Lime Plants Research Articles

Optimalisasi Kampung Organik sebagai Ketahanan Pangan di Kelurahan Rejowinangun Selatan

Bay leaves are one of the toga plants (family medicinal plants) which can be used to stop excessive defecation. Apart from that, bay leaves can also be used to treat gout, stroke, high cholesterol, improve blood circulation, stomach inflammation, itching and diabetes. Therefore, there is a need for education in the form of counseling regarding the use of bay leaves and how to process them as herbal medicine to help cure diseases. Kaffir lime is a natural ingredient in various food and beverage products in Indonesia and other Asian countries. Kaffir lime plants contain compounds including essential oils which are also rich in benefits such as antioxidants, antimicrobials, antileuchemicals, antitussives, insecticides, illaricides and phenolic compounds such as flavonoids, flavanones, flavones, flavonols and glycerolipids which according to research function as a source of antioxidants, anti-inflammatory , antiviral, anti-allergic, and anti-carcinogenic, anti-aging for the human body. The planting of kitchen spices in the form of bay plants and orange leaves is grown using organic and environmentally friendly materials.

Phylogenetic and Pathogenic Evidence Reveals Novel Host-Pathogen Interactions between Species of Lasiodiplodia and Citrus latifolia Dieback Disease in Southern Mexico.

Mexico ranks second in the world for Persian lime (Citrus latifolia) exports, making it the principal citrus exporter within the national citrus industry, exporting over 600,000 tons per year. However, diseases are the main factor reducing production, resulting in significant economic losses. Among these diseases, fungal diseases like dieback, caused by species of Lasiodiplodia, are an emerging issue in Persian lime. Symptoms include gummosis, twig and branch dieback, cankers, the necrosis of bark and wood, fruit mummification, and tree decline. The aim of this study was to investigate the occurrence and pathogenicity of the fungal species associated with twig and branch dieback, cankers, and decline of Persian lime trees in southern Mexico, and to elucidate the current status of the Lasiodiplodia species causing the disease in Mexico. During June, July, and August of 2023, a total of the 9229 Persian lime trees were inspected across 230 hectares of Persian lime orchards in southern Mexico, and symptoms of the disease were detected in 48.78% of the trees. Branches from 30 of these Persian lime trees were collected. Fungal isolates were obtained, resulting in a collection of 40 strains. The isolates were characterized molecularly and phylogenetically through the partial regions of four loci: the internal transcribed spacer region (ITS), the β-tubulin gene (tub2), the translation elongation factor 1-alpha gene (tef1-α), and the DNA-directed RNA polymerase II second largest subunit (rpb2). Additionally, pathogenicity was assessed, successfully completing Koch's postulates on both detached Persian lime branches and certified 18-month-old Persian lime plants. Through multilocus molecular phylogenetic identification, pathogenicity, and virulence tests, five species were identified as causal agents: L. iraniensis, L. lignicola, L. mexicanensis, L. pseudotheobromae, and L. theobromae. This study demonstrates that in southern Mexico, at least five species of the genus Lasiodiplodia are responsible for dieback in Persian lime. Additionally, this is the first report of L. lignicola and L. mexicanensis as causal agents of the disease in citrus, indicating novel host interactions between species of Lasiodiplodia and C. latifolia.

Efficient CO2 capture from lime plants: Techno-economic assessment of integrated concepts using indirectly heated carbonate looping technology

