Acute toxicity to herbicides to Oreochromis niloticus

Planta Daninha

Oliveira, T.A.¹  Byrro, E.C.M.¹  Santos, J.B.¹  Universidade Vale do Rio Doce, Governador Valadares¹  UFVJM, Diamantina¹  Universidade Federal dos Vales do Jequitinhonha e Mucuri, Diamantina¹  Braga, R.R.¹  Instituto Nacional de Pesquisas da Amazônia, Manaus¹  Botelho, R.G.¹ 

关键词: alachlor;    atrazin;    2;    4-D;    diuron;    paraquat;    picloram.;   

DOI  :  10.1590/S0100-83582009000300024

学科分类：农业科学（综合）

来源: Sociedade Brasileira da Ciencia das Plantas Daninhas (S B C P D) / Brazilian Society of Herb Science

【 摘 要 】

Two assays were carried out to evaluate Oreochromis niloticus sensitivity to different herbicides. In the first experiment, atrazin concentrations (0; 2.5; 5; 10 and 20  mg L-1) were evaluated aiming to determine lethal concentration (LC50) to O. niloticus. In the second assay, the effects of the herbicide mixtures alachlor + atrazin (5.33 + 5.33 mg L-1), diuron + MSMA (5.33 + 2.13  mg  L-1 ), paraquat (1.33  mg  L-1 ) and 2,4-D + picloran (1.28 + 0.34  mg  L-1 ), were evaluated on O. niloticus survival after 96 h of exposure. In the first assay, a sharp decrease in fingerlings survival was observed from 3  mg  L-1 of atrazin with CL50 value of 5.02  mg  L-1 and a high biomass decrease due to herbicide presence. In the second assay, a greater negative effect was observed on fingerlings by alachlor + atrazin. . After 72  h of incubation, intoxication rate showed a reduction in the number of individuals of 17.4% for paraquat, 2,4 D + picloram and diuron + MSMA, and of 100% for alachlor + atrazin. It was concluded that CL50 obtained for atrazin is inferior to that listed as toxic to trouts and that the alachlor + atrazin mixture can be characterized as a risk to O.  niloticus, even when applied at commercially recommended rates.

【 授权许可】

Unknown