• Research in Plant Disease
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• v.15 no.1
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• pp.23-29
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• 2009

Cooking oil and yolk mixture (COY), a environmentally acceptable plant protection agent, and COY+$CaCO_3$+neem oil mixture were studied to control the powdery mildew occurring on eggplant, paprika, cherry tomato and maturity tomato in glass houses and vinyl houses during 2005 to 2007. The morphological changes of the pathogenic fungi on the leaf surface before and after treatment of COY were observed. COY made of rape seed oil and COY+$CaCO_3$+neem oil mixture were sprayed three times with 5 days interval to foliar parts of eggplant, paprika and tomato and the disease development were examined 5 days after final spray. In eggplant, the control efficacy of COY to powdery mildew was 94.6%. In paprika, the control efficacy of COY to powdery mildew was 91.6% and that of COY+$CaCO_3$+neem oil mixture was 96.2% that revealed little higher than COY itself. In tomatoes(cherry or maturity tomato), the control efficacy of COY were about 91 %, however, when COY mixture were sprayed to tomato leaves and stems the powdery mildew was controlled completely. Typical and healthy mycelia, conidiophores and condia were observed through scanning electron microscope in COY unsprayed leaf surface, on the other hand destroyed and winkled mycelia and conidiophores were observed in COY treated leaves regardless host plants nor taxonomic differences of fungi.

• Research in Plant Disease
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• v.21 no.3
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• pp.208-214
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• 2015

To develop an effective biopesticide to control pepper anthracnose disease, an isolate which showed strong inhibitory effect on the mycelial growth and conidial germination of Colletotrichum acutatum was selected among the antagonistic bacterial isolates collected from pepper grown soil. The bacterial isolate was identified as Bacillus sp. KBC1004 using 16S rRNA sequence analysis. The liquid culture of KBC1004 was freeze-dried and formulated as a wettable powder(WP). The wettable powder form of KBC1004 required at least 24 hours to activate and to inhibit the conidial germination of C. acutatum. In vitro bioassay using the detached green pepper fruits, biocontrol activity of the WP was not recognizable in simultaneous inoculation, but significant disease suppression was observed pre-treatment (24 hr) of the WP before pathogen inoculation. In field experiment, 4 times foliar applications of the 1/500 diluted wettable powder from the end of June showed great control efficacy similar to that of the chemical fungicide application. These results suggest that the formulated WP product could be an alternative mean to control of pepper anthracnose disease in environmentally friendly farming practices.

• Korean Journal of Medicinal Crop Science
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• v.7 no.1
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• pp.31-36
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• 1999

This study was carried out to investigate the effect of sulfuric fertilizers on allylisothiocyanate(allylNCS) content of upland Wasabia japonica Matsum cultivated in heating condition in the winter season. The rhizome's growth characters following soil application of sulfur dust were not significantly different compared to control, though its soil acidity and available sulfur content was higher than other treatments. Total sulfur content of plant was increased by soil application as compared to foliar application and allylNCS content of rhizome increased up to 22.8% in the sulfur dust treatment. The result showed that soil application was effective for supplying $SO_4^{-2}$ in upland Wasabia japonica Matsum when cultivated in heating condition. In the analysis of correlation coefficients between growth and quality characteristics, allylNCS content of rhizome showed the significantly positive correlation with total sulfur content of shoot, rhizome and allylNCS content of shoot.

• Weed & Turfgrass Science
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• v.3 no.3
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• pp.246-252
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• 2014

This study was conducted to evaluate the effects of two amino acid fertilizers on the growth of creeping bentgrass and N uptake. Fertilizer treatments were designed as follows; non-fertilizer (NF), control (CF), recommended amount (ALF), double amount (2ALF) of amino acid liquid fertilizer (AaLF), recommended amount (ASLF) and double amount (2ASLF) of amino acid liquid fertilizer contained with saponin (AaSLF). Turf quality of treatments of AaLF and AaSLF such as turf color index, chlorophyll index and root length was similar to the treatment of CF. Dry weight and content, uptake and availability of N were investigated highest in the 2ALF and 2ASLF. These results suggested that foliar application of AaLF and AaSLF was enhanced turf quality and growth of creeping bentgrass by stimulating uptake and availability of N.

