scholarly journals Etiology, diagnostic approaches and management strategies of Acidovorax citrulli, a bacterial fruit blotch pathogen of cucurbits

2021 ◽  
Vol 57 (No. 2) ◽  
pp. 75-94
Author(s):  
Ainur Ainiah Azman Husni ◽  
Siti Izera Ismail ◽  
Noraini Jaafar ◽  
Dzarifah Zulperi
Keyword(s):  
Control Strategies ◽  
Management Strategies ◽  
Characterization Methods ◽  
Bacterial Fruit Blotch ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Wide Range ◽  
Research Findings ◽  
Management Approaches ◽  
The Impact

Bacterial fruit blotch (BFB) caused by Acidovorax citrulli, represents one of the most destructing diseases of cucurbits, especially to watermelon- and melon producing-regions. This disease has been spread sporadically to many countries globally, due to the unintentionally dispersal of contaminated commercial seeds. The BFB causes massive yield losses up to 100% under conducive conditions. Once infected, all parts of the host plants are extremely susceptible to this bacterium, especially the seedlings and fruits parts. In recent years, various management approaches and detection tools have been employed to control A. citrulli. Genotypic characterization methods revealed two distinct groups of A. citrulli strains; (i) group I strains primarily isolated from non-watermelon cucurbits and consist of moderate to highly aggressive strains from wide range of cucurbit hosts, and (ii) group II strains isolated from watermelon which are highly aggressive on watermelon, but mildly aggressive on non-watermelon hosts. In this paper, an attempt has been made to review research findings where the impact of diverse methods and management approaches were applied in detection and controlling of A. citrulli infection. A better understanding of this devastating bacterium will serve as guidelines for agricultural practitioners in developing the most efficient and sustainable BFB control strategies.

scholarly journals Coping with abrupt environmental change: the impact of the coastal El Niño 2017 on artisanal fisheries and mariculture in North Peru

2018 ◽  
Vol 76 (4) ◽  
pp. 1122-1130 ◽  
Author(s):  
Lotta Clara Kluger ◽  
Sophia Kochalski ◽  
Arturo Aguirre-Velarde ◽  
Ivonne Vivar ◽  
Matthias Wolff
Keyword(s):  
El Niño ◽  
El Nino ◽  
Management Strategies ◽  
Small Scale ◽  
Artisanal Fisheries ◽  
Economic Activities ◽  
Economic Sectors ◽  
Wide Range ◽  
The Impact ◽  
Coastal El Niño

Abstract In February and March 2017, a coastal El Niño caused extraordinary heavy rains and a rise in water temperatures along the coast of northern Peru. In this work, we document the impacts of this phenomenon on the artisanal fisheries and the scallop aquaculture sector, both of which represent important socio-economic activities for the province of Sechura. Despite the perceived absence of effective disaster management and rehabilitation policies, resource users opted for a wide range of different adaptation strategies and are currently striving towards recovery. One year after the event, the artisanal fisheries fleet has returned to operating almost on a normal scale, while the aquaculture sector is still drastically impacted, with many people continuing to work in different economic sectors and even in other regions of the country. Recovery of the social-ecological system of Sechura likely depends on the occurrence of scallop seed and the financial capacity of small-scale producers to reinitiate scallop cultures. Long-term consequences of this coastal El Niño are yet to be studied, though the need to develop trans-local and trans-sectoral management strategies for coping with disturbance events of this scale is emphasized.

Germination Biology of Sesbania (Sesbania cannabina): An Emerging Weed in the Australian Cotton Agro-environment

Weed Science ◽  
2018 ◽  
Vol 67 (1) ◽  
pp. 68-76 ◽  
Author(s):  
Nadeem Iqbal ◽  
Sudheesh Manalil ◽  
Bhagirath S. Chauhan ◽  
Steve W. Adkins
Keyword(s):  
Seed Germination ◽  
Management Strategies ◽  
Moisture Stress ◽  
Integrated Weed Management ◽  
Burial Depth ◽  
Weed Species ◽  
Physical Dormancy ◽  
Sesbania Cannabina ◽  
Wide Range ◽  
The Impact

