Effect of the interaction between fungicide application time and rainfall simulation interval on Asian Soybean Rust control effectiveness

Environmental factors affect the performance of fungicides in soybean (Glycine max (L.) Merr.). They also influence the residual activity of the products applied to the leaves. The objective of this study was to assess the control effectiveness of the interaction between fungicide application and rainfall simulation on Asian Soybean Rust (ASR). Two experiments were conducted, one in the greenhouse, in a completely randomized design, and the other in the field, in a randomized block design. Both the experiments had the same factorial arrangement of 6x5, with four replications. Factor A: Five fungicide applications time at 0400 h, 0900 h, 1400 h, 1800 h, 2300 h and, a control with no application; Factor B: four intervals of time between the application of fungicide and rainfall simulation at 0, 30, 60 and 120 min for the experiment in the greenhouse and at 2, 30, 60, 120 min for the experiment in the field. A control was included for both the experiments with no rainfall. The number of days to the appearance of the first pustules was determined, along with severity of ASR, relative chlorophyll index and productivity. It was found that the ASR control effectiveness of fungicide applications in soybean plants in sunlight was less efficient with rainfall simulation. The rainfall simulation had greater negative effect on disease control effectiveness in applications conducted at night under dew conditions. The application conducted at 0900 h showed the greatest disease control effectiveness in both greenhouse and in the field conditions. The 1400 h application showed decreased fungicide control residual and ASR control effectiveness, possibly due to a combination of the low relative humidity and high temperature. Rainfall simulation carried out at 120 min after application still had the ability to affect the ASR control effectiveness.

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Effect of adding fungicide to mixtures of triazoles and strobilurins in the control of downy mildew and Asian soybean rust

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632019v4953688 ◽

2019 ◽

Vol 49 ◽

Author(s):

Bruno Zuntini ◽

Rita de Cassia Félix Alvarez ◽

Gustavo de Faria Theodoro ◽

Alan Mario Zuffo

Keyword(s):

Downy Mildew ◽

Block Design ◽

Negative Control ◽

Soybean Rust ◽

Modes Of Action ◽

Asian Soybean Rust ◽

Randomized Block Design ◽

Product Effectiveness ◽

Seed Yields ◽

Number Of Seeds

ABSTRACT Fungicides used to control the Asian soybean rust are composed almost entirely of mixtures involving the systemic (triazoles) and meso-systemic (strobilurins) modes of action. However, to control the soybean downy mildew, only protective fungicides are available. The present study aimed to evaluate the effectiveness of fungicides with different modes of action in the control of downy mildew and Asian soybean rust. A field experiment was carried out in a randomized block design, with seven treatments [negative control; difenoconazole at V7 + (azoxystrobin + cyproconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; carbendazim and mancozeb at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + mancozeb in V7 + (azoxystrobin + tebuconazole) at R2 and R5.1; (tebuconazole + carbendazim) at V7 + (azoxystrobin + tebuconazole) at R2 and R5.1 + mancozeb at R2 and R5.1; (tebuconazole + carbendazim) at V7 + azoxystrobin + tebuconazole at R2 and R5.1 + mancozeb at R2 and R5.1 + carbendazim at R5.1] and four replicates. The following variables were evaluated: disease severity based on diagrammatic scales, phytotoxicity, product effectiveness, defoliation, number of pods per plant, number of seeds per pod, 1,000-seed weight and yield. The treatments with mancozeb addition showed to be more efficient in reducing the severity of mildew and Asian soybean rust and defoliation, providing increased seed yields for the crop. For the soybean downy mildew, the treatments with addition of mancozeb to benzimidazole, strobilurins and triazoles were more efficient in reducing the severity and for the control.

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Reduced Asian Soybean Rust Control by Commercial Fungicides Co-formulations in the 2018-2019 Growing Season in Southern Brazil

Journal of Agricultural Science ◽

10.5539/jas.v13n4p113 ◽

2021 ◽

Vol 13 (4) ◽

pp. 113

Author(s):

Erlei Melo Reis ◽

Mateus Zanatta ◽

Andrea Camargo Reis

Keyword(s):

