Microscopic Characterization of the Infectious Process, ROS Production, and Fungi Cellular Death of Alternaria alternata on Tangerine Resistant to QoIs.

Quinone outside inhibitor (QoI) fungicide resistance in Alternaria alternata populations was reported in Brazil for the first time in 2019, in São Paulo orchards, and the mutation G143A in cytochrome b (cytb) was found in resistant isolates. Our study investigated the infectious process, production of reactive oxygen species (ROS), and fungal cell death in resistant (QoI-R) and sensitive (QoI-S) A. alternata pathotype tangerine (Aapt) isolates. Morphological characterization of Aapt isolates was performed using confocal laser scanning microscopy (CLSM). Alternaria brown spot (ABS) symptoms were produced by Aapt isolates on tangelo cv. BRS Piemonte. Germination of QoI-R conidia and production of germ tubes on tangelo leaflets treated with 100 µg mL-1 of pyraclostrobin 18 h after inoculation (hai) was observed using scanning electron microscopy (SEM). At the same time, QoI-S conidial germination was inhibited on tangelo leaflets treated with pyraclostrobin. ROS production and cell death in Aapt isolates at high fungicide concentrations were observed using CLSM. QoI-S conidia exhibited high ROS production, indicating high oxidative stress. When dyed with propidium iodate (PI), QoI-S conidia emitted red fluorescence, showing cell death and confirming their sensitive phenotype. In contrast, QoI-R conidia neither produced ROS nor exhibited red fluorescence, indicating no cell death and confirming their resistant phenotype. Therefore, our findings evidence that microscopic techniques may help characterize events during fungi-plant interactions, ROS production, cell death, and Aapt phenotypes resistant and sensitive to QoIs using fluorometric protocols.

Toxicity potential of a pyraclostrobin-based fungicide in plant and green microalgae models.

Pyraclostrobin-based fungicides play an effective role in controlling fungal diseases and are extensively used in agriculture. However, there is concern regarding the potential adverse effects attributed to exposure to these fungicides on non-target organisms and consequent influence exerted on ecosystem functioning. Thus, it is essential to conduct studies with model organisms to determine the impacts of these fungicides on different groups of living organisms. The aim of this study was to examine the ecotoxicity associated with exposure to commercial fungicides containing pyraclostrobin. The focus of the analysis involved germination and initial development of seedlings of 4 plant models (Lactuca sativa, Raphanus sativus, Pennisetum glaucum and Triticum aestivum), in addition to determining the population growth rate and total carbohydrate content in microalga Raphidocelis subcapitata. The fungicide pyraclostrobin adversely influenced growth and development of the tested plants, indicating a toxic effect. The fungicide exerted a significant impact on the initial development of seedlings of all model species examined with T. aestivum plants displaying the greatest susceptibility to pyraclostrobin. Plants of this species exhibited inhibitory effects on both aerial parts and roots when treated with a concentration of 4.75 mg/L pyraclostrobin. In addition, the green microalga R. subcapitata was also significantly affected by the fungicide, especially at relatively high concentrations as evidenced by a reduction in total carbohydrate content. This commercial fungicide demonstrated potential phytotoxicity for the tested plant models and was also considered toxic to the selected microalgae, indicating an ecotoxic effect that might affect other organisms in aquatic environments.

Pesticides in vegetables and fruits from Brazil and risk assessment.

Levels of 237 pesticides were assessed in 1063 fruit and vegetable samples from 12 São Paulo markets spanning the period May 2015 to December 2022. The QuEChERS method was employed for extraction, followed by GC-MS/MS and LC-MS/MS analysis. Findings indicated that 30% of the samples contained residues below the Maximum Residue Limits (MRLs), while 6% exceeded these. Additionally, 23% exhibited excessive residues for their respective crops and 40% had no detectable residues. Health risk evaluation focused on tomatoes, cabbage and oranges, revealing exposure within 0.002-0.9% of the Acceptable Daily Intake (ADI), indicating no chronic risks. However, pyraclostrobin in orange presented a potential acute risk for adults (112%). These results underscore the necessity for continuous monitoring of pesticide residues in fruits and vegetables to safeguard consumer health, especially considering the significant levels of consumption.

Experimental and theoretical vibrational study of the fungicide pyraclostrobin.

