Excessive Moisture Conditions Research Articles

Использование индексов вегетации в почвенно-ландшафтом картографировании и агроэкологической оценке

In this work, the possibilities of using remote sensing data to clarify the contours of soil differences were evaluated. It was found that visualization of mean annual vegetation indices NDVI allows to specify actual information on the contours of productivity zones. The use of this approach allows clarifying the boundaries of soil differences and identifying the actual boundaries of lithogenic lands with different productivity. It was found that the average annual NDVI in the linear model is related to the content of physical clay, with R2=0.26, the highest NDVI values are observed on soils of medium-loamy and heavy loamy composition in conditions of excessive moisture in the foothills of the Krasnodar Territory with average annual precipitation of more than 850 mm. Keywords: VEGETATION INDICES, REMOTE SENSING DATA, LAND PRODUCTIVITY, AGRO-ECOLOGICAL ASSESSMENT

Agrobiological substantiation of growing Hungarian vetch in mixed crops

The production of high-protein feed stays an integral part of the development of feed production. The purpose of this study was to investigate the biological characteristics of Hungarian vetch when grown in agrophytocenoses using different types of winter cereals. Changes in the chemical composition of dry matter at different microstages of growth and development were studied, and the influence on the yield, nutrient content, and digestibility of plant material was determined depending on the stages of growth and development. The study was conducted using field, laboratory, laboratory-field, and statistical methods. It was found that to reach the full flowering phase, the sum of active temperatures should be 754°C, with precipitation of about 100 mm and daylight hours of 973 h. Observations of the growing season indicate the relationship between plants and the environment, which is important to consider when growing Hungarian vetch. Vetch plants reach a height of 100-104 cm in conditions of excessive moisture. The phytocoenotic balance of such mixtures, specifically vetch of the Orlan variety and winter triticale of the Bozhych and Bohodarske varieties, ensures sustainable productivity and nutritional value of plant material. The best harvesting time for high quality vetch is from the beginning to the middle of flowering, which ensures a crude protein content of 17-20% in dry matter. The effectiveness of mixed phytocoenoses has been confirmed by ecological tests of crop combination models in different soil and climatic zones of Ukraine, where yields of 36.2-51.8 t/ha of green mass and 7.1-11.5 t/ ha of dry matter were obtained over the years of use. The creation of a mixed crop allows producing high-quality plant material that is superior in energy and protein content to conventional vetch and oat mixtures. It was recommended to create such mixtures by sowing 2.5 mln/ha of cereal and 2.1 mln/ha of leguminous components after applying N45P45K45 to form a crop with high digestibility and nutrition. The system of mixed cropping of Hungarian vetch is promising for the production of silage and high-quality haylage in the face of climate change and as a precursor for post-cutting sowing of maize or sorghum crops

Assessment of vegetation cover when analyzing the carbon budget in agricultural landscapes of Karelia

The article presents the results of studying the species composition of perennial grasses and the bioproductivity of long-term phytocenoses in Karelia for the subsequent assessment of carbon pools. On the typical peat agrozeme, during the 30-year succession, there was a restructuring of the vegetation cover of hayfields with the predominance of large-grass communities at present. Based on the results of geobotanical descriptions, dominant species were identified that correspond to the conditions of excessive moisture, high trophic soils and make the main contribution to the formation of productivity of perennial herbaceous vegetation. The economically valuable harvest of dry phytomass of grass-mixed herbage amounted to 10.16 t/ha and significantly exceeded similar indicators of 5.46 - 6.79 t/ha of mixed phytocenoses. The reserves of aboveground phytomass ranged from 12.06 to 17.94 t/ha and exceeded the underground reserves by 2.1 - 3.1 times. The assessment of vegetation cover on transformed agrophytocenoses gives an idea of carbon reserves during the successional change of perennial herbaceous plants.

