Spraying of foliar herbicide to control water hyacinth may lead to mortality of the fish by root exudation of herbicide or accidental drift of herbicide. To overcome herbicide-divalent cations complex formation in hard water at improper pH, increasing herbicide dosage per drop, either by increase of dosage or by reduce the spray volume, was one of the techniques. Using radioactive 14C-glyphosate and 14C-2,4-D, effect of dosage on herbicide retained on the cuticle as dried out residue, distribution with in plant system and moved out as root exudates was assessed. Twice the recommended concentration (2x) of herbicide per drop and drop density per fed spot significantly increased the dried residue on the cuticle 67 to 91 and 68 to 79% over total activity recovered compared to x dose for glyphosate and 2,4-D, respectively.  2,4-D (2x) significantly increased the amount of herbicide cuticle loading and mobility within cuticle but differences in translocation to different  parts was not significant except in root  (2x had lower activity than x). Similarly, significant difference between 2x and x for glyphosate was observed for cuticle loading and root exudates.  At 2x dosage, root exudates of both herbicides was more after 8 days. Half-life in pond water was around 5 days for both herbicides compared to normal water 7 and 11days of glyphosate and 2,4-D respectively. The chances of hherbicide toxicity to fishes were unlikely by foliar applied herbicides.