Blast Severity Research Articles

Priming of Exogenous Salicylic Acid under Field Conditions Enhances Crop Yield through Resistance to Magnaporthe oryzae by Modulating Phytohormones and Antioxidant Enzymes.

This study explores the impact of exogenous salicylic acid (SA) alongside conventional treatment by farmers providing positive (Mancozeb 80 % WP) and negative (water) controls on rice plants (Oryza sativa L.), focusing on antioxidant enzyme activities, phytohormone levels, disease resistance, and yield components under greenhouse and field conditions. In greenhouse assays, SA application significantly enhanced the activities of peroxidase (POX), polyphenol oxidase (PPO), catalase (CAT), and superoxide dismutase (SOD) within 12-24 h post-inoculation (hpi) with Magnaporthe oryzae. Additionally, SA-treated plants showed higher levels of endogenous SA and indole-3-acetic acid (IAA) within 24 hpi compared to the controls. In terms of disease resistance, SA-treated plants exhibited a reduced severity of rice blast under greenhouse conditions, with a significant decrease in disease symptoms compared to negative control treatment. The field study was extended over three consecutive crop seasons during 2021-2023, further examining the efficacy of SA in regular agricultural practice settings. The SA treatment consistently led to a reduction in rice blast disease severity across all three seasons. Yield-related parameters such as plant height, the number of tillers and panicles per hill, grains per panicle, and 1000-grain weight all showed improvements under SA treatment compared to both positive and negative control treatments. Specifically, SA-treated plants yielded higher grain outputs in all three crop seasons, underscoring the potential of SA as a growth enhancer and as a protective agent against rice blast disease under both controlled and field conditions. These findings state the broad-spectrum benefits of SA application in rice cultivation, highlighting its role not only in bolstering plant defense mechanisms and growth under greenhouse conditions but also in enhancing yield and disease resistance in field settings across multiple crop cycles. This research presents valuable insights into the practical applications of SA in improving rice plant resilience and productivity, offering a promising approach for sustainable agriculture practices.

A Comprehensive Survey and Assessment of Rice Blast Disease Incidence from Major Rice Growing Districts of Telangana State, India

Aim: The aim of this study was to assess the incidence and severity of rice blast disease caused by Pyricularia grisea in various rice cultivars grown in Telangana State during the kharif season of 2019. Methodology: A purposive disease survey was conducted in major rice-growing areas of Telangana State. Disease incidence and severity were recorded from the tillering to grain hardening stage. Percentage disease incidence and severity were calculated at each sampling location. Additionally, pathogenicity tests were conducted on susceptible rice cultivar TN-1 using different isolates of P. grisea. Results: The study revealed significant variations in rice blast disease incidence and severity across the surveyed areas. Disease incidence ranged from 18.5% in Mancherial to 79.41% in Peddapalli, while severity ranged from 22.2% to 85.1%. All sampled cultivars exhibited varying degrees of susceptibility, with severity scores ranging from moderately resistant (2.0) to highly susceptible (9.0). TN-1 showed the highest blast severity, while WGL 1368 exhibited the least severity. Pathogenicity tests showed significant differences among P. grisea isolates, with reactions on TN-1 ranging from moderately susceptible (4.0 to 5.0) to highly susceptible (8.0 to 9.0). Conclusion: The study highlights the widespread occurrence of rice blast disease in Telangana State and underscores the varying susceptibility levels among rice cultivars. These findings emphasize the importance of continued monitoring and management strategies to mitigate the impact of rice blast disease on rice production in the region.

Field performance assessment of formulated Pseudomonas fluorescens for enhancing plant growth and inducing resistance against rice blast disease

