水稻體中 IBP와 isoprothiolane의 殘留消長에 미치는 撒布時期의 影響이 調査되었으며, 아울러 水深과 土性의 影響도 관찰되었다. IBP(17%, G)와 isoprothiolane(12%, G)을 各各 6.8과 4.8㎏ AI/㏊의 比率로 湛水土壤에 1回 撤布한 후 時期別로 水稻體中 殘留量을 gas chromatograph로 分析하였다. 撒布時期와는 無關하게 두 殺菌劑는 뿌리조직을 통해 植物體로 신속히 吸收, 轉移되었으며, 稻體中 두 殺菌劑의 濃度는 撤布時期와는 無關하게 24時間 이내에 最高에 이르렀다. 최대분얼기 撒布時 두 殺菌劑의 分解樣相은 비슷한 傾向으로 時間의 經過와 더불어 신속히 分解되었다. 한편 출수기 撒布時에 IBP의 分解樣相은 최대분얼기 撤布時와 비슷한 傾向이나 isoprothiolane의 그것은 아주 相異하였다. 즉 藥劑撒布後 3日에 나타난 最高濃度가 그후 25日까지 큰 변화없이 維持되었다. 한편 두 殺菌劑의 殘留消長에 미치는 水深의 影響은 별로 없었으며, isoprothiolane의 경우 壤土와 殖壤土에서 보다 砂壤土에서 栽培한 水稻體에서 더 높은 殘留量을 보이는 傾向이었다.

These studies were carried out to investigate the damage of root rot of hop by heptachlor residues in soil at nine farm fields and pot experiment for two years from 1980 to 1981. 1) Pot experiment results indicated that root rot of hop occurred in farm field were caused by heptachlor phytotoxicity. 2) The damage of root rot of the hop was found by heptachlor residues in soil. Hop root in the low concentration of heptachlor was turned to brown mottle, and then rotted. In high concentration, the hop root was decreased in number, blocked in growth, and resulted to greyish change with death. 3) Hop vine damaged by heptachlor was hardened and broken with ease. 4) Heptachlor epoxide which was inferred to be the main cause of hop root rot gave the damage to hop at 0.009 ppm reisdues in soil. 5) The phytotoxicity of heptachlor was proved to last for 10 years or more in this study.