Vegetative Cycle Research Articles

Anti-staphylococcal activity of soilless cultivated cannabis across the whole vegetation cycle under various nutritional treatments in relation to cannabinoid content

Antibiotic resistance in staphylococcal strains and its impact on public health and agriculture are global problems. The development of new anti-staphylococcal agents is an effective strategy for addressing the increasing incidence of bacterial resistance. In this study, ethanolic extracts of Cannabis sativa L. made from plant parts harvested during the whole vegetation cycle under various nutritional treatments were assessed for in vitro anti-staphylococcal effects. The results showed that all the cannabis extracts tested exhibited a certain degree of growth inhibition against bacterial strains of Staphylococcus aureus, including antibiotic-resistant and antibiotic-sensitive forms. The highest antibacterial activity of the extracts was observed from the 5th to the 13th week of plant growth across all the nutritional treatments tested, with minimum inhibitory concentrations ranging from 32 to 64 µg/mL. Using HPLC, Δ9-tetrahydrocannabinolic acid (THCA) was identified as the most abundant cannabinoid in the ethanolic extracts. A homolog of THCA, tetrahydrocannabivarinic acid (THCVA), reduced bacterial growth by 74%. These findings suggest that the cannabis extracts tested in this study can be used for the development of new anti-staphylococcal compounds with improved efficacy.

Fire dynamics and driving mechanisms on the Eastern Coast of China since the Late Pleistocene: evidence from charcoal records on Shengshan Island

Fires play a significant role in ecosystems, exerting a profound influence on climate, vegetation, and geochemical cycles, while being reciprocally affected by these factors. The reconstruction of past fire events serves as a valuable window into understanding environmental changes over time. To investigate the history of ancient fires on the Eastern Coast of China, we conducted the first charcoal analysis on a loess profile of Shengshan Island (East China Sea). Along with other biological and geochemical proxies, we successfully reconstructed the ancient fire dynamics and elucidated their driving mechanisms in this region since the Late Pleistocene. Our initial findings revealed a peak in charcoal concentration during the 60-50 ka period, but after calibrating for sedimentation rate, the concentration significantly decreased. Fire activities remained weak during 50-30 ka, likely due to the scarcity of combustible materials. Between 30-12 ka, fires were frequent in the early period, while gradually diminishing during the later stage. Dry climate and dense vegetation likely attributed to frequent fires in early period, while some extreme events (e.g., sudden change in temperature) may have decreased the fire frequency in later period. The Holocene (began ~12 ka) evidenced the most frequent fire events as a high charcoal concentration was recorded, likely caused by human activities. After comparing our findings with other paleoecological records from surrounding areas, we confirmed the accuracy of our reconstruction of ancient fires. This reconstruction captures not only local shifts but also broader regional changes. Overall, our study highlights the importance of calibrating sedimentation rate in charcoal profiles, while also contributing to an enhanced understanding of environmental changes along the Eastern Coast of China since the Late Pleistocene.

Reduction of the mangosteen tree (Garcinia mangostana L.) production cycle: effect of soil type and fertilisers

BackgroundShortening the vegetative cycle of slow-growing crops is a significant challenge for breeders, agronomists, and growers. This reduction is particularly crucial for the mangosteen (Garcinia mangostana) as it would make it easier for farmers to adopt this crop. The mangosteen tree is notoriously slow-growing, taking between 8 and 15 years to produce its first fruits. The plant's slow growth and late fruiting pose a significant obstacle to its adoption and spread in rural areas. In Côte d'Ivoire, these constraints have limited its cultivation to small farms owned by a few producers. However, it could be an alternative for diversifying agricultural income and contributing to poverty reduction in rural areas. This study aims to evaluate the effects of soil type and fertiliser on the agronomic parameters of mangosteen tree growth. The goal is to contribute to shortening its vegetative phase.ResultsThe study results indicate that soil type and fertiliser have a significant effect on mangosteen growth parameters. Evaluating the agronomic performance of mangosteen, it was found that lowland soil promotes better plant growth. Growth rate and height growth were found to be significantly influenced (p = 0.03). After 36 months of monitoring, the growth rates for mangosteen trees grown on lowland soil were 53.08 ± 7.30%, while those grown on forest soil were 41.51 ± 13.43%. Additionally, the use of foliar and granular N-P-K fertilisers resulted in earlier fruiting, starting from the 5th year of cultivation.ConclusionsThe results showed that fertilisers play a crucial role in managing and shortening the juvenile phase of the mangosteen tree. Foliar and NPK fertilisers performed exceptionally well, resulting in earlier fruiting of mangosteen trees, starting from the 5th year of cultivation.

