scholarly journals An Overview of the Epidemiology of Phakopsora pachyrhizi in the State of Mato Grosso, Brazil

2021 ◽  
Vol 13 (6) ◽  
pp. 110
Author(s):  
Erlei Melo Reis ◽  
Wanderlei Dias Guerra ◽  
Mateus Zanatta ◽  
Laércio Zambolim
Keyword(s):  
Environmental Effect ◽  
The State ◽  
Soybean Rust ◽  
Economic Sustainability ◽  
Phakopsora Pachyrhizi ◽  
Airborne Spores ◽  
Mato Grosso ◽  
Asian Soybean Rust ◽  
Weed Plants ◽  
Soybean Plants

This review seeks to expand the knowledge about the epidemiology of Asian sybean rust in the state of Mato Grosso and contribute to ensuring the economic sustainability of soybean crop. It is discussed the Phakopsora pachyrhizi potential of dispersal from Asia to South America and finally to Mato Grosso state. The origin of the Asian soybean rust inoculum within Mato Grosso is addressed by the survival in volunteer and soybean weed plants (Pitelli, 2015) in other crops such as cotton. Data on the adverse environmental effect on the soybean plants survival are shown mainly the water deficit from June to August. Reports on the effect air temperature and mainly solar radiation on the mortality of airborne spores during their anemophilous spread on sunny days are also discussed. This increase of knowledge aims to make the soybean-free period more efficient by the knowledge on the soybean plants survival and on the fungus viability in the month of August. Due to the proximity of soybean farms, during the soybean-free period, in other states (Tocantins, Goiás, Rondônia, etc.) and in other neighbor countries we discuss the likelihood that inoculum in the state may also originate in out-of-state crops during the Mato Grosso soybean-free period.

Use of a Canopy Opener in Fungicide Applications to Improve Asian Soybean Rust Control

2017 ◽  
Vol 60 (6) ◽  
pp. 1819-1825 ◽  
Author(s):  
Bianca Moura ◽  
Carolina Cardoso Deuner ◽  
Gustavo Luiz Visintin ◽  
Walter Boller
Keyword(s):  
Grain Yield ◽  
Plant Architecture ◽  
Spray Deposition ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Droplet Deposition ◽  
Asian Soybean Rust ◽  
Negative Effect ◽  
Soybean Plants ◽  
Pesticide Deposition

Abstract. In soybeans, the leaves of the upper canopy often act as a shield against fungicide penetration, preventing pesticide deposition on target. Fungicide applications to control Asian soybean rust (ASR) are especially difficult because the infection usually starts on the lower canopy. In this study, soybean plants of an early indeterminate cultivar and a determinate cultivar were sprayed with the fungicide azoxystrobin + benzovindiflupyr at six different times of the day with or without the addition of a curtain of chains on the spray boom, which acted as a canopy opener. The number of uredia of cm-2 and grain yield were measured to evaluate application efficacy. We found that the use of the curtain of chains reduced ASR control on the upper canopy for the indeterminate cultivar; however, less of a negative effect was observed for the determinate cultivar. The curtain of chains improved ASR control on the lower and middle canopies at more hours of the day for the determinate cultivar. For both cultivars, the curtain of chains increased ASR control at 6:00, 9:00, and 18:00 h on the lower canopy. Grain yield was also higher with the curtain of chains at 6:00 and 9:00 h for the determinate cultivar. Our results showed that using the curtain of chains could improve fungicide droplet deposition on the lower canopy, leading to greater ASR control and possibly increasing yield. However, it is important to consider the plant architecture and hour of application to maximize the benefit of the curtain of chains. Keywords: Canopy opener, Fungicide penetration, Phakopsora pachyrhizi, Plant architecture, Spray deposition.

scholarly journals Asian Soybean Rust Severity Sowed in Different Seasons

2020 ◽  
Vol 12 (10) ◽  
pp. 240
Author(s):  
Erlei Melo Reis ◽  
Luana Maria de Rossi Belufi ◽  
Wanderlei Dias Guerra ◽  
Laércio Zambolin ◽  
Mateus Zanatta
Keyword(s):  
Insect Pests ◽  
Soybean Rust ◽  
Management Systems ◽  
Phakopsora Pachyrhizi ◽  
Mato Grosso ◽  
Asian Soybean Rust ◽  
Different Seasons ◽  
Rust Severity ◽  
Sowing Period ◽  
On Farm