Response of soybean varieties to weather conditions in Primorsky Krai

Relevance. The soybean breeding process, focused on increasing the level of qualitative and reproductive indicators of the culture under the means of hybridization, further evaluation of the obtained genotypes and selection of promising samples, has an extremely relevant research direction.Results. The research determined how weather and climatic factors influenced the yield, protein content in seeds, and resistance to fungal diseases of promising soybean varieties under the conditions of Primorsky Krai. High-yielding accessions (3.08–3.59 t/ha) from combinations «Arisa × Taifun» and «NIISKH 3 × Taifun» were selected. A high TKW was characteristic of hybrid combination «Primorskaya 13 × Kofu» (207 g). During the growing season of the crop, there were conditions of insufficient (2021) and excessive (2022) moisture, which had a different effect on the yield level of soybean varieties on average according to experience (17.1 c/ha and 34.0 c/ha, respectively). The conditions of 2022 were optimal for the ontogeny of soybean. Varieties Primorskaya 1690, Primorskaya 1693, and Primorskaya 1696 had the highest yield in 2022 exceeding the standard by 38.0–54.7%. The highest yield was achieved under the conditions of short-term heavy precipitation in combination with high temperature during the growing period. Soybean seeds had a higher protein content after heavy precipitation with short periods of moisture excess from July to August. Under more favorable conditions for the development of fungal pathogens (in 2022), the degree of damage to soybean plants significantly increased (by 16.0%). The studied varieties were resistant to downy mildew and Cercospora.leaf spot (the degree of damage was up to 25.0%).

Stability of starch-proanthocyanidin complexes to in-vitro amylase digestion after hydrothermal processing.

Proanthocyanidins (PA) form poorly digestible complexes with starch. The study examined amylase degradation mechanism and hydrothermal stability of starch-PA complexes. Sorghum-derived PA was complexed with wheat starch, reconstituted into flour (10% gluten added) and processed into crackers and pancakes. In vitro digestion profile of the complexes and products were characterized. The starch-PA complexes retained more (34-84%) fragments with degree of polymerization (DP)>6,000 after 120min digestion than controls (0-21%). Debranching further revealed higher retention of DP 11 - 30 chains in the digested starch-PA complexes than controls, suggesting amylopectin complexation contributed to reduced starch digestion. Starch-PA complexes retained reduced digestibility (50-56% higher resistant starch vs controls) in the cracker, but not pancake model. However, removing gluten from the pancake formulation restored the reduced digestibility of the starch-PA complexes. The starch-PA complexes are stable to hydrothermal processing, but can be disrupted by hydrophobic gluten proteins under excess moisture conditions.

Influence of weather conditions on variability of breeding valuable characteristics of winter rye varieties in Kirov region

Long-term results of the research on the influence of weather conditions on the formation of economically biological and technological characteristics of winter rye varieties are valuable for further use in practical breeding, as well as in solving the problem of realizing their biological potential in a wide range of soil and climatic factors. The aim of the research was to evaluate the influence of weather conditions on the variability of yield, economically biological characteristics and baking properties of 10 winter rye varieties of different geographical origin for the subsequent creation of varieties adapted to the conditions of Kirov region. As a result of eight years of research (2015-2022), the variability of 19 biological and technological characters was analyzed in different weather and climatic conditions (index of environmental conditions from +1.44 to -1.39). The highly stable characteristics were grain nature, ear density and relative ear productivity (CV = 1-8 %). The least stable traits were yield and winter hardiness (CV = 75-89 %). Analysis of variability of characteristics by varieties revealed the most adapted to changes in weather conditions varieties - Rushnik, Falenskaya 4, Flora, Alisa (from 2-3 to 38-42 %). The principal component method with visualization on a biplot chart was used to assess the influence of characteristics on yield formation. It was revealed that the yield was more dependent on the weight of 1000 grains, snow mold damage, winter hardiness, resistance to lodging, length and weight of the ear, number of spikelets and grains in the ear, weight of grain per ear and plant, relative productivity of the ear. These traits determined 65.9 % of yield variability. The second biplot chart allowed to identify the most stable varieties for 8 years of study – Rushnik, Falenskaya 4, Flora and Alisa. It was found that the variety of winter rye Alisa realizes its yield potential both in years with optimal conditions of vegetation and in conditions of excessive moisture, but differs from the varieties Falenskaya 4, Flora and Rushnik in high ear productivity and can be used as a source material for breeding.

