Experimental Plots Research Articles

Evaluation of the Agro-technological and Health Characteristics of Sugar Cane Varieties (Saccharum officinarum L.) in Rainfall Conditions

Sugar cane Saccharum officinarum (Poaceae) is an important industrial crop in the Ivory Coast. Cane production involves two types of culture. The irrigated cultivation of sugar cane which is that practiced by industrialists and the cultivation in rainy conditions which is that of village producers The study aimed to improve agricultural productivity in village sugar cane plantations by selecting varieties adapted to rain conditions. The trials carried out at the CNRA research station in Ferké (north of the Ivory Coast) in experimental plots were arranged in complete randomized blocks with 7 varieties, including two controls, repeated 6 times. These experiments were carried out on two consecutive harvest cycles, a virgin and a regrowth, with cane yield, extractable sugar content and tolerance to bio-aggressors as the main selection criteria. The varieties Co 997, M 1176/77 and M 2238/89 were found to be significantly superior to controls R 570 and SP 711406. As for the variety KnH 80412, it appeared equivalent to the best control R 570. Among these 5 varieties tested under rainy conditions, the most productive was Co 997 with 60.5 t of cane / ha after 2 consecutive harvest cycles since the new plantation. These best varieties Co 997, M 1176/77 and M 2238/89 are drought tolerant and can therefore replace obsolete varieties that have become too sensitive to the major enemies of sugar cane in village cultivation in the Ferkessédougou region.

Phytoremediation with Sunflower (Helionthus annus) and Its Capacity for Cadmium Removal in Contaminated Soils

This study assessed the phytoremediation potential of sunflowers for removing cadmium from the soil around a paint manufacturing industry in Eleyele, Ibadan. Background levels of Cd in the topsoil and subsoil were determined. The site was divided into two plots. Organo-mineral fertilizer (OMF) was applied to the first plot, which served as the experimental plot, while the second plot was without OMF and served as the control. Concentrations of cadmium in the plants were determined using an Atomic Absorption Spectrophotometer. Baseline mean Cd contents were 29.23 mg/kg and 33.30 mg/kg for topsoil and subsoil, respectively. Over the planting period, the sunflower plants removed 53.1% and 51.6% of Cd from the topsoil and subsoil in the test plot, while 40.65% and 47.80% were removed from the topsoil and subsoil, respectively, in the control. Cd absorption from the contaminated soils was found to be translocated to all parts of the sunflower. The concentrations of Cd in the sunflower parts were as follows: root system (10.70 mg/kg), shoot (8.17 mg/kg), leaves (6.43 mg/kg), and seeds (2.52 mg/kg) for the test plot. For the control plots, Cd in the root, shoot, leaves, and seeds were 7.60 mg/kg, 7.43 mg/kg, 4.75 mg/kg, and 2.03 mg/kg, respectively. The study confirmed that sunflowers have the potential to remediate Cd from contaminated soil, and this potential was enhanced by the application of OMF.

Comparative Evaluation of Nano Urea Versus Conventional Urea for Nitrogen Management in Rainfed Sunflower (Helianthus annuus L.) Cultivation in Acid Sandy Loam Soils of Assam.

A field experiment was conducted during rabi, 2021-22 at the experimental plot of the Department of Agronomy, Biswanath College of Agriculture (BNCA), Assam Agricultural University (AAU), Biswanath Chariali, Assam having geographic coordinates 26°43'30'' N and 93°08'08'' E to assess nitrogen management in Sunflower (Helianthus annuus L.) with conventional and nano urea under rainfed farming situations in the North Bank Plain Zone of Assam. The experiment confined to 10 treatments in Randomized Block Design (RBD) viz., T1: Control (No Nitrogen), T2: Soil application of 50% N, T3: Soil application of 100% N (RD), T4: 3 foliar applications of 0.6% nano urea, T5: Soil application of 50% N + 2 foliar application of 1% conventional urea, T6: Soil application of 50% N + 2 foliar application of 2% conventional urea, T7: Soil application of 50% N + 2 foliar application of 3% conventional urea, T8: Soil application of 50% N + 2 foliar application of 0.2% nano urea, T9: Soil application of 50% N + 2 foliar application of 0.4% nano urea, T10: Soil application of 50% N + 2 foliar application of 0.6% nano urea. Results revealed that there was no significant effect on the seedling emergence percentage due to different nitrogen management treatments. The highest plant height (84 cm) and maximum number of leaves (33) were found in T10. T9 showed the maximum values of Relative Leaf Water Content (RLWC) (71%), leaf area index (LAI) (3.2 and 4.2 at 60 and 90 DAS), chlorophyll content index (30 DAS) and head diameter (16.70 cm). For most of the growth and phenological parameters, T9 and T10 were at par with each other. T1 (no nitrogen) was the earliest to complete its life cycle which is reflected in 50% heading (65 days) and days to maturity (97 days). Dry matter accumulation varied at different time intervals, initially, it was highest in T3 but later T9 and T10 showed the maximum values. In terms of seed yield, test weight and chaffy grain percentage (%), T9 showed the best results: (1505 kg/ha), (54 g/1000 seeds) and (20%) respectively, followed by T10. Whereas the highest stover yield was recorded in T10. The highest Benefit to Cost ratio (B:C ratio of 1.60) was obtained in the T9.

