Favorable Weather Conditions Research Articles

Assessing the Impact of Traffic Emissions on Fine Particulate Matter and Carbon Monoxide Levels in Hanoi through COVID-19 Social Distancing Periods

Hanoi, Vietnam, is usually ranked as one of the most polluted capital cities in terms of air quality, particularly PM2.5. However, there has not been enough data to determine the main source of this pollution. In this study, we utilized the rare opportunity of the COVID-19 social distancing to assess the contribution of traffic emission to PM2.5 and CO levels when traffic volume was reduced significantly in Hanoi. Hourly PM2.5 and CO concentrations were measured from nine urban and traffic monitoring stations during pre-, soft, hard, and post-social distancing periods. As a result, we observed large reductions in both PM2.5 and CO levels during social distancing periods. PM2.5 concentrations were 14–18% lower during the social distancing than before this period, while CO concentrations had a more considerable drop by 28–41%. It is known that meteorological conditions can have significant effects on the ambient levels of air pollutants. To overcome this challenge, weather normalized concentrations of those pollutants were estimated using the random forest model, a machine learning technique. The normalized weather concentrations showed smaller reductions by 7–10% for PM2.5 and 5–11% for CO, indicating the presence of favorable weather conditions for better air quality during the social distancing period. In further analysis, the apparent improvement of air quality in Hanoi during the social distancing period was in line with reducing traffic emissions while emissions from coal-fired power plants remained relatively stable.

Prospects and method of seed grain storage in a container with gas-regulating medium

The quality of seed grain storage is an important factor in increasing crop yields. Sowing with poor quality seeds even in favorable weather conditions leads to reduction in yields by more than 10 %. During storage, grain loses its weight and quality. The main causes of such losses are biological losses (resulting from grain respiration, the intensity of which depends on the temperature and humidity of the environment); losses from insect pests, rodents that can penetrate the grain mass. The existing storage methods are labor-intensive and low efficient; therefore, this paper describes the method of seed grain storage in a container with gas-regulating medium. It presents the design of the container and the results of laboratory tests to determine the effect of structural and technological parameters of the container on seed grain germination and the change of the vital activity of insect pests of cereals.

Изучение динамики численности эколого-трофических групп микроорганизмов эпифитной микробиоты Stellaria media и Urtica dioica

The dynamics of the strength of the epiphytic microbiota of the root zone and phyllosphere of the Stellaria media and Urtica dioica in the vegetation phase of plants (seedlings, flowering, fruiting) was studied. The data on the strength of microorganisms of ecotrophic groups are presented: ammonifying bacteria using mineral forms of nitrogen, bacteria of the Escherichia coli group, micromycetes and bacteria in the spore stage. It was determined that the medium-sized microbiota of the Stellaria media is more strengthen than the Urtica dioica, which is probably due to the morphoanatomical features of plants and the metabolites produced. The microbiota of the rhizosphere of plants of the Stellaria media and Urtica dioica is much more strength than the phyllosphere due to the root exudates of plants that provide food for microorganisms. The dynamics of the microbiota of the rhizosphere reflects the unequal level of metabolite production by plants in different phases of vegetation. The total strength of aerobic bacteria that metabolize organic nitrogen in the basal zone of Stellaria media increases in the flowering phase, and in the basal zone of Urtica dioica – in the phase of seedlings.The greatest strength of microscopic fungi during the flowering phase of Stellaria media is probably associated with the production of metabolites by plants and favorable weather conditions for the development of micromycetes. Micromycetes belong to the following genera: Trichoderma, Penicillium, Fusarium, Botrytis, Mucor, Aspergillus, Cladosporium. The strength of phyllosphere microorganisms varies according to the stages of plant vegetation. The Stellaria media and the Urtica dioica have a specific microbial complex, both in the aboveground and underground parts, which varies during the growing season and differs in a certain ratio of ecological and trophic groups of microorganisms.

