Phases Of Plant Development Research Articles

PHENOLIC COMPOUNDS AGRIMONIA PILOSA DEPENDING ON THE PHASE OF PLANT DEVELOPMENT

The composition and content of phenolic compounds in the organs of the above-ground part of Agrimonia pilosa Ledeb. depending on the phase of plant development were studied by high performance liquid chromatography (HPLC). Fourteen compounds found in water-ethanol extracts from organs of A. pilosa. Flavonols (kaempferol, astragalin, kaempferol-3-O-β-rutinoside, quercetin, hyperoside and rutin), flavones (apigenin, vitexin, luteolin and luteolin-7-glucoside) and phenolic acids (chlorogenic, caffeic, vanillic and ellagic acids) have been identified. Hyperoside, rutin, and ellagic acid were the major constituents in the extracts from the leaves and the reproductive organs of the species. The highest content of rutin were found in the leaves during vegetative growth and in the inflorescences (2.75 and 2.67 mg/g, respectively). The highest content of hyperoside were observed in leaves in the phase of budding and fruiting (2.02 and 2.25 mg/g). The highest content of ellagic acid were revealed in leaves in the fruiting phase and in buds (3.49 and 2.09 mg/g). The highest total phenolic content was found in the leaves during the fruiting (21.1 mg/g). Unidentified flavonols number 12 and 13 (1.62 and 2.76 mg/g, respectively) were the domi-nant components in the leaves in the growing phase. The total content of phenolic compounds in buds (9.52 mg/g) and in inflorescences (9.80 mg/g) was the same. The total content of phenolic compounds in fruits was two times less (4.24 mg/g) than in buds and inflorescences.

FLAVONOIDS OF THE EAST ASIAN SPECIES SERRATULA MANSHURICA KITAG.

One of the poorly studied and widespread plants in the Russian Far East is the Manchurian saw-wort (Serratula manshurica Kitag.). It is known that this plant is rich in phytoecdysteroids, which have high biological activity (anabolic, adaptogenic, cardiotropic, immunomodulatory effects). Two biologically active compounds of the flavonoid class were isolated from the aerial part of Serratula manshurica Kitag. Growing in the Primorsky Kray of the Far East of Russia by liquid extraction and recrystallization methods: quercetin-4'-O-β-D-glucuronopyranoside and apigenin-7-O-β-D-glucuronopyranoside. The structure of the isolated compounds was proved by UV-, NMR-spectroscopy and mass spectrometry with electrospray ionization. The quantitative content of flavonoids in the aerial part of the Serratula manshurica plant in different phenological phases of plant development (luteolin-4'-O-β-D-glucuronopyranoside, quercetin-4'-O-β-D-glucuronopyranoside, apigenin-7-O-β-D-glucuronopyranoside, 3-methylquercetin-4'-O-β-D-glucuronopyranoside, quercetin, apigenin, 3-methylquercetin, luteolin, isokaempferide) was determined by the method of reversed phase liquid chromatography (RP HPLC). It was shown that the maximum content of flavonoid aglycones in plants was observed during the beginning of the growing season and in the budding phase, and their glycosides - during the flowering phase. Thus, to obtain plant material with the maximum content of flavonoid aglycones (quercetin, 3-methylquercetin, luteolin) the collection of vegetative mass should be carried out during the beginning of the growing season, and their glycosides - during the flowering period. Serratula manshurica Kitag., which grows abundantly on the territory of Primorsky Krai, can be considered a constantly renewable and promising source for obtaining flavonoids.