Use of Statistical Tools and Artificial Intelligence for Hydrosedimentological Analysis in Experimental Units in Semiarid Brazil

Objective: To compare statistical and artificial intelligence tools to assist in the analysis and influence of hydrosedimentological variables on runoff generation and sediment yield in experimental units in the Brazilian semiarid region. Theoretical framework: The increasing frequency of extreme weather events in areas prone to natural disasters has led to economic, social, and loss of life due to the lack of urban planning, disorderly occupation in densely populated areas, intensive use of natural resources, and difficulty in maintaining and conserving natural ecosystems (CARMO & LIMA, 2020). Continuous monitoring of hydrosedimentological processes is necessary for natural resource planning and management. There is a need for expanding long-term environmental monitoring in Brazil, which is not simple and costly. In hard-to-reach areas, investment in tools and variable analysis for secure estimation of flow and erosion is necessary (AIRES, 2022). Method: Data obtained from the São João do Cariri Experimental Basin - SJCEB (13.6 km²) were used through conventional rain gauges and automatic data collection platforms from three micro-watersheds (0.16 – 1.63 ha) and two experimental plots (100 m²) located in the semiarid region of Paraíba, Northeast Brazil. For the analyses, 147 rain events that generated surface runoff in at least one of the five experimental units of the SJCEB were used, with data on area (m²), vegetation cover (0 no cover and 1 with vegetation cover over the entire area), average slope (%), daily precipitation (mm), period without rainfall (days), runoff depth (mm), and sediment yield (kg.ha⁻¹), from 2001 to 2008. The statistical and artificial intelligence tools used in the analyses were: simple linear regression, Pearson correlation, and Self-Organizing Maps (SOM). The models were implemented in the R programming language. Results and conclusion: In the statistical summary of the studied variables, precipitation ranged from 2.2 mm to 133.0 mm, with a mean of 21.1 mm. The period without rainfall ranged from 0 to 240 days, with an average of 16.2 days. Slope varied from 3.40% to 7.50%, with a mean of 5.7%. The average vegetation cover was 0.44, with a median of 0.60. The Pearson correlation analysis revealed that precipitation showed a positive and significant correlation with surface runoff and sediment yield variables, ranging from moderate to strong. Simple linear regression was unable to provide satisfactory answers to assist in the analysis of runoff and sediment yield, therefore considered inefficient for hydrosedimentological regionalization. The unsupervised SOM network, by presenting complex relationships among the studied variables, detected that sediment yield is particularly influenced by the interactions with precipitation, vegetation cover, and slope. Thus, it can be inferred that models based on unsupervised neural networks are attractive alternatives, as they were able to extract complex and nonlinear relationships among the analyzed variables. When there are complex cause-and-effect relationships between variables of hydrosedimentological processes, the use of nonlinear and multivariate models, such as artificial neural networks. Implications of the research: Manipulations in experimental areas have favored the measurement of flow and quantification of sediment yield. However, the high costs to maintain physical structures and the presence of specialized personnel for monitoring, processing, and dissemination of collected data are factors that may make it impractical to maintain and expand environmental monitoring networks in Brazil. In ungauged areas, the prediction of flow and erosion is necessary, and can be performed through mathematical, statistical, or artificial intelligence tools that facilitate the identification of priority areas for intervention. Manipulations in experimental areas have favored the measurement of runoff and sediment yield, but the high costs of maintaining the physical structures and the presence of specialized personnel to monitor, process and disseminate the collected data are factors that make maintenance and the expansion environmental monitoring networks in Brazil. In non-instrumented areas, forecasting and analysis of runoff and erosion becomes necessary, using mathematical, statistical or artificial intelligence tools that favor the identification of priority areas for intervention. Originality/value: Use of different statistical and artificial intelligence tools for hydrosedimentological regionalization in small experimental units in the Brazilian semiarid region, with emphasis on the application of unsupervised learning neural networks (SOM).