Еcological and comparative analysis of the influence of weather and climate conditions on the vegetative balance of boys of different age groups

Nowadays, when man-made and social conditionsare actively exacerbating the negative effects of environmental factors, the peculiarities of climatic influences are becoming one of the determining factors of human well-being. In the era of urbanization and industrialization, people spend most of their lives indoors in comfortable or subcomfortable microclimate conditions, which reduces its adaptive responses to changing weather parameters. As a result, the dynamic balance between the human body and the externalenvironment and the state of functional activity oforgans and systems of the body is disturbed. It hasbeen established that the body’s response to variousstressors is largely determined by the ratio of the tone of the sympathetic and parasympathetic divisions of the autonomic nervous system. It is the autonomic nervous system (ANS) and, above all, its sympathetic department that has a special role in the formation of body’s adaptive reactions, the development of meteorological reactions, i.e the autonomic nervous system is the primary site of meteorological influences that cause changes in its balance.The determination of vegetative status and direction of vegetative activity in the body of boys was performed using functionalvegetative diagnostics by the method of V. Makats. We examined 1206 boys, 215 boys aged 7–11 years, 861 — aged 12–15 years and 130 boys aged 16–21 years; FVD was conducted in the morning at 10:00-11:00. Since the state of the autonomic nervous system is decisive in the development of meteorologicalreactions analysis of the study data of vegetative tone in sunny, changeable, cloudy and rainy weather and determination of favorable and unfavorable weather conditions for the body.t was found that there are agerelated features of meteorological instability under the influence of meteorological factors on the body of almost healthy young boys. The group of boys aged 16–21 was the most sensitive to changes in weather and climatic conditions, in which the maximum deviations of the activity of functional systems from the age norm were observed and the least sensitive was the group of boys aged 12–15. When analyzing the impact of changes in weather conditions on the body of boys by the vegetative coefficient (kV) it was found that at a rate of kV 0.87–1.13 it increased as much as possible on the effects of rainy weather and was1.23, which indicates a pronounced sympathicotonia,under the influence of variable and cloudy weather on the body, sympathicotonia acquires less pronounced values, 1.08 and 1.13, respectively. Sunny weather can be considered the most ecological and physiological factor influencing the body. In a healthy body, changes in physiological processes and functional activity of systems under the influence of such factors as weather changes are easily compensated and a special role in this belongs to the autonomic nervous system, whose activity provides an adequate response to environmental factors. The knowledge of meteorological sensitivity and meteopathic reactions is necessary for the development of both preventive and curative measures aimed at increasing non-specific resistanceand adaptive mechanisms of the body, the normalization of organ and system function as a basis for normal reactions to adverse environmental changes.

Morphological diversity of seeds of Polish Festulolium cultivars depending on weather conditions

Morphological traits of seeds of Festulolium braunii (K. Richt.) A. Camus cultivars were studied in relation to weather conditions. The obtained results show that morphological traits of seeds varied among cultivars and years of cultivation. The values of seed characteristics were higher in year 2016 due to more favorable weather conditions for plant growth. It was found that the husked seeds of Festulolium cultivars were characterized by a similar length and width regardless of the year, whereas naked seeds significantly differed in these characteristics. Mean values (from the research years) of seed parameters, such as thousand seed mass, area, convex area, shape factor, rectangle, as well as naked seed width showed variations among cultivars. At the same time, it was found that the mass of 1 000 seeds of individual cultivars showed the smallest variability in both years of the study (2.56 - 4.86 %) indicating a high stability of this trait. Thousand seed mass was significantly correlated with husked seed length / husked seed width ratio and husked seed length, and weakly correlated with yield.