• Current Research on Agriculture and Life Sciences
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• v.4
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• pp.22-26
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• 1986

This study was conducted to investigate weed population dynamic in orchard and to establish an appropriate application time for oxyfluorfen. 28 weed species including Persicaria hydropiper was observed to be problem weeds in orchard. P. hydropiper was on single dominant species which increased importance value of 13.7 on May 15 to 60.79 on August 10, followed by Calystegia hederacea, Alopecurus aequalis, Capsella bursa-pastoris, Roripa islandica, Echinochloa crus-galli, Potulaca olearcea, Elusin indica. Simpson's index increase from 0.11 on May 1 to 0.40 of August 10, indicating the dominance of specific weed species. The effective herbicide to control these weeds was oxyfluorfen at 5kg prod./ha applied at pereemergence treatment on March 25, showing more than 90% control for 120 days after application. Preemergence application of oxyfluorfen at 3kg prod./ha on March 25 followed by paraquat 3kg prod./ha applied on June 25 as the foliar application can maintain the clean orchard for a year, showing on of the promising and applicable control system. The most appropriate rate and time for oxyfluorfen seemed to be 5kg prod./ha applied on March 25.

• Asian Journal of Turfgrass Science
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• v.20 no.2
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• pp.157-165
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• 2006

This study was initiated to investigate herbicidal selectivity margin with annual bluegrass and bentgrass according to growth stages through herbicidal spectrum of bispyribac-sodium and therefore to examine application possibility to prevent annual bluegrass selectively. The herbicidal efncacy by pre-emergence application was generally low. But a high herbicidal efficacy was observed over 90% for Shehpherd's purse. Foliar treatment resulted in a higher herbicidal efficacy in all tested plants except dallisgrass, lovegrass, curled dock and bentgrass as compared with pre-emergence application. We found bispyribac-sodium could be used as a selective weeding chemical between annual bluegrass and bentgrass. In regard to dose-responses to the growth stage, annual bluegrass was more susceptible to bispyribac-sodium than bentgrass for the same dosage. Particularly, bispyribac-sodium application in inflorescence emergence stage showed a greater herbicidal selectivity margin of 6.8 times with annual bluegrass over creeping bentgrass after 28 days from the application. These data demonstrated that annual bluegrass was more sensitive to bispyribac-sodium over creeping bentgrass.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.471-474
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• 2007

This study was conducted to provide basic data for productivity of Saururus chinensis Baill. depending on rhizome size. The kinds of the treatment were 4 including below 5mm of rhizome size. Major results were summarized as follows. Sprouting was earlier in above 9mm of rhizome size and the number of last sprouting was increased $84{\sim}109%$ compared with 8.0 $individual/m^2$ of 6mm of rhizome size. Growth of stem showed a good tendency in 6mm of rhizome size with the longer stem length and the thicker stem but the number of tiller was more rhizome was more thicker. Though the number of commercial leaf was more above 9mm of rhizome size leaf length, leaf width and the number of noncommercial leaf did not showed difference by rhizome size. Dry weight of commercial foliar in 9mm of rhizome size over was increased $35{\sim}37%$ compared with 6mm of rhizome size. Therefore, rhizomes size above 9mm showed most effective for increasing sprout and wight of stem and leaves of Saururus chinensis.

• Journal of Plant Biotechnology
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• v.49 no.4
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• pp.356-361
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• 2022

Bacillus sp. is a useful strain for agriculture because it promotes plant growth and controls plant pathogens through a variety of mechanisms. In this study, we obtained a microbial preparation with a high number of viable cells by culturing newly isolated soil bacteria on an optimized medium. Subsequently, we applied this preparation to lettuce to enhance its growth and yield. First, B. amyloliquefaciens ISP-5 was isolated from soil. Next, optimization of culture medium was carried out using 5 L scale fermenters. When culturing B. amyloliquefaciens ISP-5 on this optimized medium, the number of viable cells was approximately 1000 times higher than that obtained from culturing on the commercial medium. Afterwards, the plant growth promotion properties of the ISP-5 strain were evaluated using lettuce as a test plant. Foliar spray treatment of lettuce was carried out by inoculating half the standard concentration suspension (0.5 × 10⁷ cfu/ml). As a result, leaf width increased by 8.6% and leaf length increased by 12.9% compared to the control group. Live weight also increased by 24.2% and dry weight by 23.9%. Considering the results from field test, B. amyloliquefaciens ISP-5 showed potential as a plant growth-promoting bacteria.

