• Journal of Food Hygiene and Safety
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• v.38 no.4
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• pp.202-210
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• 2023

To analyze the pesticide residues in commercial bee pollen products in South Korea, 61 samples were collected and screened for 339 pesticides. Results revealed that approximately 34% (>LOQ) of samples were contaminated with at least one pesticide. The pesticide residue detection rates of domestic and imported samples were 31% and 44%, respectively. Furthermore, the pesticide residue detection rate of online distribution (60%) was higher than that of offline distribution (27%). Fifteen pesticides were discovered in bee pollen, and pendimethalin, chlorfenvinphos, chlorpyrifos, and fluazinam were detected in 7, 6, 3, and 2 order of frequency, respectively. Even though its concentration was low, chlorfenvinphos which is banned in food crops in the United States, European Union, and Korea, was detected in bee pollen samples commonly. Therefore, continuous investigation of pesticide residues in bee pollen products and their acceptance criteria is required for safety.

• Journal of Food Hygiene and Safety
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• v.38 no.3
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• pp.152-157
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• 2023

This study was aimed to investigate pesticides residue levels in nuts and seeds distributed in Gyeonggi-do. We investigated nuts and seeds in 131 products, which is pumpkin seeds (n=17), sunflower (n=12), sesame (n=23), perilla (n=11), peanut (n=18), almond (n=8), chestnut (n=6), walnut (n=14), pine nut (n=3), pecan (n=4), macadamia (n=3), brazil nut (n=5), cashew nut (n=4) and ginkgo nut (n=3). As a result of evaluating 339 pesticide residues, eight out of 131 samples were detected at the range of 0.01-0.07 mg/kg. Additionally, 7 out of 8 detected samples exceeded MRLs (Maximum Residue Limits) and 85% of them were imported. Pyraclostrobin applied on the positive list system (PLS) was detected in five Chinese pumpkin seeds samples, and the range was 0.02-0.04 mg/kg. In Indian and Korean sesame seeds, pendimethalin, boscalid, and bifenthrin were detected at 0.04, 0.05, and 0.06 mg/kg, respectively. The ratio of estimated daily intake (EDI) to acceptable daily intake (ADI) was 0.002-0.372%, indicating that the risk level was safe.

• The Korean Journal of Pesticide Science
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• v.17 no.4
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• pp.283-292
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• 2013

A series of monitoring studies were carried out to evaluate the residue level of pesticides in different native soils from 1999 to 2006. The nation-wide collection of soil samples from paddy, greenhouse, upland and orchard, were analyzed by GLC (ECD or NPD) and GC/MS. The results obtained are summarized as follows; out of 14 pesticides detected from paddy soils in 1999, the highest residue level was 0.25 mg $kg^{-1}$, and the frequency was 21.7% as butachlor, 20.0% as isoprothiolane, and 16.7% as iprobenfos. In 2003, 7 pesticides were detected and their frequencies were 0~36.0%; the frequency was 36.0% as isoprothiolane and 33.3% as oxadiazon. In the year 2000, 57 pesticides in the greenhouse soil samples were detected with the highest frequency of 65.3%. Of the pesticides detected, endosulfan and procymidone showed the frequency of 65.3 and 50.0%, respectively. In 2004, 19 pesticides were detected from greenhouse soils, and their frequencies and residue levels were decreased. Endosulfan and procymidone showed high detection frequencies and concentrations of 21.3 and 9.3% and 0.76 and 0.31 mg $kg^{-1}$, respectively. In 2001, a total of 25 pesticides were detected through monitoring in 170 upland soils and the highest residue level was 2.24 mg $kg^{-1}$. The detection frequencies showed the range of 0~53.5%. Especially, endosulfan showed the highest frequency of 53.5%. Residue levels and frequencies of pesticide in the year 2005 were almost the same compared with that of the year 2001. As a result of monitoring in 150 orchard soils in 2002, 26 pesticides were detected and the highest residue level was 1.43 mg $kg^{-1}$. Of them, the frequency of endosulfan showed the highest as 45.3%. In 2006, 20 pesticides were detected in orchard soils. The frequency of total endosulfan was the highest as 5.3% but was lower than that of the year 2002.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.69-78
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• 1984

