scholarly journals Potential of the Dithiocarbimate Fungicides on the Control of Coffee Leaf Rust and Asian Soybean Rust

2021 ◽  
Vol 13 (10) ◽  
pp. 131
Author(s):  
Lucas Fagundes da Silva ◽  
Laércio Zambolim ◽  
Antônio Eustáquio Carneiro Vidigal ◽  
Mayura Marques Magalhães Rubinger
Keyword(s):  
Leaf Rust ◽  
Global Scale ◽  
Mean Value ◽  
The Other ◽  
Soybean Rust ◽  
Control Treatment ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Coffee Leaf Rust

Coffee leaf rust (Hemileia vastatrix) and Asian soybean rust (Phakopsora pachyrhizi) are diseases that cause great losses in the productivity of these crops, not only in Brazil but on a global scale. Coffee and soybean varieties grown are susceptible to these diseases. Thus, it is necessary to search for efficient compounds for their chemical control, mainly from the group of protectors or residuals so that they can be formulated with systemic fungicides to control the diseases. This allows not only the efficient management of diseases but also the prevention of the emergence of resistant mutants in the populations of these pathogens. In this context, the present study aimed to evaluate the sensitivity and effect of bis(N-R-sulfonyldithiocarbimato)zincate(II) salts fungicides on the epidemiological components of pathosystems coffee × H. vastatrix and soybean × P. pachyrhizi. Initially, four zinc(II) complexes salts (1A, 2A, 1B, and 2B) with N-R-sulfonyldithiocarbimates were synthesized. In the first experiment, the in vitro sensitivity of H. vastatrix and P. pachyrhizi was studied for the four compounds synthesized and mancozeb at 0.5, 5.0, 50.0, 100.0 and 200.0 µmol L-1. All the compounds synthetized in this study had inhibitory effects on H. vastatrix and P. pachyrhizi. In the greenhouse it was studied the effect of bis(N-R-sulfonyldithiocarbimato)zincate(II) salts on the epidemiological components of coffee leaf rust and Asian soybean rust. For the pathosystem coffee × H. vastatrix, there were no differences in the values obtained for the bis(N-R-sulfonyldithiocarbimato)zincate(II) salts and mancozeb for the latent period. For the sporulated lesion variable, the control treatment had a mean value of 149.0 lesions/leaf, differing significantly from the other treatments. The mean value of compound 2B was estimated as 25.0 lesions/leaf, differing significantly from treatments 1A, 1B, 2B, and mancozeb. Treatments 1A, 1B, 2B, and mancozeb did not differ significantly from each other. For the Asian soybean rust, the area under the disease progress curve had a mean value of 75.8 for the control, while for the 2A treatment the value was 4.1, differing from the other compounds. The treatments 1A, 1B, 2A, and mancozeb did not differ significantly from each other. In conclusion, compounds 1A, 2A, and 1B were more efficient in the control of the coffee leaf rust, while compound 2A was efficient in the control of the Asian soybean rust.

scholarly journals Performance of prothioconazole solo or added to mancozeb in the control of Asian soybean rust

2020 ◽  
Vol 46 (4) ◽  
pp. 345-347
Author(s):  
Erlei Melo Reis ◽  
Mateus Zanatta ◽  
Andrea Camargo Reis
Keyword(s):  
Field Experiment ◽  
Grain Yield ◽  
Factorial Design ◽  
The Other ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Site Specific ◽  
Asian Soybean Rust ◽  
Rust Severity

ABSTRACT The evolution of the reduction in Asian soybean rust (caused by Phakopsora pachyrhizi) control by site-specific fungicides has been reported season after season. In a field experiment, the effect of prothioconazole solo and added to multisite mancozeb was evaluated for rust control. Treatments were evaluated in a factorial design of four prothioconazole doses and three mancozeb doses. In a set of treatments, three applications were performed in one soybean cycle and four applications in another one. The first applications were performed at GS V8, 11 days before rust detection, with 2.56% leaflet incidence, while the other applications were at 12 to 14-day interval. Rust severity was quantified, control was calculated in relation to the unsprayed treatment, and soybean grain yield was estimated as kg/ha. Fifty-one to 61% control was obtained with three sprayings and 68% to 70% control with four sprayings of prothioconazole alone. Over 80% control was obtained with at least 0.3 L/ha prothioconazole + 2.0 kg/ha mancozeb, corresponding to 75 g a.i./ha prothioconazole + 1500 g a.i./ha mancozeb. Reduction in P. pachyrhizi control by the use of the site-specific fungicide alone was confirmed, while the addition of mancozeb can recover the efficacy of the site-specific fungicide.

