Phytopathology Journal Impact Factor & Information

Publisher: American Phytopathological Society, American Phytopathological Society

Journal description

Phytopathology is the premier international journal of fundamental research regarding plant diseases, the agents that cause them, their spread, the losses they cause, and measures to control them. Subject areas include analytical and theoretical plant pathology, bacteriology, biochemistry and cell biology, biological control, disease control and pest management, ecology and population biology, epidemiology, etiology, genetics and resistance, mycology, nematology, plant stress and abiotic disorders, postharvest pathology and mycotoxins, techniques, and virology.

Current impact factor: 2.75

Impact Factor Rankings

2015 Impact Factor Available summer 2015
2013 / 2014 Impact Factor 2.746
2012 Impact Factor 2.968
2011 Impact Factor 2.799
2010 Impact Factor 2.428
2009 Impact Factor 2.223
2008 Impact Factor 2.192
2007 Impact Factor 2.377
2006 Impact Factor 2.195
2005 Impact Factor 2.049
2004 Impact Factor 2.222
2003 Impact Factor 2.45
2002 Impact Factor 2.22
2001 Impact Factor 2.126
2000 Impact Factor 2.145
1999 Impact Factor 2.632
1998 Impact Factor 2.39
1997 Impact Factor 2.365
1996 Impact Factor 2.339
1995 Impact Factor 2.378
1994 Impact Factor 2.222
1993 Impact Factor 2.273
1992 Impact Factor 2.008

Impact factor over time

Impact factor

Additional details

5-year impact 3.09
Cited half-life 0.00
Immediacy index 0.62
Eigenfactor 0.01
Article influence 0.94
Website Phytopathology website
Other titles Phytopathology
ISSN 0031-949X
OCLC 1762372
Material type Periodical
Document type Journal / Magazine / Newspaper

Publisher details

American Phytopathological Society

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author cannot archive a post-print version
  • Conditions
    • On pre-print servers, arXiv, biorxiv, PeerJ and public databases
    • Must inform publisher of pre-print deposit
    • Published source must be acknowledged
    • Must link to publisher version upon acceptance
  • Classification
    ​ yellow