Screening of flax gene pool samples by fiber yield and their adaptability to the conditions of the Central Non-Black Earth Region

The research was carried out in 2017-2019 in the conditions of the Smolensk region on sod-podzolic medium loamy slightly acidic soil. The study included 25 varieties and lines of fiber flax of domestic and foreign selection. The mid-ripening variety Impuls (Russia) was used as a standard, whose yield, depending on the test year, was 1.07...1.29 t/ha. As shown by the calculations of the index of environmental conditions, the most favorable conditions for fiber flax developed in 2018 (Ij = +0.46), and stress conditions, caused by excessive moisture during the critical period of plant growth and development (GTC = 1.7), in 2017 (Ij = -0.55). On average, over the years of research, the yield of fiber, depending on the genotype, varied in the range of 1.00...1.97 t/ha. The highest yield on average for three years of testing (1.78...1.97 t/ha) and average yield in contrasting conditions were characteristic of the varieties Cesar, Sinel, Dobrinya (Russia), Marylin (Holland), Andrea, Altea (France). Under favorable weather conditions (2018), a high potential for the yield of flax fiber compared to the average value (121.5...133.3 %) was obtained in the varieties Cesar, Dobrinya, Sinel (Russia), Belita (Belarus), Andrea, Altea (France), Marylin (Holland). Under stressful conditions (2017), high adaptability was found in the samples of the Russian selection Cesar (173.4 %), Sinel (168.0 %), Dobrinya (151.1 %), Tost 3 (128.7 %), Alfa, Universal (127.7 %). The varieties Surskiy (bi = 2.2), Belita (Belarus), l. 323-02 (Russia), Marylin (Holland) − 1.7, Alexandrit (Russia), Andrea (France) – 1.5. Were characterized by high responsiveness to cultivation conditions (bi> 1). Russian varieties with a relatively stable yield: Cesar, Sinel – 0.7, Alpha – 0.6, Lider, Smolich, Tost 3, Universal – 0.5, Impuls – 0,2 did not show reaction to changes in growing conditions (bi <1). Thus, the domestic varieties Cesar, Dobrinya and Sinel have the highest yield of flax fiber and adaptability to the soil and climatic conditions of the Central Non–Black Earth Region. Expansion of fiber flax acreage under these varieties will provide strengthening of the domestic raw material base.

ANALYSIS OF THROUGHPUT RATE OF HARVESTING AND TRANSPORTATION COMPLEX OF MACHINES FOR SUGAR BEET PRODUCTION

The article presents a methodology for analyzing the capacity of the harvesting and transport complex (HTC) for sugar beet, which is aimed at finding ways to rationally use the resource of machines in the technological complex. The reloading method of transportation of beet crop is considered, the feature of which is flexibility, adaptability to weather and climatic and economic conditions during harvesting. Under favorable weather conditions and the availability of a sufficient number of motor vehicles (MV), beets, which are taken from the combine harvester from the field by tractor semi-trailer (TS), are reloaded into heavy-duty MV, which are located on the road from the edge of the field, and transported to the sugar factory. In case of changes in conditions (in rainy weather, with overmoistened soil or with insufficient number of vehicles), a loader-cleaner is added to the complex of machines and the work of the complex switches to a transshipment or flow transshipment method. Harvesting and transportation of beets is considered as the work of the technological chain, which consists of three links: "field - beet harvester (BH)", "BH - NP", "NP - ATZ". The main steps of the throughput analysis are determination of the throughput of the first, second and third links, their comparison and subsequent selection and analysis of alternatives that allow to overcome the possible significant difference between their values. The possibility of reducing the throughput of the third link to the maximum possible - the throughput of the first link by reducing by a certain number of vehicles for the transportation of beets with a simultaneous increase in their technical speed. The given example of calculating the number of units of equipment in the harvesting and transport complex in accordance with the developed methodology proves its effectiveness and advantages. The analysis of the throughput capacity of the ZTC shows ways to improve the parameters of the transport process in the technological complex of harvesting and transport operations.