Block Design ◽

Soybean Rust ◽

Growth Stages ◽

Phakopsora Pachyrhizi ◽

Southern Brazil ◽

Control Efficacy ◽

Growing Seasons ◽

Asian Soybean Rust ◽

Randomized Block Design ◽

Commercial Fungicide

It has been a growers concen the reduction of Asian soybean rust (ASR) control by commercial fungicide co-formulations in the last growing seasons in southern Brazil. The objective of this work was to assess the ASR control efficacy by the most used co-formulations in the 2018/19 season. In a field experiment, 19 fungicides in commercial formulations to control soybean rust caused by Phakopsora pachyrhizi, were evaluated. Chemicals at their recommended doses were sprayed at four soybean growth stages. The first application was performed with 1.82% leaflet incidence and coinciding with R1 phenological stage. The others were performed at 14-18 days intervals. At stage R6, end of the epidemic and coinciding with half of the defoliation in the control plots, the leaf severity was appraised. The experiment was conducted with Ativa soybean cultivar, in 3 × 6 m plots, four replications and randomized block design. The harvest was made with a plot combine and the yield expressed in grains kg/ha. The means were compared by the Scott-Knott test. The disease control efficacy by 17 fungicide co-formulation showed control less than 57%, one with 78% and none with ≥ 80%. The unsprayed treatment severity was 81% and the greatest control of 78% resulted in 3,876 kg/ha yield. Therefore, the hypothesis raised in this work was accepted showing that the site-specific fungicides co-formulations are showing efficacy reduction season after season.

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

Summa Phytopathologica ◽

10.1590/0100-5405/220951 ◽

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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Asian soybean rust control in response to rainfall simulation after fungicide application

Acta Scientiarum Agronomy ◽

10.4025/actasciagron.v43i1.45689 ◽

2020 ◽

Vol 43 ◽

pp. e45689

Author(s):

Amanda Chechi ◽

Carolina Cardoso Deuner ◽

Carlos Alberto Forcelini ◽

Walter Boller

Keyword(s):

Control Method ◽

Rainfall Simulation ◽

Soybean Rust ◽

Time Interval ◽

Phakopsora Pachyrhizi ◽

Simulated Rainfall ◽

Copper Oxychloride ◽

Fungicide Application ◽

Asian Soybean Rust ◽

Spray Volume

Asian soybean rust (Phakopsora pachyrhizi) is the main disease that affects soybean in Brazil. Fungicide applications are the main control method, but they can be influenced by the occurrence of rain. We aimed to study the control of Asian soybean rust in response to the occurrence of simulated rainfall at different times after fungicide application. The penetrant fungicides trifloxystrobin + prothioconazole (60 + 70 g a.i. ha-1) and azoxystrobin + benzovindiflupyr (60 + 30 g a.i. ha-1) and the nonpenetrant fungicides mancozeb (1,500 g a.i. ha-1), chlorothalonil (1,440 g a.i. ha-1), and copper oxychloride (672 g a.i. ha-1) were tested using two spray volumes: 70 and 150 L ha-1. Rain was simulated from 30 to 240 minutes after fungicide application. Soybean leaflets were collected and inoculated with a spore suspension of P. pachyrhizi (5.0 x 104 mL-1) and incubated in plastic boxes for 20 days. The trials were repeated twice. Nonpenetrant fungicides were more susceptible to rain washing, mainly when the 70 L ha-1 spray volume was used. For the penetrative fungicides, the best control percentages were obtained when the rainfall occurred between 120 and 180 minutes after application, while the protective fungicides had the best control percentages when the rainfall occurred approximately 240 minutes after application. The Asian rust control is affected by the characteristics of the fungicide applied, by the time interval between fungicide application and rain occurrence and by the spray volume.

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Agronomic and Economic Evaluation of Sequential Spray of Silicon and Fungicides for a Sustainable Soybean Crop

Journal of Agricultural Studies ◽

10.5296/jas.v8i2.15676 ◽

2020 ◽

Vol 8 (2) ◽

pp. 1

Author(s):

Renato Anastácio Guazina ◽

Rosiane Araujo Rodrigues Nass ◽

Gustavo De Faria Theodoro ◽

Ricardo Carneiro Brumatti ◽

Sofia Michele Muchalak ◽

...

Keyword(s):

Sensitivity Analysis ◽

Economic Evaluation ◽

Block Design ◽

Foliar Spray ◽

Positive Control ◽

Soybean Rust ◽

Aluminum Silicate ◽

Gross Margin ◽

Soybean Cultivars ◽

Randomized Block Design

This study was carried out to determine whether the yield of soybean cultivars and the severity of Asian Soybean Rust (ASR) are influenced by foliar spray of silicon exclusively or along with a fungicide mixture, as well as the economic viability of their use for a sustainable crop. The experiment was performed in randomized-block design, five replicates, two soybean cultivars and (2×6) + 2 factorial arrangements: S1 (AlSi at R1 + R4); S2 (AlSi at R1 + R5.1); S3 (AlSi at R1 + FM at R4); S4 (FM at R1 + AlSi at R4); S5 (AlSi at R1 + FM at R5.1); S6 (FM at R1 + AlSi at R5.1); NC and PC (negative and positive control). The economic evaluation and sensitivity analysis were undertaken for Anta 82 RR. There was no interaction effect between the factors, and cultivar CD 2737 had a higher yield. ASR was less severe in CD 2737, and S3 and S5 provided the lowest disease severity. Exclusive spray of aluminum silicate was able to reduce the number of lesions with uredinia, open uredinia and uredinia per lesion. S3 increased grain yield, resulting in higher revenues and a 66.1% gross margin. Sensitivity analysis revealed that S3 was profitable in all scenarios.