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: Using host resistance is an important strategy for managing pepper root and crown rot caused by Phytophthora capsici. An isolate of P. capsici constitutively expressing a gene for green fluorescent protein was used to investigate pathogen interactions with roots, crowns, and stems of Phytophthora-susceptible bell pepper cultivar Red Knight, Phytophthora-resistant bell pepper cultivar Paladin, and Phytophthora-resistant landrace CM-334. In this study, the same number of zoospores attached to and germinated on roots of all cultivars 30 and 120 minutes post inoculation (pi), respectively. At 3 days pi, significantly more secondary roots had necrotic lesions on 'Red Knight' than on 'Paladin' and CM-334 plants. By 4 days pi, necrotic lesions had formed on the taproot of 'Red Knight', but not 'Paladin' or CM-334 plants. While hyphae were visible in the crowns and stems of all 'Red Knight' plants observed at 4 days pi, hyphae were observed in crowns of only a few 'Paladin' and in no CM-334 plants, and never in stems of either resistant cultivar at 4 days pi. These results improve our understanding of how P. capsici infects plants and may contribute to the use of resistant pepper cultivars for disease management and the development of new cultivars.
    Phytopathology 05/2015; DOI:10.1094/PHYTO-02-15-0045-R
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    ABSTRACT: A collection of 147 Potato virus Y (PVY) isolates from tomato, originating from several commercial fields and greenhouses in different regions of Poland, was tested for the presence Potato virus Y by RT-PCR. However, in some cases the results obtained were ambiguous. Therefore, a sensitive reverse transcription loop-mediated isothermal amplification method was developed for rapid detection of PVY isolates. Phylogenetic and recombination analyses were performed based on sequences of the coat protein gene. In comparison to results obtained in 2008, the presence of other strains besides PVYNWi-P was confirmed. A novel recombinant between PVYNTN and PVYNWi-P strains was detected. Our results indicate an increasing distribution and variability of the PVY population on tomato in Poland.
    Phytopathology 05/2015; DOI:10.1094/PHYTO-08-14-0219-R
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    ABSTRACT: Common scab of potato, caused by pathogenic Streptomyces spp., is an important disease not efficiently controlled by current methods. We previously demonstrated that Pseudomonas fluorescens sp. LBUM223 reduces common scab development under controlled conditions through phenazine-1-carboxylic (PCA) production, leading to reduced thaxtomin A production by the pathogen, a key pathogenicity and virulence factor. Here, we aimed at determining if LBUM223 is able to increase potato yield and control common scab under field conditions, while characterizing the biocontrol mechanisms involved. We investigated if a reduction in pathogen soil populations, activation of induced systemic resistance in potato and/or changes in txtA gene expression, involved in thaxtomin A biosynthesis in pathogenic Streptomyces spp., were involved in common scab control by LBUM223. Common scab symptoms were significantly reduced and total tuber weight increased by 46% using biweekly applications with LBUM223. LBUM223 did not reduce pathogen soil populations, suggesting that antibiosis was not involved, nor was potato systemic defense-related gene expression significantly altered between treatments. However, a significant down-regulation of txtA expression in the geocaulosphere occurred. This is the first demonstration that a Pseudomonas strain can directly alter the transcriptional activity of a key pathogenesis gene in a plant pathogen under field conditions, contributing to disease control.
    Phytopathology 05/2015; DOI:10.1094/PHYTO-12-14-0358-R
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    ABSTRACT: Many studies have investigated the effect of biochar on plant yield, nutrient uptake and soil microbial populations, however little work has been done on its effect on soilborne plant diseases. To determine the effect of maple bark biochar on Rhizoctonia damping-off, eleven plant species were grown in a soilless potting substrate amended with different concentrations of biochar and inoculated or not with Rhizoctonia solani AG-4. Additionally, the effect of biochar amendment on R. solani growth and metabolism in vitro was evaluated. Increasing concentrations of maple bark biochar increased Rhizoctonia damping-off of all eleven plant species. Using multivariate analyses, we observed positive correlations between biochar amendments, disease severity and incidence, abundance of culturable bacterial communities, and physicochemical parameters. Additionally, biochar amendment significantly increased R. solani growth and hyphal extension in vitro, and altered its primary metabolism notably, the mannitol and TCA cycles and the glycolysis pathway. One or several organic compounds present in the biochar, as identified by gas chromatography-mass spectrometry analysis, may be metabolized by R. solani. Taken together, these results indicate that future studies on biochar should focus on the effect of its use as an amendment has on soilborne plant pathogens before applying it to soils.
    Phytopathology 05/2015; DOI:10.1094/PHYTO-08-14-0231-R