Comparative assessment of the work of photosystem II in the leaves of soybean varieties and hybrids

The efficiency of PS II of soybean leaves was shown depending on the genotype of the variety, the phase of plant growth and development, and the intensity of their illumination in the field. Purpose of the work: to study the intensity of photosynthetic processes in soybean leaves using a MINI-PAM fluorometer to isolate highly active ones. The object of research was early maturing and mid-maturing varieties, white-flowered soybean hybrids. The efficiency of PS II (Y) with a sequential increase in the illumination intensity was determined in the early ripening variety Sonata and the mid-ripening Oktyabr 70. The most stable efficiency of PS II was in the leaves of the varieties Sonata and Oktyabr 70 at an illumination degree of ≈ 800 to 1500 μmol quanta m-2 s-1. The Sonata cultivar had a higher potential in the restoration of the photochemical activity of PS II. The dependence of PS II activity on the phase of plant growth and development was revealed. A high level of effective quantum yield of PS II (0.84 … 0.86 rel. units) during the growing season was noted in the leaves of new soybean varieties Kruzhevnitsa, Evgeniya, Persona and Kitrossa. Plants of the white-flowered collection had the maximum parameters of the quantum yield of PS II during the period of formation of reproductive organs. The data obtained allowed us to recommend the varieties Sonata, Kruzhevnitsa, Evgeniya, Persona, and Kitrossa, as well as hybrids KB (5) and KB (26) for inclusion in the breeding process, as they have a high level of PS II work, when creating varieties with increased photosynthetic activity.

Evaluation parameters of in vitro morphogenesis in the process of replication of potato starting material

In the process of replicating and growing the necessary volumes of in vitro material for original seed production, the period of formation of morphological structures and the achievement of microplants of standard characteristics is important. The existing method of regeneration assessment by the quantity of days from the moment of placement of micro stalks into a new nutrient medium does not allow a planned approach to the compilation and implementation of the clonal micropropagation program. The article proposes new methodological approaches to assessing in vitro potato material by the main phases of plant development in tissue culture: intensive growth (formation of 2-3 internodes), slow growth (4-6 internodes), and natural dying-off. The analysis of regenerative ability allows us to note that the effectiveness of the formation of morphological structures did not depend on the ripeness group of the studied variety samples. Presented results indicate the differentiated approach of varieties to the formation of morphological structures in the process of replication.

Microbiota in the Rhizosphere of Cereal Crops

Today, spelt wheat grain is used to produce high quality food. Intermediate wheatgrass is a promising crop for prairie restoration. One of the elements of biologization is the influence of growing crops on the microbiota of soil rhizosphere. The microbiota of spelt wheat and intermediate wheatgrass soil rhizosphere remains insufficiently studied. Aim. To study the number of individual groups of microbiota in dynamics in the rhizosphere of cereal crops (spelt wheat, intermediate wheatgrass) depending on the weather conditions and the phase of plants development. Methods. Classical microbiological, statistical methods were used in the work. In particular, the study of the number of microorganisms of different ecological and trophic groups (ammonifying, nitrifying, cellulolytic and nitrogen-fixing) was carried out according to generally accepted methods in soil microbiology. The reliability of the influence of factors was determined by the probability value «р» level which was calculated using STATISTICA 8 program. Results. The amount of ammonifying and cellulolytic microorganisms in the soil rhizosphere of spelt wheat is significantly higher compared to soft wheat. The rhizosphere microbiota amount of the intermediate wheatgrass on the 2–3 year of cultivation was more resistant to adverse environmental factors compared to soft wheat. The soil rhizosphere microbiota did not change a lot depending on the phase of plant development during the vegetation period of cereal crops (spelt wheat, intermediate wheatgrass). Conclusions. The formation of rhizosphere microbiota of spelt wheat and intermediate wheatgrass was first analyzed under the conditions of the Right-Bank forest-steppe of Ukraine. The conducted studies indicate the feasibility of growing and use of spelt wheat in breeding programs to create cultivars of soft wheat with higher activity of rhizosphere microbiota. The number of ammonifying, nitrifying and cellulolytic microorganisms of soil rhizosphere of intermediate wheatgrass was significantly higher compared to soft wheat during all growth stages. The conducted studies confirm the practical application of intermediate wheatgrass to preserve and increase soil fertility. Intermediate wheatgrass can be grown for up to three years in one field, as microbiological activity reaches its maximum development.