Report on First Inflight Data of BepiColombo's Mercury Orbiter Radio Science Experiment

BepiColombo's Mercury orbiter radio science experiment (MORE) was conceived to enable extremely accurate radio tracking measurements of the Mercury Planetary Orbiter to precisely determine the gravity field and the rotational state of Mercury, and to test theories of gravitation (e.g., Einstein's theory of general relativity). The design accuracy of the radio tracking data was 0.004 mm/s (at 1000 s integration time) for the range-rate measurements and 20 cm for the range (at a few seconds of the integration time). These accuracies are attained due to a combination of simultaneous two-way microwave links at X (7.2–8.4 GHz) and Ka-band (32–34 GHz) to calibrate the dispersive plasma noise component. In this letter, we present the first analysis of the range and range-rate data collected by ESA's deep-space antenna (DSA) during the initial cruise phase of BepiColombo. The novel 24 Mcps pseudonoise (PN) modulation of the Ka-band carrier, enabled by MORE's Ka-band transponder, built by Thales Alenia Space Italy, Rome, Italy, provided two-way range measurements to the centimeter-level accuracy, with an integration time of 4.2 s at 0.29 astronomical units. In tracking passes with favorable weather conditions, the range-rate measurements attained an average accuracy of 0.01 mm/s at 60 s integration time. Data from May 20–24, 2019 were combined in a multi-pass analysis to test the link stability on a longer timescale. The results confirm the noise level observed with the single-pass analysis and provide a preliminary indication that the MORE PN ranging system at 24 Mcps is compatible with the realization of an absolute measurement, where the need to introduce the range biases in the orbital fit is much more limited than in the past. We show that in the initial cruise test the BepiColombo radio link provided the range measurements of unprecedented accuracy for a planetary mission, and that, in general, all target accuracies for radio-metric measurements were exceeded.

317 Cattle and carbon on pastures – hearsay or evidence?

Abstract Does soil organic carbon accumulate in high density stocking of pastures? Should the detail of grazing management matter in answering this question? Would wishing that soil carbon increase with a particular type of management mean that it would actually increase? Does a practice that stores soil carbon in one region mean that it will store soil carbon in another region? How would we know the answer to any of these questions if we didn’t collect some relevant information? Soil carbon accumulation might be viewed as limited in potential in the southeastern US with the combination of highly weathered soils and favorable weather conditions for decomposition of organic matter inputs. However, these same environmental conditions could also be viewed as ideal for promoting soil carbon accumulation from a highly degraded state. In fact, there are plenty of soils in the region that have undergone severe degradation from decades of historical degradation. This presentation will explore some approaches taken to answer the question of whether soil carbon can be sequestered in managed pastures of the southeastern US. It will also probe into the question of type of management and its role in potential soil organic carbon sequestration. A combination of published and ongoing research will form the basis of this presentation.

Impact of weather and emission changes on NO2 concentrations in China during 2014-2019.

Nitrogen dioxide (NO2) is one of the most important air pollutants that highly affect the formation of secondary fine particles and tropospheric ozone. In this study based on hourly NO2 observations from June 2014 to May 2019 and a regional air quality model (WRF-CMAQ), we comprehensively analyzed the spatiotemporal variations of NO2 concentrations throughout China and in 12 urban agglomerations (UAs) and quantitatively showed the anthropogenic and meteorological factors controlling the interannual variations (IAVs). The ground observations and tropospheric columns show that high NO2 concentrations are predominantly concentrated in UAs such as Beijing-Tianjin-Hebei (BTH), the Shandong Peninsula (SP), the Central Plain (CP), Central Shaanxi (CS), and the Yangtze River Delta (YRD). For different UAs, the NO2 IAVs are different. The NO2 increased first and then decreased in 2016 or 2017 in BTH, YRD, CS, and Cheng-Yu, and decreased from 2014 to 2019 in Harbin-Changchun, CP, SP, Northern Slope of Tianshan Mountain, and Beibu-Gulf, while increased slightly in the Pearl River Delta (PRD) and Hohhot-Baotou-Erdos-Yulin (HBEY). The NO2 IAVs were primarily dominated by emission changes. The net wintertime decreases of NO2 in BTH, Yangtze River Middle-Reach, and PRD were mostly contributed by emission reductions from 2014 to 2018, and the significant increase in the wintertime in HBEY was also dominated by emission changes (93%). Weather conditions also have an important effect on the NO2 IAVS. In BTH and HBEY, the increases of NO2 in winter of 2016 are mainly attributed to the unfavorable weather conditions and for the significant decreases in the winter of 2017, the favorable weather conditions also play a very important role. This study provides a basic understanding on the current situation of NO2 pollution and are helpful for policymakers as well as those interested in the study of tropospheric ozone changes in China and downwind areas.

