• Environmental Engineering Research
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• v.24 no.1
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• pp.127-136
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• 2019

Land application of treated palm oil mill effluent (TPOME) could be used as an alternative tertiary wastewater treatment process. However, phenolic compounds in TPOME might be leached to the environment. This study investigated the ability of grasses on reducing phenolic compounds in the leachate after TPOME application. Several pasture grasses in soil pots were compared after irrigating with TPOME from stabilization ponds, which contained 360-630 mg/L phenolic compounds. The number of soil bacteria in planted pots increased over time with the average of $10^8CFU/g$ for mature grasses, while only $10^4-10^6CFU/g$ were found in the unplanted control pots. The leachates from TPOME irrigated grass pots contained lower amounts of phenolic compounds and had lower phytotoxicity than that of control pots. The phenol removal efficiency of grass pots was ranged 67-93% and depended on grass cultivars, initial concentration of phenolic compounds and frequency of irrigations. When compared to water irrigation, TPOME led to an increased phenolic compounds accumulation in grass tissues and decreased biomass of Brachiaria hybrid and Brachiaria humidicola but not Panicum maximum. Consequently, the application of TPOME could be conducted on grassland and the grass species should be selected based on the utilization of grass biomass afterward.

• Korean Journal of Plant Resources
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• v.31 no.6
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• pp.695-703
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• 2018

Previously, we have reported a plant extract isolated from Lysimachia foenum gracum Herba as a new environment friendly biopesticide that has the mycelial growth inhibition effect on Magnaporthe oryzae, the pathogenic fungus of the rice blast disease. For the finding of additional biopesticide candidate, we tested the mycelial growth inhibitory effects about 700 species of plant extracts on PDA media. Among them, the extract of Anemarrhena asphodeloides showed prominent inhibitory effect of which $IC_{50}$ was $139.7{\mu}g/ml$. Mycelial radii of M. oryzae were measured on PDA medium containing the four organic solvent fractions isolated from total extract from A. asphodeloides. Ethyl acetate fraction showed the impressive inhibitory effect of $IC_{50}$, $54.12{\mu}g/ml$. In the subsequent rice field test for the total extract of A. asphodeloides, we obtained encouraging 62.0% control rate of rice blast disease without any phytotoxicity. It is almost equivalent to that of chemical pesticides implying the applicability of the extract as a new biopesticide. In further study, the analysis of active ingredients of the extract would be necessary for the development of a new biopesticide and for the verification of cellular mechanism by which the mycelial growth of M. oryzae inhibited.

• Korean Journal of Agricultural Science
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• v.47 no.4
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• pp.1071-1081
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• 2020

Essential oils (EOs) have been shown to be plant-extracted antimicrobial agents. However, there are limited studies investigating the efficacy of EOs against pathogens. Among them, tea tree oil (TTO) is extracted from Melaleuca alternifolia, which is also used as an antifungal agent. In this study, the effect of TTO was investigated on the suppression of melon powdery mildew caused by Podosphaera xanthii and tomato leaf mold disease caused by Passalora fulva. Both powdery mildew and leaf mold diseases were significantly suppressed by a spray of TTO. Eighty percent of powdery mildew and 81% of leaf mold disease of the control value were suppressed by 0.5% TTO liquid, when sprayed 3 times every 7 days on the melon and tomato leaves. Inhibition of mycelial growth was also greatly affected by different concentrations of TTO against four different fungal pathogens. Ninety-eight percent of Pseudocercospora fuligena, 97% of P. fulva, 95% of Botrytis cinerea, and 94% of Phytophthora infestans mycelial growth were inhibited by 0.2% to 1.0% of TTO contained in plate media, respectively. However, phytotoxicity in plants by the TTO treatments was revealed when melon and tomato leaves were sprayed with a 1% and 2% concentration of TTO, respectively. Therefore, our findings show that TTO has high antifungal effects against various plant pathogens that occur during crop cultivation. We also suggest that when applying TTO to plant leaves, it is necessary to establish an accurate treatment concentration for different crops.