The quest to decarbonize the lime and cement industry is challenging because of the amount and the nature of the CO2 emissions. The process emissions from calcination are unavoidable unless carbon capture is deployed. Nevertheless, the majority of the available carbon capture technologies are expensive and energy inefficient. The indirectly heated carbonate looping (IHCaL) process is a promising technology to capture CO2 from the lime and cement production, featuring low penalties in terms of economics and energy utilization. Previous works have highlighted the potential of the IHCaL, but the optimization of the process has not been discussed in enough detail and techno-economic implications are not yet fully understood. Within this work, ten scenarios using IHCaL technology to capture CO2 from a lime plant were simulated. Hereby, different process configurations, heat recovery strategies and fueling options were computed. The calculations for the capture facilities were performed with Aspen Plus® software and EBSILON®Professional was used to simulate the steam cycles. A techno-economic assessment was included as well, aided by the ECLIPSE software.The results demonstrate that the selection of the fuel for the combustor not only affects the CO2 balance and energy performance but is also an important cost driver —there were considerable economic advantages for the computed cases with middle-caloric solid recovered fuel (SRF). The analysis shows how the heat recovery strategy can be optimized to achieve tailored outcomes, such as reduced fuel requirement or increased power production. The specific primary energy consumption (from −0.3 to +2.5 MJLHV/tCO2,av) and cost for CO2 avoided (from −11 to +25 €/tCO2,av) using SRF are considerably low, compared with other technologies for the same application. The sensitivity study revealed that the main parameters that impact the economics are the discount rate and the project life. The capture plants are more sensitive to parameter changes than the reference plant, and the plants using SRF are more sensitive than the lignite-fueled plants. The conclusions from this work open a new pathway of experimental research to validate key assumptions and enable the industrial deployment of IHCaL technology before 2030.

Enhancement of a 300 kWth pilot plant for testing the indirectly heated carbonate looping process for CO2 capture from lime and cement industry

The indirectly heated carbonate looping process (IHCaL) is a promising technology for decarbonizing the lime and cement industry. Advantages of the IHCaL are the synergy with these industries using same solid materials and the avoidance of an air separation unit (ASU), since no technical pure oxygen is necessary in this capture process. Former pilot tests showed the feasibility of the IHCaL for applications in the power plant sector. However, the integration of the IHCaL into cement and lime plants, as well as the usability of spent sorbents as educts in these processes, has not yet been proven in industrially relevant conditions. In this study, the modification of an existing 300 kWth pilot plant for demonstrating the IHCaL process are described, aiming in accelerating the demonstration in an industrially relevant environment for cement and lime industries. A flue gas circulation system and a solid fueling system into the combustor, allowing the heat generation for the calcination with e.g. waste derived fuels, have been designed and installed. Results gained during the operation with the modified reactor configuration, are presented in order to assess the performance of the new components in the framework of the IHCaL configuration. The external combustor was operated while co-firing propane with either dried lignite or waste derived fuels. The carbonator was fluidized with a real flue gas from the external combustor, having CO2 concentrations between 11 and 18 vol-%dry. The results, obtained within more than 200 h of continuous testing with modified reactor configuration, show a good hydrodynamic behavior and adequate reactor performance, while providing a sound basis for further improvement and up scaling of the technology.

Molecular characterization of selected fungal and bacterial endophytes in acid lime

Endophytes are the microorganisms that are present in living tissue of various plant parts (roots, fruits, stem, seed, leaf etc,). Endophytic microorganisms are good source of antibiotics. Endophytic antagonists were isolated from the roots of healthy acid lime plants collected from major acid lime growing areas of Andhra Pradesh. A total of 8 fungal and 10 bacterial endophytic antagonists were isolated. The antagonists were further subjected to preliminary screening, out of which only 6 endophytic fungal antagonists (EFA 1-6) and 8 endophytic bacterial antagonists (EBA 1-8) isolates showed good inhibitory effect on radial growth of Fusarium solani causing dry root rot in acid lime in vitro. Among them the one of the best fungal and bacterial antagonists that were found to be extremely efficient against Fusarium solani in dual culture assay were selected for further molecular identification. The BLAST results revealed that one of the fungal isolate had shown 100% similarity with Aspergillus fumigatus and one of the bacterial isolate had shown 95.56% similarity with Pseudomonas aeruginosa.

