scholarly journals Suitability of the MODIS-NDVI Time-Series for a Posteriori Evaluation of the Citrus Tristeza Virus Epidemic

2020 ◽  
Vol 12 (12) ◽  
pp. 1965
Author(s):  
Daniela Vanella ◽  
Simona Consoli ◽  
Juan Miguel Ramírez-Cuesta ◽  
Matilde Tessitori
Keyword(s):  
Time Series ◽  
Plant Pathogens ◽  
Management Practices ◽  
Citrus Tristeza Virus ◽  
Plant Diseases ◽  
Control Measures ◽  
Ndvi Time Series ◽  
The Impact ◽  
Tristeza Virus ◽  
Citrus Tristeza

The technological advances of remote sensing (RS) have allowed its use in a number of fields of application including plant disease depiction. In this study, an RS approach based on an 18-year (i.e., 2001–2018) time-series analysis of Normalized Difference Vegetation Index (NDVI) data, derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) and processed with TIMESAT free software, was applied in Sicily (insular Italy). The RS approach was carried out in four orchards infected by Citrus tristeza virus (CTV) at different temporal stages and characterized by heterogeneous conditions (e.g., elevation, location, plant age). The temporal analysis allowed the identification of specific metrics of the NDVI time-series at the selected sites during the study period. The most reliable parameter which was able to identify the temporal evolution of CTV syndrome and the impact of operational management practices was the “Base value” (i.e., average NDVI during the growing seasons, which reached R2 values up to 0.88), showing good relationships with “Peak value”, “Small integrated value” and “Amplitude”, with R2 values of 0.63, 0.70 and 0.75, respectively. The approach herein developed is valid to be transferred to regional agencies involved in and/or in charge of the management of plant diseases, especially if it is integrated with ground-based early detection methods or high-resolution RS approaches, in the case of quarantine plant pathogens requiring control measures at large-scale level.

scholarly journals Epidemiology of Citrus tristeza virus in nursery blocks of Citrus macrophylla and evaluation of control measures

2012 ◽  
Vol 10 (4) ◽  
pp. 1107 ◽  
Author(s):  
E. Vidal ◽  
A. Moreno ◽  
E. Bertolini ◽  
M. C. Martínez ◽  
A. R. Corrales ◽  
...  
Keyword(s):  
Citrus Tristeza Virus ◽  
Control Measures ◽  
Citrus Macrophylla ◽  
Tristeza Virus ◽  
Citrus Tristeza

scholarly journals Citrus Diseases Exotic to Florida: Citrus Tristeza Virus– Stem Pitting (CTV-SP)

EDIS ◽  
2006 ◽  
Vol 2006 (7) ◽  
Author(s):  
Kuang-Ren Chung ◽  
Ronald H. Brlansky
Keyword(s):  
Citrus Tristeza Virus ◽  
Plant Diseases ◽  
Production Costs ◽  
Brown Spot ◽  
Economic Losses ◽  
Citrus Diseases ◽  
Florida Citrus ◽  
Tristeza Virus ◽  
Stem Pitting ◽  
Citrus Tristeza

Citrus is susceptible to a large number of diseases caused by plant pathogens. Economic losses due to plant diseases can be severe, but fortunately, not all pathogens attacking citrus are present in Florida. Major citrus diseases currently present in Florida include: Alternaria brown spot, blight, citrus canker, greasy spot, melanose, Phytophthora-induced diseases (foot and root rot, brown rot), postbloom fruit drop (PFD), scab, and tristeza. An exotic, destructive disease called citrus greening (Huanglongbing) has recently been found in Florida. Any exotic diseases, if introduced, will increase production costs and decrease profitability for Florida growers. Exotic diseases affect the viability of the industry or the varieties that could be profitably grown. Background information for each exotic citrus disease will be presented in a series of fact sheets to: 1) provide a basis for evaluating exotic pathogens that may pose potential risks to Florida citrus; and 2) create a decision-making framework to prevent their introduction and spread. This paper will discuss Citrus tristeza virus-Stem Pitting (CTV-SP) disease. This article is written based on the materials used for the Workshops of the Exotic Citrus Pathogen Threat Project led by Drs. S. M. Garnsey and H. W. Browning, and approved for publication.