To control blast disease in the rice field under natural conditions, three antagonistic isolates of rhizospheric P. fluorescens were formulated in talc, kaolinite, PVP, and vegetable oil using an RCBD with three replications. At various phases of the rice plants' growth, all of the products markedly accelerated plant growth and yield-contributing characteristics. Pf-8, compounded in talc (5 %) and vegetable oil (2 %) among the three isolates of P. fluorescens, significantly elevated vegetative and yield parameters with higher (2.11 and 2.08) benefit-cost ratios, respectively. At 90 days after transplanting (DAT), T11 (5 % Pf-8 Talc) and T13 (2 % Pf-8 Vegetable oil) showed a significant reduction in blast incidence (76.81 %, 75.45 %) and severity (71.57 %, 69.82 %), with the largest populations of P. fluorescens (9.60 × 1010 and 9.51 × 1010) in the rhizosphere. Moreover, a significantly increased level of phenol and hydrogen peroxide (H2O2) was found in Pseudomonas-treated leaves (Pf-8) at 30, 60, and 90 DAT indicating a strong relationship with rice blast disease reduction. Further, blast incidence and severity showed a negative correlation with vegetative parameters, yield parameters, phenol, and H2O2. Thus, it may be claimed that using formulated P. fluorescens (Pf-8) to manage rice blast in the field could be an alternate strategy to using chemicals.

Biological control potential of worrisome wheat blast disease by the seed endophytic bacilli.

Crop production often faces challenges from plant diseases, and biological control emerges as an effective, environmentally friendly, cost-effective, and sustainable alternative to chemical control. Wheat blast disease caused by fungal pathogen Magnaporthe oryzae Triticum (MoT), is a potential catastrophic threat to global food security. This study aimed to identify potential bacterial isolates from rice and wheat seeds with inhibitory effects against MoT. In dual culture and seedling assays, three bacterial isolates (BTS-3, BTS-4, and BTLK6A) demonstrated effective suppression of MoT growth and reduced wheat blast severity when artificially inoculated at the seedling stage. Genome phylogeny identified these isolates as Bacillus subtilis (BTS-3) and B. velezensis (BTS-4 and BTLK6A). Whole-genome analysis revealed the presence of genes responsible for controlling MoT through antimicrobial defense, antioxidant defense, cell wall degradation, and induced systemic resistance (ISR). Taken together, our results suggest that the suppression of wheat blast disease by seed endophytic B. subtilis (BTS-3) and B. velezensis (BTS-4 and BTLK6A) is liked with antibiosis and induced systemic resistance to wheat plants. A further field validation is needed before recommending these endophytic bacteria for biological control of wheat blast.

Prospecting Efficacy of Native Bacterial Bioagents against Blast Disease and their Potential for Plant Growth Promotion in Finger Millet

Thirty-seven isolates of pseudomonas and bacillus were isolated from the phylloplane of healthy finger millet leaves. Two of the bacterial isolates showing maximum inhibition against the blast pathogen under invitro conditions were characterized by biochemical test and molecular characterization using 16SrRNA sequencing and also evaluated for hydrolytic enzyme activity under growth promotion activity. The isolates were identified to be Pseudomonas fluorescens (P-9) and Bacillus subtilis (B-10) showing 100% nucleotide similarity with reported strains. Field evaluation with microbial consortium (P-9 & B-10) as talc formulation resulted in significant reduction in leaf blast severity (55.15%), neck blast (44.44 %) and finger blast (46.02 % ) along with a 35.17 % increase in grain yield over control and highest cost benefit ratio of 1: 1.53 over control.

Assessing Interactions between Nitrogen Supply and Leaf Blast in Rice by Hyperspectral Imaging

Mineral nitrogen (N) supply reportedly increases rice susceptibility to the fungal pathogen Magnaporthe oryzae causing blast disease. These biotic and abiotic factors cause changes in spectral reflectance of leaves; however, the effects of N × pathogen interactions on spectral characteristics of rice have not been studied. In this study, hyperspectral imaging was used to assess the effect of N supply on symptoms of rice leaf blast under greenhouse conditions. Three rice genotypes differing in blast susceptibility grown at low, medium, and high N supply were inoculated at the four-leaf stage with three M. oryzae isolates differing in virulence. The reflectance spectra (400 to 1000 nm) of healthy and symptomatic leaves were analyzed using the spectral angle mapper algorithm for supervised classification. Mineral N supply increased the contents of chlorophyll and total N. The number and area of lesions and total blast severity varied depending on rice genotype—M. oryzae isolate interactions and the amount of mineral N applied. The reflectance spectra of healthy tissue and of blast symptom subareas differed with N supply; rice genotypes differed in the response to N supply. Infected plants at high mineral N supply could be distinguished from those at low N supply due to higher differences in the spectra of symptom subareas. Results reveal the potential (and limitations) of hyperspectral imaging for quantifying N effects on rice leaves, disease severity, and symptom expression. The impact of these findings on plant phenotyping and remote sensing under field conditions is discussed.