Phytophthora Root Rot in Rangpur Lime Cultivated in Soil Managed with Ecological and Conventional Mower

Root rot and gummosis caused by Phytophthora spp. are considered one of the most important citrus diseases in Brazil. Symptoms of Phytophthora spp. infection in citrus plants are associated with lesions on the bark at the base of the plant, roots, and even lower branches. Inappropriately performed cultural practices, such as excessive irrigation and practices that result in reduced aeration and soil drainage, favor the disease. The objective of this study was to evaluate the effect of Urochloa ruziziensis mulching provided by an ecological mower on the severity of Phytophthora nicotianae root rot and the development of citrus plants and their root system. The experiments were carried out under controlled conditions on Rangpur lime seedlings kept in pots containing soil from ‘Hamlin’ orange orchards with the use of an ecological mower or a conventional mower in the management of inter-row vegetation for six years. Urochloa ruziziensis mulching (9 t ha−1) was added or not to the pots. The inoculation of P. nicotianae in the roots occurred through infection of the soil with a solution containing mycelium and sporangia of the pathogen. A 2 × 2 × 2 factorial scheme was used, with the following factors A: soil type, B: inoculation of P. nicotianae and C: mulching of U. ruziziensis. The attributes of plant development, such as root growth, average number of leaves, leaves and dry mass of shoots and roots, in addition to assessments of the severity of disease in the roots, were evaluated. The mulch of U. ruziziensis did not promote an increase in root rot. The soil resulting from this management promoted the better development of Rangpur lime plants. Therefore, vegetation management of inter-row with an ecological mower is not associated with increased symptoms of Phytophthora root rot.

Diversity of Endophytic Fungi from Lime Plants (Citrus aurantifolia, Swingle)

Lime (Citrus aurantifolia, Swingle) is a plant with medicinal properties. This plant is needed on a large scale to produce biomass. Medicinal plants with decreasing numbers and populations can be developed through scientific technology by isolating endophytic fungi. Endophytic fungi are microorganisms that are found in plant tissues without causing damage to their host plants. This study uses the exploratory method, namely searching and finding. The purpose of this study was to identify endophytic fungi in lime plants. The study's results obtained ten isolates of endophytic fungi from different plant organs (leaves, stems, bark, roots, fruits). Endophytic fungi were identified through macroscopic and microscopic characteristics and then compared with an identification book of endophytic fungi. Eight genera were found, including Beltrania and Nigrospora on leaves, Fusarium and Chaetomium on fruit, Pythium on stems and bark, Paecilomyces on bark, Mucor and Mortierella on roots.

Evaluating the genotoxicity of salinity stress and secondary products gene manipulation in lime, Citrus aurantifolia, plants.

Salinity is a significant abiotic stress that has a profound effect on growth, the content of secondary products, and the genotoxicity of cells. Lime, Citrus aurantifolia, is a popular plant belonging to the family Rutaceae. The interest in cultivating this plant is due to the importance of its volatile oil, which is included in many pharmaceutical industries, but C. aurantifolia plants are affected by the NaCl salinity levels. In the present study, a comet assay test has been applied to evaluate the genotoxic impact of salinity at 0, 50, 100, and 200 mM of NaCl on C. aurantifolia tissue-cultured plants. Furthermore, terpene gene expression was investigated using a semi-quantitative real-time polymerase chain reaction. Results from the two analyses revealed that 200 mM of NaCl stress resulted in high levels of severe damage to the C. aurantifolia plants' DNA tail 21.8%, tail length 6.56 µm, and tail moment 3.19 Unit. The relative highest expression of RtHK and TAT genes was 2.08, and 1.693, respectively, when plants were exposed to 200 mM of NaCl, whereas pv4CL2RT expressed 1.50 in plants subjected to 100 mM of NaCl. The accumulation of transcripts for the RTMYB was 0.951 when plants were treated with NaCl at 50 mM, and RtGPPS gene was significantly decreased to 0.446 during saline exposure at 100 mM. We conclude that the comet assay test offers an appropriate tool to detect DNA damage as well as RtHK, TAT, and pv4CL2RT genes having post-transcriptional regulation in C. aurantifolia plant cells under salinity stress. Future studies are needed to assess the application of gene expression and comet assay technologies using another set of genes that show vulnerability to different stresses on lime and other plants.