Clonal micropropagation of bog cranberry (Vaccinium oxycoccos L.) in the Udmurt Republic

The paper presents the results of 2018-2019 research on improving the technology of growing planting material of bog cranberry (Vaccinium oxycoccos L.) of Krasa Severa, Severyanka, Virussaare varieties on the basis of in vitro. Studied was the effect of the concentrations of growth regulators in the composition of the nutrient medium according to Anderson's recipe on the reproduction and subsequent rooting of micro cuttings, as well as the duration of cultivation and adaptation of micro plants depending on partial pruning of shoots. It has been established that at the stage of introduction into in vitro culture, sterilization of explants with 33% hydrogen peroxide in an exposure of 5-8 minutes with washing in 5 portions of sterile distillate gives 60-80 % of viable shoots. The optimum phase of plant development for the successful introduction of in vitro culture is the swelling of buds. Cultivation of micro cuttings was carried out in a light room at a temperature of 25±2 °С, a photoperiod of 16 hours. The duration of each subculturing was 30-60 days. For the stage of actual micropropagation on Anderson's nutrient medium, an increase in the dose of cytokinin 6-benzylaminopurine (6-BAP) from 0.2 to 0.5 mg/l and an increase in the duration of cultivation from 30 to 60 days contributed to a significant increase in the multiplication factor on average for the tested cranberry varieties.According to the efficiency of micropropagation, the varieties Virussaare and Krasa Severa were distinguished – 9.3-12.0 pcs/stalk, respectively. At the rooting stage, the use of a root-forming reagent of indolyl-3-acetic acid (IUK) in doses of 0.2, 0.5 and 1.0 mg/l in the composition of Anderson's nutrient medium did not affect the quality of root formation and the length of shoots of Virussaare micro-plants. No significant varietal differences in the root-forming ability of microcuttings were found. The tendency of better rooting of micro cuttings was observed in the Virussaare variety (90.3 %) compared to the Severyanka (85.7 %) and Krasa Severa (79.3 %) varieties. Micro plants of the Krasa Severa cultivar were characterized by the longest shoots, the total number of roots was less, but their length was longer in comparison with other cultivars. For the adaptation stage, a substrate from a mixture of lowland peat and sphagnum moss was used (1:1). The efficiency of adaptation of micro plants of cranberry varieties when cutting the tip of the shoots was 100 %. Pruning of micro plants shoots contributed to the formation of more side shoots and better development of the aboveground part of the plants.

Protection of cereals from a complex of diseases

In this article lays the foundation for a program to protect various crops from a complex of diseases. The program is open for inclusion of new modules. As basic components, it uses previously developed models to protect wheat from brown rust, powdery mildew, Septoria and their complex. The new program has increased the detail of calculations based on the model of large-scale distribution of brown rust uredospores in wheat. Significant changes have been made to the basic module for protecting wheat from brown rust, which uses the results of calculations based on a large-scale spread model with a reduced space step and is the basis for comparison with other diseases. The new program was also adapted for the case of poorly defined initial conditions about the actual defeat of wheat by brown rust, powdery mildew and Septoria. Equations are given for estimating wheat damage and crop losses if there is no data on varietal characteristics, regardless of the phase of plant development.

The role of plant physiology and cultivar of chrysanthemum in the resistance against Western flower thrips

AbstractWestern flower thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae), is an economically important pest insect in vegetable and ornamental cultivation worldwide. Little is known about host plant resistance in the vegetative and generative phases of chrysanthemum [Chrysanthemum × morifolium (Ramat.) Hemsl. (Asteraceae)] and the role of resistance factors such as flavonols, flower color, and flower shape. We screened a broad range of chrysanthemum cultivars across two seasons to quantify resistance against Western flower thrips. Resistance was based on silver damage on the leaves, and relative flavonol content was measured using a Dualex Scientific 4 hand‐held sensor. There was significant variation in silver damage between cultivars, indicating different levels of resistance. There was no correlation between the relative flavonol content in middle leaves and plant silver damage. A clearer resistance level discrimination by flavonols in resistant and susceptible cultivars would be possible in the future by comparing multiple leaf positions during the ontogenetic phases of plant development. Moreover, the influence of flower color and shape on resistance to thrips was investigated by counting the adult thrips and larvae on flowers. The results showed significant differences in flower color preference by adults, but not by larvae. Flower shape influenced thrips larvae and females, but not males. The importance of the results for resistance determination is discussed.