The relationship between blast-related mild traumatic brain injury and executive function is moderated by white matter integrity.

Blast-related mild traumatic brain injury (BR mTBI) is a critical research area in recent combat veterans due to increased prevalence of survived blasts. Post-BR mTBI outcomes are highly heterogeneous and defining neurological differences may help in discrimination and prediction of cognitive outcomes. This study investigates whether white matter integrity, measured with diffusion tensor imaging (DTI), could influence how remote BR mTBI history is associated with executive control. The sample included 151 Veterans from the Minneapolis Veterans Affairs Medical Center who were administered a clinical/TBI assessment, neuropsychological battery, and DTI scan as part of a larger battery. From previous research, six white matter tracts were identified as having a putative relationship with blast severity: the cingulum, hippocampal cingulum, corticospinal tract, inferior fronto-occipital fasciculus, superior longitudinal fasciculus and uncinate. Fractional anisotropy (FA) of the a priori selected white matter tracts and report of BR mTBI were used as predictors of Trail-Making Test B (TMT-B) performance in a multiple linear regression model. Statistical analysis revealed that FA of the hippocampal cingulum moderated the association between report of at least one BR mTBI and poorer TMT-B performance (p < 0.008), such that lower FA value was associated with worse TMT-B outcomes in individuals with BR mTBI. No significant moderation existed for other selected tracts, and the effect was not observed with predictors aside from history of BR mTBI. Investigation at the individual-tract level may lead to a deeper understanding of neurological differences between blast-related and non-blast related injuries.

Automatic Detection of Rice Blast Fungus Spores by Deep Learning-Based Object Detection: Models, Benchmarks and Quantitative Analysis

The severity of rice blast and its impacts on rice yield are closely related to the inoculum quantity of Magnaporthe oryzae, and automatic detection of the pathogen spores in microscopic images can provide a rapid and effective way to quantify pathogen inoculum. Traditional spore detection methods mostly rely on manual feature extraction and shallow machine learning models, and are mostly designed for the indoor counting of a single spore class, which cannot handle the interference of impurity particles in the field. This study achieved automatic detection of rice blast fungus spores in the mixture with other fungal spores and rice pollens commonly encountered under field conditions by using deep learning based object detection techniques. First, 8959 microscopic images of a single spore class and 1450 microscopic images of mixed spore classes, including the rice blast fungus spores and four common impurity particles, were collected and labelled to form the benchmark dataset. Then, Faster R-CNN, Cascade R-CNN and YOLOv3 were used as the main detection frameworks, and multiple convolutional neural networks were used as the backbone networks in training of nine object detection algorithms. The results showed that the detection performance of YOLOv3_DarkNet53 is superior to the other eight algorithms, and achieved 98.0% mean average precision (intersection over union &gt; 0.5) and an average speed of 36.4 frames per second. This study demonstrated the enormous application potential of deep object detection algorithms in automatic detection and quantification of rice blast fungus spores.

Correlação entre resistência à brusone em cultivares de trigo e taxa de esporulação de conídios de Pyricularia oryzae Triticum

ABSTRACT: The use of resistant wheat cultivars is a fundamental strategy to minimize the damages caused by blast, a disease caused by the fungus Pyricularia oryzae Triticum (PoT). The objetive of this stydy was to (a) evaluate the reaction to blast of Brazilian wheat cultivars and (b) determine whether there is correlation between severity of symptoms on wheat spikes and “sporulation rate of PoT conidia per gram of wheat spike rachis” (Rscon). Plants of 16 wheat cultivars were grown in greenhouse until flowering (Zadoks stage 65), when their spikes were inoculated with a suspension formed by mixing the conidia of three PoT isolates. The evaluated variables were blast severity on spikes at 5, 7 and 11 days after inoculation (dai) and Rscon. Rachis were evaluated individually to determine the Rscon. Correlation analyzes were carried out between blast severity means on spikes of cultivars at 5, 7 and 11 dai and Rscon. The cultivars TBIO Mestre, TBIO Aton, ORS 1401, ORS 1403, ORS Destak, ORS Feroz, and CD 116 stood out for being classified in the statistical groups with the highest resistance to blast for the four variables considered in the study. The correlation between blast severity on spikes at 5, 7 and 11 dai and Rscon is at most moderate.

