• Korean Journal of Environmental Agriculture
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• v.20 no.3
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• pp.175-179
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• 2001

To find out the effect of cadmium(Cd) on growth of major vegetables in Korea, phytotoxicity and absorption of Cd were investigated with chinese cabbage, radish, and lettuce grown in upland soils of different Cd concentrations. Cadmium phytotoxicity was shown by growth retardation and leaf chlorosis in chinese cabbage and lettuce at the early growing stage. The threshold concentrations of growth damage resulting from the significant reduction (5%) of growth and yield of chinese cabbage and lettuce were $50{\sim}100$ and $10{\sim}25$ mg/kg soil, respectively. However, there was no significant reduction of radish yield under Cd treatment of 100 mg/kg soil. As Cd concentrations in soils increased, the contents of Cd in products were significantly increased, basically. The contents of Cd in edible part of chinese cabbage, radish, and lettuce grown at the 5 mg/kg Cd treated soils were 0.13, 0.18, and 3.37 mg/kg FW, respectively. Total absorbed Cd in the vegetables tended to occur in the following order, chinese cabbage > radish > lettuce above 25 mg/kg Cd treated soils whereas lettuce absorbed more Cd than chinese cabbage and radish below 10 mg/kg Cd concentration.

• Korean Journal of Weed Science
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• v.7 no.2
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• pp.156-164
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• 1987

Allelopathic activity of dominant upland weed species was determined using aqueous and methanol extracts and dried residues of the weeds. Germination and seedling growth of radish (Raphanus sativus L.) and sesame (Sesamum indicum L.) were greatly inhibited by 2% (w/v) aqueous extracts of Artemisia asiatica Nakai and Portulaca oleracea L., respectively. Great phytotoxicity on both indicator plants occurred by 2% (w/v) aqueous extracts of Capsel/a bursa-pastoris (L.) Medik. A complete inhibition in germination and seedling growth of radish was caused by 2% (w/v) methanol extract of A. asiatica. There was about 90% inhibition in germination and seedling growth of sesame due to 2% (w/v) methanol extracts of A. asiatica, P. oleracea and Trifolium repens L. Phytotoxic effects varied with extract solution, weed species and indicator plants employed, indicating that the weed species contained different contents and kinds of allelopathic chemicals. Water potential and pH adjusted to those of the extracts did not affect germination and seedling growth of the indicator plants. Phytotoxicity increased with increasing concentration of the extracts obtained from four suspected alleopathic weeds. Soil-incorporated plant residues of A. asiatica and P. oleracea caused greater phytotoxicity on radish than those of C. bursa-pastoris and T. repens.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.106-115
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• 1998

This study was conducted to investigate the effect of oxadiazon, molinate, thiobencarb before seeding on control of red rice and barnyardgrass in water-seeded rice. High application rate plot among oxadiazon treatment plots could observe phytotoxicity symptoms depending on field conditions, but these injury recovered gradually with time. Molinate and thiobencarb application plots at the concentration of 225~400, 210~420g ai/l0a respectively were not observed phytotoxicity. Control of red rice was different according to kinds of herbicides and application rates. Oxadiazon showed higher control performance at the concentration of more than 60g ai/10a. Control effect of molinate and thiobencarb against red rice was enhanced with the increase of application rate, and both herbicides showed satisfactory effect at more than 300g ai/10a. Control of barnyardgrass showed up to 90~100% in all tested herbicides. There was no significant yield reduction by oxadiazon, molinate, and thiobencarb application before seeding in all tested field. In the pot experiment, crop injury, seedling stand, and early growth were more advantageous at time of drainge after one day after seeding than flooding until rooting.