scholarly journals Phosphate Fertilization Reduces the Severity of Asian Soybean Rust Under High Disease Pressure

2018 ◽  
Vol 11 (1) ◽  
pp. 261
Author(s):  
Ana Claudia R. Mochko ◽  
Laércio Zambolim ◽  
Douglas F. Parreira
Keyword(s):  
Chemical Control ◽  
Good Control ◽  
Plant Diseases ◽  
Low Fertility ◽  
Soybean Rust ◽  
High Fertility ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Phosphate Fertilization ◽  
Disease Pressure

Mineral nutrition of plants is a strategy that can be used in the management of plant diseases. Therefore, the objective of this work is to determine which phosphorus dose reduces the severity of Asian soybean rust (Phakopsora pachyrhizi) with or without chemical control. Two trials were conducted under field conditions with six P doses (0, 25, 50, 100, 200 and 400 mg/dm³), and two trials in 100 L pots at P doses 0, 100, 200 and 400 mg/dm3. The inoculation of border rows and inoculation directly on plants in pots was performed with 105/mL of fungus urediniospores 15 days before the application of fungicide to increase the disease pressure. The application of fungicide (azoxystrobin + ciproconazole) was carried out at the R1 stage, and afterwards the mixture was reapplied three times in chemical control treatments. The results showed that the application of triazol + strobilurin fungicides in the presence of P decreased the severity of the disease (area under disease progress curve and disease infection rate) greater than in the absence of the fungicides. The productivity and levels of chlorophyll a, b and total also increased with chemical control in the presence of P. The dose 400 mg/dm3 of P was the most efficient in a soil with a low fertility, and 200 mg/dm³ was efficient in a soil with a high fertility. In conclusion the application of the fungicides triazol + strobilurin was very important to get good control of Asian soybean rust; phosphate fertilization contributed to the amelioration of Asian soybean rust.

scholarly journals Comparison of the efficacy of QoI fungicides, alone or in mixture with triazoles, in Asian soybean rust control, 2016/17 growing season

2019 ◽  
Vol 45 (1) ◽  
pp. 28-32 ◽  
Author(s):  
Erlei Melo Reis ◽  
Luis Henrique Carregal ◽  
Mateus Zanatta
Keyword(s):  
Grain Yield ◽  
Soybean Rust ◽  
Phenological Stages ◽  
Control Efficacy ◽  
Qoi Fungicides ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Crop Cycle ◽  
And Control ◽  
Positive Effect

ABSTRACT Evolution has been reported for the reduction in Phakopsora pachyrhizi sensitivity to the mixtures of the three site-specific mechanisms of action (DMIs, QoIs and SDHIs) used in its control. The aim of this study was to quantify the current contribution of QoIs, alone or in mixture with triazoles, in the control of Asian soybean rust. In an experiment carried out in the field, the efficacy of quinone outside inhibitors (QoIs), or strobilurins, was compared for Asian soybean rust control. The isolated effects of four doses of azoxystrobin, picoxystrobin, pyraclostrobin and trifloxystrobin were evaluated, as well as of four applications during the crop cycle. Control by commercial mixtures of these QoIs with triazoles was also compared. Severity was evaluated in four phenological stages, and control was calculated based on final severity data, area under rust progress curve, defoliation, one-thousand-grain mass, grain yield and damage caused by the disease. The lowest mean of rust control efficacy resulted from applications of azoxystrobin (15.8 and 11.19%) and pyraclostrobin (15.4 and 16.76%) and the highest mean was found for picoxystrobin (54.1 and 54.35 %) and trifloxystrobin (69.7 and 64.46%), calculated based on final severity and AUDPC, respectively. Such efficacy is not enough to cover the fungicide application cost, although there was a positive effect of treatments on disease control and grain yield.

