond to normal distribution, indicating variety of their habitat conditions. The vegetation development in spring was negatively affected by the pyrogenic factor, which formed some areas without vegetation and with poorly developed vegetation. Sharp increase in <i>NDVI</i> values in early summer occurred due to development of wetland ecosystems' edifier <i>Phragmites australis</i>, whose stems emerged from the pickle stage and developed a leaf lamina. In this period, the well-developed vegetation prevailed, its total area exceeded 97%. In autumn, the areas of the developed vegetation gradually decrease, whereas areas of the poorly developed increased. The results of the research showed effectiveness of remote sensing of wetland areas using <i>NDVI </i>and <i>VCI</i> to assess vegetation state; it also can be used for the purposes of the conservation, restoration and sustainable use of wetland ecosystems of the north-west Black Sea coastal area under increasing anthropogenic pressure and global climate change.

Airborne pollen and fungi indoors: Evidence from primary schools in Lithuania

The number of children suffering from respiratory allergies and asthma has been increasing worldwide and, hence, it is crucial to understand the burden of inhalant biological particles present in school facilities, where children spend one third of their life. From the perspective of indoor air quality, while there are numerous studies on outdoor bioaerosol exposure, there are still uncertainties regarding the diversity and deposition of airborne pollen and fungi indoors. When it comes to schools, there is limited research as to the potential bioaerosol exposure. Here we studied the indoor environment of public schools aiming to reveal whether primary schools of different sizes and at localities of different levels of urbanization may exhibit a variability in the biodiversity and abundance of particles of biological origin, which could pose a risk to child health. To achieve this, 11 schools were selected, located in a variety of environments, from downtown, to city centre-periphery, and to the suburbs. Fungal and pollen samples were collected from various surfaces in school classrooms and corridors, using passive air sampling and swab sampling. We demonstrated that fungi and pollen are detected in school premises during and after the vegetation season. The highest diversity of bioaerosols was found on the top of cabinets and windowsills, with Penicillium, Cladosporium and Acremonium being the most abundant indoors. The levels of fungi were higher in schools with more students. The diversity and amount of pollen in the spring were significantly higher than in samples collected in autumn. Our findings complemented existing evidence that bioaerosol measurements in schools (including kindergartens or informal education facilities) are vital. Hence, we here suggest that, in addition to monitoring air quality and bacterial levels indoors, fungi and pollen measurements have to be integrated in the existing regular biomonitoring campaigns so as to prevent exposure, increase awareness and manage efficiently allergic symptomatology.

Analysis of the Influence of Abiotic Factors on the Development of Microalgae in the Hyperhaline Kuyalnyk Estuary (Ukraine, the Black Sea Northwestern Coast)

Investigations were carried out in the ecosystem of the Kuyalnyk estuary during high water period in 2004-2007. Relationships between the species diversity of microalgae and their quantitative characteristics (cell numbers and biomass) and abiotic factors, including hydrophysical (water temperature, transparency, and suspended matter content), meteorological (precipitation sum), and hydrochemical (water salinity, the content of nitrogen, phosphorus, and silicon inorganic compounds, dissolved oxygen, readily oxidized organic matter, and pH) ones, were analyzed in different seasons. It has been shown that the biomass of microalgae in the Kuyalnyk estuary during vegetation season from April until October 2004-2007 correlated well with water level (<i>r</i> = -0.69) and water salinity (<i>r</i> = 0.71), and also with the content of mineral phosphorus (<i>r</i> = 0.77). The correlation with other abiotic factors was not so significant and depended on season.

Biological diversity dynamics in forest biological community at Western Siberia subtaiga ecological monitoring index plot

This article presents results of a 2001-2021 research into an index plot forest biological community in the Western Siberia subtaiga zone (Tyumen Region, Russia), providing data on dynamics and biological diversity of vegetation cover, fungi and terrestrial vertebrate communities. The current research analyses the influence of climate and weather conditions of certain vegetation seasons and perennial climate trends pertaining to global processes, on biodiversity. Over the observation period as a whole, the xerophily of the forest ecosystem increased.