AbstractSesbania [Sesbania cannabina(Retz.) Pers.] is a problematic emerging weed species in Australian cotton-farming systems. However, globally, no information is available regarding its seed germination biology, and better understanding will help in devising superior management strategies to prevent further infestations. Laboratory and glasshouse studies were conducted to evaluate the impact of various environmental factors such as light, temperature, salt, osmotic and pH stress, and burial depth on germination and emergence of two Australian biotypes ofS. cannabina. Freshly harvested seeds of both biotypes possessed physical dormancy. A boiling-water scarification treatment (100±2 C) of 5-min duration was the optimum treatment to overcome this dormancy. Once dormancy was broken, the Dalby biotype exhibited a greater germination (93%) compared with the St George biotype (87%). The nondormant seeds of both biotypes showed a neutral photoblastic response to light and dark conditions, with germination marginally improved (6%) under illumination. Maximum germination of both biotypes occurred under an alternating temperature regime of 30/20 and 35/25 C and under constant temperatures of 32 or 35 C, with no germination at 8 or 11 C. Seed germination of both biotypes decreased linearly from 87% to 14% with an increase in moisture stress from 0.0 to −0.8 MPa, with no germination possible at −1.0 MPa. There was a gradual decline in germination for both biotypes when imbibed in a range of salt solutions of 25 to 250 mM, with a 50% reduction in germination occurring at 150 mM. Both biotypes germinated well under a wide range of pH values (4.0 to 10.0), with maximum germination (94%) at pH 9.0. The greatest emergence rate of the Dalby (87%) and St George (78%) biotypes was recorded at a burial depth of 1.0 cm, with no emergence at 16.0 cm. Deep tillage seems to be the best management strategy to stopS. cannabina’s emergence and further infestation of cotton (Gossypium hirsutumL.) fields. The findings of this study will be helpful to cotton agronomists in devising effective, sustainable, and efficient integrated weed management strategies for the control ofS. cannabinain cotton cropping lands.

scholarly journals Bacteriophage Biocontrol of Acidovorax citrulli, the Causal Agent of Bacterial Fruit Blotch

Proceedings ◽  
2020 ◽  
Vol 50 (1) ◽  
pp. 10
Author(s):  
Aryan Rahimi-Midani ◽  
Tae-Jin Choi
Keyword(s):  
Crop Production ◽  
Germination Rate ◽  
Causal Agent ◽  
Head Size ◽  
Genotype I ◽  
Bacterial Fruit Blotch ◽  
Double Stranded Dna ◽  
Acidovorax Citrulli ◽  
Group I ◽  
Next Generation Sequencing Ngs

Bacterial fruit blotch caused by Acidovorax citrulli is known to be the major threat to cucurbit crop production worldwide. The pathogen can penetrate into seed coat and cause disease symptoms at any stage of plant growth, which results in fruit loss. Two main genotypes (genotype I and II) are reported in A. citrulli, in which genotype II is the main cause of Bacterial Fruit Blotch (BFB) in watermelon and group I is known to be a causal agent of BFB in melon. To date, there are no commercially available cultivars resistant to BFB, and available strategies are not able to completely manage the disease. In this study, we aim to isolate bacteriophages to control BFB. Samples collected from watermelon, melon, and pumpkin were used to isolate bacteriophages. All isolated bacteriophages were tested against 42 strains of A. citrulli, among which two phages with the ability to lyse a greater number of hosts were selected and characterized. Bacteriophage ACP17 from the Myoviridae family, with a head size of 100 ± 5 nm and tail of 150 ± 5 nm, infected 29 strains of A. citrulli mostly belonging to genotype group I, whereas the second isolated bacteriophage, ACPWH from Siphoviridae, with a head size of 60 ± 5 nm and tail of 180 ± 5 nm, infected 39 A. citrulli strains. Genome analysis of both bacteriophages using Next generation Sequencing (NGS) showed that ACP17 and ACPWH have double-stranded DNA with sizes of 156,972 kb and 424,299 kb, respectively. Watermelon seeds coated with ACPWH showed a germination rate of up to 90% in the presence of A. citrulli in contrast to untreated seed, which showed no germination or germinated juveniles with BFB symptoms in the presence of A. citrulli. The results of this study show that the use of bacteriophages of A. citrulli represents a potential biocontrol method for controlling BFB.

