Cnidium officinale M. is an important crop that is widely used as a raw material for health functional foods. However, it is experiencing cultivation difficulties due to climate change and abnormally high temperatures. In response to this problem, the characteristics and main causes of the high-temperature damage occurring in C. officinale M. cultivation fields were analyzed. A survey of five farmhouse fields in Jecheon and Bonghwa, major C. officinale M. cultivation areas in Korea in 2018, indicated that about 5% to 37% of the cultivation fields in Jecheon and 5% to 15% of the fields in Bonghwa died from wilting. The high-temperature damage of the C. officinale M. fields is divided into two categories: upper leaves drying due to solar radiation and temperature, and lower leaves dying serially to the radiant heat of the vinyl mulch. Damage caused by radiant heat was typically greater. This is due to the greenhouse effect that occurs in the small space between the black vinyl mulching and the soil. The heat radiated to the surface of the ridge creating an environmental condition that greatly exceeded the atmospheric temperature especially on hot days. As a result, short plants with underground parts, such as C. officinale M., can suffer more high-temperature damage than other plants, so it is considered that it is necessary to develop related technologies such as mulching materials that can reduce pavement temperature in the future.
The triboelectric property of a material is important to improve an efficiency of triboelectric generator(TEG) in energy harvesting from an ambient energy. In this study, we have studied the TEG property of a semicon-ducting SnO2 which has yet to be explored so far. As a counter triboelectric material, PET and glass are used. Verticalcontact mode is utilized to evaluate the TEG efficiency. SnO2 thin film is deposited by atomic layer deposition on bareSi wafer for various thicknesses from 5.2 nm to 34.6 nm, where the TEG output is increased from 13.9V to 73.5V. Tri-boelectric series are determined by comparing the polarity of output voltage of 2 samples among SnO2, PET, and glass.In conclusion, SnO2, as an intrinsic n-type material, has the most strong tendency to be positive side to lose the electronand PET has the most strong tendency to be negative side to get the electron, and glass to be between them. Therefore,the SnO2-PET combination shows the highest TEG efficiency.
Lactococcus lactis subsp. lactis ATCC l1454의 유산균 배양액을 3.96 log units, 4.10 log units 및 4.23log units의 농도로 처리한 돼지고기 등심은 4℃ 저장 9일 동안 호기성 부패세균의 증식억제와 저장 안정성 증진 가능성을 나타내었다. 유산균 배양액 처리구는 4℃ 저장 3일 동안 대조구 보다 유의적으로 낮은 pH 가를 나타내었다 유산균 배양액으로 처리한 돼지고기 등심의 외관과 냄새에 대한 관능평가 결과는 4℃ 저장 9일 동안 신선한 대조구와 유사하거나 보다 낮게 좋은 것으로 등급되었다.
사용하중하의 철근콘크리트 스래브의 비탄성 처짐을 산정하는 실용적인 방법올 제시하였다. 선형 유한요
소 해석의 탄성해석결과와 설계된 철근량을 이용하여 비탄성 처짐계수(β)를 결정하고, 이롤 이용하여 설계
된 슬래브의 사용성을 검토하기 위한 사용하중하의 처짐올 구할 수 있도록 하였다. 모서리에 지지된 슬래
브 예에서 제시한 방볍으로 구한 비탄성처짐과 실험 및 비선형해석 결과와 비교해 본 결과 서로 매우
잘 일치함올 보여 주었다. 제시된 방법올 비정형 슬래브 설계에 웅요한 문재도 고려하였다
본 연구에서는 천연 보습인자의 구성 성분인 L-α-아미노산을 피부에 주기적으로 반복 도포하여 일반적 으로 알려진 보습뿐 만 아니라 L-α-아미노산을 피부 톤과 결의 개선제로 활용하였다. L-α-아미노산의 알킬기(R)의 극성과 비극성에 따라 두 그룹으로 나누어 각질케어 효능을 확인하였다. 그 결과, 극성 알킬기를 갖는 L-α-아미노산 콤플렉스(L-α-아미노산-콤플렉스-1)가 비극성 알킬기를 갖는 L-α-아미노산 콤플렉스 (L-α-아미노산-콤플렉스-2)에 비해 21% 향상된 효능을 나타내었다. 임상 실험을 위해 20 – 40대 11인의 여성에 게 실험군으로서 L-α-아미노산 콤플렉스-1을 포함한 에멀전을 오른쪽 뺨에 8주간 매일 도포하고 대조군으로서 L-α-아미노산 콤플렉스-1를 포함하지 않은 에멀전을 왼쪽 뺨에 같은 방법으로 도포하였다. 피부 톤의 개선은 JANUS® 장비를 통해 측정하고 이미지분석 소프트웨어를 이용하여 분석하였으며, 피부 결의 개선은 phaseshift rapid in-vivo measurement of the skin (PRIMOS)장비를 이용하여 기기적으로 측정하고 분석하였다. 그 결과, 피부 톤 11.7%, 피부 결 6.7%의 개선을 확인하였다. 또한 피험자에게 심미적으로 느껴지는 개선에 대해 설문조사를 실시하여 피부개선의 체감도를 바탕으로 기기측정 결과를 통해 나타난 L-α-아미노산 도포의 효능을 평가하였다. 본 연구 결과를 통해, 약산성(pH 6.5)조건에서 피부 자극을 유발하지 않음과 동시에 생리학적인 개선을 통한 피부 톤과 결의 개선을 기대할 수 있으며, 화장품 소재로서 심미적 만족감을 줄 수 있는 물질로 L-α-아미노산이 활용될 수 있을 것이라 생각된다.