The vibrational study of the pyraclostrobin (methyl N-(2-{[1-(4-chlorophenyl)-1H-pyrazol-3-yl]oxymethyl}phenyl) N-methoxycarbamate) molecule, a synthetic fungicide for agricultural uses, was performed. Pyraclostrobin belongs to the strobilurin family and acts by inhibiting the fungus respiratory chain at the level of Complex III, becoming an excellent agent for preventive, curative and eradicative activities against a wide range of fungal plant pathogens. However, its presence needs to be monitored to avoid the excessive and/or improper use that may compromise human or environmental health. The FTIR and Raman spectra of pyraclostrobin in pure solid state were recorded and compared with those obtained from both the substance in CH2Cl2 solution and in an agricultural commercial product (Comet® BASF). The spectral analysis was complemented with quantum-chemical calculations at the DFT level (B3LYP/6-311G*) for the predictions of the molecular geometry and its vibrational behavior. The high flexibility of the molecule was explored by performing potential energy scans on several dihedral angles and the results suggested that the main conformer of pyraclostrobin is that possessing the ortho-substituted benzene ring in perpendicular orientation regarding the plane that contains the ether group and the pyrazole ring, although the presence of a second preferred conformation in the experimental vibrational spectra was not ruled out. Among the many vibrational bands of pyraclostrobin that were well identified in the spectrum of the composite product for agricultural use, the one located at 936 cm-1 stood out. This signal was assigned to a vibration of the pyrazole ring and promised to be a good candidate as marker of the presence of the fungicide in complex matrixes.

Fungicide pyraclostrobin affects midgut morphophysiology and reduces survival of Brazilian native stingless bee Melipona scutellaris.

Native stingless bees are key pollinators of native flora and important for many crops. However, the loss of natural fragments and exposure to pesticides can hinder the development of colonies and represent a high risk for them. Nevertheless, most studies are conducted with honeybees and there are not many studies on native species, especially in relation to the effects of fungicides on them. Therefore, the objective of this paper is to evaluate the effects of sublethal concentrations of pyraclostrobin, on Melipona scutellaris forager workers. These Brazilian native stingless bees were submitted to continuous oral exposure to three concentrations of pyraclostrobin in sirup: 0.125 ng a.i./µL (P1), 0.025 ng a.i./µL (P2), and 0.005 ng a.i./µL (P3). Histopathological and histochemical parameters of midgut, as well as survival rate were evaluated. All concentrations of fungicide showed an increase in the midgut lesion index and morphological signs of cell death, such as cytoplasmic vacuolizations, presence of atypical nuclei or pyknotic nuclei. Histochemical analyzes revealed a decreased marking of polysaccharides and neutral glycoconjugates both in the villi and in peritrophic membrane in all exposed-groups in relation to control-groups. P1 and P2 groups presented a reduction in total protein marking in digestive cells in relation to control groups. As a consequence of alteration in the midgut, all groups exposed to fungicide showed a reduced survival rate. These findings demonstrate that sublethal concentrations of pyraclostrobin can lead to significant adverse effects in stingless bees. These effects on social native bees indicate the need for reassessment of the safety of fungicides to bees.

A mixture of fipronil and fungicides induces alterations on behavioral and oxidative stress parameters in zebrafish.

Pesticide commercial mixtures, including the insecticide fipronil and the fungicides pyraclostrobin and methyl-thiophanate, have been used in concomitant pest control, facilitating agricultural management. Their widespread use can lead to soil and water contamination and potentially induce damages in the ecosystem, producing toxic effects in non-target organisms. Despite their toxicological potential, their effects on behavioral and biochemical parameters are not well understood. Here we investigated the effects of the mixture of fipronil and fungicides (MFF) pyraclostrobin and methyl- thiophanate on behavioral and biochemical parameters of oxidative stress in adult zebrafish. Animals exposed to the highest MFF tested concentration showed a decrease in the total distance traveled and in the number of crossings in the different zones of the tank. Furthermore, animals exposed to highest MFF tested concentration spent more time in water surface. In addition, our data showed that the exposure to this preparation promoted a decrease in non-protein thiol content as well as in catalase activity. Finally, pesticide exposure induced an increase in the superoxide dismutase/catalase ratio. Our results indicate that alterations in behavioral and oxidative parameters are involved in MFF toxicity in zebrafish. The antioxidant mechanisms analyzed were altered in concentrations that did not affect zebrafish behavior. Therefore, the assessment of oxidative stress parameters in zebrafish brains could be very useful to detect the early effects of environmental exposure to the MFF.

