A5085010129- Plant Pathogens and Fungal Diseases
- Plant Physiology and Cultivation Studies
- Banana Cultivation and Research
- Phytoplasmas and Hemiptera pathogens
- Plant Pathogenic Bacteria Studies
- Plant Pathogens and Resistance
- Fungal Plant Pathogen Control
- Cocoa and Sweet Potato Agronomy
- Mycorrhizal Fungi and Plant Interactions
- Plant Virus Research Studies
- Spectroscopy and Chemometric Analyses
- Plant-Microbe Interactions and Immunity
- Horticultural and Viticultural Research
- Garlic and Onion Studies
- Pineapple and bromelain studies
- Entomopathogenic Microorganisms in Pest Control
- Plant Disease Resistance and Genetics
- Leaf Properties and Growth Measurement
- Plant pathogens and resistance mechanisms
- Plant Disease Management Techniques
- Smart Agriculture and AI
- Yeasts and Rust Fungi Studies
- Remote Sensing in Agriculture
- melanin and skin pigmentation
- Insect behavior and control techniques
Florida Department of Citrus
2016-2025
University of Florida
2016-2025
Appalachian Fruit Research Laboratory
2021
Agricultural Research Service
2021
ARC Centre of Excellence for Plant Success in Nature and Agriculture
2017-2019
Agriculture and Food
2017-2019
The University of Queensland
2017-2019
Indigenous Wellbeing Centre
2019
University of West Florida
2018
Citrus Research International
2017
The microbiome associated with crop plants has a strong impact on their health and productivity. Candidatus Liberibacter asiaticus (Las), the bacterial pathogen responsible for Huanglongbing (HLB) disease, lives inside phloem of citrus including root system. It been suggested that Las negatively affects microbiome. On other hand, members also influence interaction between citrus. Here, we report isolation characterization multiple putative beneficial bacteria from healthy rhizosphere....
Phyllosticta citricarpa, the citrus black spot pathogen, was first identified in Florida March 2010. Subsequently, this pathogen has become established but can be easily confused with endemic nonpathogenic endophyte P. capitalensis. In study, mating-type (MAT) loci of citricarpa and capitalensis were via draft genome sequencing characterized at structural sequence levels. determined to have an idiomorphic, heterothallic MAT locus structure, whereas found a single consistent homothallic...
Citrus black spot (CBS) is a fungal disease caused by Phyllosticta citricarpa that poses quarantine threat and can restrict market access to fruits. It manifests as lesions on the fruit surface result in premature drops, leading reduced yield. Another significant affecting citrus canker, which bacterium Xanthomonas citri subsp. (syn. X. axonopodis pv. citri); it causes economic losses for growers due drops blemishes. Early detection management of groves infected with CBS or canker through...
Chemical management of Alternaria brown spot citrus is based upon the timely application site-specific fungicides, many which are vulnerable to development fungicide resistance. A rapid microtiter bioassay on colorimetric changes resazurin (RZ) dye was developed evaluate sensitivity alternata quinone outside inhibitor (QoI) fungicides. Four liquid media (complete medium, minimal potato dextrose broth, and yeast peptone broth), five conidia concentrations (from 101 105 conidia/ ml), RZ (10,...
In March 2010, citrus black spot symptoms were observed on sweet orange trees in a grove near Immokalee, FL. Symptoms fruit included hard spot, cracked and early virulent spot. Hard lesions up to 5 mm, depressed with chocolate margin necrotic, tan center, often pycnidia (140 200 μm) present. Cracked large (15 mm), dark brown, diffuse margins raised cracks. some cases, spots formed the center of lesions. Early small (up 7 mm long), bright red, irregular, indented, many pycnidia. addition, (2...
Chemical control, based on copper and quinone outside inhibitor (QoI) fungicides, has been essential for the management of brown spot citrus, caused by Alternaria alternata. However, QoI control failures were detected recently in Florida. From 2008 to 2012, 817 monoconidial isolates A. alternata from 46 citrus orchards examined sensitivity azoxystrobin (AZ) pyraclostrobin (PYR). Of isolates, 57.6% resistant both with effective concentration inhibit 50% growth (EC50) values greater than 5...
Citrus black spot (Phyllosticta citricarpa) causes fruit blemishes and premature drop, resulting in significant economic losses citrus growing areas with summer rainfall across the globe. The mating type locus of P. citricarpa has recently been characterized, revealing heterothallic nature this pathogen. However, insight into occurrence impact completing sexual cycle was lacking. To investigate reproduction, we developed a method to reliably, for first time, produce ascospores on culture...
The Global Plant Health Assessment (GPHA) is a collective, volunteer-based effort to assemble expert opinions on plant health and disease impacts ecosystem services based published scientific evidence. GPHA considers range of forest, agricultural, urban systems worldwide. These are referred as (Ecoregion × System), i.e., selected case examples involving keystone plants in given parts the world. focuses infectious diseases pathogens, but encompasses abiotic (e.g., temperature, drought,...
