• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.323-330
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• 1994

Benzyladenine(BA) and Diphenylurea(DPU) at 10ppm level were foliar-applied one to three times at an interval of 10 days from heading stage of rice variety, Dongjinbyeo. One time treatment of both cytokinins did not delayed leaf senescence substantially, but consecutive treatments of two to three times markedly retarded leaf senescence. Leaf senescence retarding effects were greater in BA than DPU. Ripened grain ratio, grain weight and grain yield were not improved by the treatments. BA treatments increased the percentage of green and white belly kernels with no effects on opaque and white core kernels. BA and DPU treatments did not altered amylose content, but BA treatments significantly decreased protein content of polished rice. Consecutive treatments of BA and DPU twice or three times at an interval of 10 days from heading increased oil content by 30 to 78% as compared to non-treated control, but one time treatment at any stage did not enhance it of polished rice. Fatty acid composition was slightly altered in favor of unsaturated fatty acid by BA and DPU treatments.

• Journal of Life Science
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• v.24 no.12
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• pp.1308-1315
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• 2014

Biological control using the plant growth-promoting Rhizobacterium (PGPR) has received significant attention in recent years. PGPR has been linked with promoting growth in economically important crops, such as potatoes, tomatoes, and rice. Bacillus mojavensis KJS-3 (Moja-3), isolated from food waste, possesses antifungal properties against Aspergillus terreus, A. fumagatus, A. flavus, and Fusarium redolense, and it may have potential in the development of products for industrial applications. The main purpose of this study was to determine the effects of spraying the PGPR Bacillus mojavensis KJS-3 on the growth of altari radish (leaf number, leaf length, leaf weight, root length, and rhizome length, adjacent portion diameter, and weight) and lettuce (leaf number, length, width, and weight). Three different concentrations of the foliar spray treatment of B. mojavensis KJS-3 were applied to the altari radish and lettuce: the recommended standard concentration of $1{\times}10^9cfu/g$, half the standard concentration of $0.5{\times}10^9cfu/g$, and double the standard concentration of $2{\times}10^9cfu/g$). The B. mojavensis strain foliar spray treatment increased the growth of the leaves and roots of the altari radish and increased the growth of the lettuce leaves. For both plants, the recommended concentration of B. mojavensis KJS-3 produced better growth than half the standard concentration, and the growth was similar with the double dose. This study demonstrates positive effects of Moja-3, suggesting it may be a potential new bio-fertilizer for improving the growth of altari radish and lettuce.

• Korean Journal of Soil Science and Fertilizer
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• v.41 no.3
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• pp.153-157
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• 2008

This study was conducted to select some effective organic materials for supplying mineral nutrients at the later red-pepper growing period under organic farming system, and to evaluate the application effect. Nutritional characteristics of organic materials, nitrogen release pattern during liquefying the selected organic materials, and crop growth were examined. Among 18 organic materials, meals such as soybean, rapeseed, cottonseed, and sunflower seed except for gluten had greater nitrogen content. Total nitrogen content liquefied solution of the mixture of organic materials and molasses or yogurt was measured after 7 days of the liquefying, thereafter, the mixture of rapeseed meal and yogurt showed the highest nitrogen, reaching about $3,000mg\;L^{-1}$. Selected liquid manure, mixture of rapeseed meal and yogurt, was applied 8 times to red-pepper plants with fertigation or foliar application. Total nitrogen of leaves at 150 days after transplanting was the highest (4.4%) in the treatment of foliar application of the selected liquid manure, whereas shoot dry weight and fresh fruit yield were the greatest in the treatment of fertigation.

• Journal of Life Science
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• v.33 no.10
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• pp.842-850
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• 2023

Pyrrolnitrin, pyrrolomycin, and pyoluteorin are functional halogenated phenylpyrrole derivatives (HPDs) derived from microorganisms with diverse antimicrobial activities. Pyrrolnitrin is a secondary metabolite produced from L-tryptophan through four-step reactions in Pseudomonas fluorescens, Burkholderia cepacia, Serratia plymuthica, etc. It is currently used for the treatment of superficial dermatophytic fungal infections, has high antagonistic activities against soil-borne and foliar fungal infections, and has many industrial applications. Since pyrrolnitrin is easily decomposed by light, it is difficult to widely use it outdoors. As an alternative, fludioxonil, a synthetically produced non-systemic surface fungicide that is structurally similar and has excellent light stability, has been commercialized for seed and foliar treatment of plants. However, due to its high toxicity to aquatic organisms and adverse effects in human cell lines, many countries have established maximum residue levels and strictly control its levels. Pyrrolomycin and pyoluteorin, which have antibiotic/antibiofilm activity against Gram-positive bacteria and high anti-oomycete activity against the plant pathogen Pythium ultimum, respectively, were isolated and identified from microorganisms. This review summarizes the biosynthesis and production of natural pyrrolnitrin derived from bacteria and the characteristics of synthetic fludioxonil and other natural phenylpyrrole derivatives among the HPDs. We expect that a plethora of highly effective, novel HPDs that are safe for humans and environments will be developed through the generation of an HPD library by microbial biosynthesis and chemical synthesis.

