• Title/Summary/Keyword: Yield stress

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Effect of Shading Methods on Growth and Fruit Quality of Paprika in Summer Season (파프리카 여름재배시 차광방법이 생육과 과실특성에 미치는 영향)

  • Ha, Jun Bong;Lim, Chae Shin;Kang, Hyo Yong;Kang, Yang Su;Hwang, Seung Jae;Mun, Hyung Su;An, Chul Geon
    • Journal of Bio-Environment Control
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    • v.21 no.4
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    • pp.419-427
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    • 2012
  • This study was carried out to investigate the effect of two shading methods, shading agent spray on the glasshouse and internal shading screen treatment, on the growth and fruit quality of paprika (Capsicum annuum L. 'Cupra' and 'Coletti') in summer season cultivation. In the shading agent treatment, a commercial shading agent diluted with water at a ratio of 1 : 4 was sprayed on the roof of a glasshouse. In the internal shading screen treatment, a 10~20% shaded screen was used during the day time when the sun radiation was greater than $700W{\cdot}m^{-2}$. Compared to the unshaded control, photosynthetic photon flux density (PPFD) decreased in the greenhouse in the shading agent (SA) and shading screen (SS) treatments by 20% and 30%, respectively. Lower air temperatures and higher relative humidities were observed in the SA than in both the control and the SS treatment. Time to reach the break point of humidity deficit $8g{\cdot}m^{-3}$ was 2 hours late in the SA than in both the control and the SS treatment. Compared to control, both the SA and the SS treatments showed lower instantaneous temperatures of leaf, fruit, and flower by $2^{\circ}C$, $5^{\circ}C$ and $3^{\circ}C$, respectively. There were no differences in number of branches, stem diameter, and leaf size among treatments although both shading treatments promoted plant height in both cultivars. Botrytis infection ratio declined with the SA treatment by 14.7% in 'Cupra' and 22.1% in 'Coletti' as compared to that in the control. Shading increased fruit size in both cultivars, whereas no differences were observed in the number of locules and thickness of fruit tissue among treatments. Shading treatment increased mean fruit weight by a range of 10 to 15 g per fruit, while it decreased soluble solids contents as compared to that in the control. Similar Hunter values were observed among treatments, while fruit firmness increased slightly in shading treatments. Compared to the control, shading treatments improved marketable fruits by 11.7~22.6% and increased the number of fruits per plant by 4~9.2 in both 'Cupra' and 'Coletti'. The results of this study indicate that shading agent application on the roof of glasshouse would be one of the most effective options to reduce heat stress imposed on the paprika crop in summer cultivation, resulting in improved crop growth and fruit yield.

Responses of Photosynthetic Characters to Waterlogging in Soybean [Glycine max (L.) Merrill] (과습에 따른 콩 광합성 관련 형질 반응)

  • Lee, Jae-Eun;Kim, Hong-Sig;Kwon, Young-Up;Jung, Gun-Ho;Lee, Chun-Ki;Yun, Hong-Tai;Kim, Chung-Kon
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.2
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    • pp.111-118
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    • 2010
  • Stress due to excess water is one of the most limiting factor for soybeans to high yield under wet climates. This study aimed to identify the photosynthetic responses of soybeans to waterlogged growing condition with 5 soybean varieties by waterlogging for 10 days at V5 and R2 stage, respectively. Chlorophyll fluorescence decreased more rapidly at R2 stage waterlogging than at V5 stage waterlogging in all soybean tested varieties. The degree of recovery was much more in Pungsannamulkong and Muhankong( 95~97% of control) than in Jangyeobkong and Myungjunamulkong at 5 days after waterlogging. Photosynthetic rate, transpiration and stomatal conductance were also increased more rapidly in Pungsannamulkong and Muhankong than in Jangyeobkong and Myungjunamulkong after waterlogging irrespective of waterlogging stages. As the result of multiple regression analysis in order to identify the effects of stomatal conductance and transpiration to the photosynthetic rate, the R2 value of stomatal conductance in control and waterlogging treatment was 0.7293 and 0.7582, respectively. If the transpiration, another dependent variable, was added to the regression formula, there was not so big difference in the variation of photosynthetic rate. This result means that if just one factor of them(the stomatal conductance and transpiration) be measured in the case of waterlogged condition, the changes of photosynthetic rate can be estimated.

