Control Of Soybean Rust Research Articles

A loop-mediated isothermal amplification assay for the rapid diagnosis of soybean rust caused by Phakopsora pachyrhizi

Soybean rust caused by the fungus Phakopsora pachyrhizi is one of the most destructive diseases to soybean production worldwide. For the rapid diagnosis and the control of soybean rust, we developed a loop-mediated isothermal amplification (LAMP) assay that targets a P. pachyrhizi-specific gene (Phapa_6409908) identified from a comparative genomic analysis of 61 Pucciniomycotina strains. Using a set of screened primers and the optimized reaction conditions of 62°C for 70 min, the LAMP assay can detect P. pachyrhizi while excluding other plant pathogens. The assay consistently showed high sensitivity in detecting low contents of P. pachyrhizi DNA (10 pg). We confirmed the practical application of this LAMP assay in diagnosing soybean rust using soybean leaf samples collected from fields in four cities of Sichuan Province, China, in 2020 and 2021. The developed LAMP assay provides a specific, sensitive, and rapid method for the diagnosis of soybean rust caused by P. pachyrhizi, which can assist in the prediction, prevention, and control of this major soybean disease.

Effect of site-specific fungicide mixtures combined with mancozeb on soybean rust control in north-western Paraguay

RESUMEN Debido a que la información sobre el uso de fungicidas para el control de la roya asiática de la soja (RAS) en Paraguay es escasa, el objetivo de este trabajo fue evaluar el efecto de 18 tratamientos (fungicidas sitio-específicos aplicados de forma aislada y en combinación con mancozeb) sobre la RAS. Se realizaron dos ensayos en La Paloma (Canindeyú, Paraguay) en dos épocas de siembra (S1: 10/10/2018 y S2: 20/01/2019) bajo un diseño factorial en bloques completos al azar (Factor A: fungicidas sitio-específicos, Factor B: fungicidas sitio-específicos + mancozeb) con cuatro repeticiones. Se realizó el análisis de varianza para cada experimento y la prueba de comparación de medias de Scott-Knott al 5 % de probabilidad. La interacción Factor A x Factor B no fue significativa para las variables evaluadas en ambas épocas de siembra. Sin embargo, el Factor A fue significativo para la severidad, ABCPE y la EC en ambas épocas de siembra, donde las mezclas picoxistrobina + benzovindiflupyr y azoxistrobina + benzovindiflupyr dieron lugar a la menor severidad de la RAS y mayor EC en S1, mientras que en S2 sobresalieron las mezclas de trifloxistrobina + prothioconazol + bixafen y trifloxistrobina + prothioconazol. Los fungicidas menos eficientes fueron picoxistrobina + ciproconazol y trifloxistrobina + ciproconazol. La adición de mancozeb a las mezclas de fungicidas sistémicos favoreció la EC en 7 % en S1 y en 3,8 % en S2 y el rendimiento en 174 kg ha-1 en S1 y 128 kg ha-1 en S2.

Impact of Fungicide Application Timing Based on Soybean Rust Prediction Model on Application Technology and Disease Control

The application of remote sensing techniques and prediction models for soybean rust (SBR) monitoring may result in different fungicide application timings, control efficacy, and spraying performance. This study aimed to evaluate the applicability of a prediction model as a threshold for disease control decision-making and to identify the effect of different application timings on SBR control as well as on the spraying technology. There were two experimental trials that were conducted in a 2 × 4 factorial scheme: 2 cultivars (susceptible and partially resistant to SBR); and four application timings (conventional chemical control at a calendarized system basis; based on the prediction model; at the appearance of the first visible symptoms; and control without fungicide application). Spray deposit and coverage at each application timing were evaluated in the lower and upper region of the soybean canopy through quantitative analysis of a tracer and water-sensitive papers. The prediction model was calculated based on leaf reflectance data that were collected by remote sensing. Application timings impacted the application technology as well as control efficacy. Calendarized system applications were conducted earlier, promoting different spray performances. Spraying at moments when the leaf area index was higher obtained poorer distribution. None of the treatments were capable of achieving high spray penetration into the canopy. The partially resistant cultivar was effective in holding disease progress during the crop season, whereas all treatments with chemical control resulted in less disease impact. The use of the prediction model was effective and promising to be integrated into disease management programs.