The impact of polyphenols on the structure of diatom communities inhabiting Cladophora glomerata mats during the vegetation cycle

Cladophora glomerata is the main macroalgae species responsible for the appearance of large mass compact algae formations, known as mats, in the fresh water of Lake Oporzynskie and the river Nielba, in western Poland. The mats are usually created by single species. In order to achieve seasonal domination, the algae secrete to the environment the allelopathic substances, which are phenolic compounds. In the period of intensive population growth, the thread-like thalli of these algae are richly incrusted with epiphytic diatoms. The amount of the secreted phenolic compounds changes in time within the vegetation period and depends on the weather conditions. The most abundant secretion of phenolic compounds takes place in July when, with increasing concentration of phenolic compounds in water, their content in the cells decreases.The main aim of the study was to establish the effect of the phenolic compounds secreted by C. glomerata thalli on the diatoms growing on them. According to our results, polyphenolic compounds have an impact not only on the abundance of diatom communities, but also on the structure of their communities. With increasing concentration of polyphenols, the abundance of Achnathidium minutissimum, Gomphonema olivaceum, Cocconeis pediculus, Navicula tripunctata decreased, while that of Amphora ovalis, Navicula rostellata, Staurosira construens, Cymbella lange-bartelotti increased. The species Cocconeis placentula reached domination thanks to the favorable influence of the environment and the effect of polyphenols secreted by the macroalgae. The variation in the diatom communities' structure was proved to also depend on the habitat parameters, mainly: EC, Turbidity, N-NH4, N-NO3, TDS.

Comparative Study of Free Amino Acid Profiles in Underground Organs of Several Species of the Genus Rumex During Different Phases of the Vegetation Cycle

Introduction. Amino acids (AA), the primary metabolites in plants, play a crucial role in various physiological processes, including the synthesis of phenolic compounds. Drug products and dietary supplements made from medicinal plants can become a rich source of both nonessential and essential amino acids. High levels of free amino acids found in herbal raw material often indicate the presence of biotic and abiotic stress in the plants. Therefore, understanding the dynamics of bioactive compound accumulation in plants throughout their phenological phases of development is critical to optimizing their potential health benefits.Aim. To compare qualitative composition and dynamics of AA accumulation in the underground organs of four representatives of the Rumex genus: R. confertus, R. crispus L., R. obtusifolius L., R. aquaticus L. of three different vegetative phases.Materials and methods. Water extracts from underground organs of the studied plants were analyzed using two different methods for qualitative and quantitative analysis. Extracts were applied to the chromatographic plates TLS Silica gel 60 F254 (Merk, Germany) 20 × 20 cm with a micro-syringe (LLC "Tsvet", Russia). After elution, the plates were treated with a 2 % ninhydrin solution. Quantitative analysis was carried out using the SF-2000 spectrophotometer (LLC "OKB Spectr", Russia).Results and discussion. The amino acid profile of the underground organs of R. confertus, R. crispus L., R. obtusifolius L., R. aquaticus L. during three vegetative phases was determined using the TLC method; the quantitative analysis performed using spectrophotometry.Conclusion. The most diverse amino acid (AA) profiles were found in the withering phase in all Rumex species, with up to 9 amino adsorption zones. In contrast, the least diverse AA profiles were observed in the flowering phase, ranging from 2 to 4 adsorption zones. The quantitative content of AA was lowest in the flowering phase, increased during the regrowth phase, and peaked in the withering phase. However, R. crispus L. showed an unusual pattern, with the highest quantitative content of AA detected in the regrowth phase.

