• The Korean Journal of Pesticide Science
• /
• v.20 no.3
• /
• pp.271-279
• /
• 2016

To evaluate exposure characteristics of the insecticide imidacloprid to apple orchard workers during treatment on orchard fields and evaluate its potential risk using a whole body dosimetry (WBD) method, 1,000-time diluted acephate+imidacloprid 25(20+5)% solutions were sprayed on 10 apple orchard fields in Cheongju with a speed sprayer at a rate of 3,000 L/ha/person, after put on clothes such as inner/outer clothes, personal air pump with a IOM sampler, nitrile glove and mask. Exposure test included mixing, loading and application steps. The test pesticide imidacloprid residues in the collected samples were analyzed with a HPLC-DAD. Recoveries ranged from 81.5 to 108.6% for analytical method validation and from 73.8 to 86.7% for field recovery. Total exposed amounts to mixer/loader and applicator were found to be 0.0014-0.0279% of total applied active ingredient of imidacloprid. Glove exposure of both mixer/loader and applicator was higher than the other parts. Margins of safety of mixer/loader and applicator were calculated to be 97-355 and 46-196, respectively, indicating that exposure risk of imidacloprid to apple orchard workers by spraying with a speed sprayer was very low.

• The Korean Journal of Pesticide Science
• /
• v.6 no.3
• /
• pp.175-182
• /
• 2002

This experiment was conducted to investigate the effects of acid rain in spraying copper hydroxide 77% wettable power(WP) on leaf surface morphology and crop injury of the garlic(Allium sativum L.). Leaf chlorosis, hooked leaves, wrinkled epidermal cells and increased stomata open of garlic were induced by foliar application of simulated acid rain(SAR). It was become to be severe in application of copper hydroxide solution after application of SAR, but those yield of garlic was not significantly different from the untreated control. Leaf chlorosis was sharply increased above 100 ppm of copper ions. Amount of solved copper ions in copper hydroxide solution was remarkably increased below pH 5.5 and the residue in garlic leaves was significantly increased by application of copper hydroxide solution after spraying SAR compared with application of copper hydroxide solution only. When calcium carbonate was applied together with copper hydroxide leaf chlorosis was less than copper hydroxide only.

• Proceedings of the Korean Society for Bio-Environment Control Conference
• /
• 1998.10a
• /
• pp.1-4
• /
• 1998

상온연무기와 같은 소량살포기에 의해 살포된 농약액의 입자경은 10-20$\mu\textrm{m}$ 이하의 것이 대부분이다. 미소 액적은 단시간에 공기의 습구 온도와 평형하게 되어 혼합, 확산되는 특성을 가지고 있으며 증발과 Drift현상이 발생된다. 시설원예의 경우 폐쇄환경에 있으므로 연무직후 온실내 작업의 제한, 부착력포의 불균일, 증발과 Drift량의 과다 등이 큰 문제가 된다. (중략)

• The Korean Journal of Pesticide Science
• /
• v.11 no.4
• /
• pp.299-304
• /
• 2007

Surveying, laboratory and field trial were performed to elucidate the causes of non-spinning syndrome of silkworm, Bombyx mori, abnormal symptoms of silkworm instars observed in certain sericultural fanning region. Mortality and growth of silkworm was still influenced by feeding the mulberry leaves sprayed with 10,000 fold diluted solution of standard spray of diflubenzuron WP (25%). Mortality and growth of silkworm fed with diflubenzuron-sprayed mulberry leaves with recommended spray solution were entirely affected even six weeks after spraying irrespective to the instars. Larval period of 5th instar and cocooning duration of silkworm was not affected in case 50m of buffer zone has maintained in near-by orchard field sprayed with diflubenzuron WP (25%). However, survival rate of pupae was not influenced in case 100 m of buffer zone has kept. Insect growth regulating insecticides were required to keep a certain distance of buffer zone when sprayed with water-diluted solution, 100 m from the application site at least in order to prevent contamination of the spraying drift by the chemicals.

• The Korean Journal of Pesticide Science
• /
• v.20 no.1
• /
• pp.1-6
• /
• 2016

In order to obtain efficient control effect of the pesticide, it is important to ensure uniform adhesion to the desired plant parts at the right time. Pesticide spray method (application technology) is an important factor affecting the efficacy and crops persistent expression. The aim of this study was to develop an efficient system to investigate the coating weight distribution of citrus leaves due to the difference between the nozzle and spray sprinkler system using dithianon used in citrus scab. Other An, engine type sprayer was used as the control. Speed sprayer and different sprinklers were wsed to way the deposit amounts of dithianon on citrus leaves. The test was conducted at the National Institute of Horticultural Herbal Science Citrus Research Station, located in the circle citrus Jeju Island. In order to examine whether the citrus orchard spray and the evenl on the whole, dithianon (43% flowable 1000-fold dilution) was sprayed, filter paper and leaves were analyzed by the height as top, middle, bottom. Speed sprayer the was most effective on depositing at the middle position, of the leaves. All other sprays the leaces except the dry mist sprinkler were not effective enough to deposit on the back sides. To achieve more deposits on the high position leaves, an improve ment in the nozzle and an efficient power system of sprayer were needed.