Comparison of Antioxidant Activities of Enzymatic and Methanolic Extracts from Ecklonia cava Stem and Leave (감태(Ecklonia cava) 줄기 및 잎의 효소적 추출물과 메탄올 추출물에 의한 항산화 활성비교)

  • Lee, Seung-Hong;Kim, Kil-Nam;Cha, Seon-Heui;Ahn, Gin-Nae;Jeon, You-Jin
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.35 no.9
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    • pp.1139-1145
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    • 2006
  • In this study, antioxidant activities of enzymatic and methanolic extracts from E. cava stem and leave were evaluated by measuring the scavenging activities on 1,1 diphenyl 2 picrylhydrazyl (DPPH), hydroxyl radical, hydrogen peroxide and the inhibitory effects on DNA damage induced by oxidative stress of cells. Enzymatic extracts were prepared by enzymatic hydrolysis of both stem and leave using food grade five different carbohydrases (Viscozyme, Celluclast, AMG, Termamyl, Ultraflo) and five proteases (Protamex, Kojizyme, Neutrase, Flavourzyme, Alcalase). The enzymatic extracts were lower than methanolic extracts in polyphenol contents, but higher in extraction yield by approximately 30%. The enzymatic extracts were superior to methanolic extracts in DPPH and H2O2 scavenging activities and DNA damage protective effect. There were no significant antioxidant activity difference between stem and leave, but the extracts of leave were relatively better than those of stem. In this study it is suggested that E. cava stem as well as its leave would be a good raw materials for antioxidants compound extraction and enzymatic hydrolysis would be a good strategy to prepare antioxidant extracts from seaweeds.

A Medium-Maturing and Good Quality Japonica Rice Variety, "Cheongan" (벼 중생 고품질 신품종 "청안")

  • Yang, Sae-Jun;Kim, Yeon-Gyu;Choi, Im-Soo;Cho, Young-Chan;Hwang, Hung-Goo;Hong, Ha-Cheol;Kim, Myeong-Ki;Oh, Myung-Kyu;Shin, Young-Seop;Lee, Jeom-Ho;Choi, Yong-Hwan;Choi, In-Bea;Kang, Kyung-Ho;Yea, Jong-Doo;Lee, Jeong-Heui
    • Korean Journal of Breeding Science
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    • v.41 no.4
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    • pp.649-653
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    • 2009
  • "Cheongan" is a new japonica rice variety developed from a cross between SR15225-B-22-1-2-1 and Iksan431 in summer season, 1997 by National Institute of Crop Science, RDA. The line SR15225-B-22-1-2-1 has good canopy architecture and multi-disease and insect resistance, and Iksan431 has translucent milled rice and good eating-quality. Heading date of Cheongan is August 13 in central lowland and mid-mountainous areas. "Cheongan" having culm length of 84 cm shows relatively semi-erect pubescent leaf blade and rigid culm, tolerance to lodging with and good canopy architecture. This variety has 14 tillers per hill and 126 spikelets per panicle. It shows tolerance to heading delay and spikelet sterility comparable to Hwaseongbyeo when exposed to cold stress. Leaf senescence of Cheongan progresses slowly during the ripening stage and the viviparous germination ratio was 59 %, similar to that of Hwaseongbyo. "Cheongan" shows moderately resistance to blast disease, but susceptible to stripe virus and brown planthopper. The milled rice of "Cheongan" exhibits translucent, clear non-glutinous endosperm and medium short grain. It shows similar amylose content of 18.7%, gelatinization temperature, and similar palatability of cooked rice compared to Hwaseongbyeo. The milled rice yield of this cultivar is about 5.54 MT/ha at ordinary season culture in local adaptability test for three years. Especially, "Cheongan" has better milling properties of higher 98.4% and 73.9% in the percentage of head rice in milled rice and milling recovery of head rice, respectively, than those of Hwaseongbyeo. "Cheongan" could be adaptable to the central and mid-southern plain area, and mid-western coastal area of Korea.