This study was conducted to select herbicides effective for upland crops and to investigate the cause of crop injury in peanut cultivated with mulching. Crop such as radish (Raphanus acanthiformis Moor.), Chinese cabbage (Brassica raps L.), soybean (Glycine max Merr.), Peanut (Archis hypogaea L.), and marsh mallow (Malva olitoria Nakai) were tolerant to napropamide [2-(${\alpha}$-naphthoxy)-N, N-diethylpropionamide], alachlor [2-chloro-2', 6'-diethyl-N-(methoxymethyl) acetanilide], trifluralin (${\alpha},{\alpha},{\alpha}$-trifluoro-2, 6-dinitro-N, N-dipropylp-toluidine) and nitrofen (2,4-dichlorophenyl-p-nitrophenylether). Napropamide, diphenamide (N, N-dimethyl-2, 2-diphenylacetamide) and alachlor were safe for red pepper (Capsicum annuum L.), eggplant (Solanum melongena L. and tomato (Lycopersicon esculentum Mill.), while trifluralin, nitrofen and chlonitrofen (2,4,6-trichlorophenyl-4-nitrophenyl ether) could be used for water melon (Citrullus battich Forsk.), carrot (Daucus carota L.) and lettuce (Lactuca scariola L.) without crop injury. Out of nine major weed species studied, Capsella bursa-pastoris Medicus was the most resistant species to the herbicides tested. Napropamide and alachlor could not control P. hydropiper, while P. oleracea and C. album were tolerant to diphenamide :and alachlor, respectively. Urea herbicides such as methabenzthiazuron [3-(2-benzothiazolyl)-1,3-dimethylurea], linuron [3-(3, 4-dichlorophenyl~l-methoxy-i-methyl urea], and isoproturon [3-(4-isopropylphenyl) -1, 1-dimethylurea]gave a great injury to the crops studied. The weeding effect was greater for broadleaf weeds than for grasses. Isoproturon and linuron provided good selectivity for marsh mallow and carrot, respectively. In peanut, the crop injury caused by Four herbicides studied was greater when cultivated with mulching than when cultivated without mulching. With dinitroaniline herbicides the crop injury decreased as the gaseous herbicide was removed out of mulching. Alachlor gave little phytotoxicity to peanut grown under mulching condition and nitralin [4-(methylsuphonyl)-2, 6-dinitro-N, N-dipropylaniline] showed less toxicity to the peanut than pendimenthalin (3,4-dimethyl-2, 6-dinitro-N-1-ethyl propylaniline) and trifluralin.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.261-270
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• 1992