Seleção de isolados bacterianos antagonistas e supressores de brusone em plantas de arroz

ABSTRACT Grain yields of rice (Oryza sativa) are affected globally by rice blast (Magnaporthe oryzae). The main objective of this study was to identify isolates of rhizobacterial antagonists of M. oryzae (BRM10781) and screen the most effective isolates for suppressing rice blast under greenhouse conditions. Two assays (E1 and E2) were performed with 22 treatments in a completely randomized design with three replicates. E1 investigated in vitro antagonism between 21 isolates and M. oryzae under laboratory conditions. The E2 experiments were conducted under greenhouse conditions, with rice cultivar BRS Primavera seeds in plastic trays containing 3 kg of fertilized soil. After 21 days, the rice leaves were spray-inoculated with a bacterial cell suspension (1 × 108 CFU) and M. oryzae (3 × 105 conidia.mL-1) or with water (absolute control). Seven isolates, Serratia marcescens (BRM65918, BRM65923, BRM65926, and BRM63532), Bacillus cereus (BRM65919), Stenotrophomonas nitritireducens (BRM65917), and Priestia megaterium (BRM65929), reduced radial growth of M. oryzae colonies from 80.26 to 77.33%. The best leaf blast severity reducers were Pseudomonas nitroreducens (BRM32112), B. thuringiensis (BRM65928), P. megaterium (BRM65916), S. marcescens (BRM65918), S. nematodiphila (BRM63522), and Enterobacter hormaechei (BRM65925), varying from 97 to 95% respectively. The isolate BRM65918 (S. marcescens) showed the best efficiency for both antagonism and disease suppression, indicating its potential as a bioproduct for the biocontrol of rice blast in rice plants.

Characterization of New Rice Genotypes for Blast and Brown Spot Disease Resistance and Iron-Toxicity Tolerance in Burkina Faso

Rice production in Burkina Faso is threatened by a number of abiotic and biotic constraints, including iron toxicity and main fungal diseases that limit the potential of cultivated varieties. The general objective of this study was to evaluate the performance of new rice genotypes against main biotic and abiotic stresses. A total of 08 genotypes were tested allowed a Fisher block design with 03 replicates. Assessments focused on severity of iron toxicity, the severity and incidence of blast and brown spot disease and agro-morphological traits. The GRS IR-6-S3-Y1-D genotype was the most sensitive to iron toxicity, while the Sahel 108, BF19AR006 and SV1CP genotypes were the most resistant. As for fungal diseases, severity scores ranged from 4.33 to 7.67 for blast and from 4.00 to 7.03 for brown spot disease while incidence rates were 88.33% and 81.67% for blast and brown spot disease respectively. Genotype IR93654-10-3-2-1-ARS-SALS was resistant to both blast and brown spot disease. Person's correlation matrix showed both positive and negative correlations between the various agro-morphological parameters and pathological traits. Hierarchical ascending classification showed that the SV1CP and IR93654-10-3-2-1-ARS-SALS genotypes performed better agronomically. with yields of over 7.000 kg/ha and showed good tolerance to iron toxicity, blast and brown spot disease.