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First Report of Bacterial Pustule on Soybeans in North Dakota

Plant Health Progress ◽

10.1094/php-br-14-0007 ◽

2014 ◽

Vol 15 (4) ◽

pp. 155-156

Author(s):

Erik C. Heitkamp ◽

Robin S. Lamppa ◽

Patricia A. Lambrecht ◽

Robert M. Harveson ◽

Febina M. Mathew ◽

...

Keyword(s):

North Dakota ◽

Economic Loss ◽

Soybean Rust ◽

First Report ◽

Fungicide Application ◽

Asian Soybean Rust

Bacterial pustule has not been previously reported on soybeans in North Dakota, and is unlikely to pose a direct yield threat to soybeans in North Dakota. However, the disease can be mistaken for Asian soybean rust, leading to unnecessary fungicide application and economic loss to the grower. Accepted 3 September 2014. Published 13 October 2014.

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In vivo sensitivity of Phakopsora pachyrhizi to fungicides

Ciência Rural ◽

10.1590/0103-8478cr20190593 ◽

2020 ◽

Vol 50 (1) ◽

Author(s):

Amanda Chechi ◽

Valéria Cecília Ghissi-Mazetti ◽

Elias Zuchelli ◽

Carolina Cardoso Deuner ◽

Carlos Alberto Forcelini ◽

...

Keyword(s):

Soybean Rust ◽

Phakopsora Pachyrhizi ◽

Copper Oxychloride ◽

Toxic Activity ◽

Site Specific ◽

Fungicide Application ◽

Asian Soybean Rust ◽

Randomized Design ◽

Completely Randomized Design

ABSTRACT: Asian soybean rust is one of the most destructive diseases that can be found in this crop. It can be largely controlled by fungicide application. The objective was to assess the sensitivity of P. pachyrhizi isolates to fungicides. The tests were performed in a completely randomized design, with six replicates. The sensitivity of twelve isolates to site-specific and multisite fungicides at concentrations of 0.1; 1.0; 10.0, and 100.0 mg L-1, plus a control with absence of fungicide (0.0 mg L-1) was assessed. Soybean leaflets were immersed in the appropriate fungicide solutions, disposed in wet chambers in plastic boxes, and inoculated using each uredinia suspension of P. pachyhrizi (5.0 x 104 uredospores mL-1), separately. Boxes were incubated for 20 days at a temperature of 23°C and a 12-hour photoperiod. Next, the number of uredinia per cm2 on the abaxial face of each leaflet was evaluated. The active ingredients prothioconazole, trifloxystrobin, fluxapiroxade, trifloxystrobin + prothioconazole, trifloxystrobin + bixafen + prothioconazole, azoxystrobin + benzovindiflupyr, and azoxystrobin + benzovindiflupyr + diphenoconazole were highly fungitoxic for the majority of the isolates, with EC50 lower than 1.0 mg L-1. Diphenoconazole, azoxystrobin, and fenpropimorph were considered moderately fungitoxic for nine of the twelve isolates, with EC50 between 1 and 10 mg L-1. The multisites mancozeb and copper oxychloride presented EC50 responses classified as low toxic for the twelve isolates and eight for chlorothalonil (EC50 between 10 mg L-1 and 50 mg L-1). Site-specific fungicides showed high-to-moderate fungitoxicity to P. pachyrhizi isolates, even as the multisites presented moderate-to-less toxic activity.