Background: In Korea, seeds of Panax ginseng C. A. Meyer need to be stored under cold temperature and high humidity condition for months to break physiological dormancy, making storage difficult until spring-sowing. This study was conducted to test the effects of seed storage conditions and seed treatment on the emergence of seedling after spring-sowing in a nursery greenhouse.
Methods and Results: After dehiscence, endocarp dried seeds in mild or completely, and wet seeds were stored in 2℃ and −3.5℃ during winter. Storage at −3.5℃ resulted in a lower emergence rate (ER) than that at 2℃, and additional cold (2℃) treatment before or after storage at −3.5℃ increased the ER. Endocarp dehydration prevented pre-germination at 2℃ storage and increased the ER of seeds stored at −3.5℃. ER was also dependent on the batch of seeds. However, seed treatments before sowing had only limited effects on ER. Root loss was the main reason for damping-off; prolonged cold storage of seeds increased damping-off, as the detection of pathogens was not high.
Conclusions: This study showed that storage conditions such as temperature and moisture content of seeds, affect the ER after spring-sowing and vitality of seedlings, suggesting further attention on seed control for secure seedling stands after spring-sowing.
Background: Some phenolics detected in the soil may inhibit the seed germination and seedling growth of ginseng (Panax ginseng). This study investigated the effect of irrigation and ginseng root residue addition on the soil microbial community and root rot disease in 2-year-old ginseng.
Methods and Results: Each 20 ℓ pot was filled with soil infected with ginseng root rot pathogens, and irrigated daily with 2 ℓ of water for one month. After the irrigation treatment, ginseng fine root powder was mixed with the irrigated soil at a rate of 20 g per pot. In descending order, NO3 −, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) decreased due to irrigation. In descending order, NO3 −, EC, Ex. K, and available P2O5 increased with the additon of ginseng powder to the soil. The abundance of Trichoderma crassum decreased with irrigation, but increased again with the incorporation of ginseng powder. The abundance of Haematonectria haematococca increased with irrigation, but decreased with the incorporation of ginseng powder. The abundance of Cylindrocarpon spp. and Fusarium spp., which cause ginseng root rot, increased with the incorporation of ginseng powder. The abundance of Arthrobacter oryzae and Streptomyces lavendulae increased with irrigation. The abundance of Streptomyces lavendulae decreased, and that of Arthrobacter spp. increased, with the incorporation of ginseng powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot increased with the incorporation of ginseng powder.
Conclusions: Ginseng root residues in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.
Background : Root rot is a major factors of replanting failure in ginseng cultivation. Some of the phenolics detected in the soil could inhibit the seed germination and seedling growth of ginseng.
Methods and Results : Water of 2 ℓ was irrigated per pot (20 ℓ) into the soil infected with ginseng root rot pathogens for one month every day. After the irrigation treatment, the powder of ginseng fine root of 20 g per pot was mixed with the irrigated soil. NO3 -, electric conductivity (EC), exchangeable Na (Ex. Na) and K (Ex. K) were decreased in descending order by irrigation. NO3 -, EC, Ex. K, and available P2O5 were increased in descending order by incorporation of ginseng powder into soil. Trichoderma crassum was decreased by irrigation, but it was increased again by incorporation of powder. Haematonectria haematococca was increased by irrigation, but it was decreased by incorporation of powder. Cylindrocarpon spp. and Fusarium spp. causing ginseng root rot were increased by incorporation of powder. Arthrobacter oryzae and Streptomyces lavendulae were increased by irrigation. Streptomyces lavendulae was decreased, and Arthrobacter spp. was increased by incorporation of powder. Aerial growth of ginseng was promoted by irrigation, and ginseng root rot was increased by incorporation of powder.
