scholarly journals Asian Rust Severity in Soybean Sown in December and February in Mato Grosso State

2021 ◽  
Vol 13 (11) ◽  
pp. 127
Author(s):  
Erlei Melo Reis ◽  
Wanderlei Dias Guerra ◽  
Laércio Zambolim ◽  
Fernando C. Juliatti ◽  
José Otávio Menten ◽  
...  
Keyword(s):  
Soybean Rust ◽  
Copper Oxychloride ◽  
Sowing Time ◽  
Mato Grosso ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Commercial Farms ◽  
Rust Severity ◽  
Crop Sustainability ◽  
On Farm

The objective of this work was to assess the effect of December sowing time with February on the Asian soybean rust severity. In on-farm trials two soybean treatments sowing in December (2020) (DSS.) and February (2021) (FSS) were assessed for Asian soybean rust severity in 24 sites, in three regions of Mato Grosso state. The DSS treatment was established in the growers commercial farms and the FSS in a 5 ha area sown specifically for this treatment. The DSS treatment was conducted in 16 sites and the FSS in eigth. For rust control fungicides with efficacy higher than 60% were sprayed consisting of DMIs, QoIs and SDHIs in double or triple mixtures, always added by multisites (chlorothalonil, mancozeb, or copper oxychloride). About eighty soybean leaflets from four plots repetitiond, demarcated at random in each field, were taken in each smpling. In laboratory leaflet severity was appraised and area under disease progress curve (AUDPC) calculated. Related to DSS, the AUDPC overall mean was 174 units and receiving 6.9 fungicide spraying and for FSS 26 units with 4.8 fungicide sprayings. Our results reinforce that the sowing time can be changed from the end of December to February to maintain soybean crop sustainability.

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 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 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.

scholarly journals Control of Asian soybean rust with mancozeb, a multi-site fungicide

2015 ◽  
Vol 41 (1) ◽  
pp. 64-67 ◽  
Author(s):  
Luís Henrique Carregal Pereira da Silva ◽  
Hercules Diniz Campos ◽  
Juliana Resende Campos Silva ◽  
Erlei Melo Reis
Keyword(s):  
Grain Yield ◽  
Analysis Of Variance ◽  
Soybean Rust ◽  
Phakopsora Pachyrhizi ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Asian Soybean Rust ◽  
Progress Curve ◽  
Fungicide Mixtures ◽  
Rust Severity

An experiment conducted in the field the action of mancozeb, a fungicide of multi-site action was tested, to control soybean rust caused by Phakopsora pachyrhizi. Its performance was compared to that of the mixture cyproconazole (DMI) + azoxystrobin (QoI). The soybean cultivar NA 7337 RR was used with a population of 400,000 plants/ha cultivated in 20m2 plots. Treatments consisted of mancozeb levels (1.5 and 2.0 kg/ha) applied four, six and eight times. The DMI + QoI mixture was applied three times at 0.3 L/ha + Nimbus. Rust severity was assessed six times in the plots and data were integrated as the area under the disease progress curve (AUDPC). The plots were harvested and grain yield was expressed as kg/ha. Data on AUDPC and yield were subjected to analysis of variance and means compared according to Turkey's test (p = 0.005). Treatments with mancozeb were superior to DMI + QoI mixture both for rust control and grain yield. Four applications of 2.0 k/ha mancozeb were more efficient than three applications of the mixture used as standard. Mancozeb has the potential to be added to fungicide mixtures in the establishment of soybean rust anti-resistance strategy.

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.

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 In vivo sensitivity of Phakopsora pachyrhizi to fungicides

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.

scholarly journals Balance among calcium, magnesium and potassium levels affecting Asian Soybean Rust severity

2015 ◽  
Vol 1 (1) ◽  
pp. 39 ◽  
Author(s):  
Guilherme Garcia Gaspar ◽  
Hideaki Wilson Takahashi ◽  
Marcelo Giovanetti Canteri ◽  
José Carlos Vieira de Almeida ◽  
Roberto Antunes Fioretto ◽  
...  
Keyword(s):  
Soybean Rust ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Calcium Magnesium ◽  
Rust Severity ◽  
Soybean Plants ◽  
Red Latosol ◽  
Good Nutritional State ◽  
Nutritional Balance

This work aimed to analyze the effect of the variation of the proportions of calcium in relation to the contentes of magnesium and potassium in the cationic capacity of change (CCC) of the soil, seeking to propitiate the  appropriate balance of bases, so that the soybean plants presented good nutritional state and had conditions of resisting to the attack of Phakopsora pachyrhizi Syd. & P. Syd. The experiment was driven in randomized blocks with eight replications and the treatments consisted of doses of Ca:Mg:K in relation to CCC of the soil being:1) without correction of the bases (original soil with 3,8%:6,6%:2,4%); 2) 35:15:5; 3) 45:15:5; 4) 55:15:5; 5) 65:15:5; 6) 75:15:5. The soybean cultivar used in the experiment was BRS 184, sowed in mud vases containing dystrophic Red Latosol (Oxisol) as substrate. The inoculation was realized in the fenologic stadium V4. The disease severity was determined through visual notes considering the percentage foliate area with visible symptoms of the disease, being calculated the Area Under Disease Progress Curve (AUDPC). The data were submitted to the variance analysis (p<0.05) and fitting to regression models. The balance among the nutrientes was analyzed being calculated the index DRIS. The contents of nutrients, the matter dry indexes (MDI) and nutritional balance index (NBI) were inserted in the program ChecarDris for obtaining of the index DRIS. The results appeared that the percentages of 55% of calcium, 15% of magnesium and 5% of potassium, increase larger nutritional balance in the soybean providing to smallest area under disease progress curve (AUDPC), reduction in the severity of the rust (%), besides increase the largest productivity.

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.

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