In on-farm trials, the foliolar severity of Asian soybean rust was evaluated in 44 areas, in three regions of Mato Grosso sown in December (2019) and February (2020). Several susceptible cultivars were used in different crop systems; insect pests and weeds were controlled with different management systems by the farmers. Forty soybean leaflets from four plots replications, demarcated at random in each field were taken. In laboratory foliolar severity was appraised. For rust control in the trials conducted in February, fungicides with efficiency greater than 60% were used consisting of DMIs, QoIs and SDHIs in double or triple mixtures, always adding multisites (chlorothalonil, mancozeb, copper oxychloride). The severity was greater in the fields sown in December (4.84% than in February 0.68%). The number of fungicides spraying/ha in December was 6.4 and February 4.6. It is discussed that through the use of multisites fungicides, the mutation potential in Phakopsora pachyrhizi is reduced and that the spores from areas cultivated in February, probably due to unfavorable environment, do not survive during the soybean free-period. Our results indicate that the sowing period can be changed from the end of December to February, since multisites fungicides are always used.

scholarly journals Identification and characterization of a new soybean promoter induced by Phakopsora pachyrhizi, the causal agent of Asian soybean rust

2020 ◽  
Author(s):  
Lisa Cabre ◽  
Stephane Peyrard ◽  
Catherine Sirven ◽  
Laurine Gilles ◽  
Bernard Pelissier ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Green Fluorescence Protein ◽  
Inducible Promoter ◽  
Soybean Rust ◽  
Limited Area ◽  
Phakopsora Pachyrhizi ◽  
Mechanical Wounding ◽  
Rust Disease ◽  
Asian Soybean Rust ◽  
Soybean Plants

ABSTRACTBackgroundPhakopsora pachyrhizi is a biotrophic fungal pathogen responsible for the Asian soybean rust disease causing important yield losses in tropical and subtropical soybean-producing countries. P. pachyrhizi triggers important transcriptional changes in soybean plants during infection, with several hundreds of genes being either up- or downregulated.ResultsBased on published transcriptomic data, we identified a predicted chitinase gene, referred to as GmCHIT1, that was upregulated in the first hours of infection. We first confirmed this early induction and showed that this gene was expressed as early as 8 hours after P. pachyrhizi inoculation. To investigate the promoter of GmCHIT1, transgenic soybean plants expressing the green fluorescence protein (GFP) under the control of the GmCHIT1 promoter were generated. Following inoculation of these transgenic plants with P. pachyrhizi, GFP fluorescence was detected in a limited area located around appressoria, the fungal penetration structures. Fluorescence was also observed after mechanical wounding whereas no variation in fluorescence of pGmCHIT1:GFP transgenic plants was detected after a treatment with an ethylene precursor or a methyl jasmonate analogue.ConclusionWe identified a soybean chitinase promoter exhibiting an early induction by P. pachyrhizi located in the first infected soybean leaf cells. Our results on the induction of GmCHIT1 promoter by P. pachyrhizi contribute to the identification of a new pathogen inducible promoter in soybean and beyond to the development of a strategy for the Asian soybean rust disease control using biotechnological approaches.

scholarly journals Identification and characterization of a new soybean promoter induced by Phakopsora pachyrhizi, the causal agent of Asian soybean rust

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
L. Cabre ◽  
S. Peyrard ◽  
C. Sirven ◽  
L. Gilles ◽  
B. Pelissier ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Green Fluorescence Protein ◽  
Inducible Promoter ◽  
Soybean Rust ◽  
Limited Area ◽  
Phakopsora Pachyrhizi ◽  
Mechanical Wounding ◽  
Rust Disease ◽  
Asian Soybean Rust ◽  
Soybean Plants

Abstract Background Phakopsora pachyrhizi is a biotrophic fungal pathogen responsible for the Asian soybean rust disease causing important yield losses in tropical and subtropical soybean-producing countries. P. pachyrhizi triggers important transcriptional changes in soybean plants during infection, with several hundreds of genes being either up- or downregulated. Results Based on published transcriptomic data, we identified a predicted chitinase gene, referred to as GmCHIT1, that was upregulated in the first hours of infection. We first confirmed this early induction and showed that this gene was expressed as early as 8 h after P. pachyrhizi inoculation. To investigate the promoter of GmCHIT1, transgenic soybean plants expressing the green fluorescence protein (GFP) under the control of the GmCHIT1 promoter were generated. Following inoculation of these transgenic plants with P. pachyrhizi, GFP fluorescence was detected in a limited area located around appressoria, the fungal penetration structures. Fluorescence was also observed after mechanical wounding whereas no variation in fluorescence of pGmCHIT1:GFP transgenic plants was detected after a treatment with an ethylene precursor or a methyl jasmonate analogue. Conclusion We identified a soybean chitinase promoter exhibiting an early induction by P. pachyrhizi located in the first infected soybean leaf cells. Our results on the induction of GmCHIT1 promoter by P. pachyrhizi contribute to the identification of a new pathogen inducible promoter in soybean and beyond to the development of a strategy for the Asian soybean rust disease control using biotechnological approaches.