Many herbicides that are applied at the soil before weed emergence inhibit plant growth soon after weed germination occurs. Plant growth has been known as an irreversible increase in size as a result of the processes of cell divison and cell enlargement. Herbicides can influence primary growth in which most new plant tissues emerges from meristmatic region by affecting either or both of these processes. Herbicides which have sites of action during interphase($G_1$, S, $G_2$) of cell cycle and cause a subsequent reduction in the observed frequency of mitotic figures can be classified as an inhibitor of mitotic entry. Those herbicides that affect the mitotic sequence(mitosis) by influencing the development of the spindle apparatus or by influencing new cell plate formation should be classified as causing disruption of the mitotic sequence. Sulfonylureas, imidazolinones, chloroacetamides and some others inhibit plant growth by inhibiting the entry of cell into mitosis. The carbamate herbicides asulam, carbetamide, chlorpropham and propham etc. reported to disrupt the mitotic sequence, especially affecting on spindle function, and the dinitroaniline herbicides trifluralin, nitralin, pendimethalin, dinitramine and oryzalin etc. reported to disrupt the mitotic sequence, particularly causing disappearence of microtubles from treated cells due to inhibition of polymerization process. An inhibition of cell enlargement can be made by membrane demage, metabolic changes within cells, or changes in processes necessary for cell yielding. Several herbicides such as diallate, triallate, alachlor, metolachlor and EPTC etc. reported to inhibit cell enlargement, while 2, 4-D has been known to disrupt cell enlargement. One potential danger inherent in the use of soil acting herbicides is that build-up of residues could occur from year to year. In practice, the sort of build-up that would be disastrous is unikely to occur for substances applied at the correct soil concentration. Crop injury caused by soil applied herbicides can be minimized by (1) following the guidance of safe use of herbicides, particularly correct dose at correct time in right crop, (2) by use of safeners which protect crops against injury without protecting any weed ; interactions between herbicides and safeners(antagonists) at target sites do occur probably from the following mechanisms (1) competition for binding site, (2) circumvention of the target site, and (3) compensation of target site, and another mechanism of safener action can be explained by enhancement of glutathione and glutathione related enzyme activity as shown in the protection of rice from pretilachlor injury by safener fenclorim, (3) development of herbicide resistant crops ; development of herbicide-resistant weed biotypes can be explained by either gene pool theory or selection theory which are two most accepted explanations, and on this basis it is likely to develop herbicide-resistant crops of commercial use. Carry-over problems do occur following repeated use of the same herbicide in an extended period of monocropping, and by errors in initial application which lead to accidental and irregular overdosing, and by climatic influence on rates of loss. These problems are usually related to the marked sensitivity of the particular crops to the specific herbicide residues, e.g. wheat/pronamide, barley/napropamid, sugarbeet/ chlorsulfuron, quinclorac/tomato. Relatively-short-residual product, succeeding culture of insensitive crop to specific herbicide, and greater reliance on postemergence herbicide treatments should be alternatives for farmer practices to prevent these problems.

• Asian Journal of Turfgrass Science
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• v.19 no.2
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• pp.65-72
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• 2005

Creeping bentgrass (Agrostis palustris Huds.) had been the problematic weed for Kentucky bluegrass (Poa pratensis L.) fairway since it shows light green color all year. Experiment was carried out to determine the best herbicides combination to control creeping bentgrass in Kentucky bluegrass. fairway without injury. To investigate the efficacy of herbicides, five post-emergence herbicides of asulam WG ($87.6\%$), imazaquin SL ($20\%$), fenoxaprop-P-ethyl EC ($7\%$), mecoprop SL ($50\%$), triclopyr-TEA SL ($30\%$) and one pre-emergence herbicide pendimethalin EC ($31.7\%$) treated on 21 Sept. and 10 Nov. 2003. Kentucky bluegrass visual quality evaluated 30 and 50 days after application for phytotoxic effects of the herbicides. As a result, asulam WG (0.2g/$m^{2}$) and imazaquin SL (0.3ml/$m^{2}$) showed approximately $90\%$ of control in creeping bentgrass, but visual quality of Kentucky bluegrass significantly decreased from 20 to 50DAT (day after treatment). However, creeping bentgrass was acceptably controlled(over $80\%$) by fenoxaprop-P-ethyl EC (0.4ml/$m^{2}$)+triclopyr-TEA SL(0.3 ml/$m^{2}$) applied twice on 21 Sept. and 1 Oct. 2003 without serious injury on Kentucky bluegrass. Therefore, it is suggested that an application of fenoxaprop-P-ethyl EC (0.4ml/ $m^{2}$)+triclopyr-TEA SL (0.3 ml/$m^{2}$) may be more effective to control creeping bentgrass in Kentucky bluegrass with the least phytotoxicity by herbicides.