Winter Wheat Grain Yield Response to Fungicide Application at Different Stages and Fusarium Head Blight Is Rather Influenced by Variety and Year

Winter wheat is susceptible to several diseases throughout the vegetative season whereas fungicide treatments are protection used to combat fungal pathogens and to improve plant growth thus mitigating grain yield reductions. One of the main diseases is Fusarium head blight (FHB) which can be a huge problem in wheat production. Twelve winter wheat varieties varying in FHB sensitivity were tested for control of FHB using fungicide treatments made in tillering or/and heading stage, with or without inoculation with Fusarium spp. to determine the grain yield response to fungicide application at different growth stages. The grain yield from fungicide treated plots was compared to non-treated plots in two seeding rates and Fusarium inoculated plots in two growing seasons (2019/2020 and 2020/2021). The average area under the disease progress curve (AUDPC) for Type I resistance was 109.48 in 2020 and 99.33 in 2021 year in VI treatment where fungicide application in heading and Fusarium inoculation simultaneously were performed. In VII treatment where only Fusarium inoculation was applied, AUDPC for Type I resistance in 2020 was 371.88 in average, while in 2021 that was 199.18 in average. Wheat varieties treated with a fungicide in the heading stage at the first year of investigation (2020) had higher grain yield, compared to non-treated plots or treated in tillering stage. These results indicated that application of fungicides in heading stage when there is sufficient moisture in May and June may increase chances of profitability from fungicide application at that growth stage. Cumulative rainfall from January till May, at year 2021 had a positive effect on the grain yield, when accumulated rainfall in this period increased chances of getting a higher yield response from fungicide application in the tillering stage. Fungicide applications should always be implemented in combination with sound agronomic management and FHB resistant varieties.

Improving the technology of obtaining high-vitamin greens of minor species of perennial onions during forcing in protected ground

In 2022-2023, experiments were conducted to study the effect of additional lighting on the growth, development, and vitamin C content of perennial onions during their forcing in protected ground in winter. Getting green vegetables in the cold season is of particular relevance in the Middle Urals, since the population during this period is particularly susceptible to immunity decrease, due to a lack of solar energy, a deficiency of vitamins and biologically active substances, therefore forced to use synthetic vitamins to strengthen its immunity. Although it is known that the vitamins contained in food bring the greatest benefit. Adding green onions to food is one of the simplest and most inexpensive ways to enrich the diet of the population. The use of perennial species of onions, which have a different appearance and taste different from each other, is also a way to diversify it. The purpose of the research: to study the effect of additional lighting on the yield of perennial onions and the vitamin C content during their forcing in winter using the method of immersion hydroponics. During the experiments, such indicators as changes in leaf length and the number of leaves on the plant, as well as individual plant productivity and yield were recorded. In addition to phenological observations, research was conducted on such indicators as the concentration of cell fluid, electrical conductivity, PH of perennial onion leaves. As a result, it was found that Allium nutans, which was grown without supplementary lighting, has the highest yield – about 2.5 kg/m2. For all the studied types of onions in 2023, results were obtained for higher electrical conductivity in onions grown with additional lighting. The difference was 27-61%. All the results obtained were processed using mathematical statistics methods. The results of experiments on the effect of additional lighting did not give unambiguous results, further more detailed study is required.

Content of Phenol Carboxylic Acids in the Water among Higher Aquatic Plants of Various Ecological Groups

