01899nam a2200253 a 450000100080000000500110000800800410001910000220006024501030008226001380018530000100032352011230033365000110145665000140146765000190148165300170150065300180151765300140153565300190154965300140156865300220158270000190160470000220162310123062018-07-30       1995    bl uuuu     u00u1 u    #d1 aFERREIRA C. J. A.  aDecomposition of organic matter in the presence of the herbicide clomazone.h[electronic resource]  aIn: INTERNATIONAL SYMPOSIUM ON MICROBIAL ECOLOGY, 7., 1995, Santos. Abstracts. Sao Paulo: Sociedade Brasileira de Microbiologiac1995  ap.175  aClomazone (2-(2-chlorophenyl) methyl-4.4-dimethyl-3-isoxazolidinone) is a post emergence herbicide widely used in rice fields in Rio Grande do Sul (Brazil) with high activity against Gramineae at the recommended application rate of 700 g/ha. The presence of this chemical in the water may affect microorganisms responsible for the decomposition of organic matter. Thus, a disturbe in the trophic chain sustained by the decompositors could happen. In the present work the decomposition rate of organic matter (Typha latifolia) exposed to several concentrations of a clomazone formulation: 0 (control), 25.0, 62.0, 156.0, 390.0 and 976.0mg/L on the basis of the active ingredient was evaluated. Five litter bags containing about 3.0g of pieces of T. latifolia leaves wereplaced in aquariums with 15 of reconstituted water. In cach aquarium were added 500g of sediment from the same place of the plant collection, as a source of decompositors microorganisms. The results relative tothe control, showed that the decomposition rate in the highest and lowest dose was reduced in 50.05 and 1,28%, respectively, after 80 days.  aBrazil  aclomazone  aorganic matter  aAgrochemical  aDecomposition  aHerbicide  aPost emergence  aRice crop  aRio grande do Sul1 aJONSSON, C. M.1 aMAIA, A. de H. N.