scholarly journals Dynamics of severity of coffee leaf rust (Hemileia vastatrix) on Coffee, in Chanchamayo (Junin-Peru)

2020 ◽  
pp. 517-529
Author(s):  
Leonel Alvarado-Huamán ◽  
Ricardo Roberto Borjas-Ventura ◽  
Viviana Castro-Cépero ◽  
Leslie García-Nieves ◽  
Jorge Jimenez-Dávalos ◽  
...  
Keyword(s):  
Leaf Rust ◽  
Rainy Season ◽  
Dry Season ◽  
Hemileia Vastatrix ◽  
Progress Curve ◽  
Production Distribution ◽  
Coffee Leaf Rust ◽  
High Precipitation ◽  
Degrees Of Severity ◽  
Regional Institute

Introduction. Coffee (Coffea arabica L.) is an important crop in producing countries like Peru, where approximately two million families depend on its production, distribution, and marketing. But in recent years, climate change has increased the presence of coffee leaf rust - CLR (H. vastatrix), a disease that has decreased Peruvian production by up to 27%. Objective. Monitor the severity of CLR in different genotypes of coffee cv. Typica from April-2017 to March-2018. Material and methods. The experiment was carried out in the coffee germplasm bank at the Development Regional Institute (IRD)-Selva of the Universidad Nacional Agraria La Molina. The severity and the area under the disease progress curve (AUDPC) in the lower, middle, and upper part of coffee trees were quantified. Result. There was high severity and AUDPC in the dry season (low precipitation) compared to the rainy season (high precipitation). Severity and AUDPC gradually decreased from the bottom to the top of the plant (lower>middle>upper). Also, UNACAF-24A, UNACAF-16, UNACAF-158, and UNACAF-162 genotypes stood out by showing lowest severity (0-1.1 %) and AUDPC (0-714) in the experiment. Conclusion. In this experiment, the genotypes in dry season presented high peaks of severity and UDPC of CLR, meanwhile, in rainy season the presence of CLR was lower. However, in both seasons, severity and AUDPC gradually decreased from the lower third to the upper thirf of the plant. Finally, UNACAF-24A, UNACAF-16, UNACAF-158, and UNACAF-162 presented the lowest degrees of severity of CLR.

scholarly journals Antifungal Activity of Root Extracts from Baccharis salicina on Germination of Uredospores of Hemileia vastatrix

2021 ◽  
Vol 25 (05) ◽  
pp. 1075-1084
Author(s):  
Anayancy Lam-Gutiérrez
Keyword(s):  
Mass Spectrometry ◽  
Antifungal Activity ◽  
Leaf Rust ◽  
High Resolution Mass Spectrometry ◽  
Multivariable Analysis ◽  
Hemileia Vastatrix ◽  
Root Extracts ◽  
Coffee Leaf Rust ◽  
Rust Pathogen

Hemileia vastatrix is a fungus associated with coffee leaf rust, the most destructive disease of Coffea arabica. The objective of this work was to evaluate the antifungal activity of alcoholic extracts from roots of Baccharis salicina and to determine the metabolites present in these fractions. Antifungal activity was evaluated under in vitro conditions by monitoring the germination ability of H. vastatrix, the coffee leaf rust pathogen. In order to determine the presence of metabolites, chemical characterization of fractions obtained from methanolic root extracts was performed with help of an untargeted metabolomic approach and by using high-resolution mass spectrometry (MS) and MS2 based on direct-injection electrospray mass spectrometry (DIESI-MS) and hierarchical cluster analysis (HCA). Germination percentage was evaluated by leaves fixation technique. The MEBs significantly decreased the percentage of germination of H. vastatrix to levels below 5% as the dose increased. The multivariable analysis confirmed that the distribution of three fractions of methanolic extracts belonged to polyketides, organoheterocyclic compounds, fatty acyls, prenol-lipids, organo-oxygen and farnesene classes. This report comprises the first study of the metabolomic profile and biological activity study of roots from B. salicina against coffee leaf rust pathogen H. vastatrix. © 2021 Friends Science Publishers

scholarly journals Nitrogen doses on soybean growth and Asian rust progress in two cultivars