Citrus canker, caused by Xanthomonas citri subsp. (Xcc) and X. fuscans aurantifolii (Xfa), is a destructive disease of citrus. It sparsely distributed in the Caribbean, effective biosecurity measures, including accurate pathogen detection systems, are essential to prevent further spread. Current in-field screening methods rely on visual symptom identification serological tools like Agdia’s axonopodis (Xac) ImmunoStrips®. However, they failed detect A w C pathotypes this study. Nucleic acid...
Species of the Colletotrichum acutatum complex cause postbloom fruit drop citrus and anthracnose rot strawberries. C. produces acervuli in diseased flowers strawberry fruit, surviving asymptomatically on vegetative tissues. Previous studies have suggested that dispersal mechanisms other than windblown rain may be involved conidia sensu lato. Our hypothesis is wind alone play a role dispersal, especially for inoculum tissue. objectives were to study pattern lato from leaves, leaves by placing...
Citrus greening disease (HLB) and citrus canker cause financial losses in Florida groves via smaller fruits, blemishes, premature fruit drop, and/or eventual tree death. Management of these two diseases requires early detection distinction from other leaf defects infections. Automated inspection with hyperspectral imagery (HSI) is tested this study. leaves bearing visible symptoms HLB, canker, scab, melanose, greasy spot, zinc deficiency, a control class were collected, images taken...
The citrus pathogen Phyllosticta citricarpa was first described 117 years ago in Australia; subsequently, from the summer rainfall citrus-growing regions China, Africa, and South America; and, recently, United States. Limited information is available on pathogen's population structure, mode of reproduction, introduction pathways, which were investigated by genotyping 383 isolates representing 12 populations States, Australia, Brazil. Populations genotyped using seven published eight newly...
ABSTRACT Blossom blight forecasting is an important aspect of fire blight, caused by Erwinia amylovora, management for both apple and pear. A comparison the forecast accuracy two common forecasters, MARYBLYT Cougarblight, was performed with receiver operating characteristic (ROC) curve analysis 243 data sets. The rain threshold Cougarblight analyzed as a separate model termed rain. Data were used whole then grouped into geographic regions cultivar susceptibilities. Frequency distributions...
Citrus black spot, a major citrus disease caused by Guignardia citricarpa, was recently introduced in Florida. The nonpathogenic fungal endophyte G. mangiferae is commonly found the same tissues as citricarpa. Quantitative polymerase chain reaction (qPCR) assays based on internal transcribed spacer (ITS)-1 genes were developed to detect, quantify, and distinguish between these morphologically similar organisms environmental samples. primer/probe sets GCITS GMITS more than 95% efficient...
Citrus black spot (CBS), caused by Guignardia citricarpa, is an emerging disease in Florida. Fungicide applications are the main control measure worldwide. The vitro activity and baseline sensitivity of G. citricarpa isolates to quinone outside inhibitor (QoI) fungicides (azoxystrobin pyraclostrobin) were evaluated. effective concentration needed reduce mycelial growth or spore germination 50% (EC 50 ) was determined for 86 obtained from Florida counties where CBS found. effect...
This revised guide addresses management of pesticide resistance and describes the Fungicide Resistance Action Committee’s (FRAC) classification fungicides bactericides registered for agricultural non-agricultural use in Florida by their modes action. A cross-reference common names active ingredients, along with corresponding examples trade names, is also provided. Written F.M. Fishel M.M. Dewdney, published UF Department Agronomy, November 2012. PI94/PI131: Committee's Classification Scheme...
The phenotypic stability, fitness components, and ability to cause disease of isolates the Alternaria alternata tangerine pathotype resistant quinone-outside inhibitors (QoIs) were studied. Stability resistance azoxystrobin (AZ) pyraclostrobin (PYR) was determined after consecutive transfers on potato dextrose agar (PDA). sensitivity QoIs did not change significantly 10 PDA compared with initial all tested. Fitness components evaluated in vitro mycelial growth, conidial germination,...
This collaborative work by over 180 researchers from 40+ countries addresses the challenges posed “phantom agents”—putative pathogenic agents named in literature without supporting data on their existence. Those remain regulatory lists, creating barriers trade and plant certification. Historically identified based solely symptoms, these lack isolates or sequence data, making reliable detection risk assessment impossible. After reviewing 120 such across 10 key genera, we recommend removal...
Apple scab (Venturia inaequalis) causes important economic losses in many apple production areas of the world. The disease is controlled by numerous fungicide applications regardless presence ascospores orchard. Airborne ascospore concentration (AAC) can be measured real time to applications. However, level heterogeneity AAC commercial orchards was unknown. Consequently, spatial distribution V. inaequalis studied a orchard 0.43 ha. potential dose (PAD) and were 40 quadrats each 108 m 2 . In...