Conclusion : The residues of ginseng root in the soil affected soil nutrients and microorganisms, and promoted ginseng root rot, but did not affect the aerial growth of ginseng.
Background : Panax ginseng C. A. meyer is currently cultivated throughout the Korea Peninsula except for Jeju Island. We divided into 3 sectors according to latitude, north, middle, and south, and compared ginseng growth and environmental factors.
Methods and Results : We surveyed 11 farms, and while temperature, plant density, sunshade material, and soil properties were varied between the farms, most north part used sunshade film and transfer-seeding, and middle-south and south part used sunshade net, and direct-seeding. From 1st to 10th of June, 2018, the temperature inside of sunshade of each farm which ranged 20.5 - 24.5℃ did not concerted with the local meteorological air temperature nor latitude. The average plant length was 66.0 ± 8.1 with a significant difference between local farms (p < 0.001). Plant length showed high correlation with stem length, stem diameter, leaf length, and leaf width, but not with chlorophyll content, thus plant length was used to compare the effects of environmental factors on plant growth. The temperature had negative correlations between plant length (r = -0.396, p = 0.056) and stem length (r = -0.420, p = 0.041), but not with others. When local farms grouped into 3 sectors, the temperature inside sunshade was lowest in south than others, and stem diameter, leaf length, and leaf width of north sector were higher than other sectors.
Conclusion : The temperature of local farm might affected by micro environment such as sunshade and geometrical properties, and partially devote on the growth difference between the local farms.
Background: Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds.
Methods and Results: The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. After May fumigation, the sowing date of maize was delayed by 15 days and thus its dry weight was decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, NO3, P2O5, and K significantly. Maize cultivation after May fumigation decreased fungi population and the ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different between treatment of May and September, but Fusarium solani showed a significant increase in September fumigation after maize cultivation.
Conclusions: Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by the amendment of mineral composition and microorganism in fumigated soil.
Background: Saline soil has negative effects on the growth of most crops. Sodium is the main element that causes salt accumulation in soil. Organic materials such as cow and poultry manure, are frequently used during the preparation stage, which causes an increase in the rate of salt accumulation in the soil.
Methods and Results: To investigate the influences of sodium on ginseng, NaH2PO4, Na2SO4, and NaCl were used to adjust the sodium concentrations at 0, 12.5, 25, 50, 75 and 100 mM in nutrient solution. In a 2-year-old ginseng, toxic symptoms appeared when the sodium treatment exceeded 50 mM. The sodium concentration in the leaves was 3.33%, which is more than twice as high as that of the control treated at 50 mM. As the sodium concentration increased, the root weight significantly decreased. In the 100 mM treatment, the weight decreased by 28% when compared to that of the control. The Amount of ginsenoside significantly increased with an increase in sodium concentrations.
Conclusions: These results suggest that the growth of 2-year-old ginseng is negatively affected when sodium exceeds 50 mM. This result can be used for a as basis in diagnosing the physiological disorders of ginseng.
Background : The first planted field is decreasing due to replant failure and climate change. As a result, there is an increasing number of cases where new soil is covered in agricultural land or clearing forest to cultivate ginsengs. In this case, it is essential to improve the chemical properties of the soil before ginseng site management. This study was carried out to investigate growth, quality of ginseng and soil chemical properties to set the concentrations of nitrogen.
Methods and Results : 0, 1, 4, 8, 16, 32 ㎏/10 a of urea were each treated at 3.3 ㎡ of the field and ginseng cultivar 'Gumpoong' was transplanted. Growth characteristics were investigated by growth period and soil chemical properties were investigated every 3 months. In 2-years-old ginseng, the root weight was the highest at 4 ㎏ treatment group of nitrogen while it showed the rate of increase in root weight is increased at 1 ㎏ treatment of nitrogen in 3-years-old ginseng. Physiological disorder and root rot symptom are increased at 8 ㎏ treatment group of nitrogen in 2- and 3-years-old ginseng. In case of soil properties, EC and Nitrate-N concentration exceeded 0.5 dS/m and 50 ㎎/㎏ respectively from 16 ㎏ treatment group of nitrogen after 14 months. The saponin content tended to decrease with increasing nitrogen treatment concentration at the 2-years-old ginseng. In the case of 3-years-old, the highest value was 0.88% at 1 ㎏ nitrogen treatment group.
Conclusion : These results indicate that the application levels of nitrogen influence growth, quality of ginseng and soil chemical properties. These data can be used to set the concentrations of nitrogen when new soil is covered in agricultural land or clearing forest to cultivate ginseng.
Background : Replant failure of ginseng is caused by soil-born pathogens causing root rot such as Cylindrocarpon destructans and Fusarium solani. Dazomet are widely used as soil fumigant to solve soilborne problems, and the degradation intermediates are toxic to nematodes, fungi, bacteria, insects and weeds.