2017 ◽  
Vol 7 (4) ◽  
pp. 440
Author(s):  
Juliano Perlin De Ramos ◽  
Jerônimo Luiz Andriolo ◽  
Ricardo Silveiro Balardin ◽  
Leandro Nascimento Marques ◽  
Pablo Tuzi Serafini ◽  
...  
Keyword(s):  
Dry Matter ◽  
Total Concentration ◽  
Soybean Rust ◽  
First Year ◽  
Thousand Grain Weight ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Field Assay ◽  
N Rates ◽  
Nitrogen Rates

The main goal of this study was to analyze the range of effects of nitrogen doses on Asian soybean rust (Phakopsora pachyrhizi Sydow) progress over two soybean (Glycine max Merril) cultivars. Two experiments were carried out in greenhouse and in the field, during the 2011/12 and 2012/13 crop years. In the greenhouse, plants were grown in sand in 2011/12 and in a mix of sand and soil in 2012/2013, and supplied with five N doses by dripping fertigation. In the field, the crop was fertilized with six nitrogen doses with broadcast applications. The pathogen was inoculated in all experiments. It was assessed the Area Under Rust Progress Curve (AURPC), defoliation, dry matter, total concentration of N in leaves, number of grains per plant, thousand grain weight and yield. In the greenhouse experiment, nitrogen rates increased the plant growth and the disease progress during the first year. In 2011/12 field assay, a slight decrease of rust progress and a slight increase in yield from 160 to 242 kg ha-1 were recorded. However, under favorable environmental conditions for Asian soybean rust, the increases in grain yield obtained by using high N rates on both cultivars were minor than the damage caused by the disease.

scholarly journals Characterizing Resistance to Phakopsora pachyrhizi in Soybean

Plant Disease ◽  
2011 ◽  
Vol 95 (5) ◽  
pp. 577-581 ◽  
Author(s):  
M. R. Miles ◽  
M. R. Bonde ◽  
S. E. Nester ◽  
D. K. Berner ◽  
R. D. Frederick ◽  
...  
Keyword(s):  
Immune Response ◽  
Partial Resistance ◽  
Single Gene ◽  
Plant Introduction ◽  
The Other ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Progress Curve ◽  
Lesion Type ◽  
Incomplete Resistance

Resistance in soybean to Phakopsora pachyrhizi, the cause of soybean rust, is characterized by either reddish-brown (RB) lesions or an immune response. The RB type of resistance can be incomplete, as evidenced by the presence of sporulating uredinia within lesions. Susceptibility, on the other hand, is exemplified by tan-colored (TAN) lesions, and can be expressed in gradations of susceptibility or partial resistance that are less well defined. This study evaluated traits associated with incomplete or partial resistance to P. pachyrhizi in soybean by comparing 34 soybean accessions inoculated with four P. pachyrhizi isolates. Six accessions produced RB lesions to all four isolates, while 19 accessions produced TAN lesions, including plant introduction (PI) 200492 (Rpp1) and the susceptible check ‘Williams’. Williams had among the largest area under the disease progress curve (AUDPC) values and area under the sporulating uredinia progress curve (AUSUPC) values, while eight accessions had lower AUSUPC values. Of the known sources of single-gene resistance, only PI 230970 (Rpp2), PI 459025B (Rpp4), and PI 594538A (Rpp1b) had lower AUDPC and AUSUPC values than Williams. PI 594538A and PI 561356 had RB lesions and had the lowest AUDPC and AUSUPC values. Of the known sources of single-gene resistance, only PI 230970 (Rpp2) and PI 594538A (Rpp1b) produced fewer and smaller-diameter uredinia than Williams. This study characterized reactions to P. pachyrhizi in 34 accessions based on lesion type and sporulation, and defined incomplete resistance and partial resistance in the soybean–P. pachyrhizi interaction.