Establishing the global isoscape of leaf carbon in C3 plants through the integrations of remote sensing, carbon, geographic, and physiological information

The carbon isotope composition (δ13CLeaf) of C3 plant leaves provides valuable information on the carbon-water cycle of vegetation and their responses to climate change within terrestrial ecosystems. However, global applications of δ13CLeaf are hindered by a lack of global long-term spatial maps (isoscapes) that capture vegetation δ13CLeaf variations. The ways in which δ13CLeaf varies over time and across regions are still unknown. In this study, we collected leaf carbon isotope samples across the globe and selected the optimal predictive model from three machine learning algorithms to construct long-term annual global δ13CLeaf isoscapes at a spatial resolution of 0.05° for natural C3 plants between 2001 and 2020. We also assessed the potential of remotely sensed spectral bands, atmospheric CO2 characteristics, geographic, and physiological information to estimate the δ13CLeaf of the global C3 plants. Our results show that the random forest (RF) algorithm can more accurately construct the δ13CLeaf isoscape (R2 = 0.61, Nash Sutcliffe = 0.61, RMSE = 1.21‰, MAE = 0.91‰) than the multilayer perceptron (MLP) and support vector machine (SVM). The inclusion of atmospheric CO2 characteristics, geographical, and physiological information greatly improves prediction compared to relying only on spectral bands. Among the variables, elevation, band 3 spectral reflectance, and solar-induced chlorophyll fluorescence were the three most important variables for constructing the isoscape model, and their relative importance all exceeded 85%. The predicted isoscape revealed strong spatial heterogeneity of δ13CLeaf for C3 plants at a global scale between different continental regions, with enriched values occurring in high-altitude cold and arid regions, and depleted values occurring in warm, humid, or tropical regions. For the first time, we estimated the global depleted rate of δ13CLeaf in C3 plant (−0.0491 ± 0.07 ‰ year−1 from 2001 to 2020). Over the past two decades, 86.49% and 1.00% of global grid cells showed more depleted and more enriched trends in δ13CLeaf of C3 plants, respectively. Our results demonstrated the potential for establishing isoscapes by combining remote sensing, atmospheric CO2 characteristics, physiological, and geographic variables using the RF machine learning algorithm. The isoscape products generated in this study are valuable for assessing carbon-water coupling of terrestrial ecosystems and for improving land surface models.

ОЦЕНКА ПРОСТРАНСТВЕННО-ВРЕМЕННОЙ ДИНАМИКИ ЗАГРЯЗНЕНИЯ РЕКИ КРАСНОЙ В КАЛИНИНГРАДСКОЙ ОБЛАСТИ

Today, the Kaliningrad region has considerablr strategic significance for the Russian Federation. Due to the fact thatthe region is separated from the main part of the country, the quality of water resources is considered a substantial factor for its economicwell-being. One of the main tools in this area is hydrochemical and hydrological monitoring of surface watercourses. The purpose ofthe work is to assess the spatio-temporal dynamics of the Krasnaya River pollution for 4 hydrological seasons in 2022-2023. Monitoringwas carried out during the autumn (10/15/22), winter (01/15/23), spring (04/23/23), and summer (07/19/23) hydrological seasons,during which water samples were taken at 4 hydraulic stations, and hydrometric characteristics were measured to calculate water flowrates. Water samples were examined for the relevant chemical indicators, on the basis of which integral indicators of water qualitywere determined. In turn, their spatio-temporal variability was determined and cartographically expressed. As a result of the study, thepaper provides information about the state of the watercourses and the influence of anthropogenic and natural factors on them. Thespecific combinatorial index of water pollution showed that the river is polluted from source to mouth. Intra-annual variability wasstudied using the WPI and has a similar spatial interpretation, water quality decreases from source to mouth with slight deviations.Temporal variability has developed in such a way that autumn is the most polluted season, while the remaining seasons have nearlyequal average water pollution indices. The main pollutants can be divided into systematic (petroleum products, iron, BOD5, COD) andnon-systematic (sulfate phosphates, ammonium, and low dissolved oxygen). A correlation was discovered between chemical pollutionand the quantitative characteristics of river flow, natural cycles of aquatic and shore vegetation, and vehicle washing. The emissionsof iron and petroleum products do not fit into any specific regular system: the sources of the former are groundwater, of the latter –anthropogenic activities. In general, the situation with water quality on the Krasnaya River is rated as satisfactory.

Slower changes in vegetation phenology than precipitation seasonality in the dry tropics.

The dry tropics occupy ~40% of the tropical land surface and play a dominant role in the trend and interannual variability of the global carbon cycle. Previous studies have reported considerable changes in the dry tropical precipitation seasonality due to climate change, however, the accompanied changes in the length of the vegetation growing season (LGS)-the key period of carbon sequestration-have not been examined. Here, we used long-term satellite observations along with in-situ flux measurements to investigate phenological changes in the dry tropics over the past 40 years. We found that only ~18% of the dry tropics show a significant (p ≤ .1) increasing trend in LGS, while ~13% show a significant decreasing trend. The direction of the LGS change depended not only on the direction of precipitation seasonality change but also on the vegetation water use strategy (i.e. isohydricity) as an adaptation to the long-term average precipitation seasonality (i.e. whether the most of LGS is in the wet season or dry season). Meanwhile, we found that the rate of LGS change was on average ~23% slower than that of precipitation seasonality, caused by a buffering effect from soil moisture. This study uncovers potential mechanisms driving phenological changes in the dry tropics, offering guidance for regional vegetation and carbon cycle studies.

