農藥의 劑型, 撒布時期 및 使用回數를 달리 하였을 때 水稻의 收穫物中 農藥殘留量 변화를 調査하기 위하여 isoprothiolane과 chlorpyriphos-methyl의 乳劑 및 粒劑에 대하여 豊産벼를 대상으로 試驗한 結果는 다음과 같다. 1) Isoprothiolane 乳劑는 收穫期에 近接하여 撤布할수록 볏짚中 殘留量이 높았으나 粒劑는 收穫 30日前 살포에서 最高水準에 달하였다. Chlorpyriphos-methyl은 劑型에 관계없이 收穫期에 近接 살포할수록 볏짚 殘留量이 높았으나 그 水準은 isoprothiolane 보다 현저히 낮았다. 2) 玄米中 殘留量은 chlorpyriphos-methyl 乳劑의 경우 볏짚에서와 類似한 分解率을 보였으나 isoprothiolane 乳劑는 볏짚에서 보다 그 殘留量이 安定하였다. 粒劑는 樂劑와 無關하게 玄米로의 移行이 매우 輕微하였다. 3) 搗精에 의한 玄米中 殘留量의 除去率은 乳劑의 撤布時期가 收穫期에 인접할수록 높았고 撒布回數와는 관계가 없었다. 4) 水稻栽培期間中 撒布農藥의 收穫物中 殘存率은 볏짚에 0.19%∼0.99%, 玄米에 0.01∼0.48%, 白米에 0.15%이었다.

The present study was performed to elucidate pesticide residues in paddy rice applied with different application schedules and frequencies of pesticide formulations. Pungsanbyeo(Japonica×Indica hybrid) of rice(Oryza sativa L.) was chosen as target crop. Isoprothiolane(diisopropyl-l,3-dithiolan-2-ylidene malonate) 40EC (emulsifiable concentrates), 12G (granular), and chlorpyriphosmethyl [0,0-dimethyl 0-(3, 5, 6-trichloro-2-pyridyl) phosphorothioate] 25EC, 3G were selected as pesticide formulations. The closer the isoprothiolane EC application to harvest, the higher the residues in rice straw retained at harvest; however the G application on 30 days before harvest resulted in highest residue. Chlorpyriphosmethyl residues were higher as it was applied nearby to harvest. Degradation rate of chlorpyriphos-methyl in husked rice was quite similar to in rice straw, on the other hand isoprothiolane in the rice was more stable than that in rice straw. Translocated amount of applied G formulation to husked rice was meager irrespective to the chemicals. Percent reduction of isoprothiolane residues in husked rice by polishing was not related to application frequencies but to application date before harvest. Residual portions in rice straw, husked rice and polished rice of total input amount during rice cultivation were ranged from 0.19% to 0.99%, 0.01% to 0.48%, and 0.15%, respectively.