Biochemical and physiological mechanism induced by melatonin in Mexican lime (Citrus aurantifolia Swingle) plants: cold and freezing stress

Biochemical and physiological mechanism induced by melatonin in Mexican lime (Citrus aurantifolia Swingle) plants: cold and freezing stress

Detection of "Candidatus Liberibacter asiaticus" Using Conventional PCR and Nested-PCR and Identification of Primer Sensitivity through Q-PCR in HLB Infected Mandarin Orange and Acid Lime Plants in Tamil Nadu

One of the most destructive citrus diseases in the world is called citrus Huanglongbing (HLB). For effective HLB associated ‘Candidatus liberibacter spp.’ prevention, sensitive and precise diagnostics are essential. Candidatus Liberibacter asiaticus (CLas), Candidatus Liberibacter africanus (CLaf), and Candidatus Liberibacter americanus (CLam) are among the ‘Candidatus liberibacter spp.’ that infect citrus. The most common of these is the species known as Las. To assess the impact of citrus greening disease in the citrus orchard, leaf samples exhibiting greening symptoms were picked up from 210 mandarin orange trees from nine localities in four districts and among them 189 plants showed HLB positive and leaf samples are picked up from 216 acid lime trees from nine localities in six districts of Tamil Nadu where citrus is cultivated in a larger area and among them 202 plants showed HLB positive. A “conventional singleplex polymerase chain reaction (PCR) Nested PCR and Q-PCR (Quantitative PCR)” was performed on the extracted DNA samples to detect Ca. Liberibacter asiaticus. Among all the mandarin orange growing localities from “Kanalkadu and Thandikudi in Dindigul district” and among the acid lime fields, the samples from “Sankarankoil from Tirunelveli district and Kallar from Nilgiris district” showed consistent amplification of 1160 base pairs fragment by using specific primers OI1 and OI2C and also 703 base pairs fragment with gene-specific primers A2 and J5 targeting beta-operon (rpiKAJL-rpoBC) gene which is a ribosomal protein gene of Ca. Liberibacter asiaticus, these results showed that these districts are exclusively positive to Clas . The nested PCR method significantly increased the sensitivity to identify Las up to 10 times and 100 times, respectively, compared to qPCR and conventional PCR in this study. A set of nested PCR primer pairs were examined to diagnose Las. Nested PCR was used to analyse 14 samples from 2 different citrus cultivars in 2 different districts. Among those again kanalkadu orchard for mandarin orange and Sankankoil orchard for acid lime showed more disease incidence and consistent amplification. The findings indicate that all the samples tested positive for HLB; the samples of blotched and chlorotic leaves from the acid lime field at Sankarankoil (thirunelveli district) and mandarin orange field at kanlakaadu (Dindigul district) had the highest positive detection rate (100%). The outcomes show that the nested PCR primer pairs are capable of detecting Las in a variety of symptomatic tissues, citrus cultivars, and geographical locations. The set of nested PCR primers used in the current work will be a very helpful addition to the existing methods for Las detection.

Physio-biochemical Mechanisms of Acetic Acid Involved in Cold and Freezing Tolerance in Mexican Lime Plants (Citrus aurantifolia Swingle)

Physio-biochemical Mechanisms of Acetic Acid Involved in Cold and Freezing Tolerance in Mexican Lime Plants (Citrus aurantifolia Swingle)

Differential Expression of miRNAs Involved in Response to Candidatus Liberibacter asiaticus Infection in Mexican Lime at Early and Late Stages of Huanglongbing Disease

Huanglongbing (HLB) is one of the most destructive diseases threatening citriculture worldwide. This disease has been associated with α-proteobacteria species, namely Candidatus Liberibacter. Due to the unculturable nature of the causal agent, it has been difficult to mitigate the disease, and nowadays a cure is not available. MicroRNAs (miRNAs) are key regulators of gene expression, playing an essential role in abiotic and biotic stress in plants including antibacterial responses. However, knowledge derived from non-model systems including Candidatus Liberibacter asiaticus (CLas)-citrus pathosystem remains largely unknown. In this study, small RNA profiles from Mexican lime (Citrus aurantifolia) plants infected with CLas at asymptomatic and symptomatic stages were generated by sRNA-Seq, and miRNAs were obtained with ShortStack software. A total of 46 miRNAs, including 29 known miRNAs and 17 novel miRNAs, were identified in Mexican lime. Among them, six miRNAs were deregulated in the asymptomatic stage, highlighting the up regulation of two new miRNAs. Meanwhile, eight miRNAs were differentially expressed in the symptomatic stage of the disease. The target genes of miRNAs were related to protein modification, transcription factors, and enzyme-coding genes. Our results provide new insights into miRNA-mediated regulation in C. aurantifolia in response to CLas infection. This information will be useful to understand molecular mechanisms behind the defense and pathogenesis of HLB.