Extended theoretical modeling of reverse intersystem crossing for thermally activated delayed fluorescence materials.

Thermally activated delayed fluorescence (TADF) materials and multi-resonant (MR) variants are promising organic emitters that can achieve an internal electroluminescence quantum efficiency of ~100%. The reverse intersystem crossing (RISC) is key for harnessing triplet energies for fluorescence. Theoretical modeling is thus crucial to estimate its rate constant (kRISC) for material development. Here, we present a comprehensive assessment of the theory for simulating the RISC of MR-TADF molecules within a perturbative excited-state dynamics framework. Our extended rate formula reveals the importance of the concerted effects of nonadiabatic spin-vibronic coupling and vibrationally induced spin-orbital couplings in reliably determining kRISC of MR-TADF molecules. The excited singlet-triplet energy gap is another factor influencing kRISC. We present a scheme for gap estimation using experimental Arrhenius plots of kRISC. Erroneous behavior caused by approximations in Marcus theory is elucidated by testing 121 MR-TADF molecules. Our extended modeling offers in-depth descriptions of kRISC.

Manifestation of agronomically valuable traits in the progeny of a sorghum mutant carrying the genetic construct for RNA silencing of the γ-kafirin gene.

Improving the nutritional value of grain sorghum, a drought- and heat-tolerant grain crop, is an important task in the context of global warming. One of the reasons for the low nutritional value of sorghum grain is the resistance of its storage proteins (kafirins) to proteolytic digestion, which is due, among other things, to the structural organization of protein bodies, in which γ-kafirin, the most resistant to proteases, is located on the periphery, encapsulating more easily digested α-kafirins. The introduction of genetic constructs capable of inducing RNA silencing of the γ-kafirin (gKAF1) gene opens up prospects for solving this problem. Using Agrobacterium-mediated genetic transformation of immature embryos of the grain sorghum cv. Avans we have obtained a mutant with improved digestibility of endosperm proteins (up to 92 %) carrying a genetic construct for RNA silencing of the gKAF1 gene. The goal of this work was to study the stability of inheritance of the introduced genetic construct in T2-T4 generations, to identify the number of its copies, as well as to trace the manifestation of agronomically valuable traits in the offspring of the mutant. The mutant lines were grown in experimental plots in three randomized blocks. The studied lines were characterized by improved digestibility of kafirins, a modified type of endosperm, completely or partially devoid of the vitreous layer, an increased percentage of lysine (by 75 %), reduced plant height, peduncle length, 1000-grains weight, and grain yield from the panicle. In T2, a line with monogenic control of GA resistance was selected. qPCR analysis showed that in different T3 and T4 plants, the genetic construct was present in 2-4 copies. In T3, a line with a high digestibility of endosperm proteins (81 %) and a minimal decrease in agronomically valuable traits (by 5-7 %) was selected.

Ecology of the free-living stages of cattle nematodes in the dry season in the Lerma Valley, Salta province, Argentina