Cropping system-imposed yield gap: Proof of concept on soybean cropping systems in Uruguay

Favorable weather conditions prevailing on most South American Pampas allows to grow more than one crop per year. Indeed, increasing crop intensity per unit area has been highlighted as an opportunity to increase crop production in a high food demanding world scenario. Previous studies have analyzed cropping-system yield gap by aggregating crop yields either as total amount of grain or as unit of energy. However, few cropping-system yield gap analysis have made a distinction between single (i.e., soybean sown as a single crop per year) and double-cropped soybean (i.e., soybean sown immediately after harvest of a winter cereal crop), and none of them at a country level. This article focuses on the estimation of cropping system-imposed yield gap (CSIYg), which is defined as the difference of seed yield between single soybean and double-cropped soybean. The aims of the present study were: (i) to analyze yield potential (Yp), water-limited (Yw) and yield gap (Yg) spatial and interannual variability; (ii) to investigate the concept of CSIYg for soybean using cropping systems in Uruguay as a proof of concept; and (iii) to assess differences on yield variability between single and double-cropped soybean. Yp and Yw were estimated for single and double-cropped soybean in specific locations within the major soybean crop producing areas using CROPGROW model coupled with long-term good quality weather data, soil types and dominant management practices. Estimations were scaled up following the protocols of the Global Yield Gap Atlas project. We applied a boundary function analysis to assess the differences on Yw variability between single and double-cropped soybean. At country level Yp was estimated on 6.6 and 5.7 Mg ha−1 for single and double-cropped soybean, respectively. However, we found lower differences on Yw between single and double-cropped soybean (3.6 and 3.4 Mg ha−1, respectively). We estimated CSIYg due to combined effect of weather condition and water regime on 3.2 Mg ha−1. The CSIYg representing the combined effect of weather condition, water regime and management was estimated on 1.6 Mg ha−1. Double-cropped and single soybean showed the same Yw response to precipitations and a similar Yw variability (t-test P = 0.55). Our results highlight double-cropped soybean cropping systems as an alternative for increasing grain production in this main agricultural region of the world.

Formation of Frozen Blackcurrant Fruits Quality

Aims: Fruits of a multivitamin culture of blackcurrant have a pronounced seasonality of consumption. The essence of the problem is in the scientific substantiation of the rational way of fruits freezing in order to preserve their quality.
 Place and Duration of Study: The research was conducted during four years in the conditions of the laboratory of the Department of Technology of Storage and Processing of Plant Products at Uman National University of Horticulture and the workshop for rapid freezing of Uman canning plant.
 Methodology: Prepared berries of the consumer degree of ripeness of Pilot Oleksandr Mamkin, Mynai Shmyriov, Novyna Prykarpattia, Biloruska solodka varieties in the string bags were frozen by slow (-20 to -22°С) and rapid (-30 to -32°С) methods, packed in paraffined boxes, polyethylene bags of 400–500 g by weight. Losses in fruit weight, content of ascorbic acid, dry soluble substances, sugars, acids, sugar-and-acid index were determined during and for 10 months of storage (-18°C).
 Results: True chemical composition of the fruits took into account losses of their weight. It radically changed the level of indicators. Weight losses of the fruits was lower by a third during fast freezing, however, the overall indicators did not differ significantly until the end of storage: 11.9–12.1% by slow method against 10.1–11.2% by rapid way. The highest losses in the fruits were during the first 3 months, during 4–5 months – their level was stabilized and somewhat increased to the end of storage. Advantages by fruits packing in polyethylene bags were as follows: losses were 6–7 times lower than by string bags and 4–5 times – in paraffined boxes. Advantages of rapid freezing were in 1.2–1.6 times lower losses of the components of chemical composition. Usually, the frozen fruits of Biloruska solodka variety were better than other varieties under favourable weather conditions, they were not inferior.

