Abstract Cercosporidium personatum (CP) causes peanut late leaf spot (LLS) disease with 70% yield losses unless controlled by fungicides. CP grows slowly in culture, exhibiting variable phenotypes. To explain those variations, we analyzed the morphology, genomes, transcriptomes and chemical composition of three morphotypes, herein called RED, TAN, BROWN. We characterized, for first time CP, anthraquinone (AQ) precursors dothistromin (DOT), including averantin, averufin, norsolorinic acid,...

The protectant fungicide chlorothalonil has been used for management of late leaf spot (Nothopassalora personata) peanut (Arachis hypogaea) over fifty years. However, recent concerns with regulatory issues in both the U.S. and European Union have prompted efforts to identify alternatives control. Cuprous oxide shown promise control, but a direct comparison between cuprous not previously reported. Seven field experiments were conducted Tifton, GA from 2010 2024 which effects on compared when...

Field experiments were carried out to evaluate the effects of integrated management early leaf spot, caused by Cercospora arachidicola, and spotted wilt, Tomato wilt virus (TSWV), on peanut (Arachis hypogaea) using host resistance, two tillage systems, varying fungicide programs. Effects pod yield economic return assessed. Genotypes C-11-2-39 Tifrunner demonstrated best field resistance TSWV, whereas cvs. DP-1 GA-01R line C-28-305 among genotypes with spot resistance. Epidemics both diseases...

Abstract This study assessed components of resistance for three runner-type peanut cultivars to infection by Cercospora arachidicola (Ca) and Cercosporidium personatum (Cp), the causal organisms early leaf spot late spot, respectively. Resistance were compared disease observed in field. A field monitored progression incidence severity Georgia Green, Georganic, DP-1. Time onset (TDO) temporal epidemic rate (rate) estimated with logistic model, linear model. Early was predominant Estimates TDO...

Epidemics of early leaf spot peanut (Arachis hypogaea), caused by Cercospora arachidicola, are less severe in strip-tilled than conventionally tilled fields. Experiments were carried out to characterize the effect strip tillage on epidemics and identify primary target suppression using a comparative epidemiology approach. Leaf intensity was assessed weekly as percent incidence or with Florida 1-to-10 severity scale plots that tilled. The logistic model, fit disease progress data, used...

Abstract Objective Two main fungal leaf spot diseases occur in peanut, namely early (ELS) and late (LLS), these cause a yearly average of $44 million losses. Limited genetic information, 3534 bp sequencing, exists about the causal agent LLS, Cercosporidium personatum (syn. Nothopassalora personata , syn. Phaeoisariopsis ). The extremely slow growth this fungus, approximately 1 cm colony 6 months, challenges nucleic acid extractions have hindered research on LLS. Our goal work is to provide...

Cercospora arachidicola, causal agent of early leaf spot, is an economically important peanut pathogen. Lack genetic information about this fungus prevents understanding the role that potentially diverse genotypes may have in breeding programs. Here, we report for first time a draft genome sequence C. arachidicola.

Previous research has demonstrated the efficacy of prescription fungicide programs, based upon Peanut Rx, to reduce combined effects early leaf spot (ELS), caused by Passalora arachidicola (Cercospora arachidicola), and late (LLS), Nothopassalora personata (syn. Cercosporidium personatum), but potential Rx predict each disease never been formally evaluated. From 2010 2016, non-fungicide-treated peanut plots in Georgia Florida were sampled monitor development ELS LLS. This resulted 168 cases...

Despite strong indirect evidence of post-infection activity by a selection systemic fungicides against Cercospora arachidicola, the causal organism early leaf spot peanut, direct activities in this pathosystem have yet to be reported detail. This study was conducted describe pyraclostrobin, penthiopyrad and prothioconazole on when each fungicide applied after pathogen penetration began throughout incubation period.Most C. arachidicola events occurred between 3 5 days inoculation (dai), mean...

Field experiments were carried out in Georgia and North Carolina to evaluate the efficacy of fungicides approved for organic management early leaf spot, caused by Cercospora arachidicola, late Cercosporidium personatum, peanut (Arachis hypogaea) fields planted cultivars with partial resistance one or both pathogens. Copper treatments alone mixtures resulted less disease than a non-treated control. In Georgia, sulfur provided some suppression, but not as much copper sulfate. Neem oil did...

