Persistence of IBP and Isoprothiolane in Rice Plant

수도체(水稻體)중 IBP 와 Isoprothiolane의 잔류소장(殘留消長)

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.

수도체중(水稻體中) IBP와 isoprothiolane의 잔류소장(殘留消長)에 미치는 살포시기(撒布時期)의 영향(影響)이 조사(調査)되었으며, 아울러 수심(水深)과 토성(土性)의 영향(影響)도 관찰되었다. IBP(17%, G)와 isoprothiolane(12%, G)을 각각(各各) 6.8과 4.8㎏ AI/㏊의 비율(比率)로 담수토양(湛水土壤)에 1회(回) 살포(撤布)한 후 시기별(時期別)로 수도체중 잔류량(水稻體中 殘留量)을 gas chromatograph로 분석(分析)하였다. 살포시기(撒布時期)와는 무관(無關)하게 두 살균제(殺菌劑)는 뿌리조직을 통해 식물체(植物體)로 신속히 흡수(吸收), 전이(轉移)되었으며, 도체중(稻體中) 두 살균제(殺菌劑)의 농도(濃度)는 살포시기(撤布時期)와는 무관(無關)하게 24시간(時間) 이내에 최고(最高)에 이르렀다. 최대분얼기 살포시(撒布時) 두 살균제(殺菌劑)의 분해양상(分解樣相)은 비슷한 경향(傾向)으로 시간(時間)의 경과(經過)와 더불어 신속히 분해(分解)되었다. 한편 출수기 살포시(撒布時)에 IBP의 분해양상(分解樣相)은 최대분얼기 살포시(撤布時)와 비슷한 경향(傾向)이나 isoprothiolane의 그것은 아주 상이(相異)하였다. 즉 약제살포후(藥劑撒布後) 3일(日)에 나타난 최고농도(最高濃度)가 그후 25일(日)까지 큰 변화없이 유지(維持)되었다. 한편 두 살균제(殺菌劑)의 잔류소장(殘留消長)에 미치는 수심(水深)의 영향(影響)은 별로 없었으며, isoprothiolane의 경우 양토(壤土)와 식양토(殖壤土)에서 보다 사양토(砂壤土)에서 재배(栽培)한 수도체(水稻體)에서 더 높은 잔류량(殘留量)을 보이는 경향(傾向)이었다.