• Korean Journal of Plant Resources
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• v.36 no.1
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• pp.100-106
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• 2023

In order to control the fire blight disease, all plants within the radius of the diseased orchard were removed in the early stage of the outbreak, or antibiotics control was performed for prevention. Since the beginning of antibiotics use on plants, the potential for development of resistance to antibiotics by the plant pathogen and unintended detrimental effects on the fruit trees and environment has become a problem. The purpose of this study is to determine the degree of phytotoxicity to fruit trees caused by excessive spraying of the fire blight disease disinfectant and to establish basic data for safe disinfectant guide. We analyzed whether damage to the fruit tree and the maximum residual limit of fruit was exceeded when three kinds of the fire blight disease disinfectants were continuously sprayed in excess of the number of safe use during the growing season. There was no phytotoxicity in apple 'Fuji' and pear 'Niitaka', and oxolinic acid was detected beyond the limit of quantitation in 'Fuji' grown without a bag, and the other disinfectants were detected below the maximum residue limit. When these disinfectants are continuously sprayed in excess of the number of safe, phytotoxicity may remain on the fruit. Therefore, it is necessary to observe the prescribed dilution factor and observe the safe frequency and the timing of use.

• The Plant Pathology Journal
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• v.15 no.1
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• pp.14-20
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• 1999

Twenty isolates of Helminthosporium species were obtained from various grass plants and tested for controlling efficacy on the development of plant diseases. An isolate of Helminthosporium sp. TP-4 was chosen and six antibiotic substances were purified from cultures of the fungus by repeated silica gel column chromatography and preparative thin-layer chromatography. They were identified as ophiobolin a, 6-epiophiobolin A, 3-anhydroophiobolin A, 3-anhydro-6-epiophiobolin A, iphiobolin B, and iphiobolin I mainly by mass spectrometry and nuclear magnetic resonance spectrometry. Ophiobolins inhibited the growth of a grampositive bacterium Streptomyces griseus, but were not active against gram-negative bacteria. They also showed an antifungal activity. In in vivo tests, iphiobolin B exhibited potent controlling activities against rice blast, tomato late blight, and wheat leaf rust with control values more than 90% and 70% at concentration of $500\mu\textrm{m}$/ml and 100 ${\mu}{\textrm}{m}$/ml. Ophiobolin A and 6-epiophiobolin A controlled the development of wheat leaf rust more than 80% at concentrations of 100 /ml and $500\mu\textrm{m}$/ml respectively. 3-Anhydro-6-epiophiobolin A was not active against any plant disease. On the other hand, the A-series ophiobolins other than 3-anhydroophiobolin A showed stronger phytotoxic activity in a leaf-wounding assay using 8 plant species than those of 3-anhydroophiobolin A, ophiobolin B, and ophiobolin I. The results indicate that there is little correlation between antifungal activity and phytotoxicity of ophiobolins.

• Journal of Environmental Science International
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• v.14 no.12
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• pp.1129-1139
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• 2005

A series of experiments was conducted to identify the potential of five phytoplankton species as standard test species for marine ecotoxicological tests. The candidate phytoplankton species are Skeletonema costatum, Heterosigma akashiwo, Prorocentrum micans, Isochrysis galbana, and Tetraselmis suecica. Salinity tolerance and sensitivity on potassium dichromate as a reference material were identified. Toxicity of eleven ocean dumped sewage sludges and four red tide expellent extracts were estimated by the inhibition of population growth rates (PGR) of marine diatom S. costatum, While most species revealed relatively weak tolerance on salinity, T. suecica demonstrated the highest salinity tolerance ranged from $5\~35$ psu and the others $15\~35$ psu. H. akashiwo revealed the highest sensitivity as 72h $IC_{50}$=0.76mg/L and T. suecica the lowest as 72h $IC_{50}$=8.89mg/L on potassium dichromate. Sludge extracts from industrial waste, domestic sewage and livestock farm waste sludge showed high toxicity as 72h $IC_{50}$<$2\%$ and lowest toxicity from filtration bed sludge as 72h $IC_{50}$=$30.50\%$ NOEC (No Observed Effective Concentration) of sludge extract ranged from <$0.4\%$ to $1.6\%$ and this indicated high phytotoxicity of ocean dumped sewage sludge. The test sensitivity of phytoplankton PGR inhibition was much higher than those of marine rotifer Brachionus plicatilis mortality test and bioluminescent inhibition test by marine bacteria Vibrio fischeri, and comparable with the sea urchin (Strongylocentrotus intermedius) fertilization test. As a result the phytotoxicity test using phytoplankton PGR inhibition ($IC_{50}$) must be a useful tool for marine phyto-toxicological evaluation of ocean dumped materials.