EFfect of Feed Withdrawal Time on Salmonella Contamination in the Crop, Intestinal Weight, and Blood Parameters of Broilers before Harvesting (절식 시간에 따른 육계의 소낭 내 Salmonella 오염도, 소화관 길이, 혈액 성분, 계육 품질에 미치는 영향)

  • Kim, Hee-Jin;Kang, Hwan-Ku;Hong, Eui-Chul;Kim, Hyun-Soo;Son, Jiseon;You, Are-Sun;Kang, Bo-Seok;Jeon, Jin-Joo
    • Korean Journal of Poultry Science
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    • v.48 no.4
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    • pp.287-295
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    • 2021
  • In this study, we aimed to evaluate the impact of different feed withdrawal periods (2, 3, 4, 5, and 6 h) on Salmonella contamination in the crop, intestinal weight, and blood parameters of broilers before harvesting. A total of 100 broilers (initial live weight 1.906±0.06 kg) were randomly assigned to the same five treatment groups and broilers had access to water but no feed before catching. Feed withdrawal times were 2, 3, 4, 5, and 6 h prior to slaughter. Measurements included live weight, pre-slaughter weight, carcass weight, weight of gastrointestinal tract. In addition, Salmonella and Campylobacter contamination in the crop, serum biochemical profiles, counts of leukocytes, erythrocytes, and platelets, and meat quality were assessed. The results demonstrate that carcass weight, blood corticosterone, meat pH, meat color, and water holding capacity did not differ based on the feed withdrawal time. Carcass yield increased as the withdrawal time increased, but the weights of the crop, proventriculus, jejunum, ileum, and rectum were significantly reduced by 6 h (P<0.05). Salmonella counts were the lowest in the crops subjected to 6 h of feed withdrawal (P<0.05). Shear force was highest in chicken breast meat after 6 h of feed withdrawal (P<0.05). However, when the feed was withdrawn after 6 h, the shear force increased, but it did not affect the sensory characteristics in consumers, and the Salmonella count also decreased and had a reduction effect on contamination during slaughter. These findings can serve as reference data for setting the feed withdrawal time.

A Very Early-Maturing, Cold Tolerant and High Quality japonica Rice Variety 'Hanseol' (극조숙 고품질 내냉성 벼 신품종 '한설')

  • Lee, Jeong-Heui;Shin, Young-Seop;Jeong, O-Young;Kim, Myeong-Ki;Kim, Yeon-Gyu;Kim, Hong-Yeol;Lee, Jeom-Ho;Lee, Jeong-Il;Cho, Young-Chan;Jeon, Yong-Hee;Choi, Yong-Hwan;Yang, Chang-Ihn;Hong, Ha-Cheol;Won, Yong-Jae;Shin, Jin-Chul;Kim, Hyung-Yoon;Seo, Dae-Ha;Hwang, Hung-Goo;Yea, Jong-Doo
    • Korean Journal of Breeding Science
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    • v.42 no.6
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    • pp.632-637
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    • 2010
  • 'Hanseol' is a new very early-maturing, cold tolerant and high quality japonica rice variety developed from a cross of 'Jinbu24' and 'Jinbu25' by the rice breeding team of National Institute of Crop Science (NICS), Rural Development Administration (RDA) in 2009. The heading date of this variety is July 25, which is four days earlier than check variety, 'Jinbubyeo'. 'Hanseol' has 65 cm of culm length, 99 spikelets per panicle, 82.9% of ripened grain rate, and 21.5 g of 1,000 grain-weight of brown rice. This variety shows susceptibility to bacterial leaf blight and virus diseases, and insect pests. It is tolerant to cold stress in terms of less heading delay and high fertility in cold water irrigated cultivation. This variety shows delayed leaf senescence and considerable tolerance to viviparous germination at ripening stage. The milled rice of this variety exhibits translucent, clear non-glutinous endosperm and medium-short grain. 'Hanseol' showed low gelatinization temperature and 6.1% protein content, 19.1% amylose content and good palatability of cooked rice. The milled rice yield of this variety is about 5.43 MT/ha at ordinary culture in local adaptability test for three years. 'Hanseol' would be highly adaptable to mid-north and mid-mountainous areas, and mid-northern alpine area in Korea.