The relationship between productivity and hydrothermal conditions for growing soybeans on rainfed lands in the Middle Volga region

Relevance. One of the most important factors that determine the effective cultivation of soybeans in the Middle Volga region is the use of modern highly productive varieties adapted to growing conditions. To create a competitive variety, it is important to select sources that are adapted to the environmental factors of a particular region.Methods. Field experiments were carried out according to generally accepted methods. All counts and observations were carried out according to the Methodological Guidelines for Studying the Collection of Legumes. In 2016–2019, 36 early maturing and medium early maturing varieties of soybeans of various ecological and geographical origin, as well as breeding material created in local conditions, were studied in the breeding nursery.Results. It was found that the duration of the growing season over the years of study was largely determined by the duration of the flowering — ripening period (r = 0,96). Correlation analysis showed that a significant role in the formation of the yield of soybeans is played by hydrothermal conditions that develop during the generative phase of plant development. There is a high correlation between the level of yield and the average daily temperature and the sum of active temperatures (r = 0,79–0,82) during the flowering — ripening period. In the breeding nursery, the cultivars that most fully realize the genetic potential and reliably exceed the standard in productivity by 12,0–22,0% were identified: k-177, k-445/2 and IHAR-NK 88/2.

Resistance of rice genotypes to fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an important rice pest which consumes leaf area during all phases of plant development. The objective of this study was to identify rice genotypes that provide antixenosis and antibiosis to fall armyworm. Antixenosis was investigated by measuring non-preference in free-choice and no-choice tests while antibiosis was determined by measuring biological parameters and nutritional indices of S. frugiperda in twelve rice genotypes. The genotype Miúdo Branco showed antixenosis to S. frugiperda, whereas the genotypes IR 64 and Bacaba Branco showed antibiosis to S. frugiperda by affecting insect development and prolonging insect life cycle. Insects that fed on Bacaba Branco genotype demonstrated the lowest nutritional indices. Since Miúdo Branco, IR 64 and Bacaba Branco showed moderate resistance, rice producers could use these genotypes as part of a control strategy for S. frugiperda.

Resistance of rice genotypes to fall armyworm Spodoptera frugiperda (Lepidoptera: Noctuidae)

ABSTRACT The fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae), is an important rice pest which consumes leaf area during all phases of plant development. The objective of this study was to identify rice genotypes that provide antixenosis and antibiosis to fall armyworm. Antixenosis was investigated by measuring non-preference in free-choice and no-choice tests while antibiosis was determined by measuring biological parameters and nutritional indices of S. frugiperda in twelve rice genotypes. The genotype Miudo Branco showed antixenosis to S. frugiperda, whereas the genotypes IR 64 and Bacaba Branco showed antibiosis to S. frugiperda by affecting insect development and prolonging insect life cycle. Insects that fed on Bacaba Branco genotype demonstrated the lowest nutritional indices. Since Miudo Branco, IR 64 and Bacaba Branco showed moderate resistance, rice producers could use these genotypes as part of a control strategy for S. frugiperda.

Effect of presowing seed treatment on photosynthetic pigments content and enzyme activity in Hordeumvulgare L. plants

The use of nanoparticles in pre-sowing seed treatment increases the resistance of plants to pathogenic microflora, adverse weather conditions and increases the yield of crops. The study aimed to study the effect of molybdenum nanoparticles, a suspension of iron and silicon and preparations based on humic acids on the content of photosynthetic pigments, the activity of antioxidant enzymes in Hordeumvulgare L. plants and its productivity. The content of chlorophyll a and b, carotenoids in different phases of plant development was determined using the standard method with Smashevsky modifications, catalytic activity according to the Ebi method, superoxide dismutase according to Hyannopolitis and Rice with some modifications of Polesskaya. Barley seed treatment with preparations based on iron, silicon, molybumum, bogum and molybdenum nanoparticles M Mo stimulates an increase in the level of photosynthetic pigments and the activity of antioxidant enzymes in plants. Using a composition created based on Fe3O4 (10–3 mg/L) and SiO2 (10–4 mg/L) nanoparticles in a 1: 1 ratio for the presowing treatment of barley seeds increases grain yield.