scholarly journals Comparative Severity Analysis of Asian Soybean Rust in Soybean Farms Sown in December and February in Mato Grosso, 2018/19 Growing Season

2020 ◽  
Vol 12 (9) ◽  
pp. 130
Author(s):  
Erlei Melo Reis ◽  
Rodrigo Marcelo Pasquali ◽  
Luana Maria de Rossi Belufi ◽  
Wanderlei Dias Guerra ◽  
Mateus Zanatta
Keyword(s):  
Linear Regression Analysis ◽  
The State ◽  
Soybean Rust ◽  
Phenological Stages ◽  
Mato Grosso ◽  
North West ◽  
The North ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Seeding Time

The objective of this work was to compare the leaflet severity of Asian soybean rust in farms sown in December and February in the state of Mato Grosso. In the survey, 28 fields were sampled in 14 counties in the North, West and South regions of the state. A total of 40 leaflets were collected per plot, in randomized treatments with four replication and three crop phenological stages. Leaflet severity was assessed according to a diagrammatic scale. The data were expressed as leaflet severity, submitted to linear regression analysis, calculated the area under the disease progress curve (AUDPC) considering the three phenological stages sampled, and the means compared by the Tukey’s test. Leaflet severity was significantly higher in the fields sown in December than in February, as well the number of fungicides sprayings. Our results indicate that the proposed change in seeding time from December to February can be implemented by significantly reducing risks and in compliance with the principles of IN 002/2015.

scholarly journals Morphologic and Pathometric Characterization of the Asian Soybean Rust (Phakopsora pachyrhizi) in Santa Fe Province, Argentina

Plant Disease ◽  
2005 ◽  
Vol 89 (6) ◽  
pp. 684-684 ◽  
Author(s):  
R. N. Pioli ◽  
M. V. Cambursano ◽  
E. N. Morandi
Keyword(s):  
Growing Season ◽  
Brown Spot ◽  
Soybean Rust ◽  
Disease Spread ◽  
Phakopsora Pachyrhizi ◽  
Santa Fe ◽  
Asian Soybean Rust ◽  
Soybean Plants ◽  
Soybean Leaves

The Asian soybean rust caused by the fungus Phakopsora pachyrhizi was cited for the first time in Argentina during the 2002-2003 growing season (3). During 2003-2004, the disease spread to other northern provinces and was also observed in north-central Santa Fe, the main producing soybean province of the country. Because the disease appeared at the end of the crop growing season (late March to early April) it had little or no impact on crop yields. The objectives of this study were to characterize morphologically and pathometrically the disease on soybean and check the presence of P. pachyrhizi on volunteer soybean plants that could eventually carry the disease to the next growing season. The study was conducted in the San Justo Department, Santa Fe Province (between 30 and 31°S latitude), where the presence of the soybean rust was molecularly confirmed by Sistema Nacional Vigilancia y Monitoreo (on-line publication at www.sinavimo.gov.ar ). Three field locations were sampled and identified as M1, M2, and M3. Transversal cuts of soybean leaves through rust lesions and histo-pathological staining were used for micromor-phologic characterization of the developmental stages of P. pachyrhizi. The disease incidence was estimated as the proportion of affected soybean plants and leaves. Average severity, expressed as the percentage of leaf area affected, including chlorosis, was measured on the terminal leaflet of leaves sampled from the lower one-third of the canopy. Three replicates of 10 plants, randomly chosen, were used. The number of uredinia per square centimeter and per lesion (symptomatic foliar area showing chlorosis and necrosis caused by the fungus) was measured on the undersides of the sampled leaflets at ×40 magnification (1). Typical signs and symptoms of P. pachyrhizi coexisted on soybean leaves with brown spot (Septoria glycines), downy mildew (Peronospora manshurica), anthracnose (Colletotrichum truncatum), and blight and leaf spot (Cercospora kikuchii) and also with bacteria (Pseudomonas and Xanthomonas spp.). Uredinia and telia of the P. pachyrhizi cycle were observed. Uredinia were also observed on soybean petioles. The average size of urediniospores (n = 60) was 23.3 × 16.6 μm. Telia were located adjacent to the uredinia. These telia were dark and crusty with four stacked layers of teliospores. Rust incidence in plants was 100% for the three fields, while the incidence in leaves was 100% for M1 and M2 and 60% for M3. Average disease severity was 50.3, 25.6, and 14.8% for M1, M2, and M3, respectively. The mean number of uredinia per square centimeter was 327, 179, and 177, for M1, M2, and M3, respectively. The number of uredinia per lesion ranged from 1 to 6. P. pachyrhizi was also found on volunteer soybean plants that emerged shortly after harvest. On 40 leaflets, the foliar incidence was 25%, showing one to two lesions with one to two uredinios per leaflet (2). The volunteer soybean plants could constitute a potential early source of inoculum. References: (1) M. Marcchetti et al. Phytopathology. 66:461, 1976. (2) R. Pioli et al. La roya asiática en Santa. Fe, Arg. XII Cong. AAPRESID, II Sem. Internac. Soja, Arg. 283–290, 2004. (3) R. L. Rossi. Plant Dis. 87:102, 2003.