SCREENING RICE HYBRID GENOTYPES FOR BLAST AND BROWN SPOT DISEASES RESISTANCE AND YIELD PERFORMANCE

Rice occupies a prominent place among the cereals produced in Burkina Faso. However, its production faces constraints that impact the performance of the varieties developed. The aim of the present study was to evaluate new hybrid rice varieties with regard to their resistance to blast and brown spot diseasesand their agronomic performances. The plant material consisted of 9 rice varieties, including 04 local controls. Trials were set up in a Fisher block design with 03 replicates at Bama, Banfora and Sindou sites over a two-year study period. Data were collected on the severity and incidence of blast and brown spot disease, as well as on agronomic parameters. The study showed that hybrids were the most resistant to blast and brown spot disease. In addition, maturity was later at the Sindou site than at the other two sites. The WDR1517, WDR73 and WDR737 hybrids were the latest to reach semi-maturity, with cycles ranging from 120 to 132 days. However, hybrids WDR3015 and WDR306 performed better agronomically, with yields of over 9,000 kg/ha on all sites. Yield stability analysis showed that hybrid WDR73 was the most stable of the varieties, with an average yield of 8310 kg/ha. The three-dimensional analysis also proved that these varieties would adapt to our countrys 03 agro-ecological areas.

Hydroxamate siderophores secreted by plant endophytic Pseudomonas putida elicit defense against blast disease in rice incited by Magnaporthe oryzae.

Our study focuses on hydroxamate-type siderophores from Pseudomonas putida BP25, known for chelating ferric iron and aiding microbial growth in iron-deficient environments. Confirmed through CAS-agar and tetrazolium tests, a purified siderophore extract was obtained via ion-exchange chromatography. Applying varying concentrations of this siderophore to rice seedlings demonstrated concentration-dependent effects on shoot and root phenotypes. Prophylactic application on rice leaves significantly reduced blast severity (68.7%-97.0%), surpassing curative application (47.5%-86.87%). Additionally, the siderophore treatment elevated peroxidase, polyphenol oxidase, and total phenols in rice plants. Defense-related genes linked to salicylic acid (OsPR1.1, OsNPR1, and OsPDF2.2), and other pathways (Oshox24, OsCLE, and OsGLP3-3, OsEIN2.4, and OsCSE) promoting blast suppression showed upregulation. However, the OsACS6 gene associated with ethylene-induced internodal elongation was significantly downregulated. Overall, our findings propose that the siderophore from P. putida BP25 induces defense gene transcription, offering potential for sustainable rice production via bio-formulation.

Survey and Surveillance on Major Rice Diseases Severity in Karnataka, India

Rice blast, sheath blight and Grain discoloration diseases of rice were becoming a serious threat to rice crop in Karnataka. The patterns of spatio-temporal distribution of disease incidence were examined in two seasons (Kharif 2012 and 2013) with main objective of statues of rice diseases in paddy growing areas of Karnataka and variability with climatic condition. Most of the fields in the paddy growing areas of Karnataka were diseased, but significant differences in disease incidence occurred among the some sites in paddy growing areas of Karnataka. The leaf blast severity showed that the highest mean per cent disease incidence 37.20 was observed in Mandya district.and sheath blight severity showed that the highest mean per cent disease incidence 41.76 was observed in Yadgir district. The spatio-temporal distribution of grain discoloration incidence in Kharif 2012 and 2013 varied with districts, the maximum disease was in Bellary (33.82% and 31.24%) followed by Koppal (31.78% and 27.16%), for sheath blight, maximum disease was in Yadgir (36.23% and 41.76%) followed by Raichur (27.16% and 30.59%) and maximum leaf blast disease was in Mandya (37.20% and 36.91%) followed by Ramanagar (36.67% and 36.54%) respectively. Many fungi have been isolated from discolored grain, Curvularia lunata (Wakker) Boed. were found as a dominant pathogen. Survey and surveillance were serve as a precursor for evolving management strategies against the disease effective for the zone in an integrated way for sustainable development of crop in the state.

Evidence of antagonism in vitro and in vivo of extracts from Banisteriopsis laevifolia (A. Juss) B. Gates against the rice blast fungus