Ecological Plasticity and Stability of Spring Bread Wheat Varieties by Yield Level in Agro-Ecological Zones of the Forest-Steppe and Polissia of Ukraine

The weather conditions in the two ecological zones Forest-Steppe and Polissia of Ukraine differed considerably in temperature regime and rainfed environments both during growing season as a whole and during particular phases of plant development. This made it possible to estimate spring bread wheat varieties by the levels of realizing their plant productivity potential. The productivity of spring wheat plants mainly depends on the growing zone (29.2%), hydrothermal vegetation conditions (16.3%), as well as their interaction (27.1%). There have been identified the varieties of spring bread wheat Simkoda myronivs’ka, Struna myronivs’ka, MIP Zlata (UKR), Koksa (POL), Leguan (CZE) with increased yield level that were recommended to be grown in ecological zones Forest-Steppe and Polissia. The calculation of ecological plasticity and stability allowed differentiating the varieties of spring bread wheat in accordance with their responsiveness to variatione of growing conditions as well as with adaptive potential. High plasticity by yield level under growing conditions of the Forest-Steppe and Polissia zones was determined in the varieties: Koksa (POL) (b_i = 1.02), Simkoda myronivs’ka (UKR) (b_i = 1.02), Granny (AUT) (b_i = 1, 03), Heroinia (UKR) (b_i = 1.01), Etiud (UKR) (b_i = 1.02). These varieties may be characterized by adaptive properties as intensive ones with a pronounced response to the environment, i.e. relatively high grain yields may be resulted from a specific response to more favorable growing conditions. There were identified the most stable varieties for terms of yield in two ecological zones Yasna (POL), Siuita, Panianka, Kharkivs’ka 26, Elehiia myronivs’ka (UKR).

Effect of different sowing times on the plant developmental parameters of wheat (Triticum aestivum L.): A review

Studies on plant development phases and yield component patterns of wheat are essential for a better understanding of adaptation in wheat. Temperature is an important climatic factor which has profound effects on the yield of rabi crops. Changes in temperature affect the grain yield, mainly through phenological development processes. Winter crops are especially vulnerable to high temperature during reproductive stages and differential response to temperature change (rise) to various crops has been noticed under different production environments. The effect of temperature on the wheat phenological can easily by seen in Central India because of high inter-annual fluctuations in the productivity due to fluctuations in temperature. The productivity of wheat is largely dependent on the magnitude of temperature change. 1 °C increase in temperature throughout the growing season will have no effect or slight increase on productivity in North India. But, an increase of 2 °C temperature reduced potential grain yield at most of the places (Agrawal and Sinha, 1993). Deshmukh et al. (2015) reported that significant increase yield when the wheat crop was sown at 45 MW than 48 MW. Grain yield was significantly higher when crop was sown at 45 MW sowing.

