The runoff in forced drainage and leaching where pretilachlor was applied before the transplanting of rice plants was investigated by lysimeters. The concentration of pretilachlor in forced drainage in 2009 and 2010 was 174.0 and 112.3 µg/L, respectively. Each total amount of pretilachlor in forced drainage was 52.2 mg and 252.6 mg, and the runoff percentage was 8.7 and 42.1, respectively. On the other hand, the total amount of leaching was 0.7 mg and 3.3 mg, and each percentage was 0.1 and 0.6, respectively. Based on these data, the forced drainage at the time of transplanting was considered to be strongly involved in the pretilachlor outflow from paddy fields. © Pesticide Science Society of Japan

View full abstract