• Korean Journal of Food Science and Technology
• /
• v.43 no.3
• /
• pp.263-270
• /
• 2011

This study was performed to acquire processing and reducing factors of difenoconazole during ginseng processing, and to establish the maximum residue limits of ginseng and its commodities. Difenoconazole was used in two fields (Wonju and Icheon) containing 6 year old ginseng plants. The amount of residue at Wonju and Icheon were

• Food Science and Preservation
• /
• v.14 no.2
• /
• pp.119-123
• /
• 2007

Sprays containing chitosan, grain amino acids, or wood vinegar, were applied to vine leaves of the Campbell Early grape variety, and effects on the quality and storability of grapes were investigated. Weights of grape clusters and individual bemies did not differ significantly from the values seen when traditional agnicultural chemical treatment was used. The percentage of clusters over 300g in weight was, however, higher after spraying with chitosan, grain amino acids, or wood vinegar, than after agricultural chemical treatment, Grape moisture contents, levels of soluble solids, and reducing sugar concentrations, did not differ when the traditional treatment and the newer sparys were compared. Among minerals, the levels of potassium, iron and zinc measured in fresh grapes were increased by the clitosan, grain amino acids, and wood vinegar spray. After 8 weeks of MA storage, reducing sugar levels decreased, and titratable acidities increased, compared to levels measured at the beginning of storage. This was true regardless of the method of vine treatment the hardness of berries decreased slightly over 4-6 weeks of storage, and increased thereafter. The weight losses of grapes were relatively low(0.28-0.35%) on storage after any vine treatment tested. Grapes from vines sprayed with chitosan or grain amino acids showed a lower decay rate than did fruit from vines that had received a traditional agricultural chemical treatment. Sensory evaluation results indicated that the marketability of grapes from vines treated with traditional agricultural chemicals was better than that of grapes from vines sprayed with chitosan, grain amino acids, or wood vinegar.

• The Korean Journal of Pesticide Science
• /
• v.16 no.4
• /
• pp.328-335
• /
• 2012

In order to use in the classification of minor crop for the mutual application of safe use guideline, it was investigated the residue property of fungicide dimethomorph and pyraclostrobin in green onion, a stem-crop. After pesticides were applied 2 times with 1 week interval in that day of harvest, 3 days, 7 days, 10 days and 14 days before harvest, a green onion was harvested. The residue of dimethomorph in a green onion was 26.31 and 39.08 mg/kg in that day of harvest, however, in according to elapse time, it was reduced to 6.86 and 9.34 mg/kg in 14 days before harvest. In case of pyraclostrobin, it was also reduced from 13.46 and 39.08 mg/kg to 3.57 and 5.21 mg/kg. Based on the residue in that day of harvest, the deposit of spray solution in a green onion was calculated. The deposit of spray solution of dimethomorph was 274.35~345.84 mL/kg, in case of pyraclostrobin, it was calculated 213.65~343.33 mL/kg. When the amount of the deposit of both pesticides was compared in a green onion, it was so similar. On the other hand, it was estimated the predicted dissipation curve of pesticides in the green onion during cultivation. The half-life of dimethomorph was 6.95~7.45 days, in case of pyraclostrobin, 7.15~7.45 days. When both pesticides were compared with the residue property, the deposit of spray solution and half-life of dissipation were so similar.

• Korean Journal of Food Science and Technology
• /
• v.39 no.5
• /
• pp.575-579
• /
• 2007

This study was performed to acquire scientific data for establishing the maximum residue limits (MRLs) of pesticides in Korean red ginseng and its extract. Pesticides (azoxystrobin, fenhexamid, cyprodinil) were applied to a cultivated field of ginseng, and the fresh ginseng was harvested and processed to make Korean red ginseng and its extract. The reduction rates of the residue pesticides were calculated by determining the pesticide contents in each stage of ginseng processing. The residue levels in fresh ginseng were 0.12 ppm for azoxystrobin, 0.19 ppm for fenhexamid, and 1.78 ppm for cyprodinil. The residue levels in Korean red ginseng were 0.24, 0.54, and 1.49 ppm, and in the extract 0.81, 1.93, and 3.66 ppm for azoxystrobin, fenhexamid, and cyprodinil, respectively. The steaming and processing of fresh ginseng increased azoxystrobin and fenhexamid residues, but cyprodinil was reduced. The reduction rates (dry basis) of azoxystrobin, fenhexamid, and cyprodinil were 0.66, 0.94, and 0.28 for Korean red ginseng, and 3.25, 4.94, and 1.01 for the extract, respectively.

• The Korean Journal of Pesticide Science
• /
• v.16 no.4
• /
• pp.391-394
• /
• 2012

Exposure and risk assessment during mixing/loading of chlorpyrifos emulsifiable concentrate (EC, 20%) were carried out. Limit of detection and limit of quantitation were 0.02 and 0.1 ng, respectively. Calibration curve linearity and reproducibility were excellent. Recovery of chlorpyrifos from gloves was 72.3-103.4%. During mixing/loading procedure, average hand exposure amount of chlorpyrifos was 3.9 mg which is corresponding to 0.004% of total active ingredient in the prepared spray mixture. In calculation of MOS (Margin of Safety) for risk assessment, male Korean average body weight and AOEL (Acceptable Operator Exposure Level) were used. Nine events of mixing/loading procedure were assumed per day. And 75 percentile of 30 repetition (4.6 mg) was used as for the worst case. MOS was more than 1 for total repetition, indicating mixing/loading work was of least risk. However, MOS of individual repetition was examined, two cases were less than 1 suggesting careful work habit is essential in mixing/loading procedure.