The composition and content of phenol carboxylic acids was studied in water bodies among higher aquatic plants of various ecological groups: emergent (<i>Typha angustifolia</i> L., <i>Scirpus lacustris</i> L., and <i>Phragmites australis</i> (Cav.) Trin. ex Steud.), submerged (<i>Ceratophyllum demersum</i> L. and <i>Myriophyllum spicatum</i> L.), and with floating leaves (<i>Trapa natans</i> L. and <i>Nuphar lutea</i> L.). The following acids were found in the water among higher aquatic plants: benzoic, lilac, vanillic, gallic, <i>n</i>-oxybenzoic, protocatechuic, α-resorcylic, β-resorcylic, salicylic, ferulic, caffeic, cinnamic, coumaric, and sinapic. Their total concentration in the water among the specimens of <i>T. angustifolia</i> accounted for 114.7 μg/L, <i>Sc. lacustris</i> - 24.71 μg/L, <i>T. natans</i> - 56.14 μg/L, <i>N. lutea</i> -19.3 μg/L, <i>C. demersum</i> -25.42-38.66 μg/L, and <i>M. spicatum</i> - 1.42-2.83 μg/L. The analysis of the content of phenol carboxylic acids in the water among the specimens of <i>Ph. australis</i> during the spring-autumn period revealed significant differences both in the ratio of individual acids and in their distribution by groups. The maximal concentration of benzoic and salicylic acids in the water was registered at the beginning of <i>Ph. australis</i> development, whereas the maximal content of vanillic and gallic acids - during plant active vegetation. The lowest content of cinnamic and ferulic acids was recorded at the beginning of vegetation season. Cluster analysis of the content of phenol carboxylic acids in the water among the specimens of <i>C. demersum</i> and <i>M. spicatum</i> at two sampling stations (Sobache Gyrlo Bay and Verblyud Bay in the Kaniv Reservoir) made it possible to reveal two groups of the studied substances. The first group included benzoic and gallic acids and the second group - other acids. The use of the principal component analysis (PCA) made it possible to establish a significant correlation between the composition and content of phenol carboxylic acids in the water among higher aquatic plants and dominant plant species. This fact is indicative of the leading role of higher aquatic plants in the formation of the pool of these substances in the water.

Biochar made from chicken manure - a fertilizer that can ensure the carbon neutrality of agricultural soils in conditions of elevated temperatures

Amendment of soil with biochar instead of mineral or organic fertilizers might be one of techniques wich reduce carbon dioxide emissions into the atmosphere. The effect of biochar based on chicken manure on the biomass and respiratory activity of agricultural soil microorganisms was evaluated in lab conditions at normal (average climatic norm for the vegetation season in central Russia, 15 °C) and elevated (25 and 35 °C) temperatures. It was shown that the introduction of 10% biochar by mass did not lead to an increase emission of CO2 from the soil relative to the control at 15 °C for 60 days of the experiment. An increase in temperature caused an increase in carbon dioxide emissions from the control soil by 35% and 91% and a decrease in moisture by 24% and 42% at 25 and 35°C, respectively. Microbial biomass increased in the control soil by 32% at 25°C and decreased by 34% at 35°C. Soil amendment with biochar led to the leveling of the effect of elevated temperatures on all three parameters. Thus, biochar made from chicken manure allowed one of the characteristics of soil fertility to be preserved and did not lead to the loss of greenhouse gases.

Vascular Flora from Ecoton Zones of the Slatioara Secular Forest

The purpose of this study is to generate essential scientific information regarding the floristic composition and the structures of the ecotone vegetation in the natural forest Codrul Secular Slătioara, because so far no such studies have been carried out in this reserve. Also, the results of this study provide important data, which can be the basis for the development of strategies for the conservation and sustainable use of some herbaceous species, valuable due to genetic and socio-economic, respectively of a regular forest monitoring program. The floristic studies were carried out in the 2020 to 2021 vegetation season. Based on the specialized literature, plant species were identified and then processed from the point of view of bioforms, floristic elements and ecological indices. The economic categories in which the identified species fall were also analyzed. Thus, a total of 292 species belonging to 46 botanical families were identified and their distribution by ecosystems is as follows: in the forest, 90 species were identified, in the lands adjacent to the forest, in the meadows, 202 species were found and in the area of border, 120 species of vascular plants were identified. Most of the species identified in the study area are hemicryptophytes, heliophiles, and eurytherms, which grow on dry to moderately moist, eurytrophic soils. More than 50% of the identified species belong to several categories of useful plants (fodder, medicinal, melliferous, edible).