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    ABSTRACT: Xylella fastidiosa is unique among insect-transmitted plant pathogens because it is propagative but noncirculative, adhering to and multiplying on the cuticular lining of the anterior foregut. Any inoculation mechanism for X. fastidiosa must explain how bacterial cells exit the vector's stylets via the food canal and directly enter the plant. A combined egestion-salivation mechanism has been proposed to explain these unique features. Egestion is the putative outward flow of fluid from the foregut via hypothesized bidirectional pumping of the cibarium. The present study traced green fluorescent protein-expressing X. fastidiosa or fluorescent nanoparticles acquired from artificial diets by glassy-winged sharpshooters, Homalodisca vitripennis, as they were egested into simultaneously secreted saliva. X. fastidiosa or nanoparticles were shown to mix with gelling saliva to form fluorescent deposits and salivary sheaths on artificial diets, providing the first direct, conclusive evidence of egestion by any hemipteran insect. Therefore, the present results strongly support an egestion-salivation mechanism of X. fastidiosa inoculation. Results also support that a column of fluid is transiently held in the foregut without being swallowed. Evidence also supports (but does not definitively prove) that bacteria were suspended in the column of fluid during the vector's transit from diet to diet, and were egested with the held fluid. Thus, we hypothesize that sharpshooters could be true "flying syringes," especially when inoculation occurs very soon after uptake of bacteria, suggesting the new paradigm of a nonpersistent X. fastidiosa transmission mechanism.
    Phytopathology 05/2015; 105(5):608-20. DOI:10.1094/PHYTO-09-14-0258-R
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    ABSTRACT: Xanthomonas oryzae pv. oryzicola and X. oryzae pv. oryzae are two pathovars of X. oryzae that cause leaf streak and blight in rice, respectively. These two bacterial pathogens cause different disease symptoms by utilizing different infection sites on rice. Compared with X. oryzae pv. oryzae, the molecular virulence mechanism of X. oryzae pv. oryzicola remains largely unknown. Previously, we identified a unique diffusible signal factor (DSF)-controlled virulence-related gene (hshB) in X. oryzae pv. oryzicola Rs105 located in the nodB-rghB locus, which is absent in X. oryzae pv. oryzae PXO99(A). In the present study, we identified two additional genes within this locus (hshA and hshC) that were unique to X. oryzae pv. oryzicola Rs105 compared with X. oryzae pv. oryzae PXO99(A), and we found that the transcription of these genes was regulated by DSF signaling in X. oryzae pv. oryzicola. The mutation of these genes impaired the virulence of the wild-type Rs105 when using a low inoculation density of X. oryzae pv. oryzicola. In contrast to hshB, the mutation of these genes did not have any visible effect on characterized virulence-related functions, including in vitro growth, extracellular polysaccharide production, extracellular protease activity, and antioxidative ability. However, we found that mutation of hshA or hshC significantly reduced the in planta growth ability and epiphytic survival level of X. oryzae pv. oryzicola cells, which was the probable mechanisms of involvement of these two genes in virulence. Collectively, our studies of X. oryzae pv. oryzicola have identified two novel DSF-controlled virulence-associated genes (hshA and hshC), which will add to our understanding of the regulatory mechanisms of conserved DSF virulence signaling in Xanthomonas species.
    Phytopathology 05/2015; 105(5):588-96. DOI:10.1094/PHYTO-07-14-0190-R
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    ABSTRACT: Wheat streak mosaic virus (WSMV) causes significant yield loss in hard red winter wheat in the U.S. Southern High Plains. Despite the prevalence of this pathogen, little is known about the physiological response of wheat to WSMV infection. A 2-year study was initiated to (i) investigate the effect of WSMV, inoculated at different development stages, on shoot and root growth, water use, water use efficiency (WUE), and photosynthesis and (ii) understand the relationships between yield and photosynthetic parameters during WSMV infection. Two greenhouse experiments were conducted with two wheat cultivars mechanically inoculated with WSMV at different developmental stages, from three-leaf to booting. WSMV inoculated early, at three- to five-leaf stage, resulted in a significant reduction in shoot biomass, root dry weight, and yield compared with wheat infected at the jointing and booting stages. However, even when inoculated as late as jointing, WSMV still reduced grain yield by at least 53%. Reduced tillers, shoot biomass, root dry weight, water use, and WUE contributed to yield loss under WSMV infection. However, infection by WSMV did not affect rooting depth and the number of seminal roots but reduced the number of nodal roots. Leaf photosynthetic parameters (chlorophyll [SPAD], net photosynthetic rate [Pn], stomatal conductance [Gs], intercellular CO2 concentration [Ci], and transpiration rate [Tr]) were reduced when infected by WSMV, and early infection reduced parameters more than late infection. Photosynthetic parameters had a linear relationship with grain yield and shoot biomass. The reduced Pn under WSMV infection was mainly in response to decreased Gs, Ci, and SPAD. The results of this study indicated that leaf chlorophyll and gas exchange parameters can be used to quantify WSMV effects on biomass and grain yield in wheat.
    Phytopathology 04/2015; DOI:10.1094/PHYTO-07-14-0194-R