• Korean Journal of Weed Science
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• v.18 no.1
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• pp.1-11
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• 1998

This experiment was conducted to investigate weed infestation and to determine effective weed control methods in direct-seeded rice. Twenty two weed species occurred in dry- and water-seeded rice, which was mainly composed of annual weeds. Dominant weed species in dry-seeded rice were Cyperus difformis, Echinochloa crus-galli, Aneilema keisak and Digitaria sanguinalis in discending order. Dominant weed species in water-seeded lice were E. crus-galli, C. difformis, Monochoria vaginalis and Scirpus juncoides. E. crus-galli emerged at 7 days after sowing. In water-seeded rice, E. crus-galli emerged at 5 days after sowing, and M vaginalis, S. juncoides and C. difformis at 8~10 days after sowing. Mean days to emerge important weeds was 20 days in dry-seeded rice and 13 days in water-seeded rice. Leaf development of weeds was faster than that of rice in dry-seeded rice. In water-seeded rice, E eras-galli was more vigorous than rice, but leaf development of other weeds were slower than that of rice. Changes in number of weeds and dry weight oil weed species varied depending upon weed species in the direct-seeded rice. Dry weight of weeds were increased greatly from 30 days to 60 days after sowing in dry-seeded rice. Number of weeds tended to increase up to 40 days after sowing drastically, and then trend of the increase was dull thereafter. Dry weight and number of weeds increased up to 20~60 days after sowing in water-seeded rice. Most effective herbicide treatments was foliar application of cyhalofop/bentazon at 20 days after sowing followed by fenoxaprop/bentazon at 45 days after sowing in dry-seeded rice. All herbicide treatments except foliar applications were very effective to control weeds in water-seeded rice. Slight phytotoxicity was observed in foliar applied fenoxaprop/bentazon at 45 days after sowing in water-seeded rice, but it did not affect rice yield.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.1
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• pp.10-16
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• 2022

This study was conducted to examine the dry matter yield and weed control of alfalfa according to postemergence herbicides treatment during spring seeding alfalfa. The seeding time of alfalfa was April 21, 2021, the seeding amount was 20 kg/ha, and the seeding method was by 20 cm wide. The alfalfa harvest was carried out at the early bloom stage (10% of flowering), and the harvest date was June 29, 2021. The test treatments were non herbicide (NH), hand weeding (HW), herbicide 1 (Trifluralin, H1), herbicide 2 (S-metolachlor, H2), herbicide 3 (Alachlor, H3), and herbicide 4 (Pendimethalin, H4). Alfalfa plant height was significantly highest in H2 (62.1±1.4 cm) followed by H3 (61.7±1.6 cm), HW (58.5±1.0 cm), H1 (57.2±1.3 cm), H4 (56.1±1.3 cm), and NH (54.1±1.2 cm) (p<0.05). Based on HW, H2 and H3 were high and H1 and H4 were short, but NH was significantly shorter than HW and H1~H4 (p<0.05). The dry matter yield of alfalfa in NH, HW, H1, H2, H3, and H4 were 717.2±94.2, 2,613.8±254.1, 1,667.8±94.1, 2,498.3±120.2, 2,435.0±118.3, and 1,793.7±354.3 kg/ha. HW is the highest among them (p<0.05). The feed composition of alfalfa was 22~24% of the dry matter yield, and the CP content were significantly higher in NH (23.6 %) (p<0.05). The NH had higher (p<0.05) NDF and ADF, but RFV was lower (p<0.05). The weed plant height was NH 98.0±3.3cm, HW 73.3±1.7 cm, H1 91.9±1.5 cm, H2 53.3±5.8 cm, H3 81.4±3.5 cm and H4 96.6±2.2 cm, and H2 was significantly smallest in the group (p<0.05). The weed dry matter yield was NH 4,770.4±232.5 kg/ha, HW 316.3±91.9 kg/ha, H1 2,353.4±173.7 kg/ha, H2 114.5±10.2 kg/ha, H3 752.7±440.6 kg/ha and H4 2,220.6±775.6 kg/ha. The weed control value was HW 94.1%, H1 53.5%, H2 98.2%, H3 84.9%, H4 48.7%, the weed value of H2 is similar to weed control value of HW. Considering the above results, postemergence herbicide treatment controlled weeds by more than 50% compared with no treatment, and among herbicides, H2 (S-metolachlor) was found to be on a similar level to hand weeding.