• The Plant Pathology Journal
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• v.22 no.3
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• pp.271-277
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• 2006

The interaction effects of ozone $(O_3)$ and anthracnose (Colletotrichum acutatum) disease were examined in green fruits and seedlings of pepper (Capsicum annuum). Pre-treatment with $(O_3)$ as a factor causing predisposition to the disease prior to infection was investigated in green fruits and stems using an $(O_3)$ concentration of 150 nL/L, which is easily reached in summer in Korea. $(O_3)$ treatment increased antioxidative responses in pepper foliar tissues, and defense against anthracnose was examined in fruits and stems. Anthracnose severity on stems of the $O_3-treated$, ozone-sensitive 'Dabotop' cultivar was always lower than that on untreated plants, but the difference was not always significant (p=0.147). Significantly lower anthracnose severity was found on $O_3-treated$ green 'Dabotop' fruits as compared to untreated green fruits in three of eight replicate experiments. In contrast, hypersensitive responses in 03treated seedlings were significantly accelerated compared to those in untreated seedlings by about 7.8 h (p<0.001). This confirmed previous evidence of increased transcription of plant defense genes with $(O_3)$ treatment. $(O_3)$ treatment significantly decreased chlorophyll concentrations in the leaves in four replicate experiments (p<0.01). $(O_3)$ increased hypersensitive responses in the leaves of pepper seedlings, but this increase did not contribute to the control of anthracnose severity on fruits. Antioxidant reactions to $(O_3)$ were limited to chlorosis and changes in hypersensitive responses in leaves.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.52 no.4
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• pp.380-386
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• 2007

This study was conducted to clarify the effective application method, uptake, and translocation of germanium(Ge) in mungbean plants. The foliar application of liquid Ge at 7 mg/l during the flowering period, seeds containing 38.7, $14.1{\mu}g/kg$ of Ge, from the first and second harvesting. It had 2.5 and 2.3 times more Ge than the seeds raised by using granule Ge at 7 mg/kg with basal fertilization. The foliar application of Ge at 3.5, 7, 14 and 28 mg/l during the flowering period, yielded a relatively high record of seeds containing $14.9{\sim}77.8{\mu}g/kg$ and $6.9{\sim}26.7{\mu}g/kg$ of Ge, from the first and second harvesting. However, seeds from the first harvesting contained $2.2{\sim}4.1$ times more Ge than the seeds of from the second harvesting. On the other hand, seeds from first and second harvesting of the non-treatment group Ge contained 1.9 and $3.2{\mu}g/kg$, respectively. When the foliar application of Ge at 7 mg/l was conducted two or three times, the Ge content of the seeds in the first to third harvesting were all over $20{\mu}g/kg$. This indicates that a certain level of Ge can be accumulated. In seeds of mungbean containing $96{\mu}g/kg$ of Ge, cotyledon had $138{\mu}g/kg$ of Ge, which was 79% more than seed coat per unit weight. The growth and quantity of mungbean was not significantly different according to the formulation of Ge, the concentration and the frequency of foliar application of Ge used for in study.