Chemical parameters and ruminal disappearance of Secale cereale rye forage in different harvest systems with or without fungicide / Parâmetros bromatológicos e desaparecimento ruminal da forragem do centeio Secale cereale em diferentes sistemas de corte com ou sem fungicida

The objective of the study was to evaluate the chemical parameters and the ruminal disappearance of dry matter of forage from the rye Secale cereale, cv. Temprano managed in different harvest regimes at the vegetative stage, with or without application of a fungicide based on Fluxapyroxade + Piraclostrobin at the pre-flowering stage. This was a randomized block experimental design and the treatments consisted of evaluating the forage harvested at floury grain stage, as follow, SCSF: no cut at the vegetative stage, no application of fungicide; SCCF: no cut at the vegetative stage with fungicide application; UCSF: one cut at the vegetative stage, no application of fungicide; UCCF: one cut with fungicide application; DCSF: two cuts at the vegetative stage, no fungicide application; DCCF: two cuts with fungicide application. In general, one cut at the vegetative stage and a subsequent cut for ensiling at floury grain stage was the best system used in cv. Temprano, based on the chemical parameters and ruminal disappearance. This system provided a better composition of fiber carbohydrates with lower contents of Acid Detergent Fiber (41.55%) and Lignin (10.79%) after cutting and resulted in a better disappearance rate of dry matter at the rumen level (0.46 %) per hour of exposure, highlighting the cut at the vegetative stage that produced a material with 20.76% Crude Protein and 52.69% Neutral Detergent showing its nutritional quality for use in grazing land or as haylage. The application of fungicide provided significant improvements in the contents of crude protein (8.24% vs 7.23%) and mineral matter (3.02% vs 2.82%) of the plant at the time of ensiling, which generated better dry matter disappearance rates in the rumen.(AU)

O objetivo do estudo foi avaliar os parâmetros bromatológicos e o desaparecimento ruminal da matéria seca da foragem de centeio Secale cereale, cv. Temprano manejado em diferentes regimes de cortes no estádio vegetativo, com ou sem aplicação de fungicida a base de Fluxapiroxade + Piraclostrobina no estádio de pré-florescimento. O delineamento experimental foi o de blocos ao acaso e os tratamentos constaram da avaliação das forragens colhidas no estádio de grão farináceo, sendo SCSF: sem corte no vegetativo e sem aplicação de fungicida; SCCF: sem corte no vegetativo com aplicação de fungicida; UCSF: um corte no vegetativo sem aplicação de fungicida; UCCF: um corte com aplicação de fungicida; DCSF: dois cortes no vegetativo sem aplicação de fungicida; DCCF: dois cortes com aplicação de fungicida. De maneira geral, a realização de um corte no estádio vegetativo e posterior corte para ensilagem no estádio de grão farináceo foi o melhor sistema empregado no centeio cv. Temprano com base nos parâmetros de bromatologia e desaparecimento ruminal. Esse sistema proporcionou melhor composição dos carboidratos fibrosos com menores teores de Fibra em Detergente Ácido (41,55%) e Lignina (10,79%) após o corte e gerou melhor taxa de desaparecimento ruminal da matéria seca a nível ruminal (0,46%) por hora de exposição, ressaltando ainda o corte do vegetativo que produziu um material com 20,76% de Proteína Bruta, Fibra em detergente neutro de 52,69% evidenciando a sua qualidade nutricional para uso em pastejo ou como silagem pré-secada. O uso do fungicida proporcionou melhoras significativas nos teores de proteína bruta (8,24% vs 7,23%) e matéria mineral (3,02% vs 2,82%) da planta no momento da ensilagem, o que gerou melhores índices de desaparecimento da matéria seca no rúmen.(AU)

From the environment to the host: How non-azole agrochemical exposure affects the antifungal susceptibility and virulence of Cryptococcus gattii.

Agrochemicals such as the non-azoles, used to improve crop productivity, poses severe undesirable effects on the environment and human health. In addition, they induce cross-resistance (CR) with clinical drugs in pathogenic fungi. However, till date emphasis has been given to the role of azoles on the induction of CR. Herein, we analyzed the effect of a non-azole agrochemical, pyraclostrobin (PCT), on the antifungal susceptibility and virulence of the human and animal pathogens Cryptococcus gattii and C. neoformans. We determined the minimum inhibitory concentration (MIC) of fluconazole (FLC), itraconazole, ravuconazole, amphotericin B, and PCT on colonies: (i) that were not exposed to PCT (non-adapted-NA-cultures), (ii) were exposed at the maximum concentration of PCT (adapted-A-cultures) and (iii) the adapted colonies after cultivation 10 times in PCT-free media (10 passages-10p-cultures). Our results showed that exposure to PCT induced both temporary and permanent CR to clinical azoles in a temperature-dependent manner. With the objective to understand the mechanism of induction of CR through non-azoles, the transcriptomes of NA and 10p cells from C. gattii R265 were analyzed. The transcriptomic analysis showed that expression of the efflux-pump genes (AFR1 and MDR1) and PCT target was higher in resistant 10p cells than that in NA. Moreover, the virulence of 10p cells was reduced as compared to NA cells in mice, as observed by the differential gene expression analysis of genes related to ion-metabolism. Additionally, we observed that FLC could not increase the survival rate of mice infected with 10p cells, confirming the occurrence of permanent CR in vivo. The findings of the present study demonstrate that the non-azole agrochemical PCT can induce permanent CR to clinical antifungals through increased expression of efflux pump genes in resistant cells and that such phenomenon also manifests in vivo.