• Korean journal of applied entomology
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• v.61 no.2
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• pp.299-305
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• 2022

We investigated the occurrence and damage information of 9 species (7 families) of insect pests in two places of rucola (Eruca sativa Mill.) cultivated houses in Gyeonggi Province from 2019 to 2021, and selected five insecticides that could efficiently control the beet armyworm, Spodoptera exigua. Five insecticides (spineram SC, fluxametamide EC, chlorantraniliprole WG, cyantraniliprole DC, and emamectin benzoate EC) showed high control effects over 95% against 3^rd instar larvae of S. exigua at the two places of rucola cultivation, and there was no phytotoxicity at double dose of concentration.

• Korean journal of applied entomology
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• v.61 no.1
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• pp.275-281
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• 2022

We investigated the occurrence pattern of the Asian Corn Borer, Ostrinia furnacalis in job's tears, and we tested the field control effects of 5 insecticides and 3 eco-friendly materials. Adults of O. furnacalis began to occur in May and have passed three generations until the end of October. As results of the field test, five insecticides (novaluron, lufenuron, spinetoram, cyclaniliprole, flufenoxuron) and three eco-friendly materials (gosam extracts 90%, neem extracts 60%, citronella oil 30 + derris extracts 20 + cinnamon extracts 10%) showed high control effects against O. furnacalis in two different areas, and no phytotoxicity even at double dose of pesticides.

• Journal of Practical Agriculture & Fisheries Research
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• v.14 no.1
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• pp.47-59
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• 2012

The effects of organic calcium compounds (ACa) tree-spray for late growing stage on the mineral nutrition concentration of fruit, russet and quality in 'Fuji' apple were investigated. Optimum spray concentration of leaves by ACa tree-spray during late growth stage were ranged 125 times among 1,000 times. Also, Optimum concentration of fruits was effected to 125 times. Optimum spray times of leaves effected by ACa 500 times tree-spray during late growth stage were effective in one times (Sept. 25) and three times (Sept. 25, Oct. 5, 15). Also, Optimum times concentration of fruit skin was effected to one times (Sept. 25) and fruit flesh was effected two times (Sept. 25, Oct. 5) and three times (Sept. 25, Oct. 5, 15). Phytotoxicity by tree-spray of ACa concentration and times different not occur to leaf and fruit.

• Korean Journal of Environmental Agriculture
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• v.27 no.2
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• pp.185-190
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• 2008

In order to obtain the basic information for agricultural utilization of Germanium(Ge), the growth characteristics and the germanium uptake by water celery were investigated at different concentration of germanium in soil. This experiment was carried out in the Wagner pot(1 $5,000^{-1}a$). Germanium concentrations in soil for water celery cultivation were maintained at 0.26, 25.0, 62.5, and 125.0 mg $kg^{-1}$, respectively. The treatment of over Ge 25.0 mg $kg^{-1}$ in the soil led to germanium phytotoxicity such as reduction of plant height and fresh weight. The contents of germanium in water celery were increased with the increase of germanium concentration in the soil. When water celery was cultivated from soil maintained with Ge 25.0 and 62.5 mg $kg^{-1}$, its germanium contents in plant were 89.9 and 371.6 mg $kg^{-1}$, respectively. Then, the efficiency of germanium uptake of water celery in Ge 25.0 and 62.5 mg $kg^{-1}$ maintained plots was 1.7 and 2.4%, respectively. When water celery was cultivated from soil maintained with Ge 25.0, 62.5 and 125.0 mg $kg^{-1}$, its content of amino acid was found to be 89.8, 198.4, and 318.2 mg $g^{-1}$, respectively. To investigate the effect of N fertilizer application in uptake of germanium by water celery, these were treated with nontreatment, 1.0, 1.5 and 2.0 times of N application based on soil testing for cultivation of water celery. However, the amount of the N fertilizer application did not affect the contents of germanium in the water celery. When water celery was cultivated from soil maintained with two kinds of inorganic and organic germanium 50 mg $kg^{-1}$, respectively, the content of germanium were 24.2 mg $kg^{-1}$ in the Ge-132 treatment and 11.8 mg $kg^{-1}$ in the $GeO_2$ treatment.