The objective of this work was to describe the dynamics of development and survival of the free-living stages of cattle gastrointestinal nematodes (GIN) in fecal matter (FM) and pasture during the dry season in the Lerma Valley, Salta province, northwestern Argentina (NWA) to contribute to GIN management. The climate in the region is characterized by a rainy summer followed by a dry season from middle autumn to early spring. Fecal matter from calves naturally infected with GIN was deposited on three experimental field plots in April, July and October 2019, corresponding to the beginning, middle and end of the dry season, respectively. Each experimental unit consisted of 7 stools of about 800 g and had four repetitions. To determine the development from egg to infective larvae (L3), the first sampling (5 g fecal matter) was performed from the 10th day post-contamination and continued every 3 days until L3 were found. Subsequently, a monthly sampling was made until two consecutive negative results were obtained. Sampling of pasture began three days after the L3 recovery from FM, and continued monthly until two negative results were obtained. The following parameters were evaluated: development time and development rate from egg to L3; permanence time of L3 in feces; time of appearance on pasture; migration rate; and permanence time of L3 on pasture. The main genera of parasites present were Cooperia and Haemonchus. Significant differences were observed in the development time among contamination months (p < 0.001); development time was highest in the July contamination (28 days), with October and April contamination averaging 9 and 10 days, respectively. Development time also showed significant differences (p < 0.01) among contamination months, being highest in October (31.48%). The highest permanence time in fecal matter values were recorded in the July contamination (183 days) and migration rate was highest in the October contamination (42.49%). The highest time of appearance on pasture value was recorded in the July contamination (117 days). Finally, the highest permanence time of L3 in feces values were detected in the October contamination (148 days). The results of this work show that fecal contamination in the NWA region in the dry season would play an epidemiological role in the GIN cycle as a source of infection for the next productive cycle in the rainy season.

Фенотипическая изменчивость селекционных линий чечевицы (Lens culinaris L.) по элементам семенной продуктивности в экологических условиях Омской области

Abstract. The article presents the results of studying the main elements of seed productivity (number and weight of seeds per plant, weight of 1000 seeds) in 15 breeding lines of F6-7 generations of lentils obtained from interspecific crossings of varieties Aida (Russia), Vekhovskaya (Russia), Vostochnaya (Russia) and Shyrayly (Kazakhstan). The purpose of the study is to study the phenotypic variability of lentil breeding lines according to the elements of the crop structure and select valuable genotypes as sources of productivity to create varieties adapted to the conditions of the region. Methods. Phenotyping of the breeding material was carried out in the field and laboratory conditions in 2020–2022 at the training and experimental field of the Omsk State Agrarian University. During the study period, very dry climatic conditions developed in 2020 (HTC = 0.62) and 2021 (HTC = 0.68), slightly dry – in 2022 (HTC=1.02). The soil of the experimental plot is meadow-chernozem, medium-thick (45 cm), low-humus (3.95 % of humus), medium loamy (35 % of physical clay) with a soil solution reaction close to neutral (pH = 6.5). The predecessor is spring soft wheat. Results. As a result, it was found that out of 15 lines, only 11 show stable seed productivity in all weather conditions and belong to the intensive type of cultivation, and 4 are characterized as unstable and semi-intensive type. The variability of the number of seeds per plant is significantly affected by the genotypic features of the breeding line (42.8 %). The phenotypic variability of the weight of seeds per plant is due to the conditions of growth of the agricultural crop (40.3 %), and the weight of 1000 seeds is due to the interaction of two factors simultaneously (57.0 %). By the method of principal component analysis, the studied breeding lines are divided into three main clusters according to the type of stability and intensity. Scientific novelty. Based on the research, valuable genotypes were selected that will be used as sources of seed productivity in further breeding and the creation of new adapted, high-yielding varieties of lentils in the region.

Ignition Delay and Reaction Time Measurements of Hydrogen–Air Mixtures at High Temperatures

Induction and reaction times of hydrogen–air mixtures (ϕ = 0.5–2) have been measured behind reflected shock waves at temperatures of 1000–1600 K, pressures of 0.1, 0.3, 0.6 MPa in the domain of the extended second explosion limit. The measurements were performed in the shock tube with a completely transparent test section of 0.5 m long, which provides pressure, ion current, OH and high-speed chemiluminescence observations. The experimental induction time plots demonstrate a clear increasing of the global activation energy from high- to low temperature post-shock conditions. This trend is strongly pronounced at higher post-shock pressures. For a high-temperature range of T &gt; 1200 K, induction time measurements show an activation energy for the global reaction rate of hydrogen oxidation of 64–83 kJ/mole. Detected reaction times exhibit a big scatter and a weak temperature dependence. The minimum reaction time value was nearly 2 µs. Obtained induction time data were compared with calculations carried out in accordance with the known kinetic mechanisms. For current and former shock-tube experiments within a pressure range of 0.1–2 MPa, critical temperatures required for strong (1000–1100 K), transient and weak auto-ignition modes behind reflected shock waves were identified by means of the pressure and ion-probe measurements in stoichiometric hydrogen-air mixture. The transfer from the strong volumetric self-ignition near the reflecting wall to the hot spot ignition (transient) was established and visualized below &lt;1200 K with a post-shock temperature decreasing.

