scholarly journals Incidence, Spatial Pattern and Temporal Progress of Fusarium Wilt of Bananas

2021 ◽  
Vol 7 (8) ◽  
pp. 646
Author(s):  
Daniel W. Heck ◽  
Miguel Dita ◽  
Emerson M. Del Ponte ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Fusarium Wilt ◽  
Temporal Dynamics ◽  
Secondary Infection ◽  
Regional Scale ◽  
Management Strategies ◽  
Gompertz Model ◽  
Spatial And Temporal Dynamics ◽  
Sigmoidal Curve ◽  
Average Loss ◽  
The Impact

The effective management of Fusarium wilt of bananas (FWB) depends on the knowledge of the disease dynamics in time and space. The objectives of this work were: to estimate disease intensity and impact, and to investigate the spatial and temporal dynamics of FWB. Fields planted with Silk (n = 10), Pome (n = 17), or Cavendish (n = 3) banana subgroups were surveyed in Brazil, totaling 95 ha. In each field, all plants were visually assessed, and diseased plants were georeferenced. The incidence of FWB and the impact of the disease on the yield on a regional scale were estimated. Spatial patterns were analyzed using quadrat- and distance-based methods. FWB incidence ranged from 0.09% to 41.42%, being higher in Silk fields (median = 14.26%). Impacts of epidemics on yield ranged from 18.4 to 8192.5 kg ha−1 year−1, with an average of 1856.7 kg ha−1 year−1. The higher economic impact of the disease was observed on Silk cultivar with an average loss of USD 1974.2 ha−1 year−1. Overall, estimated losses increased on average by USD 109.8 ha−1 year−1 at each 1% of incidence. Aggregation of FWB was detected by all analytical methods in 13 fields (1 of Cavendish, 11 of Pome, and 1 of Silk). In the other 17 fields, at least one analytical method did not reject the null hypothesis of randomness. One field (5 ha), composed of six plots, was selected for spatial and temporal studies during two years with bi-monthly assessments. A sigmoidal curve represented the FWB progress and the Gompertz model best-fitted disease progress. The level of aggregation varied over time, and evidence of secondary infection to neighboring and distant plants was detected. FWB is a widespread problem in Brazil and yield losses can be of high magnitude. Epidemiology-based management strategies can now be better established.

scholarly journals Incidence, Spatial Pattern and Temporal Progress of Fusarium Wilt of Bananas

2021 ◽  
Author(s):  
Daniel W. Heck ◽  
Miguel Dita ◽  
Emerson M. Del Ponte ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Fusarium Wilt ◽  
Secondary Infection ◽  
Regional Scale ◽  
Management Strategies ◽  
Gompertz Model ◽  
Effective Management ◽  
High Magnitude ◽  
Sigmoidal Curve ◽  
Level Of Aggregation ◽  
The Impact

The effective management of Fusarium wilt of bananas (FW) depends on the knowledge of the disease dynamics in time and space. The objectives of this work were: To estimate disease intensity and impact, and to investigate the spatial and temporal dynamic of FW. Fields planted with Silk (n = 10), Pome (n = 17) or Cavendish (n = 3) banana subgroups were surveyed in Brazil, totaling 95 ha. In each field, all plants were visually assessed and diseased plants were georeferenced. The incidence of FW and the impact of the disease on yield on a regional scale were estimated. Spatial patterns were analyzed using quadrat- and distance-based methods. FW incidence ranged from 0.09 to 41.42%, being higher in Silk fields (median = 14.26%). Impacts of epidemics on yield ranged from 18.4 to 8,192.5 kg.ha-1.year-1, with a median of 935.2 kg.ha-1.year-1. The higher economic impact of the disease was observed on Silk cultivar with a median loss of US$ 910.5 ha-1.year-1. Overall, estimated losses increased on average by US$ 109.8 ha-1.year-1 at each 1% of incidence. Aggregation of FW was detected by all analytical methods in 13 fields (1 of Cavendish, 11 of Pome and 1 of Silk). In the other 17 fields, at least one analytical method did not reject the null hypothesis of randomness. One field (5 ha), composed of six plots, was selected for spatial and temporal studies during two years with bi-monthly assessments. A sigmoidal curve represented the FW progress and the Gompertz model best fitted disease progress. The level of aggregation varied over time, and evidence of secondary infection to neighboring and distant plants were detected. FW is a widespread problem in Brazil and yield losses can be of high magnitude. Epidemiology-based management strategies can now be better established.

scholarly journals Long-term monitoring of crab Cardisoma guanhumi (Decapoda: Gecarcinidae) captures in Jobos Bay Estuary, Puerto Rico