Suppression of citrus canker disease mediated by flagellin perception.

Citrus cancer, caused by strains of Xanthomonas citri (Xc) and Xanthomonas aurantifolii (Xa), is one of the most economically important citrus diseases. Although our understanding of the molecular mechanisms underlying citrus canker development has advanced remarkably in recent years, exactly how citrus plants fight against these pathogens remains largely unclear. Using a Xa pathotype C strain that infects Mexican lime only and sweet oranges as a pathosystem to study the immune response triggered by this bacterium in these hosts, we herein report that the Xa flagellin C protein (XaFliC) acts as a potent defence elicitor in sweet oranges. Just as Xa blocked canker formation when coinfiltrated with Xc in sweet orange leaves, two polymorphic XaFliC peptides designated flgIII-20 and flgIII-27, not related to flg22 or flgII-28 but found in many Xanthomonas species, were sufficient to protect sweet orange plants from Xc infection. Accordingly, ectopic expression of XaFliC in a Xc FliC-defective mutant completely abolished the ability of this mutant to grow and cause canker in sweet orange but not Mexican lime plants. Because XaFliC and flgIII-27 also specifically induced the expression of several defence-related genes, our data suggest that XaFliC acts as a main immune response determinant in sweet orange plants.

Resposta fotossintética de citros a isolados de Citrus tristeza virus com potencial para proteção cruzada

Abstract The objective of this work was to evaluate the photosynthetic response of citrus varieties to the inoculation of isolates T30 and T3 of Citrus tristeza virus (CTV) characterized as having potential to provide cross-protection against severe CTV isolates in citrus. Citrus plants of 'Campbell' orange, 'Persian' lime, and 'Key' lime were subjected to inoculations by both isolates by patch. Noninoculated plants were used as the control. Symptom expression, photosynthetic and transpiration rates, and stomatal conductance were evaluated by IRGA. Stomatal density and size were evaluated by epidermal impressions. The CTV isolates were also evaluated and molecularly characterized by RT-PCR and Sanger sequencing. 'Campbell' orange and 'Persian' lime plants remained asymptomatic after the inoculations. The inoculation treatments with both CTV isolates did not reduce photosynthetic capacity, transpiration rate, and stomatal conductance, in comparison with the control. Stomatal density and size varied according to the citrus species. T30 and T3 do not affect the photosynthetic responses of 'Campbell' orange and 'Persian' lime; therefore, these isolates have the potential to provide cross-protection to citrus varieties against severe isolates of CTV.

Sistem Pakar Diagnosis Penyakit Pada Tanaman Jeruk Gerga Dengan Metode Forward Chaining Studi Kasus Balai Penyuluhan (BPP) Kecamatan Jangkat Kabupaten Merangin

Citrus fruit is one of the most popular types of fruits by the people of Indonesia because of its freshness and contains many types of vitamins. However, the population of citrus plants has experienced a high increase due to the limited knowledge of farmers in terms of proper citrus farming. Another obstacle that causes citrus fruit products in Indonesia to not meet expectations is the emergence of pests and diseases. Many losses are caused by plant diseases that are too late to diagnose, and have reached a severe stage causing crop failure. The purpose of the study was to build an Expert System for Diagnosis of Diseases in Citrus with the Forward Chaining Method Case Study at the Agricultural Extension Center (BPP) in Jangkat District, Merangin Regency, a system that can replace the temporary role of experts or experts in identifying citrus plant diseases quickly and accurately. An expert system for diagnosing citrus plant diseases is needed as a means of consultation and a means of learning for farmers, especially from the Extension Center. For this reason, the difficulties experienced by farmers can be overcome by providing a software (expert system) in the form of an application program to determine diseases that attack citrus or lime plants as well as proper handling and prevention methods. The input in this system is in the form of disease data, symptom data, and rule data. The output is a checking report. The result of this research is a system for diagnosing citrus plant diseases. Keywords— citrus plant diseases, Diagnosis, expert system, forward chaining.

