Abstract
In order to enhance the fungicidal activity of the thifluzamide formulation against rice sheath blight, the surfactants which was able to facilitate the foliar uptake or increase the leaf deposit of thifluzamide on rice plants were selected, and the formulations containing the surfactants were tested to compare the fungicidal efficacy against the rice sheath blight with a control WP formulation. The WP suspension containing dodecaethylene glycol monohexadecyl ether as an activator increased the foliar uptake of thifluzamide on rice plants, but its fungicidal efficacy against rice sheath blight was decreased. The addition of the combined surfactants with either heptaethylene glycol monoisododecy ether or heptaethylene glycol monotridecyl ether and sodium dioctylsulfosuccinate to WP suspension increased the leaf deposition of thif1uzamide at around 5 times of that without a spreader-sticker that median control concentrations of thifluzamide against rice sheath blight were decreased to 4.4 mg $L^{-1}$ and 3.4 mg $L^{-1}$, respectively.
벼의 줄기에 주로 발생하는 잎집무늬마름병에 대한 thifluzamide의 방제 효과를 증진하기 위하여 벼 경엽을 통한 thifluzamide의 침투성을 강화하거나 벼 부착량을 증진할 수 있는 계면활성제를 선발하고 이를 함유하는 제제의 병 방제 효과를 측정하였다. 수화제 현탁액에 dodecaethylene glycol monohexadecyl ether를 첨가함으로써 벼 잎에 대한 thifluzamide의 침투성을 증진할 수 있었으나 병 예방효과는 오히려 감소하였다. 비이온성 계면활성제와 음이온성 계면활성제를 혼합하여 수화제 현탁액에 첨가하였을 때 유효성분 부착량이 약 5배 증대되었으나 잎집무늬마름병 예방효과는 약간 증가하여 $EC_{50}$가 5.8 mg $L^{-1}$에서 각각 4.4 mg $L^{-1}$와 3.4 mg $L^{-1}$로 감소하였다.