• Applied Biological Chemistry
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• v.32 no.2
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• pp.154-161
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• 1989

1,3-Dimethyl-4-acyl-5-hydroxypyrazoles were treated with methyl isocyanate to give corresponding carbamates. They were 1,3-dimethyl-4-benzoyl-pyrazol-5-yl N-methylcarbamate(V), 1, 3-dimethyl-4-(2-chlorobenzoyl)-pyrazol-5-y1 N-methyl-carbamate(VI), and 1, 3-dimethyl-4-(2,4-dichlorobenzoy1)-pyrazol-5-yl N-methyl-carbamate(VII). The structures of the compounds were fully identified by UV, IR, $^{1}H-NMR$ and $^{13}C-NMR$. The synthesized carbamate compounds were tested for the phytotoxicity on the seed germination and the seedling growth of rice, radish, green-pea and turf grass. At 50ppm concentraction, the germination of seeds was not significantly affected. At higher concentraction, however, phytotoxic tendency on the seed germination and seedling growth was observed. In addition, these compounds were less phytotoxic to rice and turf seedlings as compared with radish and green pea seedlings.

• Journal of the Korean Chemical Society
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• v.25 no.1
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• pp.38-43
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• 1981

Pyrrolidone-anilide derivatives from L-glutamic acid and anilines were synthesized as follows: The products were identified by elementary analysis, IR, NMR and Mass spectra with (R)-2-pyrrolidone-5-carbox-anilide, (R)-2-pyrrolidone-5-cabox-p-chloroanilide, (R)-2-pyrrolidone-5-carbox-o-toluidide, (R)-2-pyrrolidone-5-carbox-m-toluidide and (R)-2-pyrrolidone-5-carbox-p-toluidide. The products were testes for their phytotoxicity on the germination and the seedling growth of radish and rice plants. Among them, (R)-2-pyrrolidone-5-carbox-anilide and (R)-2-pyrrolidone-5-carbox-p-chloroanilide derivatives were strongly inhibitory especially on the germination and the seedling growth of radish seeds. All the compounds also showed an inhibitory activity upon the germination of rice seeds. Additionally, the inhibiting rate of radish growth differs according to the isomeric position(ortho, meta and para) of the methyl group; (R)-2-pyrrolidone-5-carbox-m-toluidide derivative was more effective than both (R)-2-pyrrolidone-5-carbox-o-toluidide and (R)-2-pyrrolidone-5-carbox-p-toluidide derivatives.

• Korean journal of applied entomology
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• v.26 no.2 s.71
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• pp.107-111
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• 1987

Experiments were caried out to invesstigate the effects of seed disinfectant and the chemical control method in the paddy field for the rice white-tip nematode, Aphelenchoides besseyi. All three seed disinfectants tested, MEP 50% EC, Fenthion 50% EC, Dasuzin 34% EC showed effective control without any symptom of phytotoxicity. Mixed treatments with fungicides, Benoram 40% Wp, proraz-25% EC, TCM 30% EC also showed the effective control and no phytotoxicity. Effective chemical control methods for the rice white-tip nematode in paddy fields was seed disinfectant before seeding and Carbofuran 3% G. on the day before the transplanting, or seed disinfectatnt + Carbofuran 3% G. water surface treatment on the early stage of injury.

• Journal of Korean Society of Environmental Engineers
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• v.36 no.6
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• pp.396-401
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• 2014

Nanomaterials have been widely used in many fields. This study investigates the effects of metal oxide nanoparticles (CuO, NiO, $TiO_2$, $Fe_2O_3$, $Co_3O_4$, ZnO) on germination and germination index (G.I.) of seeds, Lactuca and Raphanus. Under aqueous exposure, CuO on Lactuca shows the most significant impacts on activities compared to others, showing $EC_{50s}$ for germination and G.I. as 0.46 mg/L and 0.37%, respectively. The effects of nanoparticle phytotoxicity on seed Lactuca was much higher than that of Raphanus. In general, the toxicities on seed germination and germination index were as following orders : CuO > ZnO > NiO ${\gg}$ $TiO_2$, $Fe_2O_3$, $Co_3O_4$. No measurable inhibition was observed at 1,000 mg/L (maximum exposure concentration) of $TiO_2$, $Fe_2O_3$, $Co_3O_4$.