Identification of asymptomatic plants infected with Citrus tristeza virus from a time series of leaf spectral characteristics

2017 ◽  
Vol 141 ◽  
pp. 340-350 ◽  
Author(s):  
Andreia M. Afonso ◽  
Rui Guerra ◽  
Ana M. Cavaco ◽  
Patrícia Pinto ◽  
André Andrade ◽  
...  
Keyword(s):  
Time Series ◽  
Citrus Tristeza Virus ◽  
Spectral Characteristics ◽  
Tristeza Virus ◽  
Citrus Tristeza

scholarly journals Incidence, Transmissibility, and Genotype Analysis of Citrus tristeza virus (CTV) Isolates from CTV Eradicative and Noneradicative Districts in Central California

Plant Disease ◽  
2005 ◽  
Vol 89 (8) ◽  
pp. 859-866 ◽  
Author(s):  
R. K. Yokomi ◽  
R. L. DeBorde
Keyword(s):  
Citrus Tristeza Virus ◽  
Transmission Rate ◽  
Aphis Gossypii ◽  
Cotton Aphid ◽  
Central California ◽  
Virus Incidence ◽  
The Impact ◽  
Tristeza Virus ◽  
Tulare County ◽  
Citrus Tristeza

Growers in 45% (44,100 ha) of the citrus acreage in California stopped eradicating Citrus tristeza virus (CTV)-infected trees from their fields in 1995-96. The impact of leaving infected trees on the rate of CTV spread was determined by comparing temporal incidence of CTV in plots in Strathmore, Tulare County without eradication with incidence in a plot in McFarland, Kern County with eradication. From 1997 to 2003, CTV incidence in the Strathmore plots ranged from 6 to 42%, with annual spread rates from 1.6 to 3.6%. CTV incidence in the McFarland plot increased from 0 to 5% between 2001 and 2003 before infected trees were removed. Using a subplot hierarchical bulk sampling method, virus incidence over a 3-year period in a 6.5 km2 area near McFarland was estimated to range from 0.09 to 0.69%, which indicated that CTV suppression was still being achieved in this area. Vector tests using the cotton aphid, Aphis gossypii, identified highly transmissible isolates (30 to 61% transmission rate) and a larger proportion of highly transmissible isolates were found in the McFarland plots. Thirty-six CTV isolates from recently infected plot trees were obtained and analyzed. None of these isolates reacted with monoclonal antibody MCA13 that detects presumptive CTV severe strains. Molecular analysis using polymerase chain reaction and sequence-specific primers showed that all isolates had a genotype identical to the T30 mild isolate from Florida.

scholarly journals Potential of Sentinel-2 satellite images to monitor vine fields grown at a territorial scale

OENO One ◽  
2019 ◽  
Vol 53 (1) ◽  
Author(s):  
Nicolas Devaux ◽  
Thomas Crestey ◽  
Corentin Leroux ◽  
Bruno Tisseyre
Keyword(s):  
Time Series ◽  
Temporal Resolution ◽  
Vegetation Index ◽  
Management Practices ◽  
Regional Scale ◽  
Time Lag ◽  
Short Note ◽  
Ndvi Time Series ◽  
The Impact ◽  
Sentinel 2

