2025-07-022025-07-02https://periodicos.udesc.br/index.php/agroveterinaria/article/view/2392510.5965/223811710112002046Dado curado por Luana Pantzier em 03/07/2025 para a atividade avaliativaThe prevalence of powdery mildew (Microsphaera diffusa) on soybean (Glycine max) is increasing in Brazil. This fact suggests that actions to control this disease have to be taken. One of these actions is the application of fungicides. Therefore, four field experiments, in a completely randomized block design with four (tests 1 and 2) or three (tests 3 and 4) replications, were performed to evaluated the effect of fungicides against the soybean powdery mildew. These experiments were conducted in Londrina, PR (1999/2000) where soybean is constantly and extensively cultivated. The cultivar EMBRAPA 48 was used and just one application of the products was made at the growth stage R4. The treatments of Test 1 (ai = active ingredient; cp = commercial product) were: - prochloraz [450g ai/L] + propiconazole [250g ai/L] (0.5L cp/ha + 0.25L cp/ha); tebuconazole-1 [250g/L] + prochloraz (0.3+0.5); prochloraz (0.5); tebuconazole-1 (0.2); tebuconazole-2 [200g/L] (0.75); tebuconazole-1 + propiconazole (0.3+0.25); tebuconazole-1 + carbendazin-1 (0.3+0.35); propiconazole + carbendazin-1 (0.2+0.35); and the control (water). The treatments of test 2 were: carbendazin-1 (0.5); propiconazole (0.5); propiconazole (0.3); tebuconazole-1 (0.4); tebuconazole-1 + carbendazin-1 (0.4+0.3); tebuconazole-2 (0.5); carbendazin-2 [500g/L] (0.5); prochloraz (0.75); and the control (water). The treatments of the test 3 were similar to those of the test 1, but with the mixture of tebuconazole-1 + carbendazin-1 (0.24+0.25) replacing the treatment with tebuconazole-1 (0.2). The treatments of test 4 were similar to those of test 2, but the treatments with tebuconazol-1 + carbendazim-1 and prochloraz (0,75) were replaced by treatments with tebuconazole-1 (0,6) and tebuconazole-2 (0,75). The best fungicides to control powdery mildew were: test 1 - tebuconazole-2 (0.75), prochloraz + propiconazole (0.5+0.25), propiconazole + carbendazin-1 (0.2+0.35), and tebuconazole-1 + propiconazole (0.3+0.25); test 2 - carbendazin-1 (0.5), carbendazin-2 (0.5), and tebuconazole-2 (0.5); test 3 - prochloraz + propiconazole (0.5+0.25), tebuconazole-1 + prochloraz (0.3+0.5), and tebuconazole-1 + propiconazole (0.3+0.25), and; test 4 - all treatments with fungicides were efficient.A ocorrência do oídio (Microsphaera diffusa) da soja (Glycine max) tem aumentado nas últimas safras. Esse fato sugere rapidez na tomada de ações para o controle da doença. O controle químico seria uma das medidas indicadas. Portanto, quatro experimentos conduzidos no campo (1999/2000) foram realizados na região de Londrina/PR com o objetivo de avaliar a eficiência de fungicidas para o controle do oídio na cultivar EMBRAPA 48. Os ensaios foram delineados em blocos ao acaso, sendo dois ensaios com quatro repetições e os demais com três repetições. Em cada teste foi feita uma aplicação dos produtos no estágio R4 da soja. Os tratamentos do ensaio 1 foram (ia = ingrediente ativo; pc = produto comercial): procloraz [450g ia/L] + propiconazol [250g ia/L] (0,5L pc/ha + 0,25L pc/ha); tebuconazol-1 [250g/L] + procloraz(0,3 +0,5); procloraz (0,5); tebuconazol-1 (0,2); tebuconazol-2 [200g/L] - (0,75); tebuconazol-1 + propiconazol (0,3+0,25); tebuconazol-1 + carbendazim-1 [500g/L] (0,3+0,35); propiconazol + carbendazim-1 (0,2+0,35); e testemunha (água). Os tratamentos do ensaio 2 foram: carbendazim-1 (0,5); propiconazol (0,5); propiconazol (0,3); tebuconazol-1 (0,4); tebuconazol-1 + carbendazim-1 (0,4+0,3); tebuconazol-2 (0,5); carbendazim-2 [500g/L] (0,5); procloraz (0,75); testemunha. O ensaio3 foi uma repetição modificada do ensaio1, porém retirou-se o tratamento com tebuconazol-1 (0,2) e adicionou-se o tratamento em mistura tebuconazol- 1 + carbendazim-1 (0,24+0,25). O ensaio 4 foi uma repetição aproximada do ensaio 2 com a ausência dos tratamentos tebuconazol-1 + carbendazim-1 e procloraz (0,75), mas com a adição dos tratamentos isolados com tebuconazol-1 (0,6) e tebuconazol-2 (0,75). Os tratamentos com fungicidas que mais se destacaram, reduzindo a severidade do oídio e favorecendo o aumento de produtividade da soja foram tebuconazol-2 (0,75), procloraz + propiconazol (0,5+0,25), propiconazol + carbendazin-1 (0,2+0,35) e tebuconazol-1 + propiconazol (0,3+0,25) no ensaio 1. No ensaio 2, os melhores tratamentos foram carbendazim-1 (0,5), carbendazim-2 (0,5) e tebuconazol-2 (0,5). No ensaio 3, as misturas de fungicidas mais eficientes foram procloraz + propiconazol (0,5+0,25), tebuconazol-1 + procloraz - (0,3+0,5) e tebuconazol-1 + propiconazol (0,3+0,25). No ensaio 4, todos os tratamentos com fungicidas foram eficientes.application/pdfCopyright (c) 2002 Authors & Revista de Ciências Agroveterináriashttps://creativecommons.org/licenses/by-nc/4.0Glycine maxChemical controlControle químicofungicidefungicidaMicrosphaera diffusafungicide, Microsphaera diffusaGlycine maxinfo:eu-repo/semantics/article