Вплив абіотичних факторів на ріст і розвиток рослин пастернаку посівного

The main factors that have a great influence on plant growth, as well as on increasing the yield and its quality characteristics, are biotic and abiotic. Combinations of abiotic stresses, such as drought and heat, have a much greater impact on yields and product quality. The response of plants to these stresses can vary depending on the species, as well as at different stages of development. Understanding the mechanisms and how they protect plants from stress has become vital to improving the yield and quality of parsnip products in changing climatic conditions. The research aimed to study the influence of abiotic factors (temperature and precipitation) on yield, duration of phenological phases of plant growth and development, dynamics of growth of leaves and roots of parsnip in the Right Bank Forest-Steppe of Ukraine. The research was conducted in the field experiment of the Department of Vegetable Growing and Closed Soil in NL "Fruit and Vegetable Garden" NUBIP of Ukraine in the Right Bank Forest-Steppe of Ukraine during 2015-2017. The area of the accounting plot was 11.3 m2, the repetition of the experiment was 4 times. The arrangement of the research plots was systematic. As a result of research, it is established that the shortest period of sowing-seedlings lasted 16 days in the options for sowing in the 3rd decade of May and the 1st decade of June. Significant delay for 21 days of this period was observed for sowing from the 1st to the 3rd decade of April. The duration of the period from the beginning of root formation to beam ripeness was the smallest for sowing in the 1st decade of April – 28 days, and the largest for sowing in the 1st decade of June – 51 days. The vegetation period ranged from 110 to 165 days and passed for the sum of temperatures (> 10 °С) 1102.4-1439.0 °C and the sum of precipitation 128.1-225.2 mm. During sowing in April, an intensive increase in root crops from 2.9 to 3.5 g/day was observed in the second half of August. During sowing in May, the largest increase in root crops from 2.1 to 2.7 g/day was observed in the first half of September. Thus, for sowing in the 1st decade of June, this figure was highest in the second half of September (1.9 g/day). The option for sowing in the 1st decade of April provided a high yield of root crops of 50.3 t/ha, which is 5.3 t/ha or 11.8% significantly more than the control. When sowing in the following periods, a significant decrease in yield was observed compared to the control, namely: for the 3rd decade of April – by 3.5 t/ha, or 7.7%, for the 1st decade of May – by 8.8 t/ha, or 19.6%, for the 2nd decade of May – by 17.4 t/ha, or 38.6%, for the 3rd decade of May – by 23.0 t/ha, or 51.1%, for the 1st decade of June – by 31.7 t/ha, 70.6% compared to the control. There was a direct strong relationship (r = 0.74-0.99) between the growing season and yield, root weight, marketability, and biochemical parameters, namely: dry matter, dry soluble matter, sugars, vitamin C. The inverse of the strong (r = -0.98) was observed between the duration of the growing season and nitrates. Increasing the growing season by 10 days increases the yield to 6.9 t/ha, marketability up to 2.7%, root weight up to 31 g, dry matter content up to 0.7%, dry soluble matter up to 0.3%, sugars up to 0,5%, vitamin C to 0.8 mg/100 g and reduces the nitrate content to 8.4 mg/kg. Leaf area, photosynthetic potential, net photosynthesis productivity are in strong direct connection (r = 0.92-0.98) with yield. As the leaf surface area increases to 1.0 thousand m2/ha, the yield increases to 0.7 t/ha. Increasing the photosynthetic potential to 0.05 million m2 per day/ha increases the yield to 0.2-1.2 t/ha. Also, the yield increases to 0.3-0.7 t/ha by increasing the net productivity of photosynthesis to 0.05 g/m2 per day. Promising for further study is molecular knowledge of plant responses to abiotic stress, likely to pave the way for making crops resistant to climate change and increase the economic efficiency of production.

Formation of reproductive organs in an early-ripening soybean variety, depending on the daylight duration

To study the reaction of an early-ripening soybean variety to the formation of plant reproductive organs under the influence of different length of daylight hours, studies of 2 sowing periods in a growing house with a new early-ripening variety Sentyabrinka of the FSBSI FRC VNII of Soybean were conducted. Artificial reduction of the daylight duration to 8 hours was established from the phase of the 3rd triple leaf with alternating day and night periods in each variant 7 times during the growing season. The control was plants whose growth and development took place in natural light conditions. According to the research results, it was found that the change in the daylight duration during the vegetation period had a significant impact on the duration of the phases of plant growth and development, the growing season as a whole. When sowing soybeans on May 28 with a natural daylight, the height of plants and their seed productivity were higher than those of plants with a shortened daylight. At this sowing period, the highest productivity was obtained from one plant – 9.3 g, which is 1.0 g more compared to soybean plants with a sowing period of June 3. The growth of plants, the formation of reproductive organs and the seed productivity of the early-repining variety Sentyabrinka depended on the duration of daylight, which can be regulated by the sowing period.

