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 Potassium Fertilization Reduces the Severity of Asian Soybean Rust Under High Disease Pressure

2019 ◽  
Vol 11 (11) ◽  
pp. 116
Author(s):  
Laércio Zambolim ◽  
Ana Claudia R. Mochko ◽  
Douglas Ferreira Parreira ◽  
Samuel Vasconcelos Valadares
Keyword(s):  
Chlorophyll A ◽  
Chemical Control ◽  
Block Design ◽  
Soybean Rust ◽  
Cellular Processes ◽  
Asian Soybean Rust ◽  
Potassium Fertilization ◽  
Progress Curve ◽  
Severity Of The Disease ◽  
Disease Pressure

Potassium (K) is one of the essential nutrients for plants and is involved in many cellular processes which might influence the severity of diseases. There are few reports of the effect of increasing concentrations of K in the field on the severity of the Asian soybean rust (ASR) caused by Phakopsora pachyrhizi. In this context, the objective of this work was to verify the influence of increasing concentrations of K on ASR, in the absence and presence of chemical control, in conditions that highly favored the development of the disease. Two experiments were conducted under field conditions and two also in the field but in pots with a capacity of 100 L. Evaluated concentrations of K were 0.0, 100, 200, and 400 mg/dm³, respectively in a randomized complete block design. The application of the fungicide mixture azoxystrobin (200 g/L) + cyproconazol (80 g/L) was performed at 45, 60, and 75 days after emergence. The severity of the disease, area under the disease progress curve (AUDPC), rate of disease progression (r), soybean productivity, and contents of chlorophyll a, b and total were evaluated. The severity, AUDPC, and r decreased with the increase of the concentration of K and fungicide application, while the rate of disease control and soybean productivity increased. Contents of chlorophyll a, b and total also had higher values according to the increase in the concentration of K. Potassium fertilization reduced the severity of ASR and grain yield under high disease pressure with or without chemical control.

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.

scholarly journals CHEMICAL CONTROL OF ASIAN SOYBEAN RUST AS A FUNCTION OF CULTIVAR, ROW SPACING AND SPRAY BAR SUPPORT SYSTEMS

2019 ◽  
Vol 39 (4) ◽  
pp. 504-511
Author(s):  
Laercio L. Hoffmann ◽  
Rafael Roehrig ◽  
Walter Boller ◽  
Carlos A. Forcelini
Keyword(s):  
Chemical Control ◽  
Support Systems ◽  
Soybean Rust ◽  
Row Spacing ◽  
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 Effects of Silicon Applications on Soybean Rust Development Under Greenhouse and Field Conditions

Plant Disease ◽  
2011 ◽  
Vol 95 (3) ◽  
pp. 317-324 ◽  
Author(s):  
E. M. Lemes ◽  
C. L. Mackowiak ◽  
A. Blount ◽  
J. J. Marois ◽  
D. L. Wright ◽  
...  
Keyword(s):  
Field Experiments ◽  
Production Systems ◽  
Disease Onset ◽  
The United States ◽  
Plant Diseases ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Soybean Production ◽  
Progress Curve ◽  
Production Areas

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is one of the most destructive fungal diseases affecting soybean production. Silicon (Si) amendments were studied as an alternative strategy to control SBR because this element was reported to suppress a number of plant diseases in other host–pathogen systems. In greenhouse experiments, soybean cultivars inoculated with P. pachyrhizi received soil applications of wollastonite (CaSiO3) (Si at 0, 0.96, and 1.92 t ha–1) or foliar applications of potassium silicate (K2SiO3) (Si at 0, 500, 1,000, or 2,000 mg kg–1). Greenhouse experiment results demonstrated that Si treatments delayed disease onset by approximately 3 days. The area under disease progress curve (AUDPC) of plants receiving Si treatments also was significantly lower than the AUDPC of non-Si-treated plants. For field experiments, an average 3-day delay in disease onset was observed only for soil Si treatments. Reductions in AUDPC of up to 43 and 36% were also observed for soil and foliar Si treatments, respectively. Considering the natural delayed disease onset due to the inability of the pathogen to overwinter in the major soybean production areas of the United States, the delay in disease onset and the final reduction in AUDPC observed by the soil Si treatments used may lead to the development of SBR control practices that can benefit organic and conventional soybean production systems.

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 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 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 Fungicide management in the Asian soybean rust

2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Antonio Luiz Viegas Neto ◽  
Cristiano Márcio Alves de Souza ◽  
Bruno Fernandes Bertoncello ◽  
Izidro Dos Santos Lima Júnior ◽  
Ligia Maria Maraschi da Silva Piletti ◽  
...  
Keyword(s):  
Experimental Design ◽  
Constant Pressure ◽  
Soybean Rust ◽  
Effective Control ◽  
Systemic Fungicides ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Crop Disease ◽  
Spray Rate ◽  
Chemical Groups

Asian soybean rust is the major crop disease and the management of the use of the fungicide is important for effective control. The objective of this work was to evaluate the management of fungicides with sequential applications to control Asian soybean rust. The experimental design used was a randomized block with four replications and eight treatments with different combinations of fungicides from the following chemical groups: triazole, strobilurin, carboxamide, and dithiocarbamate. The applications were carried out with backpack spray equipment at constant pressure (CO2) and a spray rate of 200 L ha-1. The severity of rust, the area under the disease progress curve, control efficiency, mass of 1,000 grains, and productivity were evaluated. The protective fungicide mancozeb, in mixtures with systemic fungicides, were more effective for the control of Asian soybean rust than the systemic fungicides applied without the protective fungicide.

scholarly journals Alternative products on Asian soybean rust control and their influence on defoliation, productivity and yield components

2020 ◽  
Vol 46 (2) ◽  
pp. 98-104
Author(s):  
Gislaine Gabardo ◽  
Maristella Dalla Pria ◽  
Henrique Luis da Silva ◽  
Mônica Gabrielle Harms
Keyword(s):  
Yield Components ◽  
Field Experiments ◽  
Yield Component ◽  
Soybean Rust ◽  
Strongly Correlated ◽  
Manganese Zinc ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Copper Manganese ◽  
Rust Severity

ABSTRACT To study the efficiency of Asian soybean rust (Phakopsora pachyrhizi) control and to test the effects of using alternative products and fungicides, two field experiments were conducted during the harvest seasons 2013/2014 and 2014/2015. Treatments for the experiments were: 1- control (water); 2- acibenzolar-S-methyl; 3- calcium; 4- micronutrients: copper, manganese and zinc; 5- micronutrients: manganese, zinc and molybdenum; 6- NK fertilizer; 7- Ascophyllum nodosum, and 8- azoxystrobin + cyproconazole. The evaluated variables were: Asian soybean rust severity, defoliation, productivity and yield components. Based on severity data, the area under the disease progress curve was calculated. In the two experiments, the alternative products had no effect on Asian soybean rust or defoliation. Only the treatment with fungicide controlled the disease and decreased defoliation. The yield component affected by the treatments was the number of pods per plant, in both harvest seasons. Treatment with the fungicide protected soybean from yield loss in both experiments. Defoliation was strongly correlated with the weight of one thousand seeds and the number of pods per plant, emphasizing the importance of maintaining the leaf area to ensure the maintenance of the yield components in soybean crop.

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