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.

Effect of the application time on the persistence of IBP and isoprothiolane in rice plant was studied in the field and effects of the water depth and soil texture on their persistence were also tested as a pot experiment. When granules were applied to the rice paddy water, two fungicides were readily absorbed through the root system and rapidly translocated to the upper parts of the plant. The concentrations of two fungicides in rice plant reached to the maximum within 24 hr regardless of the application time. When applied at the maximum tillering stage, the persistence pattern of two fungicides in plant showed similar trends; that is, residue levels of two compounds declined rapidly upto 7 days after application but more slowly thereafter. When applied at the heading stage, the persistence pattern of IBP in plant was similar to the maximum tillering stage while isoprothilane was quite different; 3 ppm reached on 3rd days after application was maintained almost constant for further 25 days. There was no effect of the water depth on the persistence of two compounds in plant and IBP concentration in plant was also not affected by soil texture. However, isoprothiolane in plant was higher in sandy loam than in loam and clay loam. Isoprothiolane residues in plant were much higher than those of IBP.