The influence of the vegetation cycle and the mixture (grasses and legumes) on the height of the plants on sown grasslands

The influence of the vegetation cycle and the mixture (grasses and legumes) on the height of the plants on sown grasslands

Effects of Climate Change and Phenological Monitoring of the Indigenous Godello Variety in a Territory of Heroic Viticulture and Biosphere Reserve

In the year 2023, the phenological behaviour of the indigenous Godello variety of vineyard was evaluated at Souto Chao, located in the north-west of the Iberian Peninsula, which is a wine-growing region and considered as the place of Designation of Origin (Ribeira Sacra DO). In 2017 and 2018, a similar study was carried out on the same plants of Godello variety, but this latest study aimed to ascertain the nature and extent of changes in the crop’s phenology within the timeframe between the initial two years analysed (2017 and 2018) and the present year, 2023. The scale used for study was the one proposed by the BBCH of Lorenz. The average length of the vegetative cycle in the initial two years was 167 days (161 and 174 days in 2017 and 2018, respectively), while in 2023 it was 164 days. The results obtained show a longer vegetative cycle in 2018, with significant differences between the beginning and end of the different phenological phases. Of the three years analysed, 2018 stands out showing a significant deviation from the average. Moreover, there is a close relationship between the phenological behaviour of the Godello variety and certain climatic parameters. Temperature is the most decisive factor, specifically the average annual minimum temperature, which was lower in 2018. In addition, the highest thermal requirements were observed in that same year, with figures slightly above 5200 GDD. As for the historical harvest dates, there are only two recorded years in which the grape harvest took place in August, namely in 2017 and 2023. In this geographical region, the grape harvest, with the exception of the two years mentioned above, usually takes place in September, as was the case in 2018. The vulnerability of viticulture to climate change depends on the magnitude of the impacts. Global warming is the great challenge for the wine business and will force changes in vineyard management to curb its most damaging effects. Its most obvious effects, such as the rise in average global temperature or the decrease and redistribution of rainfall, increasingly in the form of occasional and intense storms, have gone from perception to certainty.

Biomass yield and chemical composition of the cassava plant over two vegetative growth cycles

The objective of this work was to study the biomass production and chemical composition of the different parts of the cassava plant during the first and second vegetative cycles, with the aim of providing data that can contribute to the understanding of the response of cassava cultivars to different harvest ages. The experimental design consisted of randomized blocks in split plot scheme. Plots were represented by cultivars IAC 90 and IAC 118-95 and subplots by crop age (2, 4, 6, 8, 10, 12, 14, 16, and 18 months after planting). Our results showed that the ‘IAC 90’ allocated a higher proportion of assimilates to the leaves, stem and planted cutting than the ‘IAC 118-95’, which was more efficient in allocating dry matter to the storage roots. Storage roots showed an increase of more than 50% in starch content 14 months after planting. The cultivar IAC 118-95 is distinguished by the higher harvest index, allowing earlier harvesting, with possible valorisation of the leaves as industrial raw material. Variables showed different degrees of inter-relationships amongst themselves. Total plant fresh matter and dry matter yields were positively correlated with growth parameters and root starch for both cultivars. Harvest time and cultivar are key factors that should be considered to increase profits in the cassava agro-industrial chain.