scholarly journals Spray solution deposition and Asian rust control in soybean cultivars

2021 ◽  
Vol 25 (12) ◽  
pp. 862-867
Author(s):  
Antonio L. Viegas Neto ◽  
Cristiano M. A. de Souza ◽  
Izidro dos S. de Lima Júnior ◽  
Lígia M. M. da S. Piletti ◽  
Karina de J. E. Martins ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Spray Deposition ◽  
Block Design ◽  
Soybean Rust ◽  
Control Treatment ◽  
Leaf Architecture ◽  
Area Index ◽  
Soybean Cultivars ◽  
Progress Curve

ABSTRACT The control of Asian soybean rust depends on fungicide efficacy and the application technology; however, the leaf architecture of soybean cultivars may also interfere in disease control. This study aimed to evaluate Asian rust control and fungicide deposition using spray nozzles in three soybean cultivars. A randomized block design was used, with treatments arranged in a split-plot scheme; the plots were three soybean cultivars (SYN 1561 IPRO, M6410 IPRO, and M6210 IPRO) and the subplots three spray nozzles (11002 BD, AIXR 110015 and TTJ60 11002), in addition to a control with no fungicide application, and four replicates. The volume median diameter, droplet coverage, leaf area index, area under the disease progress curve, 1,000-grain weight and crop yield were evaluated. The 11002BD and AIXR11005 nozzles provided better spray deposition in cultivars with lower leaf area indexes at the R1 phenological stage. Nozzles 11002BD, AIXR110015 and TTJ60 ensured better management of Asian rust than that of the control treatment, regardless of leaf area index. Cultivar SYN1561 obtained the largest grain yield and highest leaf area index in the season with the highest rainfall, regardless of the spray nozzle used.

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 Integration between genetic and chemical control on the progress of Asian soybean rust and yield

2020 ◽  
Vol 46 (3) ◽  
pp. 198-204
Author(s):  
Deivid Sacon ◽  
Aline Netto ◽  
Michele Fochesatto ◽  
Francine Spitza Stefanski ◽  
Alessandra Gallina ◽  
...  
Keyword(s):  
Genetic Control ◽  
Chemical Control ◽  
Yield Components ◽  
Block Design ◽  
Soybean Rust ◽  
Rio Grande Do Sul ◽  
Thousand Grain Weight ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Randomized Block Design

ABSTRACT The objective of this study was to evaluate the genetic control integrated to the chemical control of Asian soybean rust (ASR) and the effects of these measures on crop yield. The experiment was conducted in Erechim, Rio Grande do Sul State, Brazil, in 2016/17 and 2017/18 crop years, under a randomized block design, in a subdivided plot scheme (cultivars in the plots and fungicides in the subplots), with four replicates. The following cultivars were used: BMX Vanguarda (without ASR tolerance); TMG 7062; TMG 7262, and TMG 7161, tolerant to ASR (Inox™ Technology cultivars). The fungicides used were: T1) control (without application of fungicides); T2) azoxystrobin + benzovindiflupyr; T3) difenoconazole + cyproconazole; T4) trifloxystrobin + prothioconazole, and T5) epoxiconazole + fluxapyroxad + pyraclostrobin. Four fungicide applications were carried out at the V6, R1, R5.1 and R6 stages. During the experiment, for the calculation of the area under disease progress curve (AUDPC), disease severity was assessed at 7-day intervals in a random sample of 10 trifolia per plot. After harvest, yield components were determined: number of grains per plant, thousand grain weight (g), and yield (kg ha-1). In 2017/18 crop year, the fungicide difenoconazole + cyproconazole was not efficient for ASR control. The soybean cultivars TMG 7062, TMG 7161 and TMG 7261 delayed the disease progression; however, only TMG 7161 presented tolerance in the presence of the inoculum in 2016/17 and 2017/18 crop years. The association between chemical and genetic control is shown to be efficient for ASR control.

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