Flutriafol and pyraclostrobin residues in Brazilian green coffees.

The aim of this work was to monitor flutriafol and pyraclostrobin residues in Brazilian green coffees. More than 10,000 samples were analyzed. The pesticides were extracted using the QuEChERS method and analyzed by LC-MS/MS. The validated method is fast, with 5 min runs, and efficient, as precision and accuracy showed RSD no greater than 5% and recoveries within the 88-119% range. LOQ for flutriafol and pyraclostrobin were 0.005 mg/kg. The results of the analyzed samples showed that the percentage of nonconformities regarding flutriafol increased throughout the years, with over 1200 samples (11.8%). On the other hand, just 15 samples (0.15%) presented residues above 10 µg/kg for pyraclostrobin. Considering that flutriafol is a toxic and carcinogenic pesticide, as well as the increase in the number of irregularities throughout the years, it becomes important to implement public actions to assure consumer safety.

Acúmulo de carboidratos no desenvolvimento de tomateiro tratado com produtos químicos / Accumulation of carbohydrates in the development of tomato plants treated with different chemical products

Este trabalho teve como objetivo estudar os efeitos fisiológicos da piraclostrobina, boscalida, reguladores vegetais e extrato vegetal no acúmulo de carboidratos durante o desenvolvimento de plantas de tomateiro (Solanum lycopersicum L.), híbrido Giuliana, em condições de ambiente protegido. Os tratamentos estudados foram: T1- testemunha; T2- piraclostrobina 0,2 g L-1; T3- boscalida 0,075 g L-1, T4- piraclostrobina 0,2 g L-1 + boscalida 0,075 g L-1, T5- IBA + GA3 + cinetina 375 mg L-1, T6- GA4+7 + benzilaminopurina 100 mg L-1 e T7- extrato vegetal 100 mg L-1. A curva de acúmulo de carboidratos foi realizada com cinco amostras, em intervalos de 20 dias entre as avaliações, sendo a 1ª avaliação realizada aos 30 dias após o transplantio, no dia da primeira aplicação dos tratamentos. A cada coleta as plantas foram separadas em caule, folha e frutos, nos quais foram avaliados os teores de açúcares solúveis totais, açúcares redutores e sacarose. Também foram avaliados os efeitos dos tratamentos no teor de clorofila e nas trocas gasosas. O delineamento experimental adotado foi inteiramente casualizado, com quatro repetições e seis avaliações destrutivas ao longo do desenvolvimento, sendo uma planta por unidade experimental em cada amostragem. A piraclostrobina e a boscalida aplicados isolados e/ou combinados favoreceram o incremento de carboidratos nas folhas, caules e frutos de...(AU)

This work had the purpose to study the physiological effects of pyraclostrobin, boscalid, plant growth regulators and plant extract on the accumulation of carbohydrates during the development of tomato plants (Solanum lycopersicum L.), hybrid Giuliana, in protected environment conditions. The treatments were: T1- control; T2- pyraclostrobin 0.2 g L-1; T3- boscalid 0.075 g L-1, T4- pyraclostrobin 0.2 g L-1 + boscalid 0.075 g L-1, T5- IBA + GA3 + kinetin 375 mg L-1, T6- GA4+7 + benzylaminopurine 100 mg L-1 and T7- plant extract 100 mg L-1. The carbohydrate accumulation curve was accomplished with 5 samples, at 20-day intervals between evaluations, the 1st evaluation being carried out at 30 days after transplantation, on the day of the first treatment application. At each sampling the plants were separated in stem, leaves and fruits, of which the contents of total soluble sugars, reducing sugars and saccharose were evaluated. The effects of the treatments on chlorophyll content and gas exchanges were also evaluated. The experimental design was completely randomized, with 4 repetitions and 6 destructive evaluations during the development, with 1 plant per experimental unit for each sampling. The pyraclostrobin and boscalid applied in isolation and/or combined favor the increase of carbohydrates in leaves, stems and fruits of tomato hybrid Giuliana.(AU)

Acúmulo de carboidratos no desenvolvimento de tomateiro tratado com produtos químicos / Accumulation of carbohydrates in the development of tomato plants treated with different chemical products