scholarly journals Automation for Water and Nitrogen Deficit Stress Detection in Soilless Tomato Crops Based on Spectral Indices

Horticulturae ◽  
2018 ◽  
Vol 4 (4) ◽  
pp. 47 ◽  
Author(s):  
Angeliki Elvanidi ◽  
Nikolaos Katsoulas ◽  
Constantinos Kittas
Keyword(s):  
Crop Production ◽  
Control Strategies ◽  
Classification Tree ◽  
Management Strategies ◽  
Total Sample ◽  
Sensor Data ◽  
Limiting Factors ◽  
Tree Model ◽  
Environment Control ◽  
The Impact

Water and nitrogen deficit stress are some of the most important growth limiting factors in crop production. Several methods have been used to quantify the impact of water and nitrogen deficit stress on plant physiology. However, by performing machine learning with hyperspectral sensor data, crop physiology management systems are integrated into real artificial intelligence systems, providing richer recommendations and insights into implementing appropriate irrigation and environment control management strategies. In this study, the Classification Tree model was used to group complex hyperspectral datasets in order to provide remote visual results about plant water and nitrogen deficit stress. Soilless tomato crops are grown under varying water and nitrogen regimes. The model that we developed was trained using 75% of the total sample dataset, while the rest (25%) of the data were used to validate the model. The results showed that the combination of MSAVI, mrNDVI, and PRI had the potential to determine water and nitrogen deficit stress with 89.6% and 91.4% classification accuracy values for the training and testing samples, respectively. The results of the current study are promising for developing control strategies for sustainable greenhouse production.

scholarly journals Efficacy of a Nonpathogenic Acidovorax citrulli Strain as a Biocontrol Seed Treatment for Bacterial Fruit Blotch of Cucurbits

Plant Disease ◽  
2011 ◽  
Vol 95 (6) ◽  
pp. 697-704 ◽  
Author(s):  
K. L. Johnson ◽  
G. V. Minsavage ◽  
T. Le ◽  
J. B. Jones ◽  
R. R. Walcott
Keyword(s):  
Biological Control ◽  
Seed Treatment ◽  
Management Strategies ◽  
Fruit Production ◽  
Management Program ◽  
Control Seed ◽  
Bacterial Fruit Blotch ◽  
Watermelon Seed ◽  
Acidovorax Citrulli ◽  
Phosphate Buffered Saline

Bacterial fruit blotch (BFB), caused by the seedborne, gram-negative bacterium Acidovorax citrulli, is a serious threat to cucurbit seed and fruit production worldwide. Because of the lack of effective management strategies, we investigated the efficacy of a nonpathogenic A. citrulli strain as a biological control seed treatment for BFB. For this study, we generated a type III secretion system mutant of A. citrulli, AAC00-1ΔhrcC, that was nonpathogenic on watermelon but retained its ability to colonize germinating watermelon seed. With watermelon seed naturally infested with A. citrulli, AAC00-1ΔhrcC reduced BFB seedling transmission by 81.8% relative to control seed. In comparison, another A. citrulli antagonist, A. avenae strain AAA 99-2, reduced BFB seedling transmission by 74.6% for seed samples from the same lot. Additionally, when female watermelon blossoms were protected with AAC00-ΔhrcC and subsequently challenged with AAC00-1, the resulting seedlots displayed 8% BFB seedling transmission. This was not significantly different than seed from blossoms protected with AAA 99-2 (4%) but significantly less than those from blossoms protected with 0.1 M phosphate-buffered saline (36%). These results suggest that nonpathogenic A. citrulli has potential as a biological control seed treatment component in a comprehensive BFB management program.

scholarly journals The EUA education policy: quality assurance strategies

Osvitolohiya ◽  
2017 ◽  
pp. 143-149 ◽  
Author(s):  
Iryna Sokolova ◽  
Keyword(s):  
Higher Education ◽  
Quality Assurance ◽  
Quality Management ◽  
Focal Point ◽  
Management Strategies ◽  
Reform Process ◽  
Policy Statement ◽  
Quality Culture ◽  
Wide Range ◽  
The Impact