2019 ◽  
Vol 67 (4) ◽  
Author(s):  
Yogani Govender
Keyword(s):  
Puerto Rico ◽  
Temporal Dynamics ◽  
Carapace Width ◽  
Management Strategies ◽  
Blue Color ◽  
Anthropogenic Pressures ◽  
The West ◽  
Significant Difference ◽  
Cardisoma Guanhumi ◽  
The Impact

Abstract: The densities of the land crab Cardisoma guanhumi has been dropping for the past decades, as a result numerous management strategies, laws and regulations throughout the tropics have been developed to reduce population declines. The reasons for declines include: overfishing, habitat degradation and loss, and continued capture in Natural Protected Areas (NPA). In Puerto Rico, an admistrative order of 1999, regulates a closed season, prohibits the captures of crabs through the year from NPA and has a legal size for capture (64 mm). The goal of this research was to monitor spatial-temporal dynamics of captures for C. guanhumi after the implementation of the admistrative order. Crabs captured from thirty-one hunters in six communities surrounding the Jobos Bay Estuary (JBE) in south east Puerto Rico was studied over a period of 15 years, 2004 through 2018. The size (carapace width and length), sex and color were documented for 1531 crabs. There was significant difference in crab size through time and space. The smallest crabs with captured in the west of JBE and in the year 2004, while the largest crabs were captured in the west and in 2013. As expected smaller hunting areas had smaller crabs due to higher hunting pressure. Further, there was significant difference in crab color by size, smaller crabs were orange, intermediate size was brown and larger crabs were blue. Color of crab can therefore be used to determine legal limit. From 2009 to 2018 three percent of hunters captured crabs smaller than the legal-size limit. Although there was no significant relationship between climate (temperature, rainfall) and crab size, smaller crabs were captured in 2013-2016 during years of lower rainfall. Also, crab size increase from 2004 until 2013 coincided with mangrove recovery in the JBE. The laws and management strategies in Puerto Rico for the protection of crabs by size and prohibition in NPA, is not enough. Therefore, the impact of climate variability, sea level rise and anthropogenic pressures on crab habitat, therefore, warrants further investigation.

scholarly journals Weevil borers affect the spatio-temporal dynamics of banana Fusarium wilt

2021 ◽  
Author(s):  
Daniel Heck ◽  
Gabriel Alves ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Fusarium Wilt ◽  
Temporal Dynamics ◽  
Insect Pests ◽  
Field Conditions ◽  
Disease Progress ◽  
Spatial And Temporal Dynamics ◽  
Comparative Epidemiology ◽  
Progress Rate ◽  
Spatio Temporal ◽  
Metamasius Hemipterus

AbstractDispersal of propagules of a pathogen has remarkable effects on the development of epidemics. Previous studies suggested that insect pests play a role in the development of Fusarium wilt (FW) epidemics in banana fields. We provided complementary evidence for the involvement of two insect pests of banana, the weevil borer (Cosmopolites sordidus L. - WB) and the false weevil borer (Metamasius hemipterus L. - FWB), in the dispersal of Fusarium oxysporum f. sp. cubense (Foc) using a comparative epidemiology approach under field conditions. Two banana plots located in a field with historical records of FW epidemics were used, one was managed with Beauveria bassiana to reduce the population of weevils, and the other was left without B. bassiana applications. The number of WB and FWB was monitored biweekly and the FW incidence was quantified bimonthly during two years. The population of WB and the incidence (6.7%) of FW in the plot managed with B. bassiana were lower than in the plot left unmanaged (13%). The monomolecular model best fitted the FW disease progress data and, as expected, the average estimated disease progress rate was lower in the plot managed with the entomopathogenic fungus (r = 0.0024) compared to the unmanaged plot (r = 0.0056). Aggregation of FW was higher in the field with WB management. WB affected the spatial and temporal dynamics of FW epidemics under field conditions and brought evidence that managing the insects may reduce FW of bananas intensity.

scholarly journals Genomic and healthcare dynamics of nosocomial SARS-CoV-2 transmission

eLife ◽  
2021 ◽  
Vol 10 ◽  
Author(s):  
Jamie M Ellingford ◽  
Ryan George ◽  
John H McDermott ◽  
Shazaad Ahmad ◽  
Jonathan J Edgerley ◽  
...  
Keyword(s):  
Infection Control ◽  
Temporal Dynamics ◽  
Management Strategies ◽  
Healthcare Setting ◽  
Location Data ◽  
Genome Data ◽  
Healthcare Settings ◽  
Movement Data ◽  
Spatial And Temporal Dynamics ◽  
Transmission Pathways