Influence of vegetation‐induced water table seasonality on groundwater chloride concentration dynamics in a riparian fen peatland

AbstractPeatlands are environments that rely mainly on high water levels to accumulate organic matter. Depending on the chemical species observed, the lowering of the water table can change biogeochemical equilibriums, with various impacts. This paper aims to understand the effect of shallow groundwater seasonality on chloride concentrations in a French riparian peatland by combining water table monitoring, geochemical and stable water isotopes analysis. Water table levels and groundwater samples were recorded and collected for 3 years, every 2 months, in nine observation wells and the nearby river. Chloride concentrations were highly variable in space and time, ranging from 10 to 100 mg L−1. They are shown to be related to the water table dynamics, which are closely linked to the life cycle of the local vegetation. These dynamics were characterized by a significant drawdown between June and October due to plant transpiration and a fast recovering period just after its senescence. Results show that the chloride accumulates within the unsaturated zone during the drying phase and is solubilized back into the groundwater during the rewetting phase, increasing its concentration. Moreover, the water table rises in autumn with various dynamics according to the location in the peatland, which induces some special differences in hydraulic gradients. Such gradients allow lateral transfers from zones of fast recovery to zones of slow recovery, where year‐to‐year chloride accumulation was observed. These complex 3D processes preclude the use of chloride to constrain how the peatland hydrogeological system functions. Conversely, the use of stable water isotopes in this work emphasizes the importance of the river's role during the summer as a water supplier to counterbalance vegetation transpiration.

Effect of Calcium Fertilization on Calcium Uptake and Its Partitioning in Citrus Trees

Calcium (Ca) plays a vital role as a macronutrient in the growth and development of plants. In order of decreasing solubility, Ca can be found in vegetal tissues as soluble Ca (Fraction I), bound Ca (mainly pectates, Fraction II), inorganic insoluble Ca (mainly phosphates and carbonates, Fraction III) and organic insoluble Ca or oxalate (Fraction IV). To explore the impact of Ca fertilizer application on plant growth and its allocation among different fractions, young citrus trees were fed over a complete vegetative cycle with a 44Ca labeled fertilizer (T1-Ca), while control plants (T2) received no Ca fertilizer. The results showed that plants receiving Ca exhibited significantly greater biomass. 44Ca derived from the fertilizer was localized mainly in sink organs (new flush leaves–twigs and fibrous roots). The primary fraction responsible for total Ca partitioning was Fraction II, followed by Fraction III or IV. Citrus plants, commonly found in calcareous soils, demonstrated improved growth with calcium treatments, indicating a positive link between calcium supplementation and enhanced development. The calcium supplied through the fertilizer (44Ca) was predominantly concentrated in sink organs (mainly in Ca-pectate fraction), including new flush leaves and twigs above ground, as well as fibrous roots below ground.

Sustainable Soil Utilization and Agriculture Production: Recommendations towards Achieving Sustainability

In particular, the nutrient cycle, soil erosion, carbon sequestration, and many different ecological systems are all impacted by current agriculture tactics. Sustainable development's negative environmental and ecological effects can be reduced through organic farming. Utilizing more organic materials in cultivation practices might decrease environmental damage by preserving the natural cycles of the environment's vegetation during the restoration process. Organic farming can also raise food quality. Chemical fertilizers, pesticides, growth hormones, and feed additives for farm animals may also be substantially avoided in organic farming. To minimize the constraints and difficult circumstances of natural farming, a combination of organic farming and new technology is of utmost importance. Innovative techniques and cutting-edge ideas are bringing farming systems closer to sustainability while also improving rural productivity and the quality of life for many farmers in a way that is good for the environment. Not only does soil provide food and nutritional support, but it also has many environmental benefits to give. Although it takes centuries to form one millimeter of soil, soil is regarded as a non-renewable resource. The phrase "Soil health" is one of the most frequently used one in agriculture. Agriculture can only continue to be sustainable if the soil is healthy. Numerous issues have put "soil health" in danger, including declining soil fertility, a lack of natural carbon and biodiversity in the soil, salinization, acidification, pollution, and soil erosion and degradation. As stated by FAO, "Soil management is sustainable if it meets the needs of the present without compromising the ability of future generations to meet their own needs."

Using remote sensing approach to analyze vegetation response to drought and landscape changes in arid regions

Arid regions, characterized by low annual precipitation, unique vegetation, and distinctive hydrological cycles, play a significant role in maintaining ecological balance. However, these regions, with their hostile and remote environments, present unique challenges for field research. This study utilizes remote sensing technology, particularly the Normalized Difference Vegetation Index (NDVI), to evaluate the ecosystem's response to drought and understand the relationship between vegetation variability and other landscape features including elevation, soil type, and changes in land use or land cover. Six sites within the city, each of 100 square kilometers and representing diverse landscapes, were selected for the study. Key datasets describing land features were collected from official and authentic websites. A series of ArcGIS-based data processing methods were applied to discern patterns in the relationship between landscape features and vegetation variability, with a particular focus on periods of wet and dry years. The wet and dry years are identified as 2005 and 2009 respectively, based on average rainfall data. Notably, NDVI values in the wet year are consistently higher than in the dry year, with the greatest differences observed in undeveloped or shrubland areas (sites 3, 5, and 6). In terms of land cover, urban development increases in sites 1, 2, and 4 between 2004 and 2008, while shrubland decreases in sites 3, 5, and 6. This development corresponds to a contraction of vegetation cover. The study areas are primarily characterized by loamy soils, with variations in clay and sand composition. These findings underscore the impacts of rainfall and urban development on vegetation health in arid regions.