Influence of spraying tips on the efficiency of chemical control of soybean rust

Asian rust is responsible for significant reductions in soybean yield. The application of fungicide is the main method of control of this disease, and to maintain the efficiency of phytosanitary treatment it is necessary to know several features of the application technology. Spray tips are fundamental for the quality of phytosanitary products application and exert a direct influence on spraying efficiency. The objective of this study was to evaluate the efficiency of different spray tips in spray deposition and leaf cover in the lower, middle and upper thirds of soybean plants in three distinct phenological stages. Another objective was to evaluate the efficiency of the commercial mixture trifloxystrobin + prothioconazole (FOX®), applied by different spray tips, in the control of Asian rust and soybean yield. The experiment was conducted for two agricultural years, and six spray tips were evaluated: TT 11001, TTJ60 11002, TXA 8003, 30HCX 12, GRD120 02 and GAT11002 in three fungicide applications with intervals of 15 days, in the phenological stages V6–V7, R1 and R4, using the working pressure of 5 bar and spray volume of 200 L ha−1. The coverage and deposition of spray promoted by all spray tips, in the three phenological stages of soybeans, were sufficient to provide satisfactory control of rust, with means of disease severity ranging from 1.69 to 4.70%, compared to the control (mean severity of 54.34%), without significant loss of yield in the sprayed plots. All evaluated spray tips can be recommended for use in spraying FOX® fungicide (trifloxystrobin + prothioconazole) in soybean crop for Asian rust control, when the spray volume applied is 200 L ha−1.

Association of hydrogen peroxide with commercial fungicide formulations in the control of Asian soybean rust

ABSTRACT: In recent years, there have been reductions in the efficacy of the fungicidal control of Phakopsora pachyrhizi, thereby hindering the management of soybean rust and compromising crop yield. This study evaluated the effects of incorporating hydrogen peroxide (H2O2) in commercial fungicide formulations on the control of soybean rust. We conducted two experiments, one of which was performed in a greenhouse environment and the other under field conditions. In both environments, we examined the following four control programs using commercial fungicide formulations: (I) azoxystrobin + cyproconazole (quinone outside inhibitor [QoI] + demethylation inhibitor [DMI]); (II) picoxystrobin + cyproconazole (QoI + DMI); (III) pyraclostrobin + epoxiconazole + fluxapyroxad (QoI + DMI + succinate dehydrogenase inhibitor); and (IV) water (H2O) (program without fungicide application), combined with the incorporation of (i) H2O2; (ii) mancozeb (positive control I); (iii) chlorothalonil (positive control II); or (iv) water (H2O) alone. Analyses of infected leaf area and grain yield revealed that the addition of H2O2 to the formulations of DMI and QoI fungicides led to a reduction in disease severity of between 33% and 44% relative to the effects of these products used alone, as well as an increase in yield and SPAD values. The use of H2O2 and multi-site fungicides alone failed to provide effective control of soybean rust. In addition to enhancing the efficacy of disease control, the use of H2O2 associated with commercial fungicide mixtures was shown to be a potential tool for the management of fungicide resistance and reduction in losses from Asian soybean rust.

Spectral responses at visible and near-infrared wavelengths of soybean plants to fungicides

ABSTRACT: The study evaluated the efficacy and soybean spectral responses to fifteen foliar fungicide mixtures labeled to control Asian soybean rust. Canopy level reflectance was measured using a multispectral camera onboard a multirotor drone before and two hours after each spray. The third application of fungicides improved control of soybean rust and increased yield. Nevertheless, up to three consecutive foliar fungicides applications did not affect the reflectance of soybean plants at visible and infrared wavelengths. Thus, drones can be a viable strategy for data acquisition regardless of the application of the fungicides.