Rice blast is a common disease caused by Magnaporthe oryzae which affects rice production worldwide, including Brazil. To reduce the use of harmful pesticides, sustainable control options are necessary for managing rice blast. One possible option is to use plant extracts because they produce secondary metabolites capable of inhibiting the pathogen and controlling the disease. This study aimed to evaluate the potential of ethanolic extracts of leaves and flowers from Banisteriopsis laevifollia, a native Brazilian plant, to antagonise M. oryzae. In vitro antifungal activity assays were carried out, in which mycelium growth reduction, conidia germination, and appressorium formation of M. oryzae were evaluated. In addition, in vivo assay for suppression of leaf blast severity by extracts was done. We also explored the identification of secondary metabolites from ethanolic extracts of leaves and flowers by HPLC–HRMS. Results showed that both leaf and flower extracts inhibited mycelial growth in 21.72% and 30.49%, respectively, due to the inhibition of ergosterol production. Additionally, both extracts inhibited melanin production in the mycelium of M. oryzae by inhibiting tyrosine production. Both leaf and flower extracts significantly inhibited conidia germination and appressorium formation. Furthermore, rice leaves treated with the extracts suppressed by 18.17% and 18.97% leaf blast severity, with the 1.00 mg/mL concentration of flower extract and 0.75 mg/mL concentration of leaf extract, respectively, showing the most significant reduction of leaf blast. The extracts contain phenolic compounds, including 2,3,7,8-tetrahydroxy-chromeno-(5,4,3)-chromene-5,10-dione, 3-(4-hydroxyphenyl)-2-propenoic acid, 2-(3,4-dihydroxyphenyl)-3,4-dihydro-1(2H)-benzopyran-3,5,7-triol, 3,4′,5,7-tetrahydroxyflavone, 3′,4′,5,7-tetrahydroxyflavone, 4′,5,7-trihydroxyflavanone, 3,3′,4′,5,7-pentahydroxyflavone, 3,3′,4′,5,7-pentahydroxyflavone -3-O-glucoside, and 3,3′,4′,5,7-pentahydroxyflavone-3-O-rutinoside, which are likely responsible for the antifungal activity of the extracts. Overall, this study demonstrates the potential of plant extracts as a sustainable alternative for the management of rice blast.

Distress tolerance mitigates effects of posttraumatic stress, traumatic brain injury, and blast exposure on psychiatric and health outcomes.

Exposure to blasts is common among service members and history of these exposures has been associated with chronic psychiatric and health outcomes. Evidence suggests that distress tolerance (DT) may moderate this relationship and be a valuable treatment target in this population. The purpose of this manuscript was to evaluate DT as a modifying factor in the association between posttraumatic stress disorder (PTSD), mild traumatic brain injury (TBI), blast exposure, and functional indicators. Participants were 275 (86.55% male) combat veterans who served in Iraq or Afghanistan after September 11, 2001. Clinical interviews for PTSD diagnosis, TBI history, and blast exposure were administered, and participants completed self-report questionnaires (DT, PTSD symptom severity, depressive symptom severity, neurobehavioral symptom severity, sleep quality, pain interference, and quality of life). DT was significantly associated with all functional indicators beyond PTSD diagnosis, mild TBI, and blast severity. There were significant interaction effects between DT and PTSD diagnosis for posttraumatic stress symptom severity, sleep quality, and quality of life. Specifically, there were significant differences in these reported functional indicators between individuals with and without a PTSD diagnosis as DT increases, such that reported symptoms were lower (quality of life better) for individuals without PTSD as DT improved. Our results demonstrate that DT might be a key factor in postdeployment function for military service members. Treatments targeting DT may be particularly effective in individuals who attribute psychiatric symptoms to history of blast exposure. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

4 TBI and Blast Disrupt Normal Relationships Between Brain Function, Cognitive Performance, and Psychiatric Symptom Severity