Regional-Scale Analysis of Vegetation Dynamics Using Satellite Data and Machine Learning Algorithms: A Multi-Factorial Approach

Abstract Accurate vegetation analysis is crucial amid accelerating global changes and human activities. Achieving precise characterization with multi-temporal Sentinel-2 data is challenging. In this article, we present a comprehensive analysis of 2021's seasonal vegetation cover in Greater Sydney using Google Earth Engine (GEE) to process Sentinel-2 data. Using the random forest (RF) method, we performed image classification for vegetation patterns. Supplementary factors such as topographic elements, texture information, and vegetation indices enhanced the process and overcome limited input variables. Our model outperformed existing methods, offering superior insights into season-based vegetation dynamics. Multi-temporal Sentinel-2 data, topographic elements, vegetation indices, and textural factors proved to be critical for accurate analysis. Leveraging GEE and rich Sentinel-2 data, our study would benefit decision-makers involved in vegetation monitoring.

Regional distribution and ecological-phytocenotic description of dominant plants of Southern Uzbekistan

This article analyzes the results of the research conducted by scientists in the study of plants of the region. Taking into account the laws of the distribution of plants in the regions, the dominant plants of the desert, hill, mountain and pasture regions of South Uzbekistan are given an ecological and phytocenotic description. In particular, the results of the expedition conducted to study the plants distributed in each region, and the results of experimental research are highlighted. According to it, information on the Latin name of plants, ecological status, distribution according to soil types, dominance characteristics, communities is provided. The formation of vegetation cover specific to the climate of each region was analyzed. In particular, dryness (lack of moisture) and high temperature for the desert determine unfavorable climatic conditions for plant life. Here, the shortness of the growing season of plants, mainly due to the lack of precipitation, early drying of the soil, often determines the summer and winter dormancy of two dormant periods in the seasonal development of plants. Despite the fact that desert conditions are unfavorable for plants, it is possible to observe their diversity during the seasonal vegetation period. Adir is located between a barren desert and a mesothermal mountain, and according to the living conditions of the plants, the stage part is arid, and the upper part is close to the mountain.

Seasonal divergence of evapotranspiration sensitivity to vegetation changes – A proportionality-hypothesis-based analytical solution

Seasonal variation of vegetation profoundly affects the water cycle. However, the seasonal divergence of evapotranspiration (ET) sensitivity in response to vegetation variations has not been fully understood. Here we derived an analytical solution to examine the impact of seasonal vegetation changes on ET with an extended Budyko framework based on an improved ET algorithm with improved water balance constraints. Results reveal a clear seasonal divergence of ET sensitivity to vegetation coverage changes across climate regimes and biomes. Generally, the high ET sensitivity to vegetation coverage has a clear north-south shift trajectory from spring to winter. For moderate-humid regions (0.7 < aridity index < 1.0), vegetation exhibits higher importance in altering ET in March-September. While for moderate-dry regions (1.0 < aridity index < 1.4), the sensitivity of ET to vegetation changes is the highest in September-November. Moreover, the spatial-temporal pattern of ET sensitivity to seasonal vegetation changes is different between short vegetation cover and forest. Additionally, negative ET sensitivity to vegetation coverage changes was discovered in regions with seasonal precipitation of less than 500 mm and sparse vegetation coverage (predominant land cover types of grassland, scrubland, and savannas). In summary, our study provides an analytical solution to estimate ET sensitivity to seasonal vegetation changes within the extended Budyko framework. The results highlight the difference in hydrological response to vegetation dynamics across seasons and vegetation types.

THE INFLUENCE OF HEAT SHOCK AND DESSICATION ON BOXWOOD (BUXUS SEMPERVIRENS L.) LEAVES' PHOTOSYSTEM II AND ANTIOXIDANT SYSTEMS ACTIVITY

This research aimed to investigate the response of one- and two-year-old Box (Buxus sempervirens L.) leaves to the action of heat shock (HS) and desiccation. These factors influenced the photosystem II activity of the leaves and the degradation of hydrogen peroxide by leaf extracts. The development of these processes was specific depending on the age of the leaves and season of their collection for analysis. Thus, the studied characteristics could assure the elaboration of new, rapid methods of assessing the resistance of leaves to high temperatures, depending on the period (season) of vegetation and their age. At different seasons of the year, the resistance of box leaves to HS tends to correspond to seasonal temperatures, reaching the highest level in summer, intermediate level in spring and autumn, and the lowest in winter. Regardless of the season, the one-year-old leaves are more resistant and have a higher capacity to recover from HS damage than the two-year-old leaves.