The Bologna Reform Process, which became the focal point of reform in most European countries, brought a wide range of quality concerns into the central arena of higher education discourse. Quality Assurance processes were supposed to support an increased institutional attention. The aim of this paper is to create a better the EUA's Input to EHEA Policy Making. EUA carries out a variety of activities that are underpinned by the belief that the main responsibility for quality assurance lies within higher education institutions. EUA Policy Statement on Quality and Quality Assurance in the European Higher Education Area аre identified and described in the article.It is determined the impact of the EUA in shaping European quality culture through the development of educational policy and decision-conceptual documents, the annual European Quality Assurance Forums to consolidate internal and external stakeholders, expand the dialogue format in the context of the EHEA changing landscape and the best practices implementation for quality assurance. The keynote presentations of the EQAF (2006-2016) focused on current trends in quality assurance. The quality culture approach promoted by EUAdiffers clearly frommore traditional quality management strategies, shifting attention to more development-oriented and value-based aspects. Based on the results of the projects different approaches towards quality, quality culture, or formal quality assurance and accreditation procedures are focusedin the paper. The Institutional evaluation programme in higher education, realizedin 45 countries, is described. Other programs and projects that define the tasks of quality management are characterized in thepaper. Trends in quality assurance are presented in the article taking into account the national and European contexts. This paper outlines EUA key objectives for 2017-2019. Support the creation of thequality culture in higher education institutionsis one of them.

scholarly journals COGNITIVE AND NON-COGNITIVE CHARACTERISTICS PREDICTING ACADEMIC SUCCESS AMONG MEDICAL STUDENTS

2019 ◽  
Vol 27 (1) ◽  
Author(s):  
Swati Yadav ◽  
Noor us Saba ◽  
Mohd. Tariq Zaidi ◽  
Nafis Ahmad Faruqi ◽  
Mohd. Faheem
Keyword(s):  
Academic Success ◽  
Medical Students ◽  
Time Management ◽  
Medical Schools ◽  
Cognitive Factors ◽  
Group Iii ◽  
Group I ◽  
Short Period ◽  
Wide Range ◽  
The Impact

Introduction: Medical undergraduates need to possess the ability to acquire knowledge on a wide range of subjects over short period of time. Medical schools worldwide use different methodologies to select ideal candidates, which include cognitive factors and non-cognitive factors. A proper selection will minimize failures during the beginning semesters and will ensure student’s capacity to withstand the standard of training. Therefore, we have decided to study the impact of cognitive and non-cognitive factors in predicting the academic success among medical students. Material & Methods: The study was a survey of 150 first year medical students of Jawaharlal Nehru Medical College (JNMC), Aligarh Muslim University (AMU), Aligarh, admitted in 2018. A data was collected from the Department of Anatomy for initial three part completion tests performance and class attendance, which was tabulated along with the information received from the questionnaire i.e. age, gender, percent secured and language in school, National eligibility cum entrance test (NEET) attempt and marks, residence, category for premedical (PMT) selection (general/ non-resident Indians (NRIs)/ handicap), parents occupation, siblings, family (nuclear/joint/rural/urban), hobbies, time management during PC (part completion) tests, coaching before PMT) given to each student separately. Observation & Results: Students were observed to lie in three groups according to their performance in PC tests: group I (>60%), group II (50-59.9%), group III (<50%). All the cognitive and non-cognitive factors were compared. Conclusion: Both cognitive and non-cognitive factors play an important role in the outcome of a medical student. Factors positively influencing the performance of a selected candidate in medical schools cannot be simply based on previous academic performance.

scholarly journals Hydro-Climatic Variability: A Characterisation and Trend Study of the Awash River Basin, Ethiopia

Hydrology ◽  
2019 ◽  
Vol 6 (2) ◽  
pp. 35 ◽  
Author(s):  
Mahtsente Tibebe Tadese ◽  
Lalit Kumar ◽  
Richard Koech ◽  
Birhanu Zemadim
Keyword(s):  
River Basin ◽  
Climatic Variability ◽  
Management Strategies ◽  
Annual Rainfall ◽  
Sustainable Water Management ◽  
Mk Test ◽  
Awash River Basin ◽  
Research Findings ◽  
Droughts And Floods ◽  
The Impact

