RESUMEN
2, 4-dichlorophenoxyacetic acid (2,4-D) is a post emergence herbicide. The tests were conducted to study the toxicity of 2,4-D using EC50 value in four dilutions. 2,4-D was applied at concentration of 25, 50, 75, 100, 200 and 300 mg l(-1) in the potato Dextrose agar medium. The effect of this herbicide was evaluated as the colony forming unit (CFU). EC50 value for 10(-3) dilution of soil was 138 +/- 5.944 mg l(-1). Soil physico-chemical parameters and mycofloral properties were also evaluated. Qualitatively 10 genera of fungi were observed in untreated soil, whereas 4 genera were found in 2,4-D administered dose.
Asunto(s)
Ácido 2,4-Diclorofenoxiacético/toxicidad , Relación Dosis-Respuesta a Droga , Herbicidas/toxicidad , Concentración de Iones de Hidrógeno , Hongos Mitospóricos/clasificación , Microbiología del Suelo , Contaminantes del Suelo/química , Temperatura , Pruebas de ToxicidadRESUMEN
Cypermethrin was administered to Heteropneustes fossilis in chronic concentration to determine lesion of liver as indicators of tissue damage. The cypermethrin dose used was 1/4 of 96 hr LC50. Histopathological changes in liver ranged from vacuolization, necrosis, fibrosis of perivascular region and disposition of yellow brown grains at different time of exposure viz; 20th, 30th, 40th and 60th days.