scholarly journals Progress of Asian soybean rust and airborne urediniospores of Phakopsora pachyrhizi in southern Brazil

2012 ◽  
Vol 38 (4) ◽  
pp. 280-287 ◽  
Author(s):  
Jefferson Fernandes do Nascimento ◽  
João Batista Vida ◽  
Dauri José Tessmann ◽  
Laércio Zambolim ◽  
Rafael Augusto Vieira ◽  
...  
Keyword(s):  
Logistic Model ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Southern Brazil ◽  
Crop Season ◽  
Disease Progress ◽  
Asian Soybean Rust ◽  
Cumulative Rainfall ◽  
Progress Curve ◽  
Soybean Plants

Asian soybean rust, caused by the fungus Phakopsora pachyrhizi, was reported at epidemic levels in 2003/2004 and is the main soybean disease in Brazil. The aim of this study was to investigate the spread of Asian soybean rust and to quantify airborne urediniospores in the region of Campo Mourão, Paraná State, Brazil. Three experiments were conducted under field conditions during the 2007/08 and 2008/09 crop seasons. Using the disease gradient method, provided by the application of increasing levels of the fungicide tebuconazole, four Asian soybean rust epidemics at different intensities were obtained in each experiment. To quantify the urediniospores, weathercock-type spore collectors were installed during and between the two crop seasons. Disease progress curves were plotted for each epidemic, and maximum severity was estimated. The curves were fit to the logistic model, which provided higher coefficients of determination and more randomly distributed residuals plotted over time. Analyses of the area under the disease progress curve showed that the largest epidemics occurred in the 2007/2008 crop season and that the progress rates were higher for severity, even among plants protected with the fungicide. The number of urediniospores collected in the air was related to the presence of soybean plants in the cultivated crops. The quantity of urediniospores was also positively correlated to the disease severity and incidence, as well as to cumulative rainfall and favorable days for P. Pachyrhizi infection.

scholarly journals Curative and eradicant action of fungicides to control Phakopsora pachyrhizi in soybean plants

2016 ◽  
Vol 42 (4) ◽  
pp. 295-302 ◽  
Author(s):  
Erlei Melo Reis ◽  
◽  
Tiago Zanatta ◽  
Mateus Zanatta
Keyword(s):  
Soybean Rust ◽  
Growth Chamber ◽  
Phakopsora Pachyrhizi ◽  
Asian Soybean Rust ◽  
Curative Action ◽  
Soybean Plants

ABSTRACT Experiments were carried out in a growth chamber and laboratory to quantify the curative and eradicant actions of fungicides in Asian soybean rust control. The experiments were conducted with the CD 214 RR cultivar, assessing the following fungicides, separately or in association, chlorothalonil, flutriafol, cyproconazole + trifloxystrobin, epoxiconazole + pyraclostrobin, cyproconazole + azoxystrobin, and cyproconazole + picoxystrobin. The fungicides were applied at four (curative) and nine days after inoculation (eradicant treatment). Treatments were evaluated according to the density of lesions and uredia/cm2, and the eradicant treatment was assessed based on the necrosis of lesions/uredia and on uredospore viability. Except for the fungicide chlorothalonil, there was curative action of latent/virtual infections by the fungicides. Penetrant fungicides that are absorbed have curative and eradicant action to soybean rust.