Исследование водоудерживающей способности Catalpa speciosa в условиях городов Караганды и Жезказгана

The study of the hydration and water-retaining capacity of plant leaves is important for assessing the possibility of their cultivation and mass use in green construction in the arid conditions of Kazakhstan. This article examines the issues of hydration and water-retaining capacity of the leaves of the valuable ornamental culture Catalpa speciosa in the conditions of the cities of Karaganda and Zhezkazgan. The indicators of hydration and weight loss during drying for 1, 3 and 6 hours were studied by leaves of plants of the 1st, 2nd and 3rd years of vegetation from May to August. It was found that the leaves of Catalpa speciosa in the conditions of the city of Karaganda had higher indicators of hydration and water-holding capacity than in the city of Zhezkazgan. The maximum values of moisture loss during drying were noted for plants of the 1st year of vegetation, the minimum values for individuals of the 3rd year. By the months of the vegetative season, the leaves lose free water as much as possible in the conditions of Karaganda in June, for Zhezkazgan in June and July; minimal moisture losses were noted for both cities — in August. Thus, critical points of water exchange intensity were identified in June and July, which require intensification of irrigation in these months. More active watering must be organized for plants in the 1st year of development. In general, good indicators of the water-holding capacity of Catalpa speciosa leaves have been established, which indicates the possibility of active use of this crop in the green construction of arid territories of Central Kazakhstan.

Improving Land Use/Cover Classification Accuracy from Random Forest Feature Importance Selection Based on Synergistic Use of Sentinel Data and Digital Elevation Model in Agriculturally Dominated Landscape

Land use and land cover (LULC) mapping can be of great help in changing land use decisions, but accurate mapping of LULC categories is challenging, especially in semi-arid areas with extensive farming systems and seasonal vegetation phenology. Machine learning algorithms are now widely used for LULC mapping because they provide analytical capabilities for LULC classification. However, the use of machine learning algorithms to improve classification performance is still being explored. The objective of this study is to investigate how to improve the performance of LULC models to reduce prediction errors. To address this question, the study applied a Random Forest (RF) based feature selection approach using Sentinel-1, -2, and Shuttle Radar Topographic Mission (SRTM) data. Results from RF show that the Sentinel-2 data only achieved an out-of-bag overall accuracy of 84.2%, while the Sentinel-1 and SRTM data achieved 83% and 76.44%, respectively. Classification accuracy improved to 89.1% when Sentinel-2, Sentinel-1 backscatter, and SRTM data were combined. This represents a 4.9% improvement in overall accuracy compared to Sentinel-2 alone and a 6.1% and 12.66% improvement compared to Sentinel-1 and SRTM data, respectively. Further independent validation, based on equally sized stratified random samples, consistently found a 5.3% difference between the Sentinel-2 and the combined datasets. This study demonstrates the importance of the synergy between optical, radar, and elevation data in improving the accuracy of LULC maps. In principle, the LULC maps produced in this study could help decision-makers in a wide range of spatial planning applications.

Shedding light on the effects of LED streetlamps on trees in urban areas: Friends or foes?