Изменчивость биохимических признаков Pinus sylvestris (Pinaceae) при адаптации форм в условиях избыточного увлажнения

Conifers are characterized by a certain degree of individual variability in the content of stress metabolites, which can be caused by genotypic variations or divergence in the growth conditions of individual trees. The purpose of the study is to evaluate the variation of biochemical traits of Scots pine, which are different in the color of male strobilus, during adaptation to the conditions of constant excessive moisture in the soil of the northern taiga. The dynamics of metabolic parameters of Pinus sylvestris L. were investigated in shrubsphagnum pine stands on marshy upland soils at the mouth of the Northern Dvina River (northern taiga subzone). From July to November 2018, needle samples from shoots were collected from 10 pine trees of each of the male strobilus types, differentiated by color. The contents of photosynthetic pigments, anthocyanins, ascorbic acid, proline, water-soluble proteins, and pH were measured under laboratory conditions. The synthesis of chlorophyll in the needles in the current year of formation decreased in trees of both forms during the dry summer period. A favorable temperature in the autumn period could promote an extension of photosynthetic pigment accumulation, which might negatively affect tree preparation for overwintering. There were no significant differences between f. erythranthera Sanio and f. sulfuranthera Kozubow in the needle content of chlorophyll and carotenoids, anthocyanins, ascorbic acid, free proline, water-soluble proteins, or pH. The similarities in the adaptation of the trees to the constant excessive soil moisture in northern taiga conditions were revealed. The seasonal factor had a considerable impact on the dynamics of biochemical parameters. Ascorbic acid, proline, and anthocyanin were more actively accumulated in the needles throughout the summer due to the high air temperature, resulting in an increase in antioxidant activity and the development of protective mechanisms aimed at reducing oxidative stress. The increase in water-soluble protein content in needles from October to November is one of the cryoprotective mechanisms of the trees for the winter period. Individual differences in ascorbic acid and proline contents in yellow microspore-bearing pine needles at the establishment of minus temperatures in November were considerably higher than in red microspore-bearing pine needles. This is regarded as the norm of the reaction for different types of trees to the influence of negative temperatures. For citation: Tarkhanov S.N., Pinaevskaya E.A., Aganina Y.E., Pakhov A.S. Variability of Biochemical Properties During Adaptation of Pinus sylvestris (Pinaceae) Forms to Excessive Moisture Conditions. Lesnoy Zhurnal = Russian Forestry Journal, 2023, no. 4, pp. 58–75. (In Russ.). https://doi.org/10.37482/0536-1036-2023-4-58-75

Organic Carbon, Nitrogen Accumulation and Nitrogen Leaching as Affected by Legume Crop Residues on Sandy Loam in the Eastern Baltic Region.

Legumes have a wide range of positive effects on soil properties, including nitrogen and carbon storage, soil structure and the phytosanitary condition of crops. From an agronomic point of view, legumes are most valued for their ability to take up atmospheric nitrogen in symbiosis with nitrogen-fixing bacteria. The aim of this research was to determine the effect of legume residues (peas, fodder beans, narrow-leaved lupins) on the N (Ntotal) and organic carbon (Corg) accumulation in soil and N leaching under temperate climate conditions. The experiment was carried out in lysimetric equipment in 2016-2023. The effect of legumes on Corg and Ntotal accumulation in soil and N leaching were studied in a Fabaceae-Cereals sequence. Three species of legumes-peas, fodder beans and narrow-leaved lupines-were tested; spring barley (Hordeum vulgare L.) was grown as a control treatment. The lysimeter surface area was 1.75 m2 and the experimental soil layer was 0.60 m (sand loam Haplic Luvisol). It was found that after harvesting, more residues were incorporated into the soil with lupines (p < 0.05), which, compared to pea and bean residues, increased Ntotal and Corg concentrations in the soil. There was a strong correlation (r = 0.95) between the Ntotal concentration in the soil and the N amount incorporated with residues. Mineral N released during residue decomposition was leached from the humic horizon under conditions of excess moisture in the autumn-winter period and increased the nitrate concentration in the lysimeter water. The increase in concentration was recorded within 5 to 6 months after the application of the residues. As a result, the N leaching losses increased on average by 24.7-33.2% (p < 0.05) during the year of legume cultivation. In the following year, after legume residue incorporation, the effect of residues on nitrate concentration and N leaching decreased and did not differ significantly from that of barley residues.

