Germinação, sanidade e tratamento de sementes de Guazuma ulmifolia Lam./Germination, sanity and seed treatment of Guazuma ulmifolia Lam

O presente estudo teve o objetivo de caracterizar a germinacao, determinar o metodo de avaliacao da sanidade e verificar a acao do tratamento das sementes de mutamba com o uso de oleos essenciais e fungicida comercial. Trabalhou-se com duas procedencias (Berilo-MG e Montes Claros-MG). Os experimentos foram realizados em delineamento inteiramente casualizado e 4 repeticoes. Avaliou-se a germinacao de sementes tratadas com acido sulfurico concentrado, por 50 minutos e, imersao em agua quente (60oC por 16 minutos), para superacao de dormencia. Realizou-se o teste conforme as Regras de Analise de Sementes, em fatorial 2x2 (2 procedencias e 2 metodos de superacao de dormencia). A sanidade avaliada pelo Blotter test e meio BDA. Para o controle dos fungos testou-se os tratamentos: carboxin 2% + tiram 2%; oleo de Cymbopogon nardus ; Lippia sidoides  (5 e 10 µl/mL); hipoclorito de sodio 2%; testemunha). A analise dos dados foi pelo software  estatistico R e, medias comparadas pelo teste Scott-Knott a 5%. As sementes de Berilo-MG apresentam germinacao superior as de Montes Claros, apos tratamento com acido sulfurico. O metodo Blotter test detecta uma maior diversidade de fungos sendo os principais, Aspergillus e Penicillium. Apesar de o fungicida comercial ter demonstrado superioridade na reducao da contaminacao fungica das sementes de Guazuma ulmifolia (99%) , o tratamento com citronela na concentracao de 10 µl/ mL, apresenta um bom potencial de reducao (63%), necessitando-se de testes com novas concentracoes do produto e avaliacao do seu efeito na germinacao e desempenho das sementes de mutamba. ABSTRACT The objective of this study was to characterize the germination, to determine the sanity evaluation method and to verify the action of the treatment of the mutamba seeds with the use of essential oils and commercial fungicide. We worked with two sources (Berilo-MG and Montes Claros-MG). The experiments were carried out in a completely randomized and 4 repetitions. The germination of seeds treated with concentrated sulfuric acid was evaluated for 50 minutes and immersion in hot water (60 ° C for 16 minutes) to overcome dormancy. The test was performed according to the Rules of Analysis of Seeds, in factorial 2x2 (2 provenances and 2 methods of overcoming numbness). The sanity was evaluated by Blotter test and BDA medium. For the control of fungi the treatments were tested: carboxin 2% + tiram 2%; Cymbopogon nardus oil; Lippia sidoides (5 and 10 μl / ml); sodium hypochlorite 2%; witness). Data analysis was by statistical software R, and averages compared by the Scott-Knott test at 5%. The seeds of Berilo-MG show higher germination than those of Montes Claros, after treatment with sulfuric acid. The Blotter test method detects a greater diversity of fungi being the main ones, Aspergillus and Penicillium . Although the commercial fungicide showed superiority in reducing the fungal contamination of Guazuma ulmifolia (99%) seeds, treatment with citronella at a concentration of 10 μl / mL showed a good reduction potential (63%), requiring tests with new concentrations of the product and evaluation of its effect on the germination and performance of the mutamba seeds.