White Leaf Spot Caused by Neopseudocercosporella capsellae: A Re-emerging Disease of Brassicaceae.

White leaf spot can cause significant damage to many economically important Brassicaceae crops, including oilseed rape, vegetable, condiment, and fodder Brassica species, and recently has been identified as a re-emerging disease. The causal agent, Neopseudocercosporella capsellae, produces foliar, stem, and pod lesions under favorable weather conditions. N. capsellae secretes cercosporin, a non-host specific, photo-activated toxin, into the host tissue during the early infection process. The pathogen has an active parasitic stage on the living host and a sexual or asexual saprobic stage on the dead host. Where the sexual stage exists, ascospores initiate the new disease cycle, while in the absence of the sexual stage, conidia produced by the asexual stage initiate new disease cycles. Distribution of the pathogen is worldwide; however, epidemiology and disease severity differ between countries or continents, with it being more destructive in Subtropical, Mediterranean, or Temperate climate regions with cool and wet climates. The pathogen has a wide host range within Brassicaceae. Brassica germplasm show varied responses from highly susceptible to completely resistant to pathogen invasion and significant susceptibility differences are observed among major crop species. Cultural practices only provide effective disease control when the climate is not conducive. An increase in the susceptible host population and favorable weather conditions have together favored the recent rise in white leaf spot disease occurrence and spread. The lack of understanding of variation in pathogen virulence and associated resistant gene sources within brassicas critically limits the potential to develop efficient control measures.

NoPv1: a synthetic antimicrobial peptide aptamer targeting the causal agents of grapevine downy mildew and potato late blight

Grapevine (Vitis vinifera L.) is a crop of major economic importance. However, grapevine yield is guaranteed by the massive use of pesticides to counteract pathogen infections. Under temperate-humid climate conditions, downy mildew is a primary threat for viticulture. Downy mildew is caused by the biotrophic oomycete Plasmopara viticola Berl. & de Toni, which can attack grapevine green tissues. In lack of treatments and with favourable weather conditions, downy mildew can devastate up to 75% of grape cultivation in one season and weaken newly born shoots, causing serious economic losses. Nevertheless, the repeated and massive use of some fungicides can lead to environmental pollution, negative impact on non-targeted organisms, development of resistance, residual toxicity and can foster human health concerns. In this manuscript, we provide an innovative approach to obtain specific pathogen protection for plants. By using the yeast two-hybrid approach and the P. viticola cellulose synthase 2 (PvCesA2), as target enzyme, we screened a combinatorial 8 amino acid peptide library with the aim to identify interacting peptides, potentially able to inhibit PvCesa2. Here, we demonstrate that the NoPv1 peptide aptamer prevents P. viticola germ tube formation and grapevine leaf infection without affecting the growth of non-target organisms and without being toxic for human cells. Furthermore, NoPv1 is also able to counteract Phytophthora infestans growth, the causal agent of late blight in potato and tomato, possibly as a consequence of the high amino acid sequence similarity between P. viticola and P. infestans cellulose synthase enzymes.