Understanding the effectiveness of infection control methods in reducing and preventing SARS-CoV-2 transmission in healthcare settings is of high importance. We sequenced SARS-CoV-2 genomes for patients and healthcare workers (HCWs) across multiple geographically distinct UK hospitals, obtaining 173 high-quality SARS-CoV-2 genomes. We integrated patient movement and staff location data into the analysis of viral genome data to understand spatial and temporal dynamics of SARS-CoV-2 transmission. We identified eight patient contact clusters (PCC) with significantly increased similarity in genomic variants compared to non-clustered samples. Incorporation of HCW location further increased the number of individuals within PCCs and identified additional links in SARS-CoV-2 transmission pathways. Patients within PCCs carried viruses more genetically identical to HCWs in the same ward location. SARS-CoV-2 genome sequencing integrated with patient and HCW movement data increases identification of outbreak clusters. This dynamic approach can support infection control management strategies within the healthcare setting.

scholarly journals An Epidemiological Comparison of the US and Canadian Plum pox virus Eradication Programs

2012 ◽  
Vol 13 (1) ◽  
pp. 29 ◽  
Author(s):  
A. V. Gougherty ◽  
F. W. Nutter
Keyword(s):  
Temporal Dynamics ◽  
Detection Efficiency ◽  
Scientific Basis ◽  
Plum Pox Virus ◽  
Virus Eradication ◽  
Eradication Program ◽  
Spatial And Temporal Dynamics ◽  
The Us ◽  
Sampling Systems ◽  
The Impact

Plum pox virus (PPV) was first detected in North America in 1999 in Pennsylvania, and the following year in Ontario, Canada. In response to these outbreaks, both countries implemented eradications programs in an effort to eradicate the virus before it could have a significant effect on the Prunus industry in their respective countries. The objectives of this study were to: (i) quantify the impact of the US and Canadian PPV eradication programs on the spatial and temporal dynamics of PPV in Pennsylvania and Ontario; and (ii) compare the detection efficiencies of the US and Canadian PPV sampling systems. Ripley's K function revealed PPV-positive Prunus blocks in Pennsylvania to be clustered between distances of 0.7 and 4.3 km in 2000, while in Ontario, PPV-positive blocks were clustered between distances of 1 and 25 km over the period 2006-2009. A simulation model was developed to determine the relative detection efficiencies of the US and Canadian PPV eradication programs. The US eradication program was found to have a detection efficiency of 71.7%, whereas the Canadian eradication program had a detection efficiency of 40.5%. The data generated in this study should help to improve the PPV eradication programs currently used in the US and Canada, as well as provide a scientific basis to evaluate future eradication programs. Accepted for publication 23 May 2012. Published 23 July 2012.

scholarly journals Weevil Borers Affect the Spatio-Temporal Dynamics of Banana Fusarium Wilt

2021 ◽  
Vol 7 (5) ◽  
pp. 329
Author(s):  
Daniel W. Heck ◽  
Gabriel Alves ◽  
Eduardo S. G. Mizubuti
Keyword(s):  
Fusarium Wilt ◽  
Temporal Dynamics ◽  
Insect Pests ◽  
Field Conditions ◽  
Disease Progress ◽  
Spatial And Temporal Dynamics ◽  
Comparative Epidemiology ◽  
Progress Rate ◽  
Spatio Temporal ◽  
Metamasius Hemipterus

Dispersal of propagules of a pathogen has remarkable effects on the development of epidemics. Previous studies suggested that insect pests play a role in the development of Fusarium wilt (FW) epidemics in banana fields. We provided complementary evidence for the involvement of two insect pests of banana, the weevil borer (Cosmopolites sordidus L., WB) and the false weevil borer (Metamasius hemipterus L., FWB), in the dispersal of Fusarium oxysporum f. sp. cubense (Foc) using a comparative epidemiology approach under field conditions. Two banana plots located in a field with historical records of FW epidemics were used; one was managed with Beauveria bassiana to reduce the population of weevils, and the other was left without B. bassiana applications. The number of WB and FWB was monitored biweekly and the FW incidence was quantified bimonthly during two years. The population of WB and the incidence (6.7%) of FW in the plot managed with B. bassiana were lower than in the plot left unmanaged (13%). The monomolecular model best fitted the FW disease progress data, and as expected, the average estimated disease progress rate was lower in the plot managed with the entomopathogenic fungus (r = 0.002) compared to the unmanaged plot (r = 0.006). Aggregation of FW was higher in the field with WB management. WB affected the spatial and temporal dynamics of FW epidemics under field conditions. Management of the insects may reduce yield loss due to FW.

scholarly journals The CarboCount CH sites: characterization of a dense greenhouse gas observation network