Aim: The aim of this short note is to provide first insights into the ability of Sentinel-2 images to monitor vine growth across a whole season. It focuses on verifying the practical temporal resolution that can be reached with Sentinel-2 images, the main stages of Mediterranean vineyard development as well as potential relevant agronomic information that can be seen on the temporal vegetation curves arising from Sentinel-2 images.Methods and results: The study was carried out in 2017 in a production vineyard located in southern France, 2 km from the Mediterranean seashore. Sentinel-2 images acquired during the whole vine growing cycle were considered, i.e. between the 3rd of March 2017 and the 10th of October 2017. The images were used to compute the classical normalized difference vegetation index (NDVI). Time series of NDVI values were analyzed on four blocks chosen for exhibiting different features, e.g. age, missing plants, weeding practices. The practical time lag between two usable images was closer to 16 days than to the 10 theoretical days (with only one satellite available at the date of the experiment), i.e. near 60% of the theoretical one. Results show that it might be possible to identify i) the main steps of vine development (e.g. budburst, growth, trimming, growth stop and senescence), ii) weed management and inter-row management practices, and iii) possible reasons for significant inter-block differences in vegetative expression (e.g. young vines that have recently been planted, low-productive blocks affected by many missing vines).Conclusions: Although this experiment was conducted at a time when Sentinel-2b was not fully operational, results showed that a sufficient number of usable images was available to monitor vine development. The availability of two Sentinel satellites (2a and 2b) in upcoming seasons should increase the number of usable images and the temporal resolution of the time series. This study also showed the limitations of the Sentinel-2 images’ resolution to provide within-block information in the case of small blocks or blocks with complex borders or both.Significance and impact of the study: This technical note demonstrated the potential of Sentinel-2 images to characterize vineyard blocks’ vigor and to monitor winegrowers’ practices at a territorial (regional) scale. The impact of management operations such as weeding and trimming, along with their incidence on canopy size, were observed on the NDVI time series. Some relevant parameters (slope, maximum values) may be derived from the NDVI time series, providing new insights into the monitoring of vineyards at a large scale. These results provided areas for further investigation, especially regarding the development of new indicators to characterize block-climate relationships.

scholarly journals Microbial antagonists against plant pathogens in Iran: A review

2020 ◽  
Vol 5 (1) ◽  
pp. 404-440 ◽  
Author(s):  
Mehrdad Alizadeh ◽  
Yalda Vasebi ◽  
Naser Safaie
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Plant Disease ◽  
Plant Pathogens ◽  
Plant Diseases ◽  
Agricultural Products ◽  
Control Measures ◽  
Wide Range ◽  
Plant Disease Management ◽  
Published Research

AbstractThe purpose of this article was to give a comprehensive review of the published research works on biological control of different fungal, bacterial, and nematode plant diseases in Iran from 1992 to 2018. Plant pathogens cause economical loss in many agricultural products in Iran. In an attempt to prevent these serious losses, chemical control measures have usually been applied to reduce diseases in farms, gardens, and greenhouses. In recent decades, using the biological control against plant diseases has been considered as a beneficial and alternative method to chemical control due to its potential in integrated plant disease management as well as the increasing yield in an eco-friendly manner. Based on the reported studies, various species of Trichoderma, Pseudomonas, and Bacillus were the most common biocontrol agents with the ability to control the wide range of plant pathogens in Iran from lab to the greenhouse and field conditions.

First report of citrus tristeza virus in commercial citrus orchards in Tunisia

2021 ◽  
Author(s):  
Asma Najar ◽  
Imen Hamdi ◽  
Souad Mahmoud ◽  
Lassaad Medhioub ◽  
Imed Jaouadi ◽  
...  
Keyword(s):  
Citrus Tristeza Virus ◽  
First Report ◽  
Citrus Orchards ◽  
Tristeza Virus ◽  
Citrus Tristeza

A model for the spread and control of citrus tristeza virus disease

1989 ◽  
Vol 16 (3) ◽  
pp. 315-320
Author(s):  
Ruth Marcus ◽  
Hovav Talpaz ◽  
Moshe Bar-Joseph
Keyword(s):  
Citrus Tristeza Virus ◽  
Virus Disease ◽  
And Control ◽  
Tristeza Virus ◽  
Citrus Tristeza
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