Anomalous intralayer growth of epitaxial Si on Ag(111)

The epitaxial growth of silicene has been the subject of many investigations, controversies and non-classical results. In particular, the initially promising deposition of Si on a metallic substrate such as Ag(111) has revealed unexpected growth modes where Si is inserted at the beginning of the growth in the first atomic plane of the substrate. In order to rationalize this anomalous growth mode, we develop an out-of-equilibrium description of a lattice-based epitaxial growth model, which growth dynamics are analyzed via kinetic Monte-Carlo simulations. This model incorporates several effects revealed by the experiments such as the intermixing between Si and Ag, and surface effects. It is parametrized thanks to an approach in which we show that relatively precise estimates of energy barriers can be deduced by meticulous analysis of atomic microscopy images. This analysis enables us to reproduce both qualitatively and quantitatively the anomalous growth patterns of Si on Ag(111). We show that the dynamics results in two modes, a classical sub-monolayer growth mode at low temperature, and an inserted growth mode at higher temperatures, where the deposited Si atoms insert in the first layer of the substrate by replacing Ag atoms. Furthermore, we reproduce the non-standard Λ\\documentclass[12pt]{minimal} \\usepackage{amsmath} \\usepackage{wasysym} \\usepackage{amsfonts} \\usepackage{amssymb} \\usepackage{amsbsy} \\usepackage{mathrsfs} \\usepackage{upgreek} \\setlength{\\oddsidemargin}{-69pt} \\begin{document}$$\\Lambda $$\\end{document} shape of the experimental plot of the island density as a function of temperature, with a shift in island density variation during the transition between the submonoloyer and inserted growth modes.

Comparing Spatial Sampling Designs for Estimating Effectively Maize Crop Traits in Experimental Plots

The current study investigates the performance of various sampling designs in providing accurate estimates for crucial maize yield traits (intended for silage) including plant height, fresh/dry/ear weight, number of maize ears per plant, and total ear weight per plant, using spatial maize data. The experiment took place in an experimental field area at Aristotle University (AUTH) farm during the 2016 growing season. Nine sampling designs were statistically analyzed and compared with spatial data from an Italian maize hybrid (AGN720) to identify the most suitable and effective sampling design for dependable maize yield estimates. The study’s results indicate that, among the different sampling techniques, Stratified Random Sampling is the most effective and reliable method for obtaining accurate maize yield estimates. This new approach not only provides precise estimates but also requires fewer measurements, making it suitable for experiments where not all plants have emerged. These findings suggest that Stratified Random Sampling can be employed effectively as an alternative to harvesting the entire plot for effectively estimating maize crop traits in experimental plots.

Efficacy of bio-rational insecticide for eco-friendly management of pod borer of mung bean

Pod borer species Maruca vitrata (Geyer) and Euchrysops cnejus (Fab.) are the major limiting constraints in mung bean. The present experiment was conducted in the experimental field of the Department of Entomology, Bangabandhu Sheikh Mujibur Rahman Agricultural University, Gazipur, Bangladesh during March to June 2021 to develop an ecofriendly management approach against pod borer attacking mung bean. Four eco-friendly biopesticides (Biomax 1.8 EC (Abamectin) @ 1.2 ml/L, Tracer 45 SC (Spinosad) @ 0.4 g/, Fytomax PM (0.1% Azadirachtin) @ 5.0 ml/L, Neem Seed kernel Extract (NSKE) @ 50.0 g/L) and clean cultivation were tested against pod borers of mung bean variety BU mug 4. An untreated control treatment was maintained for comparison. The marginal benefit-cost ratio of the treatments and the impact of the treatments on the abundance of beneficial arthropods in the experimental plots were recorded. The management approaches did not affect the abundance of beneficial arthropods in the bean field. The findings revealed that the lowest rate of pod infestation (1.9% by n/n and w/w) as well as the highest marketable yield (1.55 MT/ha) and marginal benefit- cost ratio (3.02) were obtained with the foliar spray with Tracer 45 SC (Spinosad) @0.4 g/L of water at 15 days interval. Tracer 45 SC (Spinosad) @ 0.4 g/L of water at 15 day intervals is an effective, suitable, and viable approach for suppressing pod borer complex without harm to beneficial arthropods in the mung bean field. Ann. Bangladesh Agric. (2023) 27 (1): 71-79

Is Joint Management between Conservationists and Farmers Sustainable and Biodiversity-friendly? A Ten-year Study in Residual Grasslands of a Protected Area.