2015 ◽  
Vol 15 (9) ◽  
pp. 12911-12956 ◽  
Author(s):  
B. Oney ◽  
S. Henne ◽  
N. Gruber ◽  
M. Leuenberger ◽  
I. Bamberger ◽  
...  
Keyword(s):  
Carbon Flux ◽  
Temporal Dynamics ◽  
Transport Model ◽  
Atmospheric Transport ◽  
Regional Scale ◽  
Observation Network ◽  
Simulated Surface ◽  
Swiss Plateau ◽  
The Impact ◽  
Atmospheric Transport Model

Abstract. We describe a new rural network of four densely placed (< 100 km apart), continuous atmospheric carbon (CO2, CH4, and CO) measurement sites in north-central Switzerland and analyze their suitability for regional-scale (~ 100 to 500 km) carbon flux studies. We characterize each site by analyzing surrounding land cover, observed local meteorology, and sensitivity to surface fluxes, as simulated with the Lagrangian particle dispersion model FLEXPART-COSMO. The Beromünster measurements are made on a tall tower (212 m) located on a gentle hill. At Beromünster, regional CO2 signals (measurement minus background) vary diurnally from −4 to +4 ppmv on average, and are simulated to come from nearly the entire Swiss Plateau, where 50% of surface influence is simulated to be within 130 to 260 km distance. The Früebüel site measurements are made 4 m above ground on the flank of a gently sloping mountain. Nearby (< 50 km) pasture and forest fluxes exert the most simulated surface influence, except during convective summertime days when the site is mainly influenced by the eastern Swiss Plateau, which results in summertime regional CO2 signals varying diurnally from −5 to +12 ppmv and elevated summer daytime CH4 signals (+30 ppbv above other sites). The Gimmiz site measurements are made on a small tower (32 m) in flat terrain. Here, strong summertime regional signals (−5 to +60 ppmv CO2) stem from large, nearby (< 50 km) crop and anthropogenic fluxes of the Seeland region, except during warm or windy days when simulated surface influence is of regional scale (< 250 km). The Lägern-Hochwacht measurements are made on a small tower (32 m) on top of the steep Lägern crest, where simulated surface influence is typically of regional scale (130 to 300 km) causing summertime regional signals to vary from −5 to +8 ppmv CO2. Here, considerable anthropogenic influence from the nearby industrialized region near Zurich cause the average wintertime regional CO2 signals to be 5 ppmv above the regional signals simultaneously measured at Früebüel site. We find that the suitability of the datasets from our current observation network for regional carbon budgeting studies largely depends on the ability of the high-resolution (2 km) atmospheric transport model to correctly capture the temporal dynamics of the stratification of the lower atmosphere at the different sites. The current version of the atmospheric transport model captures these dynamics well, but it clearly reaches its limits at the sites in steep topography, and at the sites that generally remain in the surface layer. Trace gas transport and inverse modeling studies will be necessary to determine the impact of these limitations on our ability to derive reliable regional-scale carbon flux estimates in the complex Swiss landscape.

scholarly journals A State-Of-The-Art Perspective on the Characterization of Subterranean Estuaries at the Regional Scale

2021 ◽  
Vol 9 ◽  
Author(s):  
Nils Moosdorf ◽  
Michael Ernst Böttcher ◽  
Dini Adyasari ◽  
Ercan Erkul ◽  
Benjamin S. Gilfedder ◽  
...  
Keyword(s):  
Temporal Dynamics ◽  
Regional Scale ◽  
Geophysical Methods ◽  
Coastal Ocean ◽  
Coastal Sediments ◽  
Solute Fluxes ◽  
Spatio Temporal ◽  
Biogeochemical Transformations ◽  
The Impact ◽  
Subterranean Estuaries

Subterranean estuaries the, subsurface mixing zones of terrestrial groundwater and seawater, substantially influence solute fluxes to the oceans. Solutes brought by groundwater from land and solutes brought from the sea can undergo biogeochemical reactions. These are often mediated by microbes and controlled by reactions with coastal sediments, and determine the composition of fluids discharging from STEs (i.e., submarine groundwater discharge), which may have consequences showing in coastal ecosystems. While at the local scale (meters), processes have been intensively studied, the impact of subterranean estuary processes on solute fluxes to the coastal ocean remains poorly constrained at the regional scale (kilometers). In the present communication, we review the processes that occur in STEs, focusing mainly on fluid flow and biogeochemical transformations of nitrogen, phosphorus, carbon, sulfur and trace metals. We highlight the spatio-temporal dynamics and measurable manifestations of those processes. The objective of this contribution is to provide a perspective on how tracer studies, geophysical methods, remote sensing and hydrogeological modeling could exploit such manifestations to estimate the regional-scale impact of processes in STEs on solute fluxes to the coastal ocean.

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