Chemical composition of spring wheat at different levels of mineral nutrition

Spring wheat is widely used as a raw material for the production of human food and animal feed. This study was aimed at investigating the response of spring wheat to different levels of mineral nutrition. The article presents the results of applying mineral fertilisers when growing spring wheat of the Novosibirsk 31 variety in the Tyumen region. The following parameters were determined: wheat grain yield, grain nutritional quality (protein content, raw gluten, gluten quality, grain hardness, grain-unit value), and amino acid and elemental (N, P, K, S, Na, Mg, Ca, Cl) composition. The efficiency of mineral fertilisers was shown to depend on their dosage, as well as on soil and weather conditions. In 2018, the use of mineral fertilisers led to an increased wheat yield and an improved grain quality. Thus, in comparison with the control (no fertilisers), the wheat yield increased by 1.6 t/ha, while the protein and wet gluten content grew by 3.67% and 9.9%, respectively. The application of fertilisers allowed 3rd class wheat to be obtained, while experiments involving no fertilisers produced only 4th class wheat. It was revealed that the role of mineral fertilisers in wheat yields and their quality decreases when growing wheat on leached chernozem under favourable weather conditions. Thus, in 2019, 3rd class wheat varying in yield insignificantly was obtained in all experiments (with and without fertilisers). It was confirmed that an increase in the dose of mineral fertilisers leads to an increase in the content of glutamic and aspartic acids in the grain, at the same time as decreasing the content of arginine. The elemental composition of grain, except for nitrogen, does not depend on the dose of fertilisers.

Results of experiment with Potentilla anserina L. (Rosaceae Juss.) in Concept "Polycentric Model of Plant"

The article reviewed the data of an old experiment with Potentilla anserina in planting with a density of1, 5 and 9 ind./ m2, conducted in 1996 under natural climatic conditions on stationary sites. The study was conductedin innovative Concept “Polycentric Mmodel of Plant.” Changes in the growth indicators of the polycentric system ofthe plant from June to October were revealed in connection with seasonal changes in the climatic factor. This is thesum of the temperatures and the amount of precipitation between the periods of control observations of the plant. Themost favorable weather conditions for the formation of shoot-formation centers, mineral-nutrition centers and generationcenters as elements of Polycentric Model of Plant are determined. The maximum number of stolons, shoot-formationcenters, mineral-nutrition centers, and generation centers has been determined that can actively function on an area of 4square meters in plantings of different densities.

Factors That Limit the Adoption of Biofloc Technology in Aquaculture Production in Mexico

Aquaculture uses large volumes of water, which is generally discharged without treatment, possibly causing scarcity and contamination. A sustainable aquaculture option is biofloc technology (BFT), which recycles food residues and toxic organic and inorganic compounds from the system through microorganisms, avoiding excessive use of water and serving as natural food for cultured aquatic organisms. The aim of this study was to identify the main factors that limit a Mexican aquaculture producer from adopting biofloc technology in their aquaculture production units (APUs). Strengths and weaknesses were methodologically analyzed through 248 questionnaires, applied to fish farmers in 16 states of the country with a mixed approach (quantitative and qualitative). Findings reveal that the main obstacles in the use of BFT are due to the following: low academic level, limited administrative capacity, scarce technological equipment in facilities, diversified productive activity, and obsolete regulations. Other factors that promote the adoption of BTFs for aquaculturists are production experience, favorable weather conditions, and abundant availability of water and energy. In conclusion, the use of BTF is a sustainable option for APUs despite the limiting factors identified in this research which slow down the growth of the sector. It is advisable to study Mexican producers with BFT, in order to spread their benefits to other APUs, and further evaluate the productivity of the aquaculture sector. This study considers production aspects, and also sustainable use of its resources, specifically, surface, energy, water, and food.