Estabilidad fenotípica de cuarenta líneas avanzadas de arroz en Babahoyo, Ecuador

The crosses between Oryza sativa L. and O. rufipogon Griff., create a high genetic diversity to develop rice varieties with high yield and phenotypic stability. In the present investigation, forty advanced lines of rice were evaluated in subsidiaries F5 (dry season) and F6 (rainy season), together with three commercial controls in the town of Babahoyo, Ecuador. A Randomized Complete Block Design (DBCA) was applied with three repetitions, recording morphoagronomic and productive characters. Statistical analyzes were applied and phenotypic stability was determined using the Eberhart and Russell, AMMI, Lin and Binns, PROMVAR models. The average morphoagronomic results were: days to flowering (72), vegetative cycle (98 days), plant height (111 cm), panicle sterility (6 %); the productive variables the results were: tillers per plant (32), panicles per plant (31), panicle length (27 cm), grains per panicle (168) and yield (8,100 kg.ha-1). The stable lines identified by the models: Eberhart and Russell were 1, 2, 10, 11, 13, 18, 25, 26, 30 and 37; AMMI identified lines 8 and 22; Lin and Binns to lines 2, 12, 18, 27, 37 and 40; and PROMOTE lines 2, 10, 13, 18, 25, 30, 38, 40 and 43; concluding that seven lines (2, 10, 13, 18, 25, 30 and 40) coincided with the applied models except AMMI. The average yield of the lines mentioned in the two seasons was 7,797 kg.ha-1, higher than the average of the commercial controls that obtained 6,809 kg.ha-1.

The longevity and reversibility of quiescence in Schizosaccharomyces pombe are dependent upon the HIRA histone chaperone

ABSTRACT Quiescence (G0) is a reversible non-dividing state that facilitates cellular survival in adverse conditions. Here, we demonstrate that the HIRA histone chaperone complex is required for the reversibility and longevity of nitrogen starvation-induced quiescence in Schizosaccharomyces pombe. The HIRA protein, Hip1 is not required for entry into G0 or the induction of autophagy. Although hip1Δ cells retain metabolic activity in G0, they rapidly lose the ability to resume proliferation. After a short period in G0 (1 day), hip1Δ mutants can resume cell growth in response to the restoration of a nitrogen source but do not efficiently reenter the vegetative cell cycle. This correlates with a failure to induce the expression of MBF transcription factor-dependent genes that are critical for S phase. In addition, hip1Δ G0 cells rapidly progress to a senescent state in which they can no longer re-initiate growth following nitrogen source restoration. Analysis of a conditional hip1 allele is consistent with these findings and indicates that HIRA is required for efficient exit from quiescence and prevents an irreversible cell cycle arrest.

Optimizing herbicide doses for weed control in winter wheat (Triticum aestivum L.) in the Moscow region of Russia

One of the main reasons for the reduction of winter wheat yields in Russia, as in most major wheat-producing countries, is the massive infestation and rapid spread of annual weed species. Thus, this study was conducted during 2022 at D.N. Pryanishnikov Russian Research Institute of Agro chemistry, Russia with main objective to optimize the concentration of broad-spectrum herbicides: Lintur, VDG (659 g/kg dicamba-sodium + 41 g/kg triasulfuron), Bucephalus, KE (480g/L carfentrazone-ethyl), Camaro SE (6. 25 g/L florasulam + 300 g/L 2,4-D), Prima Forte 195 SE (180g/L 2,4-D + 10g/L aminopyralid +5g/L florasulam), and their plant growth regulator mixtures Moddus, KE (250 g/L trinexapac-ethyl) to protect winter wheat crops from weeds at Barbino (Russia). An inventory conducted on the study plot showed that the total number reached 434 pants/m2 weeds, with a total of 9 weed species namely Cirsium arvense, Cardaria draba, Galium aparine, Matricaria discoidea, Chenopodium album, Polygonum aviculare, Galeopsis tetrahit, Capsella bursa-pastoris, and Sinapis arvensis of which 73.9% are annual species with a vegetative cycle parallel to that of winter wheat. Herbicide application at 50% showed little difference in weed control efficacy (%) compared to standards and ranged from 56.0 to 100.0% depending on treatment and weed species. Both individually applied herbicides and their mixtures with Moddus and free weed control contributed to a significant increase in yield and the increase was from 12.3 to 23.7%. Yield when using the options mixture with the growth regulator Moddus was higher than the individual application of herbicides regardless of the dose. Yield at a dose of 50% was slightly higher or lower compared with the manufacturer's standard. In general, the growth regulator did not affect herbicide efficacy, but its combination with herbicides improved yield structure elements and increased yield quality of winter wheat.

