Weeds occurring in rice crops in the region of Zona da Mata, Minas Gerais State, Brazil

Abstract

In this study a survey of weeds occurring in rice (Oryza sativa L.) crops was made in Zona da Mata, MC, Brasil. The floristic composition and the structure of the weed flora were evaluated. During the first months of 1981 some representative rice fields were evaluated in counties with the highést yields in that Zona. Weeds were sampled in crops grown in humid lowland soils and then stored in the Herbário ESAL, of Escola Superior de Agricultura at Lavras, MG, BrasiL Weeds were identified and their rates of occurrence determined. Thirty-three species, from eleven botanic families were found, including eight dicotyledoneous and three monocotyledoneous. The most frequent families were Gramineae, Cyperaceae and Leguminosae and the species Fimbristylis miliacea, Ischaemum rugosum  Humenachne sp, Eriochloa polystachia and Ludwigia suffruticosa. Most of the species found in this study have not been cited previously as weeds on rice crops in the State of Minas Gerais