Scientists with the U.S. Department of Agriculture–Agricultural Research Service (USDA-ARS) and scientists University Georgia located at Coastal Plain Experiment Station in Tifton, Georgia, have been conducting research on aflatoxin contamination peanut since early 1960s. Early efforts were focused identifying risk factors for increased helped to document importance drought, high soil temperatures, pod damage. Later development screening techniques identification sources resistance...

Management of fungicide resistance in Nothopassalora personata, the cause late leaf spot peanut ( Arachis hypogaea), is a challenge production areas southeastern United States. Field experiments were conducted Tifton, Georgia, 2020 and 2021 Plains, to determine effects mixtures seven elemental sulfur products with quinone outside inhibitor (QoI) azoxystrobin on fields where QoI-resistant populations N. personata are suspected. Application or alone resulted little reduction standardized area...

Epidemics of early leaf spot, caused by Cercospora arachidicola, peanut (Arachis hypogaea) are delayed in strip-tilled compared to conventionally tilled fields. This effect may be due applications glyphosate used kill the winter cover crop fields and/or presence residue at soil surface Preplant herbicide (no herbicide, glyphosate, and paraquat), reciprocal (plus plots minus plots), added straw mulch were evaluated determine their effects on spot epidemics (AUDPC based incidence severity,...

ABSTRACT Stand establishment has been a challenge for organic peanut production in the Southeastern United States. Field experiments were conducted 2007 and 2009 research plots certified to evaluate potential of genotype selection, shelling procedure, seed treatment with Bacillus subtilis improve stand seedling emergence rates, reduce incidence Aspergillus crown rot, increase biomass. Seed 15 genotypes mechanically shelled or hand-shelled, treated B. untreated prior planting early June....

In peanut (Arachis hypogaea) production, in-furrow applications of the premix combination succinate-dehydrogenase-inhibitor (SDHI) fungicide and nematicide fluopyram insecticide imidacloprid are used primarily for management nematode pests preventing feeding damage on foliage caused by tobacco thrips (Frankliniella fusca). Fluopyram is also active against many fungal pathogens. However, effect early leaf spot (Passalora arachidicola) or late (Nothopassalora personata) has not been...

Reduced sensitivity to demethylation inhibitor (DMI) and quinone outside (QoI) fungicides in Nothopassalora personata, the cause of late leaf spot peanut (Arachis hypogaea), complicates management this disease Southeastern United States. Mixtures with protectant may help preserve use members both DMI QoI fungicide groups for management. Field experiments were conducted Tifton, GA, from 2019 2021 Plains, during 2020. The primary objective was determine effects mixtures tebuconazole...

ABSTRACT One of the most critical and influential factors determining ultimate crop success is plant stand establishment. Because synthetic seed treatments are not allowed in organic production systems, alternatives needed to assist resistance pathogens during germination seedling growth. Several biological control materials were evaluated laboratory assays field trials determine their potential for minimizing disease impact maximizing yield peanut production. These included Bacillus...

A greenhouse experiment was conducted to test the hypothesis that cultivar use contributed historical shifts in disease predominance patterns southeastern United States over past 50 years. Passalora arachidicola, causal agent of early leaf spot (ELS), and Nothopassalora personata, late (LLS), were inoculated separately or together on three historically dominant cultivars, Florunner (1970 1996), Georgia Green (1996 2008), Georgia-06G (2008 present), one susceptible cultivar, Valencia. These...

Despite significant research on early and late leaf spot diseases of peanut, in vitro study the respective causal agents, Passalora arachidicola Nothopassalora personata, has been limited due to cultural challenges that make growth these fungi difficult quantify with traditional methods. Studies were conducted evaluate practicality image analysis assess radial tissue volume by correlating assessments dry mass. Image was also used estimate rates for over time. Tissue area significantly...

Field experiments were conducted in Tifton, GA, 2012-2014 to determine the effect of in-furrow applications prothioconazole and early-season banded or pyraclostrobin on incidence early leaf spot (Cercospora arachidicola) peanut (Arachis hypogaea). In each year, border rows planted May as a source inoculum for plants treatment plots. Plots August September after epidemics severe Fungicide application regimes included two rates (100 200 g a.i./ha) applied at planting, a.i./ha 164 concentrated...

Irregular leaf spot (ILS) of peanut was first noticed in Florida during the late 1990s. By 2000, ILS apparent throughout much southeastern growing region United States. Experiments were conducted to identify cause ILS, characterize development over time, and evaluate effect genotype, tillage, applications fungicides bactericides on ILS. Severities near maximum levels at 33 42 days after planting (DAP) decline by 56 DAP. Incidence greater lower canopy than upper canopy. In most cases,...