Estimativas da eficácia de fungicidas para controle da ferrugem asiática da soja com base em dados da AACPD ou da severidade final da doença

ABSTRACT Data from experiments conducted in the field during four growing seasons aiming at the chemical control of soybean rust caused by Phakopsora pachyrhizi, the control values calculated for the area under the disease progress curve (AUDPC) were compared with those of the final severity. Data were analyzed according to a factorial experiment: (i) treatments with fungicides and (ii) rust control. Out of 70 treatments, the control was always lower when calculated with the AUDPC than with the final severity. In the general means for four growing seasons, the AUDPC control was of 48.5 (range 36 to 65%) and for calculation with the final severity 43.25% (range 29 to 66%). It can be concluded that, in the case of soybean rust, the control calculation shows advantage when performed with final severity data.

Expanding the Chemical Space of Succinate Dehydrogenase Inhibitors via the Carbon-Silicon Switch Strategy.

The carbon-silicon switch strategy has become a key technique for structural optimization of drugs to widen the chemical space, increase drug activity against targeted proteins, and generate novel and patentable lead compounds. Flubeneteram, targeting succinate dehydrogenase (SDH), is a promising fungicide candidate recently developed in China. We describe the synthesis of novel SDH inhibitors with enhanced fungicidal activity to enlarge the chemical space of flubeneteram by employing the C-Si switch strategy. Several of the thus formed flubeneteram-silyl derivatives exhibited improved fungicidal activity against porcine SDH compared with the lead compound flubeneteram and the positive controls. Disease control experiments conducted in a greenhouse showed that trimethyl-silyl-substituted compound W2 showed comparable and even higher fungicidal activities compared to benzovindiflupyr and flubeneteram, respectively, even with a low concentration of 0.19 mg/L for soybean rust control. Furthermore, compound W2 encouragingly performed slightly better control than azoxystrobin and was less active than benzovindiflupyr at the concentration of 100 mg/L against soybean rust in field trials. The computational results showed that the silyl-substituted phenyl moiety in W2 could form strong van der Waals (VDW) interactions with SDH. Our results indicate that the C-Si switch strategy is an effective method for the development of novel SDH inhibitors.

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

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.

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

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.

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

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.

Performance and Profitability of Rain-Based Thresholds for Timing Fungicide Applications in Soybean Rust Control.

Soybean rust (SBR), caused by the fungus Phakopsora pachyrhizi, is the most damaging disease of soybean in Brazil. Effective management is achieved by means of calendar-timed sprays of fungicide mixtures, which do not explicitly consider weather-associated disease risk. Two rain-based action thresholds of disease severity values (DSV50 and DSV80) were proposed and compared with two leaf wetness duration-temperature thresholds of daily values of infection probability (DVIP6 and DVIP9) and with a calendar program, with regard to performance and profitability. An unsprayed check treatment plot was included for calculating relative control. Disease severity and yield data were obtained from 29 experiments conducted at six sites across four states in Brazil during the 2012-13, 2014-15, and 2015-16 growing seasons, which represented different growing regions and climatic conditions. The less conservative rainfall action threshold (DSV80) resulted in fewer fungicide sprays compared with the other treatments, and the more conservative one (DSV50) resulted in fewer sprays than the DVIP thresholds. Yield was generally higher with the increase in spray number, but the economic analysis showed no significant differences in the risk of not offsetting the costs of fungicide sprays regardless of the system. Therefore, based on the simplicity and the profitability of the rain-based model, the system is a good candidate for incorporating into the management of SBR in soybean production fields in Brazil.

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

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.

