Métodos de aplicação e de avaliação do residual de fungicidas no controle de mofo-branco em soja e feijão
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Data
2015-12-16
Autores
Miorini, Thomas José Justo [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O feijoeiro e a soja são culturas importantes como fontes protéicas para o Brasil, e suas produtividades são seriamente afetadas pelo mofo-branco (causado por Sclerotinia sclerotiorum). Para o seu controle, é recomendado o manejo integrado da doença, no entanto, prevalece o controle químico. O controle químico desse fungo pode ser realizado por pulverização convencional com trator-pulverizador ou por fungigação. O trabalho objetivou avaliar indiretamente a atividade residual dos fungicidas fluazinam, procimidona e tiofanato metílico sobre o controle do mofo-branco pelo Detached leaf assay (DLA), aplicados por pulverização e por quimigação na soja e no feijão, avaliar o desenvolvimento de escleródios e a produtividade do feijoeiro submetido a aplicações por fungigação. Dois pré-testes foram conduzidos em casa de vegetação com os fungicidas aplicados em pulverização convencional no feijoeiro. Constatou-se que o DLA pode ser utilizado para avaliar indiretamente a atividade residual de fungicidas. Na cultura da soja, três experimentos foram conduzidos para avaliar o efeito da quimigação, da pulverização de fungicidas associados a óleo mineral e do método de Quenchers para avaliar a concentração de fungicidas no controle do mofo-branco. Pelo DLA, verificou-se que os fungicidas têm períodos residuais distintos entre eles e que lâminas d’água maiores diminuem mais rapidamente o residual do ingrediente ativo. O uso do óleo mineral não influenciou no período residual dos fungicidas após a primeira pulverização. Pelo método de Quencher, as taxas de decréscimo na concentração dos fungicidas foram calculadas para três ingredientes ativos com a constatação de que o fluazinam diminui mais rapidamente a concentração, seguido dos fungicidas procimidona e do carbendazim. Mais três experimentos foram conduzidos no feijoeiro a campo para estudo do residual de fungicidas com aplicação em pivô central e aplicações com aspersores em 2013 e 2014, com avaliação do desenvolvimento de escleródios e produtividade nestes dois últimos. No experimento sob pivô, observou-se diferenças na Área Abaixo da Curva de Progresso da Doença (AACPD) entre as diferentes lâminas d’água. Lâminas d’água maiores diminuíram mais rapidamente o período residual dos produtos fitossanitários. Tratamentos com procimidona apresentaram maior produtividade em 2013, porém em 2014, maior produtividade foi obtida com fluazinam independente da lâmina d’água e do modo de pulverização. Em 2014, constatou-se que o período residual dos fungicidas na fungigação foi menor do que na pulverização convencional.
Dry bean and soybean are very important crops as protein source in Brazil, and their yields are seriously affected by white mold (Sclerotinia sclerotiorum). To control this pathogen, integrated disease management is recommended, however, chemical control is commonly used. Fungicides can be applied by sprayer application with tractor or chemigation. The present study aimed to evaluate indirectly the residual activity of fluazinam, procymidone and thiophanate methyl on white mold control by Detached Leaf Assay (DLA), applied by conventional application (sprayer) and chemigation in soybeans and dry beans, and investigate sclerotia formation of S. sclerotiorum and yields in dry bean by chemigation application. Two pre-tests were performed under greenhouse conditions, where fungicides were applied in conventional manner (sprayer). DLA can be used to assess, indirectly, the residual activity of fungicides applied for white mold control. In soybean, three field experiments were conducted to evaluate the effect of chemigation, effectiveness of fungicides applied with adjuvant, and Quenchers method for assessing the concentration of three fungicides for white mold control. It was observed with DLA that fungicides have different effects on the residual period, where higher water levels decreased more quickly the residual activity of the active ingredient. The use of adjuvant did not influence the residual period after the first application. For Quencher method, the rates of decrease in the concentration of fungicides were calculated showing that the concentration decreases more quickly in fluazinam fungicide, followed by procymidone and carbendazim. Three experiments were conducted in dry bean to study the residual activity of fungicides with an application by center pivot and two applications with sprinkler irrigation in 2013 and 2014, evaluating the S. sclerotiorum sclerotia and yield in sprinkler experiments. In the experiment via pivot, differences were observed in area under disease progress curve (AUDPC) between different water levels. Higher water levels more rapidly decreased residual fungicide activity. Treatments applied with procymidone showed higher productivity in 2013, however, 2014 resulted in the highest productivity when treated with fluazinam, regardless water levels and application method. In 2014, the residual activity of fungicide decreased more quickly in applications via chemigation when compared with sprayer application.
Dry bean and soybean are very important crops as protein source in Brazil, and their yields are seriously affected by white mold (Sclerotinia sclerotiorum). To control this pathogen, integrated disease management is recommended, however, chemical control is commonly used. Fungicides can be applied by sprayer application with tractor or chemigation. The present study aimed to evaluate indirectly the residual activity of fluazinam, procymidone and thiophanate methyl on white mold control by Detached Leaf Assay (DLA), applied by conventional application (sprayer) and chemigation in soybeans and dry beans, and investigate sclerotia formation of S. sclerotiorum and yields in dry bean by chemigation application. Two pre-tests were performed under greenhouse conditions, where fungicides were applied in conventional manner (sprayer). DLA can be used to assess, indirectly, the residual activity of fungicides applied for white mold control. In soybean, three field experiments were conducted to evaluate the effect of chemigation, effectiveness of fungicides applied with adjuvant, and Quenchers method for assessing the concentration of three fungicides for white mold control. It was observed with DLA that fungicides have different effects on the residual period, where higher water levels decreased more quickly the residual activity of the active ingredient. The use of adjuvant did not influence the residual period after the first application. For Quencher method, the rates of decrease in the concentration of fungicides were calculated showing that the concentration decreases more quickly in fluazinam fungicide, followed by procymidone and carbendazim. Three experiments were conducted in dry bean to study the residual activity of fungicides with an application by center pivot and two applications with sprinkler irrigation in 2013 and 2014, evaluating the S. sclerotiorum sclerotia and yield in sprinkler experiments. In the experiment via pivot, differences were observed in area under disease progress curve (AUDPC) between different water levels. Higher water levels more rapidly decreased residual fungicide activity. Treatments applied with procymidone showed higher productivity in 2013, however, 2014 resulted in the highest productivity when treated with fluazinam, regardless water levels and application method. In 2014, the residual activity of fungicide decreased more quickly in applications via chemigation when compared with sprayer application.
Descrição
Palavras-chave
Quimigação, Sclerotinia sclerotiorum, Phaseolus vulgaris L., Glycine max L. Merrill, Método da folha destacada, Chemigation, Detached leaf assay