The objective of this study was to characterize, quantify and validate the variability and trends of hydro-climatic variables in the Awash River Basin (ARB) in Ethiopia using graphical and statistical methods. The rainfall and streamflow trends and their relationships were evaluated using the regression method, Mann–Kendall (MK) test and correlation analysis. The analysis focused on rainfall and streamflow collected from 28 and 18 stations, respectively. About 85.7% and 75.3% of the rainfall stations exhibited normal to moderate variability in annual and June to September rainfall, respectively, whereas 96.43% of rainfall stations showed high variability in March to May. The MK test showed that most of the significant trends in annual rainfall were decreasing except in two stations. These research findings provide valuable information on the characteristics, variability, and trend of rainfall and streamflow necessary for the design of sustainable water management strategies and to reduce the impact of droughts and floods in the ARB.

scholarly journals Evaluating the Effectiveness of Vaccines Using a Regression Discontinuity Design

2019 ◽  
Vol 188 (6) ◽  
pp. 987-990
Author(s):  
Nicole E Basta ◽  
M Elizabeth Halloran
Keyword(s):  
Randomized Clinical Trials ◽  
Regression Discontinuity ◽  
Control Strategies ◽  
Regression Discontinuity Design ◽  
Vaccination Programs ◽  
Wide Range ◽  
Quasi Experimental ◽  
Psychology Literature ◽  
And Control ◽  
The Impact

Abstract The regression discontinuity design (RDD), first proposed in the educational psychology literature and popularized in econometrics in the 1960s, has only recently been applied to epidemiologic research. A critical aim of infectious disease epidemiologists and global health researchers is to evaluate disease prevention and control strategies, including the impact of vaccines and vaccination programs. RDDs have very rarely been used in this context. This quasi-experimental approach using observational data is designed to quantify the effect of an intervention when eligibility for the intervention is based on a defined cutoff such as age or grade in school, making it ideally suited to estimating vaccine effects given that many vaccination programs and mass-vaccination campaigns define eligibility in this way. Here, we describe key features of RDDs in general, then specific scenarios, with examples, to illustrate that RDDs are an important tool for advancing our understanding of vaccine effects. We argue that epidemiologic researchers should consider RDDs when evaluating interventions designed to prevent and control diseases. This approach can address a wide range of research questions, especially those for which randomized clinical trials would present major challenges or be infeasible. Finally, we propose specific ways in which RDDs could advance future vaccine research.

scholarly journals Joining two worlds - When academia meets real life and vice versa

2019 ◽  
Vol 29 (Supplement_4) ◽  
Author(s):  
J Ese ◽  
C Ihlebak
Keyword(s):  
Academic Freedom ◽  
Social Inequalities ◽  
Real Life ◽  
Wide Range ◽  
Research Findings ◽  
Complex Relationships ◽  
The One ◽  
Innovation Clusters ◽  
Holding Back ◽  
The Impact

Abstract Partnerships between academic institutions and actors outside of academia have for some time been considered a universal remedy for solving complex issues in a wide range of fields; ranging from themes as different as commercial developments in innovation clusters to reducing social inequalities or working against climate change. Such partnerships are strongly encouraged by governing bodies, and are sometimes prerequisites for being eligible as applicants for funding schemes like H2020. A proof of the impact this model of cooperation has had, is the fact that partnership is the only organisational structure that has been elevated to be part of the UN17 goals for sustainable development. Throughout history, academia has had a complex relationship with the society to which it belongs. On the one hand, academia depends on being seen as valuable, often through visible and concrete impact on society. On the other hand, within academia there is a strong norm of academic freedom stating that such freedom is best accommodated for through a certain degree of insulation between academia and society. This way of understanding academic freedom is an important cornerstone of the Humboltian university ideals as well as in the Mertonian CUDOS norms. Practice and policy actors may also find partnerships with academia complex to navigate. However, such partnerships can be valuable through ensuring that policies and developments are based on research findings and best practices. Furthermore, academics may educate and train practitioners, and evaluate and do research on their initiatives. However, partnerships can also be challenging for practitioners, as academics have to follow strict principles for research design and have little room for holding back results that may put the practitioners in a bad light. In this presentation the complex relationships between academia and practice are presented, both by examining advantages and by taking a critical stance.

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