Abstract
The effects of 24 ionic and nonionic surfactants on paraquat (1, 1' -dimethyl-4 4'-bipyridinium) efficacy were investigated with several annual plant species under greenhouse conditions. The paraquat efficacy was decreased or even lost when treated with the anionic surfactants tested. However, the efficacy of paraquat was significantly increased by 7 nonionic surfactants such as sorbitan palmitate, sorbitan stearate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene stearyl ether, polyoxyethylene laurylamine ether, and polyoxyethylene stearylamine ether. Among these tested surfactants, 0.08% of polyoxyethylene laurylamine ether most significantly increased the paraquat activity, and the $GR_{50}$ value of paraquat with polyoxyethylene laurylamine ether was 1.6 times lower than the $GR_{50}$ value without polyoxyethylene laurylamine ether. In in vitro experiments, cellular leakage and chlorophyll contents between the application with and without polyoxyethylene laurylamine ether did not show significant changes. The absorption rate of $^{14}C$ paraquat in the treatment with polyoxyethylene laurylamine ether showed an absorption rate of 1.6 times higher than without surfactant. These results suggest that using compatible surfactants would increase the paraquat efficacy, and this increasing are due to improved absorption rate with the surfactant.
24개의 계면활성제를 대상으로 하여 paraquat의 효력에 미치는 영향을 온실조건에서 1년 생 잡초를 대상으로 조사하였다. Paraquat에 음이온 계면활성제를 혼합 처리하면 paraquat의 효력이 감소하거나 완전히 상실되었지만, sorbitan palmitate, sorbitan stearate, polyoxyethylene sorbitan monopalmitate, polyoxy-ethylene sorbitan monostearate, polyoxyethylene stearyl ether, potyoxyethylene laurylamine ether, 및 polyoxyethylene stearylamine ether 등 비이온 계면활성제를 혼합 처리한 경우에는 paraquat의 활성이 크게 증가되었다. 이들 중 Polyoxyethylene laurylamine ether를 0.08%로 혼합 처리하였을 때 가장 높은 활성을 나타내었고 혼합처리하지 않은 것에 비하여 1.6배 낮은 $GR_{50}$ 값을 나타내었다. 오이 잎을 이용한 in vitro실험에서 paraquat에 polyoxyethylene laurylamine ether를 혼합 처리하여도 세포질 유출량은 차이를 보이지 않았지만, $^{14}C$- paraquat 의 cuticle층 내로 침투되는 속도는 1.6배 높게 나타나 polyoxyethylene laurylamine ether를 혼합 처리하였을 때 paraquat의 활성이 증가하는 주원인으로 생각되었다.