Este trabalho teve como objetivo estudar os efeitos fisiológicos da piraclostrobina, boscalida, reguladores vegetais e extrato vegetal no acúmulo de carboidratos durante o desenvolvimento de plantas de tomateiro (Solanum lycopersicum L.), híbrido Giuliana, em condições de ambiente protegido. Os tratamentos estudados foram: T1- testemunha; T2- piraclostrobina 0,2 g L-1; T3- boscalida 0,075 g L-1, T4- piraclostrobina 0,2 g L-1 + boscalida 0,075 g L-1, T5- IBA + GA3 + cinetina 375 mg L-1, T6- GA4+7 + benzilaminopurina 100 mg L-1 e T7- extrato vegetal 100 mg L-1. A curva de acúmulo de carboidratos foi realizada com cinco amostras, em intervalos de 20 dias entre as avaliações, sendo a 1ª avaliação realizada aos 30 dias após o transplantio, no dia da primeira aplicação dos tratamentos. A cada coleta as plantas foram separadas em caule, folha e frutos, nos quais foram avaliados os teores de açúcares solúveis totais, açúcares redutores e sacarose. Também foram avaliados os efeitos dos tratamentos no teor de clorofila e nas trocas gasosas. O delineamento experimental adotado foi inteiramente casualizado, com quatro repetições e seis avaliações destrutivas ao longo do desenvolvimento, sendo uma planta por unidade experimental em cada amostragem. A piraclostrobina e a boscalida aplicados isolados e/ou combinados favoreceram o incremento de carboidratos nas folhas, caules e frutos de...

This work had the purpose to study the physiological effects of pyraclostrobin, boscalid, plant growth regulators and plant extract on the accumulation of carbohydrates during the development of tomato plants (Solanum lycopersicum L.), hybrid Giuliana, in protected environment conditions. The treatments were: T1- control; T2- pyraclostrobin 0.2 g L-1; T3- boscalid 0.075 g L-1, T4- pyraclostrobin 0.2 g L-1 + boscalid 0.075 g L-1, T5- IBA + GA3 + kinetin 375 mg L-1, T6- GA4+7 + benzylaminopurine 100 mg L-1 and T7- plant extract 100 mg L-1. The carbohydrate accumulation curve was accomplished with 5 samples, at 20-day intervals between evaluations, the 1st evaluation being carried out at 30 days after transplantation, on the day of the first treatment application. At each sampling the plants were separated in stem, leaves and fruits, of which the contents of total soluble sugars, reducing sugars and saccharose were evaluated. The effects of the treatments on chlorophyll content and gas exchanges were also evaluated. The experimental design was completely randomized, with 4 repetitions and 6 destructive evaluations during the development, with 1 plant per experimental unit for each sampling. The pyraclostrobin and boscalid applied in isolation and/or combined favor the increase of carbohydrates in leaves, stems and fruits of tomato hybrid Giuliana.

Controle de helmintosporiose em milho pipoca com a aplicação de fungicidas em diferentes épocas / Northern leaf blicht control in popcorn with the fungicide applied in different times

The popcorn culture is extremely susceptible to foliar diseases that relate to plants, reduce photosynthetic area, considerably reducing production. Although there are fungicides registered for the control of these diseases, there are still questions to which fungicides and times which apply the product to greater efficiency in control. The objective of this study was to evaluate the performance of three fungicide (pyraclostrobin + epoxyconazol 0.75 L c.p. ha-1 , trifloxystrobin + protioconazol to 1.00 L c.p. ha-1 and carbendazim + tebuconazole + cresoxim methyl 0,5 L c.p. ha-1 and the check without fungicide) in the Exserohilum turcicum control. Fungicides were applied at four growth stages of popcorn: V8, VT, R2 and V8 plus R2, totaling 16 treatments with six replications. The assay was performed in the agricultural season 2012/2013 on the campus of the Faculdade Integrado de Campo Mourão-PR. We used the design on track with split plots. In this assay were evaluated: the area under the disease progress curve (AUDPC), and plant height, ear, number of rows of grain and grain number in row, yield per plant and expandability. There was a trend for lower AUDPC treatments with fungicides pyraclostrobin + epoxyconazol for all application times compared to the other treatments evaluated. However, the lowest AUDPC were observed with the application of fungicides pyraclostrobin + epoxyconazol and carbendazim + tebuconazole + cresoximmethyl applied at V8 plus R2.

