The transfer pattern of chlorpyrifos present in soil to cucumber plants were assessed and reported with plant growth, concentration dependency, and duration. Cucumber seedlings cultivated in a growth chamber for 30 days and a greenhouse for 120 days. Weight and length of cucumbers cultivated in the chamber increased with the increasing time, while the uptake of chlorpyrifos by cucumber increased a period from 0 to 15 days and decreased after 15 days. Uptake rates of chlorpyrifos into a cucumber plant were 1.01 .3% to initial amounts treated with 20 and 40 mg/kg to soil. Most chlorpyrifos residues were detected in root, followed by stem and leaf. Results of the greenhouse test showed that chlorpyrifos amounts in cucumber fruits were present less than LOQ (0.02 mg/kg), and chlorpyrifos was mainly found in the root of the cucumber plant. Chlorpyrifos absorbed in a cucumber under greenhouse condition was smaller than that in chamber condition as 0.03~0.04%. Degradation patterns of chlorpyrifos in soils were similar during indoor and outdoor tests with half-lives of 25.8~73.0 days. These results may be useful for establishing the management strategy of residual pesticides in soil environment.

The uptake and transportation patterns of the residual boscalid and chlorfenapyr were investigated from the soils to Korean cabbages. The recovery rates of the pesticides spiked in the soils and Korean cabbages were 87.5 to 105.2%. Korean cabbages were cultivated in soils treated with two different concentrations of the pesticides as low (3.0 mg/kg) and high (6.0 mg/kg) concentrations in greenhouse for 28 days. The initial level of boscalid was determined as 2.77 and 5.66 mg/kg for the low and high concentration of boscalid-treated soils, respectively. After 28 days of treatment, the residual boscalid in soils decreased to 0.53 and 1.60 mg/kg for the low and high concentration of boscalid-treated soils, respectively, and thus it was reduced to 71.7 to 81.9%. The initial level of chlorfenapyr was determined as 2.38 and 6.43 mg/kg for the low and high concentration of chlorfenapyr-treated soils, respectively. After 28 days of treatment, the residual chlorfenapyr in soils decreased to 1.36 and 2.91 mg/kg for the low and high concentration-treated soils, respectively, and thus it was reduced to 42.9 to 54.8%. The residual pesticide analysis was done with 2 day intervals from 21 days-cultivated Korean cabbages after seeding. Uptake rates of boscalid from the soil to Korean cabbages were 2.4 and 2.2% for the low-and high-concentration of boscalid-treated soil, respectively. However, the uptake rate of chlorfenapyr by the cabbages was 1.5 and 1.3% for the low and high concentration-treated soil, respectively. The uptake rate of chlorfenapyr by the cabbages was lower than that of boscalid. These results showed that the residual pesticides in soil could be absorbed by Korean cabbages depending on their physicochemical properties.

BACKGROUND: It is important to understand residual patterns of pesticides applied on crops for ensuring their safety in agricultural products. However, there are few studies on the residual patterns of pesticides in minor crops, which are small in cultivation area. In this study, residual amounts of bifenthrin and chlorfenapyr sprayed on perilla leaf as a minor crop were investigated to know their residual patterns. METHODS AND RESULTS: Bifenthrin and chlorfenapyr were sprayed 2 or 3 times on perilla leaves at a week interval prior to harvest, and the perilla leaves were collected at 0, 1, 3, 5 and 7 days after the final application of pesticides. Recoveries for residual analysis of pesticides spiked on perilla leaves with concentrations of 0.1 and 0.5 mg/kg were 81.9-104.8%. The residual amounts of pesticides interpreted using first order kinetics model show that dissipation constants of bifenthrin and chlorfenapyr in perilla leaves

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