Spray volume deposits and fungicide efficacy on soybean rust (Phakopsora pachyrhizi)

Soybean rust (SBR), caused by Phakopsora pachyrhizi, is one of the most destructive fungal diseases affecting soybean yields in many countries. Fungicide application methods that provide better SBR control efficacy may reduce soybean losses due to this disease. We investigated the effects of spray volumes applying the fungicide pyraclostrobin plus epoxiconazol at 133 + 50 g a.i. ha-1 by a conventional sprayer (CS) and an air-assisted sprayer (AAS). Field experiments were conducted comparing the effects of spray volumes of 110, 160, and 210 L ha-1 and two application techniques (CS and AAS) on spray deposits and SBR control. Fungicide efficacies were measured by disease severity, thousand seed weight, and yield. Correlations between disease severity and yield were also assessed. All treatments were applied with an Advance 2000 AM18 sprayer. In general, SBR disease and yield did not differ significantly when fungicide applications were applied with AAS compared to CS. Increasing the spray volume from 110 to 210 L ha-1 did not increase spray deposit coverage on soybean leaves. Low disease severity was obtained by fungicide applications using a spray volume of 210 L ha-1. Safe recommendations of ground spray volumes for SBR control should be between 160 and 210 L ha-1, using hydraulic nozzles.

Spray volumes and fungicide rates on Asian soybean rust control

ABSTRACT The aim of this study was to assess the effect of different spray volumes and fungicide rates on Asian soybean rust control. Experiments were conducted in the field and in the laboratory during 2014 and 2016. We varied the fungicide rates (45 + 52.5, 60 + 70 and 75 + 87.5 g a.i. ha-1 for the mixture trifloxystrobin + prothioconazole, and 45 + 22.5, 60 + 30 and 75 + 37.5 g a.i. ha-1 for azoxystrobin + benzovindiflupyr) and the spray volume (100, 150 and 200 L ha-1) for application on soybean plants in the field. Another experiment was conducted in the laboratory, using the recommended rates of the fungicides trifloxystrobin + prothioconazole (60 + 70 g a.i. ha-1) and azoxystrobin + benzovindiflupyr (60 + 30 g a.i. ha-1). The spray volume of 200 L ha-1 resulted in the best disease control only for the third out of three applications carried out in the field (control between 68.4% and 70.1%). However, there was no statistical difference in grain yield for all tested spray volumes when we used the recommended fungicide rates (3422, 3526 and 3601 kg ha-1) or higher rates (3529, 3586 and 3550 kg ha-1). The decrease in the fungicide rate directly implied reduced rust control for both experiments (20 to 39% in the field and up to 71.4% in the laboratory).

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

Product deposition and foliar surface cover are highly impacting factors on the efficiency of foliar fungicides applied to soybean cultivars, due to their low mobility, with side effects on Asian soybean rust (ASR) control. Spray bar support systems, such as the air curtain (Vortex®) and the use of nozzles along the bar (Dropleg®), stand out as an alternative to obtain a better distribution of fungicide throughout the plant. In this study, two spray bar support systems (Vortex® and Dropleg®) were, therefore, evaluated and compared with the conventional spraying method based on the biological efficacy in ASR control. In order to do this, two harvests, with three spacing between rows and two cultivars were employed. Vortex® and Dropleg® spray bar support mechanisms do not effectively contribute to the optimization of Asian soybean rust control or to the grain crop yield, regardless of cultivar and row spacing. Decreasing the row spacing did not influence the level of control of Asian soybean rust, as the highest grain yield was obtained with the smallest spacing. The cultivar with genetic resistance to Asian rust showed lower levels of this disease, thus, greater control against the use of fungicides.