A cultura do milho pipoca é extremamente suscetível a doenças foliares, que ao incidirem nas plantas,diminuem a área fotossintética, reduzindo consideravelmente a produção. Apesar de existirem fungicidasregistrados para o controle destas doenças no milho (Zea mays), ainda há dúvidas de quais fungicidas e emquais épocas aplicar o produto para uma maior eficiência no controle. Objetivou-se neste trabalho avaliar odesempenho de três fungicidas (piraclostrobina + epoxiconazol a 0,75 L p.c. ha-1, trifloxistrobina +protioconazol a 1,00 L p.c. ha-1e carbendazim + tebuconazol + cresoxim-metílico a 0,5 L p.c. ha-1, além deuma testemunha) no controle da helmintosporiose. Os fungicidas foram aplicados em quatro estádiosfenológicos da cultura do milho pipoca: V8, VT, R2 e em V8 e R2, totalizando 16 tratamentos, com seisrepetições. O ensaio foi realizado no ano agrícola 2012/2013 no Campus da Faculdade Integrado de CampoMourão-PR. Utilizou-se o delineamento em faixa com parcelas subdivididas. Neste ensaio foram avaliadas:a área abaixo da curva de progresso da doença (AACPD), altura de plantas e de inserção de espiga, númerode fileiras de grãos e número de grãos na fileira, produção por planta e capacidade de expansão. Verificouseuma tendência de menor AACPD com os tratamentos fungicidas piraclostrobina + epoxiconazol paratodas as épocas de aplicação comparadas aos demais tratamentos avaliados. Porém, as menores AACPDforam observadas com a aplicação dos fungicidas piraclostrobina + epoxiconazol e carbendazim +tebuconazol + cresoxim-metílico aplicados em V8 e R2.

Controle de helmintosporiose em milho pipoca com a aplicação de fungicidas em diferentes épocas / Northern leaf blicht control in popcorn with the fungicide applied in different times

The popcorn culture is extremely susceptible to foliar diseases that relate to plants, reduce photosynthetic area, considerably reducing production. Although there are fungicides registered for the control of these diseases, there are still questions to which fungicides and times which apply the product to greater efficiency in control. The objective of this study was to evaluate the performance of three fungicide (pyraclostrobin + epoxyconazol 0.75 L c.p. ha-1 , trifloxystrobin + protioconazol to 1.00 L c.p. ha-1 and carbendazim + tebuconazole + cresoxim methyl 0,5 L c.p. ha-1 and the check without fungicide) in the Exserohilum turcicum control. Fungicides were applied at four growth stages of popcorn: V8, VT, R2 and V8 plus R2, totaling 16 treatments with six replications. The assay was performed in the agricultural season 2012/2013 on the campus of the Faculdade Integrado de Campo Mourão-PR. We used the design on track with split plots. In this assay were evaluated: the area under the disease progress curve (AUDPC), and plant height, ear, number of rows of grain and grain number in row, yield per plant and expandability. There was a trend for lower AUDPC treatments with fungicides pyraclostrobin + epoxyconazol for all application times compared to the other treatments evaluated. However, the lowest AUDPC were observed with the application of fungicides pyraclostrobin + epoxyconazol and carbendazim + tebuconazole + cresoximmethyl applied at V8 plus R2.(AU)

A cultura do milho pipoca é extremamente suscetível a doenças foliares, que ao incidirem nas plantas,diminuem a área fotossintética, reduzindo consideravelmente a produção. Apesar de existirem fungicidasregistrados para o controle destas doenças no milho (Zea mays), ainda há dúvidas de quais fungicidas e emquais épocas aplicar o produto para uma maior eficiência no controle. Objetivou-se neste trabalho avaliar odesempenho de três fungicidas (piraclostrobina + epoxiconazol a 0,75 L p.c. ha-1, trifloxistrobina +protioconazol a 1,00 L p.c. ha-1e carbendazim + tebuconazol + cresoxim-metílico a 0,5 L p.c. ha-1, além deuma testemunha) no controle da helmintosporiose. Os fungicidas foram aplicados em quatro estádiosfenológicos da cultura do milho pipoca: V8, VT, R2 e em V8 e R2, totalizando 16 tratamentos, com seisrepetições. O ensaio foi realizado no ano agrícola 2012/2013 no Campus da Faculdade Integrado de CampoMourão-PR. Utilizou-se o delineamento em faixa com parcelas subdivididas. Neste ensaio foram avaliadas:a área abaixo da curva de progresso da doença (AACPD), altura de plantas e de inserção de espiga, númerode fileiras de grãos e número de grãos na fileira, produção por planta e capacidade de expansão. Verificouseuma tendência de menor AACPD com os tratamentos fungicidas piraclostrobina + epoxiconazol paratodas as épocas de aplicação comparadas aos demais tratamentos avaliados. Porém, as menores AACPDforam observadas com a aplicação dos fungicidas piraclostrobina + epoxiconazol e carbendazim +tebuconazol + cresoxim-metílico aplicados em V8 e R2.(AU)

