| Popis: |
The effects of benthiocarb herbicide on the population growth of planktonic organisms were examined to evaluate its toxicity in natural rivers as run-off from rice fields. The organisms used in thisexperiment were Chlorella saccharophila and Brachionus plicatilis. Concentrations of the herbicidewere regulated to sub-acute levels at: 0.0 ppm as control, 0.003 ppm, 0.01 ppm, 0.03 ppm, 0.1 ppm,and 0.3 ppm. Ethanol was used to dilute the original concentrated benthiocarb. The effects of ethanolon the growth of plankton were also observed.There were no significant differences found among the culture experiments conducted for the growthof C.saccharophila and B.plicatilis below the herbicide concentration of 0.3 ppm. However, inthe ethanol experiments, the growth rate of plankton was less than that at a 0.3 ppm herbicide concentration. Careful utilization of ethanol for dilution is suggested for practical use. |