• Korean Journal of Environmental Agriculture
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• v.15 no.4
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• pp.425-433
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• 1996

Pepper plants were water-logged at 0, 5, 10 and 15 cm at transplanting and flowering stages under the condition of greenhouse. Treatment of water-logging times were 6, 12, 24, 48 and 120 hours. The results obtained are summarized as follows. At the transplanting stage, plant height, number of leaves, shoot and root fresh weight decreased by water-logging at 0cm for 24 hours and at 5cm or more for 6 hours. Number of fallen leaf was negligible by 12 hours water-logging at 0cm, however, its increased by more increased the water-logging depth and time. Diffusion resistance and chlorophyll content of leaf, and root activity decreased at more than 24 hours of water-logging regardless of the water-logging depth treatments. Photosynthesis and respiration rate diminished by increased the water-logging depth at 120 hours water-logging treatment. Plant diseases, mainly anthracnose(Colletotrichum) occurred in proportion to increase the depth and time of water-logging. It was not possible to control the diseases by fungicides. At the treatment of foliar spray of urea for recovery to water-logging damage, the efficiency was not found on plant height, but the number of leaves. Number of fruit and weight of fruit per plant showed no difference from no water-logging to 24 hours water-logging at 0cm, but its decreased that more than 24 hours water-logging at 0cm and more than 6 hours water-logging at 5cm or more. The averaged weight of a fruit on survival plants increased by more hours and deeper water-logging. There was positive correlation between all the investigated characteristics of growth and yield. There was, however, negative correlation between the characteristics and diffusion resistance of leaf stomata. The correlation between number of fallen leaf and averaged weight of a fruit was not significant. At flowering stage, number of fruit and weight of fruit per plant showed a similar tendency to no water-logging and by 12 hours water-logging at 0cm and 5cm, but significantly decreased at more than 24 hours water-logging from 0 to 5cm, and more than 6 hours water-logging at 10cm or more. The averaged weight of a fruit on survival plants increased by more hours and deeper water-logging except for 120 hours water-logging at all water depths.

• Horticultural Science & Technology
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• v.17 no.5
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• pp.572-577
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• 1999

Research was initiated to evaluate plant growth regulator effects on the vertical shoot growth of Korean lawngrass and to determine desirable growth regulator and its rate. The experiments were conducted twice at different sites in 1995. All the tested growth regulators inhibited the growth, but the inhibition period was variable among the product in Experiments I and II. During the first week after treatment, there was approximately 10 to 20% growth reduction in most of the treated plots. In the amidochlor-treated plots, growth suppression was effective for 3 to 4 weeks at low to medium rates ($0.60mL{\cdot}m^{-2}$). A Type II growth regulator, trinexapac-ethyl exceeding the medium rate of $0.08mL{\cdot}m^{-2}$ consistently tended to suppress vertical shoot growth for 8 weeks, being above 35% reduction in both experiments. In the plots applied with mefluidide, growth suppression appeared with foliar discoloration 3 or 4 days earlier than the other growth regulators and continued to work till the 8 weeks after treatment. Suppression intensity on vertical shoot growth increased with time after treatment up to a certain period of time, depending on growth regulators. Generally, the higher the application rate, the greater the suppression intensity. Seasonal variation of activity and effectiveness of growth regulators was observed, resulting in lower suppression intensity in July than in June. It is expected to reduce mowing requirements by 30 to up to 60% for a certain period with a specific growth regulator. In low to medium maintenance of Korean lawngrass turf, a long-term suppression may be more effectively accomplished with trinexapac-ethyl rather than mefluidide and amidochlor in terms of vertical shoot growth inhibition. Therefore, turf managers will need to select proper growth regulator and determine optimum rate of application for turfgrass management, based on a defined period of mowing reduction.