Unraveling the role of informal mutual aid networks in maintaining urban farms in Lubumbashi, Democratic Republic of Congo

IntroductionThe multiple constraints of urban agriculture have prompted farmers in Lubumbashi to turn to informal mutual aid networks. The survey data collected from 88 farmers chosen at random from the 202 farmers previously interviewed enabled us to decipher the crucial role of mutual aid in maintaining urban farms.MethodsThe survey data collected from 88 farmers chosen at random from the 202 farmers previously interviewed enabled us to decipher the crucial role of mutual aid in maintaining urban farms.ResultsThe results show that 79.5% of the surveyed farmers resort to mutual aid to ensure the vegetable production cycle. More specifically, this mutual aid consists in sharing resources, for which the farmer would interact 15.1 times with other farmers, and in sharing agricultural know-how, for which the farmer would interact 11.6 times with other farmers. Four categories of resources are defined in this mutual aid network: highly exchanged resources with a high exchange intensity (hoes, watering cans, plant protection products and chicken droppings), highly exchanged resources with a low exchange intensity (land capital, spades, and seeds), lowly exchanged resources with a low exchange intensity (motor pumps and buckets) and non-exchanged resources (financing, labor, chemical fertilizers). Agricultural know-how such as soil preparation, soil fertility management, pest control and sales techniques are widely shared. Characteristics such as gender, age, experience, religious affiliation, and farmer status in the household are statistically significant explanatory factors of mutual aid. In addition, neighborhood relations, kinship and religious affiliation are social ties that enable farmers to help each other.DiscussionThe results provide useful information on the crucial role played by informal mutual aid networks in maintaining urban farms in the face of the negative consequences of chaotic urbanisation and climate change. The study recommends that policymakers and agricultural extension services take these networks into account when drawing up policies for disseminating innovations. For, although informal, they constitute powerful and inexpensive channels of communication in an inoperative institutional context of urban agriculture.

The Early Effect of Plant Density on Soil Physicochemical Attributes and Bacterial and Understory Plant Diversity in Phoebe zhennan Plantations

The effect of stand density on the soil bacterial community and diversity remains unclear. Spectrophotometry and full-length 16S rRNA sequences were used to determine the effects of planting density on soil physicochemical attributes and the diversity of soil bacterial and understory vegetation in a young Phoebe zhennan plantation at five densities. The findings showed that stand density had significant effects on the total nitrogen, ammonium nitrogen (NH4+-N), nitrate-nitrogen (NO3−-N), organic carbon, and the dominance and evenness of shrubs. Candidatus Udaeobacter and Candidatus Soilbacter were the two most common genera across the five stand densities. The density D5 (850 stems/hm2) demarcated from the others with a lower diversity of soil bacteria. Overall, the relatively low- and middle-density plantations were more conducive to complex and stable understory vegetation, bacterial communities, and soil nutrient cycles. The functional categories of the bacterial communities revealed a high proportion associated with chemoheterotrophy, aerobic chemoheterotrophy, and nitrogen fixation. Bacterial diversity and function were significantly influenced by soil pH, NH4+-N, NO3−-N, total phosphorus, and available phosphorus. However, there were no significant correlations between soil physicochemical attributes, understory vegetation, and bacterial diversity. Therefore, we speculated that the key drivers of the soil bacterial community were the soil physicochemical attributes and that stand density affected the soil bacterial community diversity by changing the soil physicochemical attributes. Overall, P. zhennan plantations with densities below 600 stems/hm2 were conducive to complex and stable soil bacterial communities and nutrient cycles.