Comparing paleo reconstructions of warm and cool season streamflow (1400–2018) for the North and South Saskatchewan River sub-basins, Western Canada

The North and South Saskatchewan River sub-basins comprise the Saskatchewan River Basin (SRB), which originates in the eastern slopes of the Rocky Mountains of Alberta (Canada) and Montana (USA), extending across the vast landscape of three Canadian Provinces. The SRB is the most populated region of the Northern Great Plains, where water demands from agriculture, industry, and municipalities can be a substantial proportion of supply during periods of low flow and hydrological drought. Changing climatic conditions and shifts between periods of extreme wet and dry weather emphasize the need for a better understanding of past and future seasonal variability of the surface water balance within and between the sub-basins. Climate extremes, such as hydrological drought and excessive moisture conditions occurring simultaneously can create detrimental effects. Using a multi-species network of over 80 tree-ring chronologies, warm (May through August) and cool (December through April) season streamflow (1400–2018) were independently reconstructed for the North and South Saskatchewan River sub-basins. Departures from seasonal flow and spectral and wavelet analyses of the reconstructions indicate significant variability at inter-annual and multi-decadal scales.

Adaptation and Morphological State of Different Forms of Pine under Conditions of Constant Excessive Moisture in Soils of the Northern Taiga

Adaptation and Morphological State of Different Forms of Pine under Conditions of Constant Excessive Moisture in Soils of the Northern Taiga

Изменчивость морфоструктурных показателей разных возрастных поколений в популяциях сосны (Pinus sylvestris L.) в условиях постоянного избыточного увлажнения почв северной тайги Архангельской области

The data is presented for studying the variability of morphostructural parameters of different age (g1 and g2) pine populations under conditions of constant excessive soil moisture of the northern taiga of the Arkhangelsk region. The frequency of occurrence distribution of the age and morphostructural parameters (size of the trunk and crown, self-pruning, length of coarse bark, size and number of side shoots, length and life span of needles) of trees is shown. It has been established that pine trees with smaller trunk and crown sizes, worse self-pruning are more common. Greater height and diameter of the trunk, length and diameter of the crown, better self-pruning, a greater length of the coarse bark is observed in the older generation (g2). This is due to the older age of the trees. It has been established that the relationship between the height of the trunk and the age of the trees is higher in the samples of young generative trees. It was revealed that the young generation (g1) has a significantly greater length and mass of cones, the length, width and height of the apophysis of seed scales compared to the older generation (g2).

Климатический отклик в камбиальном росте форм сосны (Pinus sylvestris L.) таежной зоны Европейского Cевера России

A study was carried out to identify the climatic response in the pine cambial growth under the conditions of excessive moisture in the soils of the northern and middle taiga. The results of the pine trees growth with different apophysis of the cones seed scales from different habitats (the basins of the Northern Dvina, Pinega, Vaga rivers and the mouths of the Mezen and Vychegda rivers) are presented. Significant differences in growth were established between trees with a «convex» and «flat» apophysis of the cones seed scales in the basins of the Northern Dvina, the Pinega and the Vaga rivers and the mouth of the river Vychegda. The values of radial growth in trees with a «flat» apophysis of the cones seed scales are lower than in trees with a «convex» one. It was revealed that different forms of pine have low and close values of the «sensitivity» index (19...27 %), and the variability of this indicator in the more northern coenopopulations is characterized as medium, and in others as medium increased. According to the «stress index», trees of different forms are characterized by a stable and less resistant state to conditions of excess moisture. The cenopopulation of pine at the mouth of the river Mezen and the river basin Pinega established close average values for this indicator. In the river basin of the Northern Dvina, in trees with a «convex» shape of apophysis of the cones seed scales, the average value of the «stress index» is lower than with the «flat» apophysis. In the river basin Vaga and the mouth of the river Vychegda the value of the «stress index» is higher in trees with a «convex» apophysis than in trees with a «flat» shape. Significant correlations were established for the radial growth of various pine trees and air temperature in the study areas. The results obtained can be used in solving environmental problems connected with climate change.