Objective:Determine how characteristics of deployment mild traumatic brain injury (TBI) and blast exposure influence the relationship between the functional brain connectome with cognitive outcomes and symptom severity.Participants and Methods:N = 181 Iraq and Afghanistan combat veterans completed structured clinical interviews, cognitive testing, self-report questionnaires, and magnetoencephalography (MEG). MEG data were acquired in the resting-state with eyes open. MEG data were beamformed to identify brain regions active at rest. Functional brain connectomes representing the unique network present for a given individual were created using active brain regions identified for each participant. Network metrics describing these connectomes were calculated at the participant level. Cognitive tests included the WAIS-IV, Trail Making Test Parts A&amp;B, and the Controlled Oral Word Association test. Due to differences in normative data across tests, raw scores were used in analyses. Symptom measures included the PTSD Checklist - 5 (PCL-5), Patient Health Questionnaire (PHQ-9), Neurobehavioral Symptoms Inventory (NSI), Quality of Life After Brain Injury (QOLIBRI), Pittsburgh Sleep Quality Index (PsQi), the Distress Tolerance Scale (DTS), and the PROMIS Pain Interference Scale (PROMIS-PI).Results:Hierarchical linear regression analyses revealed that several network metrics were significantly related to both cognitive outcomes and symptom severity after adjusting for demographic covariates and clinical characteristics.The relationship between Global Efficiency (GE) and cognitive outcomes was moderated by deployment TBI on the WAIS-IV Full Scale Index (FSI), Perceptual Reasoning Index (PRI), and General Ability Index (GAI). In all cases, when deployment TBI was absent, greater GE was associated with poorer cognitive scores. The relationship between GE and symptom severity was moderated by the severity of blast exposure. Greater GE was associated with lower symptom severity at lower blast severities for the PHQ-9 and QOLIBRI A (thinking) and E (negative emotions). Moderation effects were also observed for the PSQI. In the absence of deployment TBI, greater GE was associated with better sleep quality; however, in the presence of deployment TBI, greater GE was associated with poorer sleep quality. Other connectome-outcome relationships were not consistently moderated by Deployment TBI or blast historyConclusions:Results demonstrated relationships between several aspects the functional connectome of the brain with both cognitive outcomes and symptom severity beyond effects of common demographic and clinical variables. Moderation analyses revealed that the relationship between GE of the connectome and outcomes is frequently disrupted by deployment TBI and blast. GE is a measure of the ease of information transfer through the network. These results identified consistent relationships between GE and outcomes in the absence of deployment TBI or blast, but these relationships disappear when deployment TBI or blast are present. Participants in this study were on average 11 years post-TBI or blast exposure, suggesting these are chronic rather than acute effects. GE was significantly correlated with most symptom severity measures as well as the WAIS-IV PRI, GAI, VCI, and FSI. Future efforts to normalize the relationship between GE and outcomes following TBI may improve rehabilitation outcomes and directly affect areas of concern commonly reported by service members following TBI or blast exposure.

Analyses of Productivity and Profitability in Boro Rice Cultivation within Blast-Affected Areas of Kushtia District

This study evaluated the profitability dynamics of blast affected Boro rice cultivation within specific regions of Kushtia District of Bangladesh during the period of 2018-19. A total of 90 farmers, with 30 from each upazila, were selected randomly for participation in this study. The findings revealed substantial yield losses, with the most significant impact observed among11% farmers affected by a disease severity scale of 9 in BRRI dhan28, resulting in a yield loss of 3.92 t/ha. Similarly, a blast severity scale of 9 led to yield losses of 2.0 t/ha in BRRI dhan29, affecting 7% of farmers. The Miniket cultivar exhibited a yield loss of 1.70 t/ha among 56% of farmers with a severity scale of 5. Interestingly, Mirpur experienced devastating losses for both BRRI dhan28 and BRRI dhan29, while Kushtia Sadar suffered significant yield losses for the Miniket cultivar based on disease severity and yield impact. Application of Nativo 75 WG (0.40 Kg/ha) and Trooper 75 WP (0.50 Kg/ha) at the lowest (3%) disease incidence resulted in a remarkable 68.97% increase in yield for BRRI dhan29 in Bheramara. Conversely, spraying of Amistar Top 325 SC (0.56 l/ha) did not lead to increase yield. In Miniket cultivar at Bheramara, Nativo 75 WG (0.45 Kg/ha) and Amistar Top 325 SC (0.37 l/ha) resulted in a lower yield of 2.99 t/ha due to application at a higher (50%) disease incidence. Furthermore, a yield increase of 69.67% was observed with the application of Nativo 75 WG (0.34 kg/ha) in the Miniket cultivar at Kushtia Sadar. The highest gross return, gross margin, net return, and benefit-cost ratio were recorded in Bheramara, amounting to Tk 1,24,084/ha, Tk 46,037/ha, Tk 5,797/ha, and 1.05, respectively. Notably, BRRI dhan29 exhibited the maximum gross return and yield of Tk 1,32,435/ha and 6.14 t/ha, respectively, whereas BRRI dhan28 demonstrated the lowest gross return and net return of Tk 1,09,737/ha and (-) Tk 8,321/ha, respectively, due to higher blast disease incidence. Labor costs constituted the largest share (34.10%) of the total rice production expenses. Despite BRRI dhan28 exhibiting lower net and gross returns per hectare due to higher blast disease incidence, the highest yields in BRRI dhan29 were attributed to its comparatively lower disease infection rate among the three varieties. Evidently, the cultivation of the Miniket cultivar resulted in higher net returns due to its superior market price and quality, especially when disease incidence was lower compared to BRRI dhan28. This emphasizes the importance of blast management strategies and the use of resistant varieties with high yield potential and market value in ensuring sustainable productivity and profitability in Boro rice production. Bangladesh Rice J. 26 (2): 1-18, 2022