Severity analysis of fruit plant diseases based on leaf symptoms using ImageJ software

Diseases in plants are abnormal and detrimental physiological processes plants. Plant organs commonly affected by the disease are leaves, roots, fruit, and stems. Diseases in plants can generally be caused by bacteria, fungi, viruses, and algae that cause diplodia, red rust patches/spots, scabies, and downy mildew. This study aims to determine the severity of disease in fruit plants using ImageJ and plantix. Based on the results of the study, found five types of fruit plants were used, namely grape vines (Vitis vinifera), sapodilla (Manilkara zapota), mango (Mangifera indica), rambutan (Nephelium sp.), and lime plants (Citrus aurantifolia) with different severity of plant diseases. The highest severity of the disease was found in rambutan leaves (43.73%) caused by fungi, and the lowest severity was found in lime leaves (16.12%) caused by fungi.

BIOFERTILIZERS IN MEXICAN LIME (Citrus aurantifolia (Christm.) Swingle): ARBUSCULAR MYCORRHIZAL FUNGI AND Azospirillum brasilense IN GREENHOUSE

<p><strong>Background:</strong> The majority of terrestrial plants have evolved in symbiosis with beneficial microorganisms, which help them acquire minerals that are scarce in soil, such as phosphorus and in some cases nitrogen. Thus, the development and use of biofertilizers based on microorganisms is important for partial or total replacement of chemical fertilizers. The use of arbuscular mycorrhizal fungi (AMF) and <em>Azospirillum</em> <em>brasilense </em>helps to boost Mexican lime (<em>Citrus aurantifolia</em>) plant growth, making them more vigorous and productive. <strong>Objective: </strong>To evaluate the effect of beneficial microorganisms in Mexican lime plant growth in a greenhouse. <strong>Methodology: </strong>An experiment with Mexican lime was established under greenhouse conditions and a completely randomized bifactorial design: (A) beneficial microorganism with four levels: consortium HMA Cerro del Metate; <em>Rhizophagus intraradices</em> (Ri); <em>Azospirillum brasilense</em> (Ab); and without microbial inoculum (WI); (B) chemical fertilization N-P-K (nitrogen-phosphorus-potassium) with four levels: high (180-180-180 kg ha<sup>-1</sup>); intermediate (90-90-90 kg ha<sup>-1</sup>); low (45-45-45 kg ha<sup>-1</sup>) and without fertilization. In total, 16 treatments with seven replicates were performed; plant growth and microbiological response variables were evaluated with an analysis of variance (ANOVA) and Tukey’s multiple comparison of means tests. <strong>Results</strong>: Significant effects (Tukey, <em>P≤0.05</em>) of the mycorrhizal consortium Cerro del Metate were found, followed by <em>R.</em> <em>intraradices </em>and lastly <em>A. brasilense,</em> which proved that these microorganisms promoted plant growth. Mycorrhization significantly increased (<em>P≤0.05</em>) plant growth rate, as well as dry biomass, observing a mycorrhizal colonization from 16 to 30%. Fertilization only showed a significant interaction (Tukey, <em>P≤0.05</em>) with <em>A. brasilense</em>. <strong>Implications</strong>: The use of native microorganisms and preferably consortia may have better adaptability than commercial ones, which can be explained in part by the effects found in this study. <strong>Conclusion</strong>: Mexican lime plants showed a significantly positive (<em>P≤0.05</em>) response to inoculation with AMF, showing greater plant growth than the other treatments.</p>

Dynamics of Aleurocanthus woglumi Ashby (Hemiptera: Aleyrodidae) in Tahiti acid lime (Citrus latifolia) orchards under different fertilizer applications