Streetlamp illumination disturbs the natural physiological processes and circadian rhythms of living organisms, including photosynthesizing “citizens”. The light-emitting diode (LED) technology has replaced high-pressure sodium lamps. Therefore, the effects of LED streetlamps on urban trees need to be elucidated as these new lamps have a different light spectrum (with a peak in the blue and red regions of the spectrum, i.e., highly efficient wavebands for photosynthesis) compared to older technologies. To address the above-mentioned issue, two widely utilised tree species in the urban environment, including Platanus × acerifolia (P) and Tilia platyphyllos (T), were grown with or without the effect of LED streetlamps using two realistic illumination intensities (300 and 700 μmol m−2 s−1). Gas exchanges and biochemical features (starch, soluble sugar, and chlorophyll content) of illuminated vs non-illuminated trees were compared during the whole vegetative season. Our results showed that both tree species were strongly influenced by LED streetlamps at physiological and biochemical levels. Specifically, the mature leaves of P and T streetlamp-illuminated trees had a lower CO2 assimilation rate at dawn and had higher chlorophyll content, with lower starch content than controls. Our results showed that the differences between the effects of the two selected light intensities on the physiochemical attributes of P and T trees were not statistically significant, suggesting the absence of a dose-dependent effect. The most significant difference between T and P trees concerning the LED-triggered species-specific effect was that the delay in winter dormancy occurred only in P individuals. This study provided insights into the extent of LED streetlamp disturbance on trees. Our findings might raise awareness of the necessity to provide less impacting solutions to improve the wellness of trees in the urban environment.

Eggplant Disease Detection Using Yolo Algorithm Telegram Notified

Eggplant (Solanum Melongena L) is a type of seasonal vegetable. Eggplants vary in shape and color from white to green to purple. Facts prove that eggplant plants face several threats to their survival and growth, including disease disturbances such as leaf beetles, fruit rot, mealybugs, etc. One way to treat and monitor eggplant plants is to install a camera to capture accurate and fast image data. The image captured by the camera will be digitally processed, which can be used by deep learning methods on object recognition and evaluation system in eggplant plants. Digital image processing can present the color accuracy of leaves, and fruit stems in eggplant plants for solutions and innovations. Digital image processing is the study of image processing techniques. Processed images are still images or images captured with a model camera. In this study, the images taken were of colored leaves attacked by eggplant rot and brown stem rot. The color model used in this study to transform images to color uses the red-green-blue color function. This study uses the YOLOv4 algorithm implemented on a mobile computing device such as Raspberry Pi 4 to select images of eggplant plants captured by a camera. The image data that has been processed will produce results in plant disease diagnoses based on the image captured by the camera. The results will be announced immediately or announced on the Telegram application. We can then detect diseases in eggplant plants and provide immediate preventative measures for diseased plants to maximize yield.

Cultivation of one-year poplar plants rooted in autumn and spring with the use of different methods of cutting planting material

Purpose. Study of the peculiarities of growing one-year cutting seedlings of four cultivars of the black poplar under the conditions of the Right Bank Forest Steppe using cuttings with a perpendicular and oblique section.&#x0D; Methods. Field, laboratory, statistical.&#x0D; Results. Cuttings of cultivars ‘Dorskamp’, ‘I-45/51’, ‘Robusta’ and Toropohrytskyi’s poplar 20 cm long were planted in November and early April for three years. The cuttings for rooting were cut from one-year-old shoots using secateurs, with cuts (i) perpendicular to the axis of the shoots and (ii) an angle of 45º. In an average of 3 years, autumn planting of the varieties ‘I-45/51’ (by 6%) and ‘Robusta’ (by 25%) showed better rooting of cuttings with perpendicular cuts. Cuttings of ‘Dorskamp’ variety with oblique cuts rooted by 11 % and Toropohrytskyi’s poplar by 7% better. When planted in spring, the rooting index of cuttings with a perpendicular cut in the ‘Dorskamp’ variety was 24% higher, in ‘I-45/51’ by 30% higher, and in ‘Robusta’ variety 54 % higher. Cuttings with an oblique cut rooted better in Toropohrytskyi’s poplar (by 20 %). The height of the rooted cuttings was the largest for autumn planting of the same variety (192.9 cm). Also, cuttings with an oblique cut had an advantage in height in the variety ‘Dorskamp’ (by 12%). In the varieties ‘I-45/51’ and ‘Robusta’, cuttings with a perpendicular cut had a higher height by 16 and 5 %, respectively. For spring planting, plants of the ‘Dorskamp’ variety had a maximum height, both when using cuttings with a perpendicular cut (197.9 cm), and with an oblique cut (195.6 cm). Plants of the ‘I-45/51’ variety with a perpendicular cut had a height of 149.1 cm and oblique 126.5 cm. In ‘Robusta’, cuttings with an oblique cut were 8% smaller. The cuttings of Toropohrytskyi’s poplar at both planting seasons were taller than cuttings with an oblique cut.&#x0D; Conclusions. The effectiveness of using cuttings with a perpendicular or oblique cut depends on the cultivar of poplar, the timing of planting and the weather conditions during vegetation season. In the conditions of the Right Bank Forest Steppe, for the cultivation of Toropohrytskyi’s poplar, it is recommended to use autumn planting of cuttings with an oblique cut. Cuttings of the varieties ‘I-45/51’ and ‘Robusta’ should be planted in autumn using a perpendicular cut, and ‘Dorskamp’ with the same cut, but in spring.