Performance of new flat fan nozzle design in spray deposition, penetration and control of soybean rust

Fungicide application technology to control soybean rust (SBR) is lacking and requires optimization to improve spray coverage in the lower part of the crop canopy as well as the spray distribution uniformity. The goal of this study was to evaluate the effects of flat fan nozzles with different angles and spray volumes on the optimization of fungicide application in soybean, as well as on SBR and its effect on crop yield. For this purpose, a 2-year (2016–2018) field experiment was conducted in Botucatu, SP, Brazil. Three spray nozzles were evaluated: flat fan, double flat fan and angled flat fan, with two spray volumes. A quantitative analysis of the spray deposition was conducted, assessing the spray deposits on the lower and upper part of the plants with Brilliant Blue tracer. Furthermore, SBR severity was evaluated based on the number of pustules cm−2 and on the AUDPC, as well as the establishment of treatment control efficacy and its effect on soybean yield. Irrespective of the spray nozzles and volumes, the penetration of the droplets into the crop canopy was impaired at the reproductive stage, with less deposition in the lower part of the plant, although the larger spray volume provided greater spray deposition. All the treatments promoted effective control of the disease, with no changes in efficacy due to a larger spray volume or angled nozzles. The correct spray volume, especially with respect to the different growth stages, greatly influences spray deposition and penetration.

Effect of Selected Biopesticides in Reducing Soybean Rust (Phakopsora pachyrhizi) Development.

The intensive use of fungicides in controlling soybean rust (SBR), a damaging foliar fungal disease of soybean caused by the obligate fungus Phakopsora pachyrhizi, may have accelerated the insensitivity of P. pachyrhizi populations to fungicides. The objective of this study was to determine the effect of selected biopesticides and their application time on reducing SBR infection. There were differences (P < 0.05) in percent rust reduction values for application times, biopesticide treatments, and their interaction in detached-leaf and whole-plant greenhouse experiments. All application times and nearly all biopesticide treatments reduced (α = 0.05) fungal infection compared with the nonfungicide control. Among the treatments, Bacillus subtilis QST 713 and acibenzolar-S-methyl often reduced fungal sporulation more than the other treatments in detached-leaf and whole-plant greenhouse experiments. The identification of biopesticides effective to P. pachyrhizi may be a valuable alternative or complement to synthetic fungicides and may be useful in integrated pest management programs for SBR control.

The Arabidopsis non-host defence-associated coumarin scopoletin protects soybean from Asian soybean rust.

SummaryThe fungus Phakopsora pachyrhizi (Pp) causes Asian soybean rust (SBR) disease which provokes tremendous losses in global soybean production. Pp is mainly controlled with synthetic fungicides to which the fungus swiftly develops fungicide resistance. To substitute or complement synthetic fungicides in Asian soybean rust control, we aimed to identify antifungal metabolites in Arabidopsis which is not a host for Pp. Comparative transcriptional and metabolic profiling of the Pp‐inoculated Arabidopsis non‐host and the soybean host revealed induction of phenylpropanoid metabolism‐associated genes in both species but activation of scopoletin biosynthesis only in the resistant non‐host. Scopoletin is a coumarin and an antioxidant. In vitro experiments disclosed fungistatic activity of scopoletin against Pp, associated with reduced accumulation of reactive oxygen species (ROS) in fungal pre‐infection structures. Non‐antioxidant and antioxidant molecules including coumarins with a similar structure to scopoletin were inactive or much less effective at inhibiting fungal accumulation of ROS and germination of Pp spores. When sprayed onto Arabidopsis leaves, scopoletin also suppressed the formation of Pp pre‐infection structures and penetration of the plant. However, scopoletin neither directly activated defence nor did it prime Arabidopsis for enhanced defence, therefore emphasizing fungistatic activity as the exclusive mode of action of scopoletin against Pp. Because scopletin also protected soybean from Pp infection, the coumarin may serve as a natural fungicide or as a lead for the development of near‐to‐nature fungicides against Asian soybean rust.

Comparação da eficácia de fungicidas IQes, isolados ou em mistura com triazóis, no controle da ferrugem asiática da soja, safra 2016/17

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.