Citrus black fly Aleurocanthus woglumi Asbhy is an important citrus pest because it causes significant losses in production. The objective of this study was to evaluate the incidence and distribution of A. woglumi egg laying, eggs and nymphs on Citrus latifolia (Tahiti acid lime) plants grown under different fertilizer applications. The experiment was carried out in a citrus orchard in the municipality of Paço do Lumiar, MA, Brazil. A randomized block design in a 3×5×3 factorial arrangement (three evaluation times, five treatments, and three plant strata) was used with 4 replications. The experimental unit consisted of three plants and treatments with different fertilizations were applied to the soil: T1: control (no fertilizer application); T2: organic fertilizer (bovine manure); T3: organic fertilizer + potassium silicate (K2O3Si); T4: NPK; T5: NPK + K2O3Si. The number of egg laying, eggs and nymphs of A. woglumi was evaluated in the basal, mid and apical strata of C. latifolia plants at 30, 60 and 90 days after fertilizer application. Reductions in the number of eggs and nymphs were observed in treatments with organic fertilization + K2O3Si and NPK + K2O3Si. Citrus latifolia plants treated with K2O3Si were less susceptible to A. woglumi and plants fertilized with NPK present higher susceptibility (p<0.05). There was a higher incidence of egg laying, eggs and 1st instar nymphs in the apical stratum and 2nd, 3rd and 4th instar nymphs in the basal and mid strata in C. latifolia (p<0.05). The addition of K2O3Si to organic and mineral fertilization is recommended as a viable alternative to reduce the population level of A. woglumi in citrus plants

Exogenous Melatonin Protects Lime Plants from Drought Stress-Induced Damage by Maintaining Cell Membrane Structure, Detoxifying ROS and Regulating Antioxidant Systems

Lime is an important commercial product in tropical and subtropical regions, where drought stress is becoming one of the most severe environmental challenges in the agricultural sector. Melatonin is an antioxidant molecule that helps plants regulate their development and respond to a variety of stresses. In this research, the effects of exogenous melatonin treatments were evaluated at different concentrations (0, 50, 100, and 150 μM) on biochemical aspects and gene expression in two species of lime plants (“Mexican lime” and “Persian lime”) under normal (100% field capacity (FC)) and drought stress conditions (75% and 40% FC). The experiments were factorial and based on a completely randomized design (CRD) with four replicates. Drought stress caused electrolyte leakage (EL) as well as accumulations of hydrogen peroxide (H2O2) and malondialdehyde (MDA), indicating the occurrence of damage to cellular membranes. In contrast, the melatonin pretreatment at various concentrations reduced the levels of EL, H2O2 and MDA while mitigating the negative effects of drought stress on the two lime species. The application of melatonin (100-μM) significantly increased the level of proline content and activity of antioxidant enzymes in plants under drought stress compared to control plants. According to real-time PCR analysis, drought stress and melatonin treatment enhanced the expression of genes involved in ROS scavenging, proline biosynthesis, and cell redox regulation in both species, as compared to their respective controls. According to these findings, melatonin is able to detoxify ROS and regulate antioxidant systems, thereby protecting lime plants from drought stress-induced damages.

Detection of huanglongbing of citruses (Citrus sp.) through Sentinel-2satellite images in Huimanguillo, Tabasco, Mexico

Objective: Develop a fast, practical, and inexpensive methodology for determining plants with HLB symptoms by exploring the potential use of Sentinel-2 satellite images. Design/Methodology/Approach: Sentinel-2 images were used to perform a supervised classification to discriminate healthy Persian lime trees and trees with HLB molecularly verified by qPCR, and other land uses in the citrus growing area of Huimanguillo, Tabasco. Results: The results showed that in the green (560nm), red (665 nm), and near-infrared (705 nm) band regions, the spectral response of trees with HLB is higher than that of healthy trees. Likewise, there is an area of 26.96 and 12 981 hectares of Persian lime affected and free of HLB, respectively, with an accuracy of 0.84 % and a Kappa coefficient of 0.83. Field verification corroborated three plantations where plants with HLB were previously detected and are currently in production. Study Limitations/Implications: The study was carried out in the season of less cloud cover, as this is a limiting factor for the image analysis since it can lead to inadequate tracking of the affected area. Findings/Conclusions: The results showed that it is possible to differentiate Persian lime plants affected by HLB from healthy plants using Sentinel-2 satellite images