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    ABSTRACT: Switchgrass (Panicum virgatum L.) cultivars are currently under development as lignocellulosic feedstock. Here we present a survey of three established switchgrass experimental nurseries in Nebraska in which we identified Panicum mosaic virus (PMV) as the most prevalent virus. In 2012, 78% of 139 symptomatic plants tested positive for PMV. Of the PMV-positive samples, 17% were co-infected with PMV and its satellite virus (SPMV). Less than 14% of all sampled plants in 2012 were positive for four additional viruses known to infect switchgrass. In 2013, randomized sampling of switchgrass individuals from the same 2012 breeding plots revealed that infection by PMV or PMV+SPMV was both more prevalent and associated with more severe symptoms in the cultivar Summer, and experimental lines with Summer parentage, than populations derived from the cultivar Kanlow. A three-year analysis, from 2012-2014, showed that previously uninfected switchgrass plants acquire PMV or PMV+SPMV between harvest cycles. In contrast, some plants apparently did not maintain PMV infections at detectable levels from year-to-year. These findings suggest that PMV and SPMV should be considered important pathogens of switchgrass and serious potential threats to biofuel crop production efficiency.
    Phytopathology 04/2015; DOI:10.1094/PHYTO-03-15-0062-R
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    ABSTRACT: Zebra chip (ZC) of potato is putatively caused by the fastidious, phloem-limited bacterium 'Candidatus Liberibacter solanacearium' (Lso), which is transmitted by the potato psyllid (Bactericera cockerelli). The disease, which significantly impacts both crop yield and quality, was first identified in the United States from south Texas in 2000. It reached epidemic levels in north Texas and certain production areas in Colorado, Nebraska and New Mexico from 2004 - 2007 and it caused severe losses in fields in Oregon, Washington and Idaho in 2011. The potato plant is susceptible to infection at all developmental stages, but disease management programs have focused on vector control through early and repeated insecticide applications, in an effort to minimize early to mid-season infections which are most damaging. Growers often terminate spray programs 2 - 3 weeks prior to crop harvest due to lack of visible treatment effects on crop yield or quality. However, recent studies on vector transmission and host-pathogen interactions have revealed that late-season infections pose a significant, previously unrecognized, threat to crop quality. The pathogen can move from an infected leaf to tubers within 2 days, however tubers infected < a week before harvest will remain asymptomatic and the pathogen will be undetectable. When these tubers are placed into storage, they are assumed to be disease free. However, Lso can continue to multiply in respiring tubers during storage, resulting in reduced tuber quality. Perspectives on the significance of late-season infections and some of the more important issues associated with those infections are discussed.
    Phytopathology 04/2015; DOI:10.1094/PHYTO-12-14-0365-FI
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    ABSTRACT: The study of microorganisms that reside on plant leaf surfaces, or phyllosphere microbiology, greatly benefits from the availability of artificial surfaces that mimic in one or more ways the complexity of foliage as a microbial habitat. These leaf surface proxies range from very simple, such as nutrient agars that can reveal the metabolic versatility or antagonistic properties of leaf-associated microorganisms, to the very complex, such as silicon-based casts that replicate leaf surface topography down to nanometer resolution. In this review, we summarize the various uses of artificial surfaces in experimental phyllosphere microbiology and discuss how these have advanced our understanding of the biology of leaf-associated microorganisms and the habitat they live in. We also provide an outlook into future uses of artificial leaf surfaces, foretelling a greater role for microfluidics to introduce biological and chemical gradients into artificial leaf environments, stressing the importance of artificial surfaces to generate quantitative data that support computational models of microbial life on real leaves, and rethinking the leaf surface ('phyllosphere') as a habitat that features two intimately connected but very different compartments, i.e. the leaf surface landscape ('phylloplane') and the leaf surface waterscape ('phyllotelma').
    Phytopathology 04/2015; DOI:10.1094/PHYTO-02-15-0050-RVW
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    ABSTRACT: MILDEW LOCUS O defines a major susceptibility gene for powdery mildew and recessive mlo resistance alleles are widely used in breeding for powdery mildew resistance in spring barley. Barley powdery mildew resistance, which is conferred by mlo genes, is considered to be costly in terms of spontaneous defense reactions and enhanced susceptibility to cell-death inducing pathogens. We assessed fungal infestation of barley (Hordeum vulgare) grain by measuring fungal DNA after natural infection with Fusarium spp. and Ramularia colly-cygni or after inoculation with Fusarium spp. in the field. Powdery mildew resistant mlo5-genotypes did not show enhanced Fusarium spp. or R. collo-cygni DNA content of grain over four consecutive years. Data add to our understanding of pleiotropic effects of mlo-mediated powdery mildew resistance and contributes to the discussion of whether or not application of barley mlo mutations may support pathogenesis of cell death-inducing fungal pathogens under field conditions.
    Phytopathology 04/2015; DOI:10.1094/PHYTO-12-14-0381-R