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Reproductive and vegetative behavior of hybrid jabuticaba tree under flowering induction

Pesquisa Agropecuária Tropical ◽

10.1590/1983-40632018v4851911 ◽

2018 ◽

Vol 48 (2) ◽

pp. 118-125

Author(s):

Carlos Kosera Neto ◽

Alexandre Hack Porto ◽

Marciéli da Silva ◽

Juliana Cristina Radaelli ◽

Américo Wagner Júnior

Keyword(s):

Block Design ◽

Irrigation Management ◽

Calcium Carbide ◽

Flowering Induction ◽

Randomized Block Design ◽

Control Growth ◽

Development Data ◽

Long Time ◽

Negative Effect ◽

And Control

ABSTRACT Brazil is one of the countries with the greatest vegetal diversity in the world, especially for the Myrtaceae family, to which the jabuticaba tree belongs. Its fruits are of great acceptability, but it is little explored commercially, because it takes a long time to reach the production stage. This study aimed to evaluate the vegetative and reproductive behavior of hybrid jabuticaba trees under flowering induction treatments. A randomized block design was used, with the following treatments: calcium carbide, etefon, paclobutrazol, daily irrigation management and control. Growth and reproductive development data were evaluated. For vegetative growth, there was no difference among the treatments, demonstrating no negative effect. On the other hand, paclobutrazol showed to be the most promising treatment, because it anticipates flowering, is effective in induction and results in a higher production.

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CRESCIMENTO E NUTRIÇÃO MINERAL DE MUDAS DE BARBATIMÃO SOB EFEITO DA OMISSÃO DE NUTRIENTES

FLORESTA ◽

10.5380/rf.v43i4.29443 ◽

2013 ◽

Vol 43 (4) ◽

pp. 569 ◽

Cited By ~ 1

Author(s):

Leandro Carlos ◽

Nelson Venturin ◽

Renato Luiz Grisi Macedo ◽

Emilio Manabu Higashikawa

Keyword(s):

Mineral Nutrition ◽

Dry Matter ◽

Block Design ◽

Nutrient Deprivation ◽

Nutritional Requirements ◽

Limiting Factor ◽

Randomized Block Design ◽

Complete Treatment ◽

Negative Effect ◽

And Control

Com o objetivo de avaliar os requerimentos nutricionais e os efeitos da omissão de nutrientes no desenvolvimento de mudas de barbatimão (Stryphnodendron adstringens (Mart.) Coville), conduziu-se um experimento com o uso da técnica de elemento faltante. Foram empregados 12 tratamentos, em um delineamento de blocos inteiramente casualizados, com oito repetições. Adotaram-se os seguintes tratamentos: completo 1 (adubado com N, P, K, S, B, Cu, Zn e calagem como fonte de Ca e Mg e corrigindo acidez do solo), completo 2 (completo 1 – calagem, tendo CaSO4.2H2O e MgSO4.7H2O como fontes de Ca e Mg sem corrigir acidez do solo), C1 - N, C1 - P, C1 - K, C1 - S, C1 - B, C1 - Zn, C1 - calagem, C2 - Ca, C2 - Mg e testemunha. Foram medidos diâmetros e alturas das plantas, as quais foram separadas em parte aérea e sistema radicular. As mudas foram secas e pesadas, sendo determinados os teores de nutrientes na matéria seca da parte aérea. O fósforo e o boro foram os nutrientes mais limitantes, e a calagem afetou negativamente o crescimento. A sequência de exigência nutricional apresentada pelas mudas de barbatimão em relação ao tratamento completo, em ordem decrescente, foi: P > B > Zn > Mg > K > N > S > Ca.Palavras-chave: Nutriente faltante; cerrado; nutrição florestal. AbstractGrowth and mineral nutrition in seedlings of barbatimão subjected to nutrient deprivation. Aiming to evaluate nutritional requirements and effects of nutrient depravation in developing of seedlings of barbatimão (Stryphnodendron adstringens (Mart.) Coville), we conducted an experiment in a green house. We employed 12 treatments in a fully randomized block design with eight replications. We applied the following treatments: complete 1 (C1-fertilized with N, P, K, S, B, Cu, Zn and lime as Ca and Mg sources), complete 2 (complete 1 – lime with CaSO4.2H2O and MgSO4.7H2O as Ca and Mg sources), C1-N, C1-P, C1-K, C1-S, C1-B, C1-Zn, C1-lime, C2-Ca, C2-Mg, and control. We measured diameters and heights and separated them into shoot and root system. We dried the samples, weighed them and determined the nutrients levels in shoot dry matter. As result, we identified that phosphorus and boron were the most limiting factor to growth, as well as liming had a negative effect on growth; the sequence of nutritional requirements presented by barbatimão seedlings in relation to complete treatment was: P> B> Zn> Mg> K> N> S> Ca.Keywords: Nutrient missing; savannah; forest nutrition.

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

Transactions of the ASABE ◽

10.13031/trans.12130 ◽

2017 ◽

Vol 60 (6) ◽

pp. 1819-1825 ◽

Cited By ~ 2

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.

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