Probing the effects of silicon amendment on combined stressors on rice: Lead pollution and blast fungus (Magnaporthe oryzae) infection

As agroecology deteriorates, agricultural production is threatened by the combined stressors of exposure to environmental pollutants and pathogenic microbes. Proper agronomic practices for crop growth management and fertilization require understanding plant tolerance strategies. Both rice blast and heavy metals substantially impair rice crops, while silicon (Si) is an effective amendment to alleviate the combined stressors. Herein, this study was conducted to investigate the rice physiology and pathology perspective on the mechanism of Si alleviation against both lead (Pb) toxicity and Magnaporthe oryzae infection, utilizing pot experiments with inoculation of the virulent Magnaporthe oryzae strain. Exogenous Si reduced the phyto-availability and plant absorption of Pb, resulting in a 73.5% reduction in exchangeable Pb concentration in soil and a 40.23% reduction in rice plants. Furthermore, Si addition boosted the plant antioxidant system by increasing the activities of related enzymes, as the activities of catalase, superoxide dismutase, and polyphenol oxidase were significantly improved while the activity of peroxidase in rice panicles decreased. As a result, an improvement in dry matter quantity by 19.19% was observed compared to treatments without Si application, and the panicle blast severity (PBS) was reduced by 0.4–37.52%. Notwithstanding the interaction between the combined stressors, this study revealed that the speciation of Pb formation in the rhizosphere was the primary contributor to the alleviation of abiotic stresses, whereas the regulation of oxidative stress by enzymatic antioxidants played a dominant role in alleviating Magnaporthe oryzae colonization and impairments. The regulation process may reveal the mechanism of siliceous fertilizer functioning in the paddy system. Thereby the role of exogenous Si in anti-fungal, heavy metal toxicology, and plant physiology needs further study to fully elucidate the role of Si amendment, which is proposed to be considered from the perspective of soil chemistry and plant physiology.

A novel fine-tuned deep-learning-based multi-class classifier for severity of paddy leaf diseases.

Paddy leaf diseases have a catastrophic influence on the quality and quantity of paddy grain production. The detection and identification of the intensity of various paddy infections are critical for high-quality crop production. In this paper, infections in paddy leaves are considered for the identification of illness severity. The dataset contains both primary and secondary data. The four online repositories used for secondary data resources are Mendeley, GitHub, Kaggle and UCI. The size of the dataset is 4,068 images. The dataset is first pre-processed using ImageDataGenerator. Then, a generative adversarial network (GAN) is used to increase the dataset size exponentially. The disease severity calculation for the infected leaf is performed using a number of segmentation methods. To determine paddy infection, a deep learning-based hybrid approach is proposed that combines the capabilities of a convolutional neural network (CNN) and support vector machine (SVM). The severity levels are determined with the assistance of a domain expert. Four degrees of disease severity (mild, moderate, severe, and profound) are considered. Three infections are considered in the categorization of paddy leaf diseases: bacterial blight, blast, and leaf smut. The model predicted the paddy disease type and intensity with a 98.43% correctness rate. The loss rate is 41.25%. The findings show that the proposed method is reliable and effective for identifying the four levels of severity of bacterial blight, blast, and leaf smut infections in paddy crops. The proposed model performed better than the existing CNN and SVM classification models.