• Korean Journal of Medicinal Crop Science
• /
• v.1 no.2
• /
• pp.104-108
• /
• 1993

This experiment was conducted to obtain the basic information for the increase ofgermination percent by the treatment of stratification, soaking and $Gibberellin(GA_3)$ in Angelica gigas Seeds caltivated in 1989. The germination percent was increased by 30% with stratification, and the effect of low temperature did not differ significantly. The optimum soaking temperature and periods were found to be 4days at $20^{\circ}C\;and\;6dys\;l0^{\circ}C$ of water temperature. When exchanged water every day during soaking period, inhibitors were more extracted than non-exchange one. The exogenous application of $GA_3$ also increased germination percent about 20% campared with control, and the reasonable level was 2ppm in soaked seed and 5ppm in non-soaked seed.

• Applied Biological Chemistry
• /
• v.26 no.2
• /
• pp.132-136
• /
• 1983

The indole-3-acetic acid(IAA) oxidase activity of shoot and root tips of etiolated pea seedlings (Pisum sativum L. var. Sparkle) during and after chilling was determined. The IAA oxidase level of root tips was 4 to 15 times as high as that of shoot tips. During chilling the seedlings apical and subapical 5 mm shoot sections increased in IAA oxidase activity but apical and subapical 5 mm root sections decreased. When chilled plants were returned to $25^{\circ}C$ to recover, the enzyme activity had a tendency to restore to the activity level of controlled plants.

• Research in Plant Disease
• /
• v.14 no.1
• /
• pp.32-36
• /
• 2008

Bacterial wilt caused by Ralstonia solanacearum has become a severe problem on tomato in Korea and no effective control measures are available yet. Pseudomonas species play key roles for the biocontrol of many plant diseases especially in soil. A rhizobacterial population of 150 Pseudomonas strains, isolated from the rhizosphere soil of various plants grown at different sites, was screened for 2,4-diacetylphloroglucinol producing gene (PhlD) by PCR. Two strains (P83 and P84) among them were found to be phlD positive. When the isolates were analysed by 16S rDNA (Sensu Stricto), all isolates yielded amplified products of 1,018bp. Of the 150 isolates of Pseudomonas spp., a bacterial strain P. putida P84 isolated from tomato rhizosphere showed to suppress a wide range of phytopathogenic bacteria in vitro. The best source of carbon for P84 strain were glucose, arabinose, inositol and melibiose. In greenhouse experiments, P84 strain suppressed the development of bacterial wilt in tomato with a control value of 60%.

• Korean Journal of Medicinal Crop Science
• /
• v.23 no.2
• /
• pp.150-154
• /
• 2015

Physiological disorders such as symptoms in leaf colored with brown spots are so many occurred in ginseng garden cultivated with paddy soil. This study was carried out to inhibit the symptoms of brown-colored leaf in 3-year-old ginseng by fertilizing calcium hydroxide [$Ca(OH)_2$] of 100 ~ 400 kg per 10a on paddy soil before transplant of seedling. Soil pH was rapidly increased, while Fe was decreased in soil by the increase of application level of calcium hydroxide. Soil pH was increased from 4.53 to 6.18 when calcium hydroxide was fertilized at level of 100kg per 10a. The content of Fe in ginseng leaf was decreased more than the control by fertilizing calcium hydroxide in soil. Ratio of brown-colored leaf and plant height and leaf area were decreased by the increase of calcium hydroxide. Ratio of survived root and yield of root showed the peak at the application level of 100 kg per 10a, and both of them were gradually decreased by the increase of calcium hydroxide. The decrease of missing plant rate above the application level of 200 kg per 10a had a negative effect on the decrease of yield of root.

• Journal of agriculture & life science
• /
• v.46 no.4
• /
• pp.101-111
• /
• 2012

Soybean cyst nematode(SCN) (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide. Yield loss due to SCN is estimated 7.6 million megagrams in the USA and nearly 9 million worldwide. SCN causes yield reductions by feeding on plant nutrients, retarding root growth, and inhibiting Bradyrhizpbium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotation with nonhost crops. Genetically diverse field populations of SCN combined with the limited germplasm base of commercial soybean for resistance could potentially leads to population shifts over time, and this makes controlling H. glycines more difficult. This paper reviewed the importance of soybean, soybean cyst nematode, researches on resistance to SCN, and prospects. Tremendous effort must still be endeavored for elucidating resistance mechanisms and managing H. glycines in the soybean field.