Gas exchange and fluorescence in ‘sutil’ lime (Citrus aurantifolia Swingle) under different soil moisture levels

The Portoviejo valley in the Manabi province, Ecuador, is an important ‘Sutil’ lime (Citrus aurantifolia Swingle) producer, but since the water resources in the region are of vital importance, a good management of the irrigation is needed. The objective of this research was to know the physiological response of the plant expressed in terms of gas exchange and fluorescence, under different levels of irrigation. The study zone is located at Maconta site, 40 masl, in an orchard with 15 year old plants grafted on rootstock ‘Cleopatra’, planted at 6 x 6 m. The following irrigation treatments were tested, according to the atmospheric demand: 0.3ET0, 0.5ET0, 0.7ET0, 0.9ET0, and a control (farmer's irrigation). A randomized complete block design with five treatments and six replications was established. Significant differences (P≤0,05) were found among treatments measured in the dry season, where the photosynthesis rate (A) was higher in the control treatment, decreasing in those treatments with water restrictions (0,3ET0) or excess (0,9ET0) in the soil. Similar behavior was observed in stomatal conductance (gs) and transpiration (T); the increase or decrease of A, would be associated with T and gs. The water use efficiency (WUE) was higher in the treatment of 0,5ET0 than in the rest of treatments, suggesting that the increase in this variable would be due to a good equilibrium of the Ci/Ca, ratio, avoiding water loss and still maintaining active physiological processes. Low values of the Fv/Fm ratio existed in conditions of excess moisture. The performance of gs in both periods leads to deduce the rapid adaptation of the crop to different levels of soil moisture.

Waterlogging Stress Physiology in Barley

Barley (Hordeum vulgare L.) is the most susceptible cereal species to excess moisture stress. Waterlogging-induced hypoxia causes major morphological, physiological, and metabolic changes, some of which are regulated by the action of plant growth regulators and signal molecules including nitric oxide. Recent studies have evidenced the participation of phytoglobins in attenuating hypoxic stress during conditions of excessive moisture through their ability to scavenge nitric oxide and influence the synthesis and response of growth regulators. This review will highlight major cellular changes linked to plant responses to waterlogging stress with emphasis on phytoglobins.

Yield of Amaranth (Amaranthus) Depending on the Cultivar in the Conditions of Ukrainian Western Forest-Steppe

Amaranth is called the culture of the future due to its unique food, feeding and medicinal properties. The acreage of Amaranth in Ukraine is very small, which can be explained by the lack of adaptive cultivation technologies, especially for growing this crop for grain. The purpose of the research was to establish the most productive cultivars for growing in the conditions of excessive and sufficient moisture in the western forest-steppe on dark grey soil. For this purpose, field research was conducted in the experimental field of Lviv National Agrarian University. The total area of the site was 30 m2, recording – 20 m2. The studies were conducted in three repetitions. The authors studied seven of the most common cultivars of Amaranth in Ukraine: Kharkivskyi 1, Lera, Sam, Studentskyi, Polishchuk, Aztec, Ultra. It was established that the yield of amaranth considerably depended on the hydrothermal conditions of the year. It was lower in years with excessive rainfall in the first half of vegetation (2019 and 2020). The highest grain yield (2.46-4.35 t/ha) was formed in 2021 when the amount of precipitation in May, June and July was within the normal range. A strong inverse correlation was established (r=-0.82–r=-0.95) between the yield of amaranth cultivars and the amount of precipitation. The highest grain yield (4.03 t/ha) among the studied amaranth cultivars was obtained in Kharkivskyi 1. The lowest yield was formed in the Ultra cultivar (1.97 t/ha), which is less than in the Kharkivskyi 1 cultivar by 2.06 t/ha. The study of elements of the yield structure showed that the height of the plant had a positive effect (r=0.63) on the level of amaranth grain yield, while average relationship was observed between panicle length and yield (r=-0.36). The weight of 1000 seeds in the cultivars ranged from 0.74-0.88 g. The low mass of seeds per plant had the greatest impact on yield (r=0.99). The highest yield of amaranth of the Kharkivskyi 1 cultivar was formed with the following ratio of the main elements of the crop structure: the number of plants – 21 p/m2 and the mass of seeds from the plant – 19.2 g. To obtain a high stable yield of amaranth grain, additional research is required to clarify the main elements of cultivation technology for these soil and climatic conditions

