부산대학교 도서관

Isoprothiolane (di-isopropyl 1,3-dithiolane-2-ylidenemalonate) is a systemic thiolane fungicide and is registered for the control of rice blast in Taiwan. The degradation of isoprothiolane in flooded soils, water, and rice plants was studied in a semi-open model ecosystem under local conditions. In the heading stage, rice plants were separately treated with 40% isoprothiolane at 1 and 3 L/ha. Water, soil, and rice plants were sampled and analyzed during the rice growing periods, and rice samples was also taken and analyzed after harvesting. The results showed that isoprothiolane degraded in flooded soils, water, and rice plants. DT50 values for the dissipation of isoprothiolane in soils, field water, and rice plants were 11~30, 12~14, and 5~6 days, respectively. The concentration of isoprothiolane in rice plants was higher than those in the other environmental compartments. The residue of isoprothiolane in the harvested rice sample was 0.13 mg/kg with the recommended application rate and method.