Analysis of honey productivity of robinia (Robinia pseudoaca-cia L.) plantations in forest vegetation conditions of the steppe don region

Robinia (Robinia pseudoacacia L.) is known for high honey productivity: in Ukraine, in Romania it is 600-800 kg, in Nonblack soil area it is up to 360 kg from 1 ha of a continuous forest stand.According to observations of the scientists, a bee family can collect up to 8 kg of honey under favorable weather conditions from a Robinia tree, and under adverse weather there were from 4 to 6 kg of Robinia honey in strong families at the apiary.The task of our study was to determine honey productivity of Robinia depending on locality, exposure and the slopesteepness. Optimum forest vegetation conditions for maximum nectar emission by Robinia flowers were defined. A number of methods defining taxation indices, sugar content in nectar, blooming intensity and honey productivity was used to solve the assigned tasks. Carried out comparative analysis of honey productivity indices showed that local topography influences the blooming terms of plants and nectar emission. So, the most productive locality for beekeeping is locality with gulches. It provides the best honey yield under favourable meteorology and forest vegetation conditions.

Biological Features of the Northwest Pre-Caspian Saiga Population at Different Sizes

The abundance of the saiga antelope (Saiga tatarica tatarica L., 1766) in the Northwest Pre-Caspian region has remained at an extremely low level over the past 20 years. Comparison of some biological parameters of the population for periods with different numbers of animals made it possible to reveal a number of low-population features. Thus, along with a decrease in the number of saigas (from 800 000 heads in 1958 to 4500 in 2016), its habitat area also decreased (from 60 000–70 000 to 2000–3000 km2, respectively), and a significant part of the population transitioned to a sedentary lifestyle in the protected areas of the Chernye Zemli ecoregion. A long-time deficiency of sexually mature males in the population (less than 10%) led to a decrease in its growth and, consequently, to a decrease in its number. At the same time, the total fecundity of females decreased (from 1.27 ± 0.25 calves in years of high abundance to 0.92 ± 0.39 recently) due to an increase in barrenness in different age groups caused by the lack of males in the population. Males prevail over females in newborns (51.9 and 48.1%, respectively). The increased weight of newborn saiga calves (100 g on average for both males and females) and their decreased mortality in the first days after birth (under favorable weather conditions) indirectly indicate the normal course of embryogenesis and a sufficient quantity and quality of feed. An increase in the proportion of sexually mature stags will lead to an increase in the population number, as the reproductive functions of the population practically did not change during the period of its depression.

Agriculture of Novosibirsk Oblast in the 1980s and Early 1990s: Development and Reform Problems

The research reveals the peculiarities of agricultural development in the Novosibirsk region at the late Soviet stage in order to find out concrete and reliable ideas about the causes, progress and consequences of agrarian reform of the early 1990s. We analyzed the changes in the organizational, economic and sectoral structure of the industry, the problems of the functioning of the collective farm and state farm system and the implementation of measures in the region to resolve them, factors that contributed to the growth and decline of agricultural production are analyzed. The content, directions and some economic consequences of the implementation of the agrarian reform of 1990 in the Novosibirsk region. In the 1980s the agro-industrial complex of the region developed due to the specialization and concentration of production, inter-farm cooperation of collective and state farms, their integration with industrial and trade organizations. The production of pork, poultry, eggs grew, and the gross grain harvest increased. The factors in the development of agriculture were the use of intensive technologies and favorable weather conditions. For agriculture in the Novosibirsk Region, the eleventh five-year plan (1981-1985) began with two consecutive lean years. The years of the twelfth five-year plan (1986-1990) were generally more productive. Agriculture did not meet the growing demand of the population for food. The material and technical resources of the industry have been largely wasted. Collective and state farm workers did not see any sense in increasing production productivity and sought to move to cities that attracted them with a higher standard of living. Attempts to improve the situation by democratizing management system in collective and state farms and by means of incentives for personal subsidiary plots did not produced desired results. The development of contractor relations in collective and state farms, rural settlements and the production base of farms looked like a more promising direction in the evolution of the agrarian sector of the economy. In 1990, due to the low growth rates of agricultural production, the government launched an agrarian reform, which opened the way for further development of the socio-economic infrastructure of the village, multi-structure and market. However, radical reformers insisted on forced transition to market relations and cut of state aid to producers. The implementation of these policies has led to negative consequences.