Yielding capacity of amaranth grain (Amaranthus hypochondriacus) depending on fertilizers

The research was conducted on the research field of Lviv National Agrarian University on dark gray podzolic light loamy soil. Hydrothermal conditions differed from the average of many years data by more precipitation. In 2019, during the growing season it fell by 53 mm above the rate, in 2020 - by 129 mm, in 2021 - by 73 mm. The aim of the research to define the amaranth nutrition system in conditions of sufficient and excessive moisture, seven rates of mineral fertilizer application were studied: N0P0K0, N40P20K40, N80P40K80, N120P40K80, N160P80K120, N200P80K120, N200P80K160. Under the influence of fertilizers, plant height increased from 147.1 cm to 208.2 cm, panicle length - from 32.2 cm to 71.7 cm, seed weight from one plant - from 12.9 g to 27.8 g, weight of 1000 grains - 0.86 g to 0.91 g. The number of plants before harvest was in the range of 18-20 plants/m2. Increasing of the application rate of mineral fertilizers from N0P0K0 to N200P80K160 provides the increase of the yielding capacity of amaranth grain of the variety Kharkiv 1 from 2.31 t/ha to 4.88 t/ha, or by 2.57 t/ha. Yield depended mostly on nitrogen fertilizers, application of N40 on variants with the rate of N120P40K80 and N200P80K120 fertilizers resulted in a further increase of the yield by 0.41 t/ha and 0.34 t/ha. Increasing the potassium rate by K40 on variant N200P80K160 did not provide a significant (0.04 t/ha) increase of the yield. The highest level of yielding capacity is formed by the following structural elements: grain weight from one plant - 27.8 g and number of plants - 18 p/m2.

Assessing the Response of Diverse Sesame Genotypes to Waterlogging Durations at Different Plant Growth Stages.

Sesame is sensitive to waterlogging, and its growth is devastatingly impacted under excess moisture conditions. Thus, waterlogging tolerance is crucial to alleviate yield constraints, particularly under expected climate change. In this study, 119 diverse sesame genotypes were screened for their tolerance to 12, 24, 48, and 72 h of waterlogging relative to non-waterlogged conditions. All plants died under 72 h of waterlogging, while 13.45%, 31.93%, and 45.38% of genotypes survived at 48, 24, and 12 h, respectively. Based on the seedling parameters and waterlogging tolerance coefficients, genotypes BD-7008 and BD-6985 exhibited the highest tolerance to waterlogging, while BD-6996 and JP-01811 were the most sensitive ones. The responses of these four genotypes to waterlogged conditions were assessed at different plant growth stages—30, 40, and 50 days after sowing (DAS)—versus normal conditions. Waterlogging, particularly when it occurred within 30 DAS, destructively affected the physiological and morphological characteristics, which was reflected in the growth and yield attributes. Genotype BD-7008, followed by BD-6985, exhibited the highest chlorophyll and proline contents as well as enzymatic antioxidant activities, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT). These biochemical and physiological adjustments ameliorated the adverse effects of waterlogging, resulting in higher yields for both genotypes. Conversely, JP-01811 presented the lowest chlorophyll and proline contents as well as enzymatic antioxidant activities, resulting in the poorest growth and seed yield.