Methods and Results : The effects of cultivation of green manure crop, maize before and after soil fumigation on the control of ginseng root rot disease were compared using soil of field where 6-years-old ginseng was harvested. Fumigant (dazomet) were used for soil fumigation in May and September, respectively. Maize was grown for soil management before and after soil fumigation. Maize cultivation after May fumigation was delayed the sowing day by 15 days, and the fresh and dry weight decreased significantly. Maize cultivation after May fumigation increased pH but decreased EC, NO3, P2O5, and K significantly. Maize cultivation after May fumigation decreased fungi population and ratio of fungi and bacteria. Growth of 2-years-old ginseng was improved and the incidence of ginseng root rot was significantly decreased by maize cultivation after May fumigation. After harvesting 2-years-old ginseng, the population of Cylindrocarpon destructans was not different among treatments, but Fusarium solani showed a significant increase in September fumigation after maize cultivation.
Conclusion : Maize cultivation after soil fumigation was effective in inhibiting ginseng root rot by improvement of mineral composition and microorganism in soils.
Background: The application of crop rotation systems may reduce the occurrence of soil-borne diseases by releasing allelochemicals and by subsequent microbial decomposition. Methods and Results: For reduction of ginseng root rot by the crop rotation system, after harvesting 6-year-old ginseng, fresh ginseng was grown along with continuous cultivation of sweet potato, peanut, and bellflower. Growth of 2-year-old ginseng was significantly inhibited in the continuous cultivation than in the first cultivation. Sweet potato, peanut and bellflower cultivations assisted in obtaining normal yields of ginseng in the first year after the harvest of 6-year-old ginseng. Salt concentration, potassium and sodium contents were gradually decreased, and, organic matter was gradually increased through cirp rotation. Phosphate, calcium and magnesium contents were not altered. The density of the root rot fungus was gradually decreased by the increase in crop rotation; however it was decreased distinctly in the first year compared to the second and third year. The severity of root rot disease tended to decrease gradually by the increase of crop rotation. Conclusions: Short-term crop rotation for three years promoted the growth of ginseng, however root rot infection was not inhibited significantly, although it was somewhat effective in lowering the density of the root rot pathogen.
Background : Ginseng (Panax ginseng C.A. Meyer) is one of the most important medicinal plants in Korea, but its yields are often reduced by a variety of root pathogens. The root rot of ginseng is a destructive soil-borne disease caused by Cylindrocarpon destructans (teleomorph: Ilyonectria radicicola). Methods and Results : Ilyonectria radicicola and its Cylindrocarpon-like anamorph represent a species complex that is commonly associated with root rot disease symptoms on virulence. During the course of this study, several species could be distinguished from I. radicicola sensu stricto based on morphological and culture characteristics. As results of investigated culture characteristics, optimal temperature for mycelial growth of isolates were 20℃, and colony pattern and color were slightly different on PDA. Isolates of I. radicicola were analyzed for their genetic relatedness based on several genes and microsatellite region. I. radicicola group was divided into two small groups. Conclusion : Therefore, we were able to confirm pathogenicity and genetic difference between the isolates in each of the groups of the pathogen. Among these isolates, 21.5% were classified as highly virulent and 78.5% were weakly virulent. *(Corresponding
Background : The fungus Cylindrocarpon destructans (Zins) Scholten is the cause of root rot in many ginseng production areas. Root exudate composition and quantity vary in relation to plant nutritional status, but the impact of the differences on rhizosphere microbial communities is not known. Methods and Results : Five kinds of rotation crops, sudan grass soybean peanut sweet potato, perilla were grown for one year in ginseng garden harvested 6-year-old ginseng. The ratio of gram-negative bacteria, fungi, bacteria, total microbial biomass, aerobic/anaerobic microbes were increased by rotational crop cultivation, while the ratio of actinomycetes and the ratio of saturated to unsaturated fatty acids were decreased. The increase in the fungal density or the increase in the proportion of fungi to the bacteria tended to increase the incidence of root rot, but there was no significant difference. The yield of ginseng root showed a highly significant negative correlation with actinomycetes. The correlation between the soil chemical properties and the incidence of root rot was analyzed by cultivating 23 kinds of green manure crops for one year in field where cultivated ginseng continuously. The survival rate of ginseng showed a highly significant positive correlation with soil acidity and a highly significant negative correlation with nitrate nitrogen, and a significant negative correlation with soil salt concentration. Conclusion : Rotation crops improved soil microbial communities, lowered the rate of fungi and increased the proportion of bacteria, the survival rate of ginseng was significantly correlated with soil acidity, nitrate nitrogen and soil salinity.