• FLOWER RESEARCH JOURNAL
• /
• v.17 no.4
• /
• pp.303-307
• /
• 2009

The purpose of this study was to investigate the effects of ethephon, paclobutrazol, and uniconazole on the flowering of potted Yarrow (Archillea millefolium). Each plant growth regulator was sprayed two times before stem elongation period of yarrow. The tallest was 45.7 cm at $1000mg{\cdot}L^{-1}$ ethephon and the shortest was 11.1 cm at 20 uniconazole. Uniconazole delayed flowering and decreased the number of flowers. Both uniconazole at 20 ppm and paclobutrazol at 200 ppm decreased the number of florets to 90.0% and 43.6% of control, respectively. In ethephon, number of florets was increased 34.1% compared with control. In addition, ethephon and paclobutrazol increased the number of mean auxillaly flowers to 28.6% and 23.5% of control, respectively. On the other hand, uniconazole decrease the number of auxillary flowers to 55.3%. Thus, paclobutrazol was recommended as a suitable plant growth regulator for yarrow pot plant production.

• The Korean Journal of Mycology
• /
• v.47 no.3
• /
• pp.233-240
• /
• 2019

This study was performed to develop a useful method for substrate pH adjustment in bottle cultivation of Grifola frondosa. Four types of organic acid solution-citric acid, malic acid, tartaric acid, and succinic acid-were added at 0.5% to 3.0% (w/v) into the substrate. The pH after the organic acid treatments ranged from 3.8 to 4.8 for the mycelial growth of G. frondosa after sterilization. Supplementation with succinic acid at 0.5% resulted in a shorter cultivation period and higher consistent yields compared to other organic acid treatments. These results indicate that the technique we developed is beneficial for higher production of G. frondosa using bottle cultivation.

• The Journal of Natural Sciences
• /
• v.11 no.1
• /
• pp.105-111
• /
• 1999

The objectives of this research were to determine growth characteristics of commercial cultivars of strawberry grown in Korea, then to differentiate each cuitivar into cropping system based on degree and duration of domancy and to determine starting date of greenhouse heating as forced culture. The date of floral differentiation on cuitivars such as 'Chodong' 'Shuko' 'Nyoho' was from Sep. 20 to 22. However those of 'Toyonoka', 'Reiko', 'Hokowase' etc. were Sep. 26 to 30 and that of 'Morioka(No. 16)' was Oct. 19. It indicated that the cultivars with short dormancy period 'Nyoho', 'Reiko', 'Toyonoka' etc. were suitable for forcing culture, cultivar with ordinary dormancy period such as 'Suhong' was for nearly forcing culture, cultivar with long dormancy period such as 'Hokowase' was for semi-forcing culture, and cultivar with extreamly long dormancy period such as 'Morioka (No. 16)' was for retarding culture.

• Korean Journal of Soil Science and Fertilizer
• /
• v.42 no.5
• /
• pp.341-347
• /
• 2009

Soil microbial community has been changed after the treatment of anaerobic fermentation using wheat bran or rice bran was applied to the soil. In the dilution plate technique, the number of anaerobic bacteria and fungi was higher in rice bran-treated soil than in non and wheat bran-treated soil, but of yeast was higher in wheat bran-treated soil than in non and rice bran-treated soil. Specially, the fungi were not detected in the wheat bran-treated soil. Identified by 16S rDNA sequencing, the number of aerobic bacteria was similar in all treatments, the dominant bacteria was the genus Bacillus. In the phospholipid fatty acid (PLFA) technique, both Gram-positive and Gram-negative bacteria change slightly in all treatments for 20 days of fermentation process but, after 20day, increased rapidly in wheat or rice bran-treated soil. In conclusion, the microbial communities structure was dramatically changed after the treatment of wheat or rice bran to soil.

• Research in Plant Disease
• /
• v.27 no.4
• /
• pp.164-171
• /
• 2021

In August 2020, 377 anthracnose strains were isolated from anthracnose-infected peppers collected from 25 farms in Sunchang-gun, Jeollabuk-do. Inhibition rate of mycelial growth of 11 pepper anthracnose fungicides registered in Korea was investigated for 62 strains selected by region and the degree of susceptibility to each fungicide was investigated. As a result of the fungicide susceptibility test of anthracnose to the fungicide, no resistant strains were observed in fluazinam, prochloraz manganese, and benomyl, but resistant strains appeared in at least three areas for other fungicides, and all strains in all regions were resistant to dithianon. Through this, it was confirmed that the fungicide resistance was expressed in the strain group due to the continuous treatment of the fungicide in some areas. By region, resistant strains to seven pesticides appeared in Sunchang-eup and Paldeok-myeon, and resistant strains to six pesticides appeared in Geumgwa-myeon, Bokheung-myeon, Ssangchi-myeon, Yudeung-myeon, and Pungsan-myeon. There was no significant correlation between fungicide registration time and emergence of resistant strains.