Tratamento de sementes com fungicidas e inseticidas como redutores dos efeitos do estresse hídrico em plantas de soja / Seed treatment with fungicides and insecticides reducing the hydric stress on soybean plants

O objetivo do trabalho foi avaliar o efeito de quatro tratamentos de sementes: água (T1), carbendazim + thiram (T2), fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) sobre parâmetros de crescimento de plantas de soja submetidas a dois regimes hídricos (presença e ausência de estresse hídrico) estabelecidos logo após a emergência das plântulas. O experimento foi conduzido em casa de vegetação e campo. Na casa de vegetação, nos tratamentos sem estresse hídrico, foram feitas quatro irrigações por dia e, nos tratamentos com estresse hídrico, foi realizada uma irrigação a cada três dias. Neste ensaio, foi avaliada a estatura de plantas, comprimento radicular, volume radicular, massa seca da parte aérea, massa seca radicular e área foliar. No ensaio de campo, o estresse hídrico foi estabelecido pela construção de túneis baixos de polietileno que impediram o fornecimento de água pela irrigação e chuva. No campo, foram avaliados estatura de planta, teor relativo de clorofila, emergência, ataque de lagarta-elasmo e rendimento de grãos. Nos dois ambientes, as plantas foram mantidas sob estresse até 28 dias após a emergência. Em casa de vegetação, todos os parâmetros foram influenciados pelo tratamento de sementes na presença e ausência de estresse hídrico. No campo, o tratamento com fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) proporcionaram maior estatura de planta e teor relativo de clorofila em ambos os regimes hídricos e maior emergência e rendimento de grãos em plantas sem e com restrição hídrica, respectivamente. Conclui-se que o tratamento de sementes com esses produtos promove alterações benéficas nas plantas, aumentando sua tolerância ao estresse hídrico, com efeito positivo sobre o rendimento de grãos da soja.

The objective of this research was evaluate four seed treatments: water (T1), carbendazim + thiram (T2), fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) on growth parameters of soybean plants with or without low water availability. The experiments were conducted under field conditions and greenhouse. In greenhouse, in treatments without low water availability, it was made four irrigations by day and in treatments with low water availability, it was made one irrigation each three days. In this trial, it was evaluated the plant height, root length, root volume, dry shoot weight, dry root weight and foliar area. In the field trial, low water availability was established by construction of low tunnels of polyethylene which prevented the water supply by irrigation and rain. In the field, it was also evaluated the plant height, the relative chlorophyll content, emergence, lesser cornstalk borer attack and grain yield. In the both environment, the plants were kept on stress until 28th days after emergence. In greenhouse, all the parameters were influenced by seed treatments with or without low water availability. In field, the treatment with fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) promoted higher plant height and relative chlorophyll content in both hydric schemes, higher emergence and grain yield in plants without and with lower water availability, respectively. It was concluded that seed treatment with these products promote benefit changes in plant, increasing its tolerance to hydric stress, with positive effect on soybean grain yield.

Tratamento de sementes com fungicidas e inseticidas como redutores dos efeitos do estresse hídrico em plantas de soja

The objective of this research was evaluate four seed treatments: water (T1), carbendazim + thiram (T2), fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) on growth parameters of soybean plants with or without low water availability. The experiments were conducted under field conditions and greenhouse. In greenhouse, in treatments without low water availability, it was made four irrigations by day and in treatments with low water availability, it was made one irrigation each three days. In this trial, it was evaluated the plant height, root length, root volume, dry shoot weight, dry root weight and foliar area. In the field trial, low water availability was established by construction of low tunnels of polyethylene which prevented the water supply by irrigation and rain. In the field, it was also evaluated the plant height, the relative chlorophyll content, emergence, lesser cornstalk borer attack and grain yield. In the both environment, the plants were kept on stress until 28th days after emergence. In greenhouse, all the parameters were influenced by seed treatments with or without low water availability. In field, the treatment with fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) promoted higher plant height and relative chlorophyll content in both hydric schemes, higher emergence and grain yield in plants without and with lower water availability, respectively. It was concluded that seed treatment with these products promote benefit changes in plant, increasing its tolerance to hydric stress, with positive effect on soybean grain yield.