In recent decades, there has been a discernible reduction in temperate and Mediterranean grasslands with consequences on the decline of biodiversity and landscape heterogeneity. When this decline is due to agricultural abandonment, a renewed joint management, combining bush clearing by conservationists and grazing by farmers, should favor the maintenance of grasslands, their protected habitats and species and forage production. Rainfall irregularity explains part of the variation of these parameters. To verify these hypotheses, we conduct a comprehensive, multi-scale, multi-taxa study over a ten-year period in a Mediterranean protected area. At the regional scale, experimental plots in which this joint management was implemented are representative of residual managed grasslands of the protected area. At the mesoscale, rainfall irregularity is the main factor explaining inter-annual differences in the biomass of open landscapes, while fauna depends on management, tree cover and trophic resources. At the local scale, in a representative experimental plot, clearing had an immediate negative impact on plant richness and bird and positive on forage. Over a decade, plant biodiversity increased while forage, specialist plants and bird maintained, despite the regrowth of bush. Drought had a negative impact on richness, plant and forage abundance and phenological asynchrony on butterflies. In conclusion, joint management has positive, neutral and negative impacts to be considered before implementing this strategy. This long-term monitoring study draws important lessons for designing a sustainable management of grasslands under abandonment and irregular climate, that should be applied in temperate and Mediterranean regions that are increasingly vulnerable to these trends.

A scarab beetle (Coleoptera: Scarabaeidae) causes tree mortality, delayed growth, and yield reduction in cacao with genotype-specific susceptibility to herbivory.

This study explored the impact of Leucothyreus femoratus, a previously unreported folivorous pest in cacao cultivation, on cacao tree survival, development, and yield. The study was conducted in an experimental cacao plot in the Colombian plains, it featured 20 cacao genotypes in an agroforestry system, with plantain and Mexican sunflower providing temporary shade, and yopo offering permanent shade. We found an infestation rate of 2.9 ± 0.3 adult beetles per cacao tree. L. femoratus larvae were discovered in association with the roots of all plants within the agroforestry arrangement; however, yopo and plantain exhibited the highest incidence of root-feeding larvae among these associated plants. Interestingly, male and female L. femoratus displayed distinct leaf consumption patterns in the laboratory, with females consuming more foliage relative to their body weight. Moreover, field observations highlighted the detrimental impact of L. femoratus herbivory on cacao tree survival and growth, leading to leaf skeletonization, reduced plant height, and stem diameter. Trees with over 50% leaf consumption suffered more than 20% mortality. Additionally, herbivory negatively affected cacao yield, correlating higher leaf surface damage with a decrease in harvested pods. The study also identified varying antixenotic resistance in different cacao genotypes, with some consistently displaying resistance while others showed variable levels during tree establishment and production stages. This research underscores the significant role of L. femoratus as a cacao pest, emphasizing its adverse effects on cacao tree survival, development, and yield. Consequently, implementing effective control measures is vital for ensuring sustainable cacao cultivation. © 2023 Society of Chemical Industry.

Experimental evidence that competition strength scales with ecological similarity: a case study using Anolis lizards.

Interspecific competition is widely considered a powerful process underlying species coexistence and ecological community structure. Although coexistence theory predicts stronger competition between more ecologically similar species, empirical support has largely relied on inferring competition from patterns of species co-occurrence. Coexistence theory also posits that species can only coexist when individuals compete more with conspecifics than with other species, however, few field studies-particularly in reptiles-have simultaneously estimated the strength of both intra- and interspecific competition among co-occurring species. Using an array of 12 experimental plots, we manipulated species presence and population size by plot of three native Anolis lizard species to empirically estimate the strength of competition on one anole species driven by two other species of varying ecological similarity. We observed that the strength of competition-as determined by relative growth rates and gravidity-was highly predictable and correlated to ecological similarity. Interspecific competition was strongest among species of highest ecological similarity, and intraspecific competition-induced by the addition or removal of conspecifics-was consistently the most intense. By employing direct experimental manipulations, our study provides an empirical investigation of the strength of competition as it relates to ecological similarity.