scholarly journals Overwinter and Survival of Asian Soybean Rust Caused by Phakopsora pachyrhizi in Volunteer Soybean Plants in Entre Ríos Province, Argentina

Plant Disease ◽  
2006 ◽  
Vol 90 (6) ◽  
pp. 826-826 ◽  
Author(s):  
A. N. Formento ◽  
J. de Souza
Keyword(s):  
Growing Season ◽  
Soybean Rust ◽  
Limiting Factor ◽  
Research Station ◽  
Phakopsora Pachyrhizi ◽  
Asian Soybean Rust ◽  
On Line ◽  
Freezing Temperatures ◽  
Soybean Plants ◽  
Entre Rios

Asian soybean rust (ASR) caused by Phakopsora pachyrhizi was initially reported in the Province of Entre Ríos, Argentina in April 2004 (1). During the 2004-2005 growing season, ASR was observed in the main soybean-producing (Glycine max) region of the country (4) and it was observed on kudzu (Pueraria lobata) in Misiones and Santa Fe provinces (2). Of the environmental factors affecting rust survival over the winter, temperature is probably the most important one with no germination occurring below 7°C (3). The objectives of this study were to analyze the subfreezing daily air temperatures in the presence of new erumpent uredinia and the germination of P. pachyrhizi urediniospores. Ten sites with volunteer plants close to the meteorological station were found in the Paraná Research Station (31°51′S, 60°31′W). Weekly, from June 2004 through December 2005, sites were randomly sampled for volunteer plants (n = 15). The presence of the ASR was confirmed with a polymerase chain reaction (PCR) assay by SINAVIMO (4). The ASR incidence (ASRI) and erumpent uredinia incidence (EUI) was estimated as the proportion of affected plants. Uredinia were classified as: new erumpent with colorless spores; mature cinnamon with pale cinnamon-brown spores; and dead, empty, and dark without spores. The disease density was estimated as an average of the diseased leaflets according to the following scale: light (number of lesions 1 to 100), moderate (101 to 500), and heavy (>500). The ability of urediniospores from the erumpent pustules to germinate was tested during July 2004 and September 2005 on 1.5% of water agar and kept at 25 ± 2°C for 2 days. The subfreezing daily air (0.05 m height) temperature was registered. During the complete evaluation period, surviving plants from the Vc to R6 stages were observed. However, plants with ASR were only observed from June to July 2004 and May to September 2005. Locally, first planting dates begin in October. New uredinia were observed close to mature and dead uredinia on unifoliate and trifoliate leaflets, and petiols and stems in plants from the V2 to R5 stages. There were 13 days with below freezing temperatures from 1 June to 31 July 2004 (-0.1 to -7.4°C), and ASRI and EUI was 100%. The ASR mean density was light. The coldest temperature was -7.4°C on 11 July 2004, and thereafter, no uredinia were observed until the next growing season. From 25 April to 16 September 2005 there were 20 days with below freezing temperatures (-0.1 to -4.9°C). The ASRI and the EUI were 92.3 (76.9), 75.0 (58.3), 59.1 (32.6), 50.0 (40.9), and 36.7 (23.3)% in May, June, July, August, and September, respectively. The incidence of plants with a moderate to heavy disease level was 50.0, 41.7, 28.6, 29.5, and 10% respectively. Germination rate of urediniospores collected in July 2004 was 11% and 28% in September 2005. Low temperatures do not seem to be a limiting factor for the survival of P. pachyrhizi, and urediniospores could survive on volunteer plants until new soybean plants grow. Since another host is rare or absent in the region, volunteer soybean plants may provide a reservoir of inoculum for the next season. References: (1) A. N. Formento. Roya de la soja en Entre Ríos. INTA-EEA Paraná. On-line publication. INTA, 2004. (2) A. N. Formento and J. de Souza. INTA-EEA Paraná. Serie Extensión No. 32, 2004. (3) M. Marchetti et al. Phytopathology 66:461, 1975. (4) SINAVIMO. Sistema Nacional Argentino de Vigilancia y Monitoreo de Plagas, Roya de la soja. On-line publication. SENASA, 2004.

Sign in / Sign up

Export Citation Format

Share Document