Efeito da aplicação de silicato de cálcio e de cinza de casca de arroz sobre a incidência de fungos associados a manchas em sementes de arroz irrigado

Abstract

The aim of this study was to evaluate the effect of calcium silicate and rice husk ash (CCA) application on the incidence of fungi associated with spots in flooded rice seeds. Rice plants were subjected to application of calcium silicate or CCA at the levels of 0, 51, 153, 256 and 357 kg ha-1 of silicon (Si). Two experiments were performed, one in the 2007/2008 crop season and another one in the 2008/2009 season; subsequently, seed samples were analyzed in laboratory. Evaluations were performed for Seed Browning Index (IES), Si concentration in the pericarp of the seeds and determination of the diversity of seedborne fungi. There was no effect of the two employed Si sources at the used levels in both experiments, for IES and Si concentration. The phytopathogenic fungi found in both experiments were Alternaria padwickiii, Bipolaris oryzae, Botrytis cinerea, Curvularia lunata, Fusarium semitectum, F. solani, Microdochium oryzae, Nigrospora oryzae, Phoma sorghina and Pyricularia oryzae. The incidence of these fungi was not affected by the application of Si sources at the used levels.