• Korean Journal of Environmental Agriculture
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• v.13 no.3
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• pp.279-287
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• 1994

To develop mixed pesticides of herbicide and topdressing fertilizer for paddy rice, twelve mixtures were formulated with combination of urea coated with different level of acrylic acid wax(AAW) and four herbicides, which were thiobencarb, pretilachlor, mefenacet + bensulfuron-methyl and mefenacet + bensulfuron-methyl + dymron, and effects of the mixtures for weed control, phytotoxicity and rice tillering were investigated in the laboratory and the field experiments. Release rates of active ingredient of herbicides in the distilled water were over 90% during 24 hours same as that of the reference herbicides. The release rates of nitrogen showed different patterns according to coated level of granular urea with acrylic acid wax. Optimum release rate of nitrogen as $NH_4-N$ was obtained by 5.5% AAW coating on urea for thiobencarb or pretilachlor mixture, and by 4.0% AAW coating on urea for mefenacet + bensulfuron-methyl or mefenacet + bensulfuron-methyl + dymron mixture. The pesticide active ingredients of the mixtures were stable, which showed $3.7{\sim}8.0%$ of degradation rate after 90 days of storage under $50^{\circ}C$. Effects on weed control of mixtures were acceptable for both annual and perennial weeds, while ACRI-M9213 mixture showed considerable phytotoxicity at double dose of standard. When treated the mixed pesticides to paddy rice, rice growth status including culm length, ear length, panicle number and polished rice yield exhibited no significant differences compared with the conventional treatment.

• Korean Journal of Environmental Agriculture
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• v.24 no.4
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• pp.404-408
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• 2005

In order to obtain the basic information far agricultural utilization of Germanium (Ge), the growth characteristics and germanium absorption in lettuce were investigated with different concentration of germanium in soil. This experiment was carried out in the waster pot $(15,000^{-1}a)$. Germanium concentrations in soil for lettuce cultivation were maintained at 0.26, 2.0, 4.0, 6.0 and $8.0mg\;kg^{-1}$, respectively. The content of germanium in lettuce was increased with the increase of germanium concentration in soil. When lettuce was cultivated on soil supplemented with Ge $8.0mg\;kg^{-1}$, germanium phytotoxicity (reduction of plant height, No. of leaf and fresh weight) was not observed. When lettuce was cultivated on soil supplemented with Ge 4.0 and $8.0mg\;kg^{-1}$, it germanium content were found 0.75 and $1.27mg\;kg^{-1}$, respectively. Germanium absorption efficiency of lettuce was not different by germanium concentrations in the soil. When lettuce was cultivated on soil supplemented with Ge 2.0, 4.0 and $8.0mg\;kg^{-1}$, its absorption germanium efficiency was found 0.05, 0.04 and 0.03%, respectively. Germanium contents in different parts of lettuce cultivated with Ge $8.0mg\;kg^{-1}$ were $0.65mg\;kg^{-1}$ on inner leaf and $1.59mg\;kg^{-1}$ on outer leaf.

• Korean Journal of Weed Science
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• v.4 no.1
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• pp.52-61
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• 1984

Pot and laboratory tests were undertaken to investigate the influence of silicate fertilization on butachlor phytotoxicity to rice. Growth of rice seedlings at 150 ppm of $SiO_2$ was stimulated, while adverse effect was observed over 300 ppm of $SiO_2$ and growth reduction was enhanced with combination of butachlor and $SiO_2$ Rice growth in pot trial at 150kg/10a of silicate fertilization was not influenced by recommended amounts of butachlor and nitrofen, however, the growth of Seokwang byeo at 300kg/10a of silicate was markedly retarded by butachlor in the initial stage of growth. Growth reduction of Seokwang byeo caused by combined application of silicate and butachlor was recovered 50 days after herbicide application. Growth reduction from butachlor was not influenced by pH level and also degradation behaviors of butachlor in submerged soil was not altered by silicate fertilization. Adsorbed amount of butachlor on rice root was increased with addition of $SiO_2$ and its amount in Seokwang byeo was higher than that of Jinju byeo. Butachlor absorption by Seokwang byeo was accelerated by 150 ppm of $SiO_2$ applied simultaneously, but those effect was not encountered in Jinju byeo. Butachlor absorption of rice seedlings was also increased by 150 ppm of $K_2O$, while CaO hindered the absorption and $Na_2O$ had no effect on the absorption. Residual level of butachlor in Seokwang byeo treated with combined solution of butachlor and $SiO_2$ was continued higher than that with butachlor alone during 10 days after transplantation to culture solution.