Varietal specificity of the reaction of winter rye to background changes of mineral nutrition

The study of the genetic characteristics of the reaction of plants to changes in environmental conditions makes it possible to more effectively use the achievements of breeding. In the conditions of the open forest-steppe of the Krasnoyarsk Territory in 2019 - 2020, a study of the yield of winter rye was carried out on a site with a low nitrogen content against two backgrounds: without fertilizers (control) and with fertilization. The object of the research is the varieties included in the State Register for the East Siberian region Yeniseyka (standard), Sinilga, Krasnoyarskaya universal and the Arga variety undergoing state testing. In the dry 2019 year, the average yield in the control variant was 27.5 c(centner) / ha, the increase from fertilization was 8.2 c / ha. In conditions of excessive moisture in 2020, it was respectively - 32.7 c / ha and 13.6 c / ha. The response of varieties to background changes of mineral nutrition was different. The most responsive to fertilization was the Arga variety, the most stable was the Sinilga variety. Krasnoyarskaya universal and Arga surpassed Yeniseyka and Sinilga in average yield by 2.3-2.7 centners / ha and were more resistant to lodging. Arga had an advantage in productivity with a sufficient supply of nutrients, the Krasnoyarsk universal was characterized by greater stability and less response to agrotechnical background changes.

Preparation of Breathable Cellulose Based Polymeric Membranes with Enhanced Water Resistance for the Building Industry.

This study focuses on the development of advanced water-resistant bio-based membranes with enhanced vapour permeability for use within building envelopes. Building walls are vulnerable to moisture damage and mold growth due to water penetration, built-in moisture, and interstitial condensation. In this work, breathable composite membranes were prepared using micro-fibrillated cellulose fiber (CF) and polylactic acid (PLA). The chemical composition and physical structure of CF is responsible for its hydrophilic nature, which affects its compatibility with polymers and consequently its performance in the presence of excessive moisture conditions. To enhance the dispersibility of CF in the PLA polymer, the fibers were treated with an organic phosphoric acid ester-based surfactant. The hygroscopic properties of the PLA-CF composites were improved after surfactant treatment and the membranes were resistant to water yet permeable to vapor. Morphological examination of the surface showed better interfacial adhesion and enhanced dispersion of CF in the PLA matrix. Thermal analysis revealed that the surfactant treatment of CF enhanced the glass transition temperature and thermal stability of the composite samples. These bio-based membranes have immense potential as durable, eco-friendly, weather resistant barriers for the building industry as they can adapt to varying humidity conditions, thus allowing entrapped water vapor to pass through and escape the building, eventually prolonging the building life.

Correlation analysis of the parameters of oats assimilation apparatus and productivity elements

On sod-podzolic soils, new data is obtained on the functioning of the photosynthetic structures of oat leaves in various climatic conditions and of biomass accumulation (plant productivity). Based on three-year data (2015-2017) of field experiments with 29 oat genotypes, the relationship between the development of productivity elements and the characteristics of the plant assimilation apparatus is analyzed. The pigment content (chlorophyll a, chlorophyll b, carotenoids) was evaluated in acetone extracts on a UVmini-1240 spectrophotometer (SHIMADZU Corporation, Japan). Statistically significant correlations were established between the total leaf surface area and grain mass per plant (r = 0.664), the number of spikelets in a panicle, grain mass per panicle and the mass of the panicle itself (r = 0.548 ... 0.613). These correlations decreased during a drought and increased in conditions of excessive moisture. Oat genotypes with a larger sub-flag leaf had a larger panicle, with a large number of spikelets, grains and of larger grain mass per panicle and plant. During a drought, these correlations decreased. The correlation of the flag leaf area with the grain mass of the panicle and plant under stressful conditions of excessive moisture or a drought increased. With excessive moisture, an increase in the proportion of chlorophyll a in the total chlorophyll pool and in the composition of the reaction centers of photosystems was observed in genotypes with an increased number of spikelets and grains in a panicle, with larger grain masses per panicle and plant, and a mass of 1000 grains. During a drought, the correlation of the content of chlorophylls a and b increased with the following signs: panicle length, panicle mass, number of spikelets in a panicle, and number of grains in a panicle. However, an increase in panicle mass and the number of grains in it was accompanied by a decrease in the proportion of chlorophyll a in the total pigment pool and in the composition of reaction centers.