Mulching as a restoration method of revegetation at ash and slag dumps of Burshtyn TPP

The study of the effect of mulching to establish vegetation cover at industrial sites is promising and relevant in terms of environmental restoration and reduction of environmental risks in the area of influence of industrial facilities. The study aims to investigate and evaluate the effectiveness of mulching and sowing seed mixtures as a method of establishing vegetation cover at ash and slag dumps of thermal power plants. To conduct the study, the soil cover of ash and slag dumps was assessed, and experimental plots were laid out for mulching and sowing seed mixtures. The study revealed that ash and slag dumps ecotopes are characterised by a high concentration of pollutants, namely heavy metals, which makes it difficult for vegetation to grow there. In the course of studying the ecological features of the ecotopes and phytodiversity of the territory, a list of species of native flora for seed mixtures was proposed. Mulching was done on the experimental plots and seed mixtures were sown. Mulching has proven to be an effective method for accelerating the processes of natural regeneration of vegetation in areas affected by anthropogenic impact. The results of the study can be used in practice by ecologists, environmental organisations, and a wide range of specialists to develop and implement measures to restore the ecological balance of degraded and technologically transformed ecosystems

Crop growth dynamics: Fast automatic analysis of LiDAR images in field-plot experiments by specialized software ALFA.

Repeated measurements of crop height to observe plant growth dynamics in real field conditions represent a challenging task. Although there are ways to collect data using sensors on UAV systems, proper data processing and analysis are the key to reliable results. As there is need for specialized software solutions for agricultural research and breeding purposes, we present here a fast algorithm ALFA for the processing of UAV LiDAR derived point-clouds to extract the information on crop height at many individual cereal field-plots at multiple time points. Seven scanning flights were performed over 3 blocks of experimental barley field plots between April and June 2021. Resulting point-clouds were processed by the new algorithm ALFA. The software converts point-cloud data into a digital image and extracts the traits of interest-the median crop height at individual field plots. The entire analysis of 144 field plots of dimension 80 x 33 meters measured at 7 time points (approx. 100 million LiDAR points) takes about 3 minutes at a standard PC. The Root Mean Square Deviation of the software-computed crop height from the manual measurement is 5.7 cm. Logistic growth model is fitted to the measured data by means of nonlinear regression. Three different ways of crop-height data visualization are provided by the software to enable further analysis of the variability in growth parameters. We show that the presented software solution is a fast and reliable tool for automatic extraction of plant height from LiDAR images of individual field-plots. We offer this tool freely to the scientific community for non-commercial use.

Establishment of an Ex Situ Collection of Glycyrrhiza glabra L. as a Prerequisite for Field Cultivation in Bulgaria

Glycyrrhiza glabra L. (Fabaceae), commonly known as licorice, is a perennial medicinal plant. Its healing properties are due mainly to the secondary metabolites glycyrrhizin and flavonoids accumulated in the roots of plants aged 3 years or more. Overexploitation of licorice populations in Bulgaria led to their rapid decrease. The species is protected by the national Biodiversity Act. The present study aimed at establishing of an ex situ collection of G. glabra using plant material originating from its Bulgarian populations in order to evaluate the main characteristics of the cultivated plants and their potential use as a source of plant material for the creation of a plantation. Plants were obtained from stolon cuttings of donor wild-growing plants from three Bulgarian populations and then cultivated for 3 years in the experimental field plot. Plants originating from all three populations produced glycyrrhizin and flavonoids in similar concentrations under the controlled conditions of the ex situ collection, despite the significant inter-population differences noted in situ. The soil type and supply of soil organic matter, total nitrogen and other nutrients turned out to be most important for the quality of plants in terms of both their growth and biosynthetic capacity. In addition, in vitro micropropagation has proven to be a suitable method for accelerating seedling production. These results would be of practical importance in establishing an agricultural plantation of G. glabra.