Особливості зміни чисельності та складу мікробіому ризосфери пшениці озимої в процесі онтогенезу

In agroecosystems, microorganisms are the main factor in the soil formation process, plant nutrition and phytosanitary condition of the soil. Therefore, all measures aimed at restoring soil fertility and increasing productivity, environmental safety of agricultural production are closely linked to the activities of microorganisms. Increased local activity, biomass and diversity of microbiota are one of the most important characteristics that distinguish the rhizosphere from the total soil volume. The aim of the research was to study the number and composition of the microbial complex of the rhizosphere of cereals (winter wheat of different varieties of domestic selection) in the process of ontogenesis. To conduct a set of microbiological studies, soil samples were taken and prepared (typical chernozem) in compliance with the standard requirements for sample preparation and storage of samples in the laboratory. The analysis of rhizosphere soil samples was performed according to the variants of different varieties of winter wheat of domestic selection. The number of soil microorganisms was determined by the method of inoculation of suspensions on nutrient media according to generally accepted methods in microbiology. Determination of the total microbial biomass in the soil was carried out by the rehydration method, and the intensity of "respiration" of the soil, respectively, by the release of CO2 and O2 absorption by the manometric method (Warburg apparatus). It is established that varietal specificity is significantly related to the peculiarities of microbiome formation in different phases of plant growth and development, which is an integral indicator of functional and metabolic activity of soil microorganisms. The number and composition of the microbial complex of winter wheat rhizosphere in the process of ontogenesis changes significantly, especially in the ratio of the number of spore-forming and non-spore forms of microorganisms under the same conditions of crop cultivation. The total pool of saprotrophic microorganisms of the rhizosphere demonstrates the variability of biomass and changes in favor of ecoplastic Bacillus. An increase in the number of spore-forming bacteria to 4.2 x 107 CFU/g in the variants of growing certain varieties was found. It is shown that in the cultivation of different varieties of winter wheat there are stable indicators of the intensity of CO2 emissions - from 5.2 to 7.0. A similar trend can be traced to the absorption of O2 (not more than 5.3-6.8).

Орошение моркови: проблемы и перспективы

Purpose: to study modern approaches to the determination of irrigation regimes and water consumption for carrots during sprinkler irrigation. Discussion. Carrot is a vegetable crop in demand in the modern food market. In Russia, no more than 1–1.5 million tons of carrot root crops are currently cultivated, which covers the country's needs only by 70–80 %. The rest is replenished through imports. Under modern conditions, the increase of the vegetable crops yield, including carrots, is impossible without irrigation. Numerous studies confirm that, along with biological characteristics, climatic and other factors, irrigation affects the carrot yield, significantly increasing it in comparison with rainfed. The analysis of the recent research made it possible to note that the most common method of carrot crops watering is sprinkling. However, this requires significant volumes of irrigation water, and therefore, water-saving irrigation modes are in demand under modern conditions. It is known that the optimal soil water regime on carrot crops is formed when the moisture content is maintained at least 75–80 % HB. The critical period for moisture provision is from the carrots sowing to the appearance of their shoots, as well as the periods of the greatest frondescence and intensive root formation. Conclusions. Water regime management is achieved by irrigation differentiation by the plant growth and development phases, soil moisture regimes, as well as the depth of the wetted layer. The use of this methodological approach helps to reduce the total water consumption, to increase the efficiency of moisture use by crops. Using computational approaches to determine the elements of water balance, which make it possible to control the water regime of carrot crops is promising.

Phytometric criterion for assessing plant development states

A phytometric criterion for assessing plant development states based on the integral dependence of indicators with the same weighting factor is proposed, which makes it possible to obtain the dependence of the main indicators of plant development in different phases of development on the influence of the average daily air temperature and light intensity, which can be used in the energy flow control system of an industrial greenhouse during the production of plant products to ensure a given product quality, taking into account the phases of plant development.

Seasonal Dynamics of the Underground Part of the Ephemeral–Wormwood Semidesert of the Kura–Araks Lowland under Modern Climatic Conditions

This article examines the regularities of the dynamics of the underground part of the ephemeral–wormwood semidesert of the Kura–Araks lowland under conditions of climate change. It was found that the ratio of productive and unproductive roots in plants remains at a certain level regardless of the phase of plant development and the season of the year under modern climatic conditions in different years. Data illustrating repeated experiments and observations are given in the tables and figures. It is concluded that a decrease in root mass with soil depth has a pronounced pattern in plant communities.