• The Korean Journal of Pesticide Science
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• v.8 no.3
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• pp.198-209
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• 2004

In order to elucidate the behavior of the fungicide hexaconazole in soil and rice plants, rice plants were grown for 42 days in a microecosystem (pot) containing fresh and 28 day-aged soil residues of $[^{14}C]$hexaconazole. The amount of $^{14}CO_2$ evolved during 28 days of aging was 0.11 % of total $^{14}C$-radioactivity treated and the averaged weekly degradation rate was 0.03%. Mineralization rates for 42 days of rice cultivation on fresh and aged paddy soils were 0.67% of the total $^{14}C$ in case of non-rice planting on aged soil and 1.17% in case of rice planting on aged soil, whereas 1.25% in non-rice planting on fresh soil and 1.72% in case of rice planting on fresh soil, suggesting that the amounts of $^{14}CO_2$ were evolved higher from fresh soils than aged ones and from rice-planting soils than non-planting ones. The amounts of volatiles collected were very low as background levels. Most of $^{14}C$-Radioactivity was remained in soil after 42 days of rice cultivation and $^{14}C$ absorbed through rice roots was distributed more in shoots than roots and translocated into the edge of shoots of rice plants. Amounts of non-extractable $^{14}C$ in soils were higher in rice planted soil than in non-planting soil. The distribution of non-extractable $^{14}C$ was increased in the order of humin>fulvic acid>humic acid. The amounts of $^{14}C$ translocated into rotational crop Chinese cabbage were 2.36 and 3.69% of the total $^{14}C$ in case of rice planted soil containing fresh and aged residues, respectively, suggesting that small amounts of $[^{14}C]$hexaconazole and its metabolite(s) were absorbed and their bound residues were more available than their fresh ones to Chinese cabbage.