Influence of Fertilizer and Weed Management Practices on Yield, Economics and Post-Harvest Soil Properties of Onion (Allium Cepa L.) in North Central Plateau Zone of Odisha

To evaluate the nutrient and weed management practices on performance of onion, a field experiment was carried out during rabi 2017-18 and 2018-19 at the experimental plot of RRTTS, OUAT, Keonjhar, Odisha taking fifteen treatments in a split plot design. Among all the treatments, the maximum plant height was recorded in N3W4 (56.29 cm) which was closely followed by N3W3 (55.97 cm), number of leaves plant -1 was higher in N3W3 (12.47) significantly which was closely followed by N2W4 (12.33) and N2W3 (12.00) and maximum neck thickness was recorded in N1W2 (1.39cm). Among yield parameters, the average bulb weight of onion ranges from 33.56 g (N1W2) to 87.6 g (N2W3) while, the highest bulb yields of onion (17.37 and 20.40 t ha-1) was recorded for the treatment which to be exact was applied with pre-emergence application of pendimethalin @ 0.8 l ha-1 supplement with one hand weeding at 25 DAT with B:C ratio of 1.84 and 1.76 for the year 2017-18 and 2018-19 respectively. Similarly, the treatment combination of N2W3 i.e. application of 50% STBFR along with 50% FYM based on N requirement and pre-emergence application of pendimethalin @ 0.8 l ha-1 + one hand weeding at 25 DAT) was recorded the highest. The available nutrients like nitrogen, phosphorus, potash and sulphur content (284.67 kg ha-1, 14.83 kg ha-1 , 97.43 kg ha-1 &amp; 11.40 kg ha-1) in the post harvest soil was recorded highest with the treatment N2W3.

Quinoa growth and yield, soil water dynamics, root growth, and water use indicators in response to deficit irrigation and planting methods

To address the growing issue of scarce water in the arid and semi-arid areas, it is essential to investigate the potential of drought tolerant crops and implement promising farm management strategies to improve water productivity and yield production. Therefore, a split plot experiment to investigate how different irrigation levels (I-1:100% water requirement (WR), I-2:75%WR, and I-3: 50%WR) and planting methods (P-1: basin, P-2: on-ridge, and, P-3: in-furrow) interact and affect quinoa water use, yield, root growth, and water productivity in southern Iran over two growing seasons. The results showed high seasonal crop evapotranspiration (993–1030 mm) in I-1 as a result of the high advection ratio (α), which ranged from 1.02 to 1.46 from the early vegetative to the seed filling stages. The P-3 increased transpiration rate by 4.5% and 7.7%, and decreased soil evaporation by 17% and 29% compared to P-1 and P-2, respectively. Single (Kc) and dual (Kcb + Ke) crop coefficients varied between 0.41 and 1.38 over the two growing seasons. Grain yield in P-3 were 25%, 34%, and 44% higher compared to P-1 and P-2 under I-1, I-2 and I-3, respectively. The study revealed that nearly 67% and 80% of the total root dry matter was in the 0–30 cm and 0–60 cm of the soil profile in all experimental treatments, respectively. Regardless of irrigation treatment, root length density (RLD) and root mass density (RMD) were found to be 18.9% and 15.7% lower in P-1’s top 0–20 cm of the soil profile than those obtained in P-2 and P-3, respectively. Analyses showed that the increased root length in deeper soil layers contributed to higher soil water uptake, and consequently higher crop water productivity. In addition, root-to-shoot ratio increased as the amount of the applied irrigation water was decreased. Quinoa exhibited the highest acclimation to water stress in P-3 based on water stress sensitivity coefficients (λi) and yield response factor (Ky) values. Crop water productivity (WPC) and irrigation water productivity (WPI) for grain yield varied between 0.17 and 0.28 kg m−3. In conclusion, in terms of grain yield, shoot and root dry matter and water productivity, I-2 and P-3 (75% WR irrigation level and in-furrow planting method treatment) is recommended as the optimum water and planting management strategy for quinoa cultivation in the study area as a measure to address water scarcity and food sustainability. Still, to improve yield and irrigation water efficiency, the effect of soil management practices such as mulching and organic amendments on soil water retention and nutrient availability for quinoa should be investigated.