Formation of biometric parameters of switchgrass on acid soils

Purpose. To establish the peculiarities of the biometric parameters of switchgrass cultivated on acid soils attributed to the category of marginal land. Methods. Field experiment was carried out at the Uladivka-Liulyntsi Experimental Breeding Station of the Institute of Bioenergy Crops and Sugar Beet of the National Academy of Agrarian Sciences in the years 2019–2021. Switchgrass variety ‘Morozko’ was grown in the a three-factor field experiment, with the application of lime (25% of the need), MaxiMarin granulated adsorbent (30 kg/ha), potassium humate (Humifield) (50 g/ha) and Antistress AminoStar (1.0 l/ha) to the soil. The adsorbent was applied two weeks before sowing the crop locally in the rows, foliar application of fertilizers was carried out in the budding stage and the second time after two weeks. Results. In the second year of cultivation, the plant density in the tillering stage was from 12 to 21, in the third year from 16 to 23. Since the plants already formed an optically dense crop in the first half of the vegetation season, there was no further increase in the plant density, and in all treatments of the experiment, the number of plants determined in the tillering stage was preserved at the time of harvesting. Application of lime to the soil did not have a significant impact on the formation of this indicator, and the main differences were only compared to the treatments with applying the adsorbent. The height of the plants in the tillering stage in the experiment was approximately at the same level: in 2020, 24–30 cm and 2021, 12–16 cm. A tendency of the increase was noted only in the treatments with adsorbent. Starting from the stage of leaf-tube formation, the influence of the factor of foliar application of fertilizers increased significantly, the effectiveness of which increased against the background of the adsorbent application. In particular, in the treatment with potassium humate, the plants were 5–15 cm taller in both years of the experiment compared to the corresponding controls, and in the case of the combined application of potassium humate with AminoStar Antistress plant height exceeded by 5–25 cm. Soil deoxidation also had a positive effect on plant growth: on average of the treatments without liming, in the leaf-tube formation, the plants were 48–88 cm tall, while with the application of lime 54–115 cm. In 2020, similar patterns of this indicator formation were noted in the following stages of development. On the other hand, in 2021, at the later stages of the crop vegetation, the difference between these experimental treatments decreased, and in the harvesting stage, the plants in the treatments where lime was not applied were even taller by 6 cm. A similar situation was observed in the treatments with the combined application of the adsorbent and foliar application of humates: in the stage of leaf-tube formation, the plant height was significantly higher, but already in the flowering stage it was practically equal to the control treatments, and at the time of harvesting it was somewhat lower. Conclusions. The maximum values of the biometric parameters of switchgrass were obtained mostly in the treatments with the combination of all three investigated agrotechnical measures. At the same time, their formation was more significantly affected by the use of adsorbent and foliar feeding of plants than by liming the soil, the effect of which was mostly tendentious. At the same time, the effectiveness of these technological factors was largely determined by the weather conditions of the growing season, which in turn affected the growth processes of plants and caused certain variations in their biometric parameters over the years of research.