Diversidade de fungos associados a manchas em sementes de arroz irrigado com aplicação de silicato de cálcio e cinza de casca de arroz

• Autor(a) principal: Roma, Rafaela Carolina Constantino
• Data de Publicação: 2010
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: LOCUS Repositório Institucional da UFV
• Texto Completo: http://locus.ufv.br/handle/123456789/4374
• topic: Arroz - Doenças e pragas; Fitopatologia; Fungos fitopatogênicos; Arroz - Efeito do silício; Sementes - Doenças; Rice - Diseases and pests; Plant pathology; Pathogenic fungi; Rice - Effect of silicon; Seeds - Diseases; CNPQ::CIENCIAS AGRARIAS::AGRONOMIA::FITOSSANIDADE::FITOPATOLOGIA

The rice crop is of great importance on the world stage because it serves as the main food for millions of people around the world. However, several factors affect its production, mainly the diseases. The seed spot is caused by various fungi such as Bipolaris oryzae, Pyricularia grisea, Microdochium oryzae, Phoma sorghina, Cladosporium sp. and others. In seeds, this disease can cause reduction on germination and decrease on production due to the sterility of panicles. The application of silicon (Si) has been studied as an alternative in the control of plant diseases. Thus, the aim of this work was to evaluate the effect of calcium silicate and rice husk hulls in the incidence of fungi associated with flooded rice seed. Rice plants were submitted with rice husk hulls and calcium silicate in the doses 0, 153 and 357 kg/ha of Si. Two experiments were performed, one in the 2007/2008 harvest season and another in 2008/2009 and later seed samples were analyzed in the laboratory. Evaluations of Browning Index Seeds (BIS), the Si concentration in the pericarp of the seeds and determination of seedborne fungi were executed. There was no significant difference from the F test for IES and Si concentration for the two sources of Si in the doses used in both experiments. The efficiency of the products used and the concentration of Si in the pericarp of the seeds were similar, independently of the applied dose. In general, the fungi found in both experiments were Bipolaris oryzae, Curvularia lunata, Fusarium semitectum, F. solani, Microdochium oryzae, Nigrospora oryzae, Pyricularia grisea, Trichoconiella padwickiii and Cladosporium cladosporioides. The incidence of these fungi was not affected by the application of rice husk hulls or calcium silicate in the doses used.