O objetivo do trabalho foi avaliar o efeito de quatro tratamentos de sementes: água (T1), carbendazim + thiram (T2), fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) sobre parâmetros de crescimento de plantas de soja submetidas a dois regimes hídricos (presença e ausência de estresse hídrico) estabelecidos logo após a emergência das plântulas. O experimento foi conduzido em casa de vegetação e campo. Na casa de vegetação, nos tratamentos sem estresse hídrico, foram feitas quatro irrigações por dia e, nos tratamentos com estresse hídrico, foi realizada uma irrigação a cada três dias. Neste ensaio, foi avaliada a estatura de plantas, comprimento radicular, volume radicular, massa seca da parte aérea, massa seca radicular e área foliar. No ensaio de campo, o estresse hídrico foi estabelecido pela construção de túneis baixos de polietileno que impediram o fornecimento de água pela irrigação e chuva. No campo, foram avaliados estatura de planta, teor relativo de clorofila, emergência, ataque de lagarta-elasmo e rendimento de grãos. Nos dois ambientes, as plantas foram mantidas sob estresse até 28 dias após a emergência. Em casa de vegetação, todos os parâmetros foram influenciados pelo tratamento de sementes na presença e ausência de estresse hídrico. No campo, o tratamento com fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) proporcionaram maior estatura de planta e teor relativo de clorofila em ambos os regimes hídricos e maior emergência e rendimento de grãos em plantas sem e com restrição hídrica, respectivamente. Conclui-se que o tratamento de sementes com esses produtos promove alterações benéficas nas plantas, aumentando sua tolerância ao estresse hídrico, com efeito positivo sobre o rendimento de grãos da soja.

Tratamento de sementes com fungicidas e inseticidas como redutores dos efeitos do estresse hídrico em plantas de soja

The objective of this research was evaluate four seed treatments: water (T1), carbendazim + thiram (T2), fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) on growth parameters of soybean plants with or without low water availability. The experiments were conducted under field conditions and greenhouse. In greenhouse, in treatments without low water availability, it was made four irrigations by day and in treatments with low water availability, it was made one irrigation each three days. In this trial, it was evaluated the plant height, root length, root volume, dry shoot weight, dry root weight and foliar area. In the field trial, low water availability was established by construction of low tunnels of polyethylene which prevented the water supply by irrigation and rain. In the field, it was also evaluated the plant height, the relative chlorophyll content, emergence, lesser cornstalk borer attack and grain yield. In the both environment, the plants were kept on stress until 28th days after emergence. In greenhouse, all the parameters were influenced by seed treatments with or without low water availability. In field, the treatment with fipronil + thiophanate methyl + pyraclostrobin (T3) and abamectin + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) promoted higher plant height and relative chlorophyll content in both hydric schemes, higher emergence and grain yield in plants without and with lower water availability, respectively. It was concluded that seed treatment with these products promote benefit changes in plant, increasing its tolerance to hydric stress, with positive effect on soybean grain yield.

O objetivo do trabalho foi avaliar o efeito de quatro tratamentos de sementes: água (T1), carbendazim + thiram (T2), fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) sobre parâmetros de crescimento de plantas de soja submetidas a dois regimes hídricos (presença e ausência de estresse hídrico) estabelecidos logo após a emergência das plântulas. O experimento foi conduzido em casa de vegetação e campo. Na casa de vegetação, nos tratamentos sem estresse hídrico, foram feitas quatro irrigações por dia e, nos tratamentos com estresse hídrico, foi realizada uma irrigação a cada três dias. Neste ensaio, foi avaliada a estatura de plantas, comprimento radicular, volume radicular, massa seca da parte aérea, massa seca radicular e área foliar. No ensaio de campo, o estresse hídrico foi estabelecido pela construção de túneis baixos de polietileno que impediram o fornecimento de água pela irrigação e chuva. No campo, foram avaliados estatura de planta, teor relativo de clorofila, emergência, ataque de lagarta-elasmo e rendimento de grãos. Nos dois ambientes, as plantas foram mantidas sob estresse até 28 dias após a emergência. Em casa de vegetação, todos os parâmetros foram influenciados pelo tratamento de sementes na presença e ausência de estresse hídrico. No campo, o tratamento com fipronil + tiofanato metílico + piraclostrobina (T3) e abamectina + thiamethoxam + fludioxonil + mefenoxan + thiabendazole (T4) proporcionaram maior estatura de planta e teor relativo de clorofila em ambos os regimes hídricos e maior emergência e rendimento de grãos em plantas sem e com restrição hídrica, respectivamente. Conclui-se que o tratamento de sementes com esses produtos promove alterações benéficas nas plantas, aumentando sua tolerância ao estresse hídrico, com efeito positivo sobre o rendimento de grãos da soja.