• Food Science and Preservation
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• v.16 no.5
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• pp.675-679
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• 2009

We investigated how Germanium (Ge) application, and the application method, affected 'Niitaka' (Pyrus pyrifolia) fruit quality in a conventional orchard. Ge-treated pears weredark yellow in color, indicating appropriate maturation. Other fruit characteristics, and weight, did not significantly differ between tests and controls. Compared to controls, fruit from Ge-treated trees had more soluble solids, a lower acid content, and fewer stone cells, which reduced fruit chewiness. Ge-treated trees showed a higher Ge concentration in fruit but a lower calcium (Ca) concentration. Other fruit mineral nutrients, includingP, K, and Mg, did not differ in level between Ge-treated fruit and controls. Ge-treated fruit showed greater firmness and a heavier specific weight during 6 months of storage, compared to control fruit. Therefore, Ge treatment reduced fruit pithiness, which can be a problem in 'Niitaka' pears. Overall, there was no significant difference between Ge-treated and control fruit qualities, but a combined Ge treatment (fertilization plus foliar application plus trunk injection) slightly improved fruit quality.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.383-388
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• 2007

This study examined the effective treatment method of selenium and translocation characteristics of selenium in order to produce mungbean containing selenium. The foliar application of selenium at 3.5, 7, 14, and $28mg/{\ell}$ during the flowering period, yielded a relatively high record of seeds containing $0.41{\sim}3.96mg/kg$ and $0.27{\sim}2.38mg/kg$ of selenium, from the first and second harvesting. However, seeds from the first harvesting contained $52{\sim}71%$ more selenium than the seeds from the second harvesting. On the other hand, seeds from first and second harvesting of the non-treatment group had the same amount of selenium at 0.02mg/kg only. When the foliar application of selenium at $7mg/{\ell}$ was conducted two or three times, seeds from the first to third harvesting contained just the equal amount of selenium. However, when it was conducted only once, seeds from the first harvesting contained 56% and 67% more than seeds from the second and third harvesting, respectively. In seeds of mungbean containing 2.05mg/kg of selenium, cotyledon had 2.99mg/kg of selenium, which was 38% more than seed coat per unit weight. When mungbean sprout was produced, selenium content was 5.51mg/kg, but seed coats by-product of sprouts had 0.78mg/kg of selenium. The growth and quantity of mungbean was not significantly different according to the concentration and the frequency of foliar application of selenium used for in study.

• Journal of Bio-Environment Control
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• v.28 no.2
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• pp.178-184
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• 2019

Strawberry ($Fragaria{\times}ananassa$) is one of the most important and popular fruit crops in the world, and 'Sulhyang' is one of the principal cultivars cultivated in the Republic of Korea for the domestic market. The growth and flower induction in strawberry is the process which influences directly on fruit bearing and yield of this crop. In this study, effect of benzyladenine (BA), gibberellic acid ($GA_3$), and salicylic acid (SA) on growth and flower bud induction in strawberry 'Sulhyang' was investigated. The 3-week-old runner plants, grown in 21-cell propagation trays, were potted and cultivated in growth chambers with $25^{\circ}C/15^{\circ}C$ (day/night) temperatures, 70% relative humidity (RH), and light intensity of $300{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ photosynthetic photon flux density (PPFD) provided by white light emitting diodes (LEDs). The runner plants were treated with one of three concentrations, 0 (control), 100, and $200mg{\cdot}L^{-1}$ of BA, $GA_3$, or SA solution. The chemicals were sprayed two times on leaves of runner plants at an interval of two weeks. After 9 weeks the results showed that the application of all chemicals caused reduction of root length and chlorophyll (SPAD) content as compared to the control. The lowest chlorophyll (SPAD) content was recorded in plants treated with $GA_3$. However, the treatment of $200mg{\cdot}L^{-1}$ $GA_3$ promoted leaf area, leaf fresh weight, and plant fresh weight. The greatest flower induction (85%) and number of inflorescences (4.3 inflorescences per plant) were observed in the treatment of $200mg{\cdot}L^{-1}\;SA$, followed by $100mg{\cdot}L^{-1}\;SA$. Overall, results suggest that foliar application of $GA_3$ solution could accelerate plant growth, while foliar application of SA solution could induce hastened flowering. Further studies may be needed to find out the relationship between $GA_3$ and SA solutions treated in a combination, and the molecular mechanism involved in those responses observed.

• Food Science and Preservation
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• v.16 no.6
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• pp.838-842
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• 2009

We explored how 'Wonwhang' pear fruit quality was affected by selenium (Se) application. The fruit skin color and fruit type differed between Se-treated trees and controls. Se-treated fruits had higher potassium and Se concentrations, more fruit soluble solids, and lower acidity, compared to the controls. All Se treatments improved fruit firmness during cold temperature storage compared to the controls. Also, Se-treated fruits had greater specific gravity and minuteness, which reduced fruit pithiness and rendered test fruits denser than the controls. Overall, Se foliar application improved fruits marketability compared to the Se fertilization or Se trunk injection.