A High-Eating Quality Rice Variety 'Cheonghaejinmi' Adaptable to Low Nitrogen Fertilizer Application (질소 소비료 적성 고양식미 벼 신품종 '청해진미')

  • Oh, Myung-Kyu;Kim, Yeon-Gyu;Kim, Myeong-Ki;Cho, Young-Chan;Hwang, Hung-Goo;Hong, Ha-Cheol;Choi, Im-Soo;Kim, Jeong-Ju;Lee, Jeom-Ho;Baek, Man-Kee;Choi, Yong-Hwan;Jeong, Jong-Min;Yang, Chang-In;Oh, Sea-Kwan;Choi, In-Bea;Won, Yong-Jae;Chun, A-Reum
    • Korean Journal of Breeding Science
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    • v.42 no.3
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    • pp.307-312
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    • 2010
  • 'Cheonghaejinmi' is a new japonica rice variety developed from three-way cross between Samjiyeon/SR14694-57-4-2-1-3-2-2//Iri402 by the rice breeding team of National Institute of Crop Science, RDA. Heading date of this variety is August 18, 4 days later than that of 'Sobibyeo' in middle plain areas. It has culm length of 78 cm, 125 spikelets per panicle, 92.5% of ripened grain rate, and 23.9 g of 1000-brown rice weight. It showed 12 days of heading delay, and 63% spikelet fertility in cold-water irrigation stress. 'Cheonghaejinmi' is susceptible to blast disease, bacterial blight, virus diseases and plant hoppers. The nitrogen use efficiency of this variety is higher than that of Sobibyeo in low nitrogen application level. Milled rice of 'Cheonghaejinmi' exhibits translucent, clear non-glutinous endosperm and medium short grain. It has 5.9% protein content, 20.3% amylose content, and 0.28 palatability index of cooked rice compared to -0.11 of Hwaseongbyeo. The milled rice yield of 'Cheonghaejinmi' was about 5.31 MT/ha at low nitrogen application level of ordinary season culture. This variety had 98.8% whole grain in milled rice and 76% milling recovery of whole grain. 'Cheonghaejinmi' would be adaptable to middle plain areas and middle-western coastal areas in Korea.

A Study on the Possibility of Recycling Coir Organic Substrates for using Strawberry Hydroponics Media (토마토 폐배지를 딸기 수경재배 배지로 재이용 가능성 연구)

  • Lee, Gyu-Bin;Park, Young-Hoon;Choi, Young-Whan;Son, Beung-Gu;Kim, Jooh-Yup;Kang, Nam-Jun;Kang, Jum-Soon
    • Journal of Korea Society of Waste Management
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    • v.34 no.2
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    • pp.205-213
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    • 2017
  • The current study was performed to investigate the effect of recycling coir substrates on the growth, fruit yield, and quality of strawberry plants. Analysis of physical properties revealed that the pH of a fresh coir substrate was 5.04 while those of substrates reused for one and two years were 5.20 and 5.33, respectively. The electrical conductivity (EC) of a new substrate was as high as $4.58dS{\cdot}m^{-1}$. This can cause salt stress after transplanting. The EC tended to decrease as the substrate was recycled, and the EC of a two-year recycled substrate was $1.48dS{\cdot}m^{-1}$. The fresh substrate had lower nitrogen and calcium concentrations, but higher phosphate, potassium, and sodium concentrations than the recycled coir substrate. The coir substrates recycled for one or two years maintained better chemical properties for plant growth than the fresh substrate. Strawberry growth varied depending on the number of years that the coir substrate was recycled. In general, strawberries grown in substrates that had been reused for two years did better than those grown in substrates that had been reused once or were fresh. Ninety days after transplanting, a plant grown in a substrate that had been reused for two years contained 25 leaves, which was 3.6 more than with a fresh substrate. In addition, the plants grown in a substrate that had been reused for two years exhibited larger leaf areas than those grown in other substrates. Coir substrates that had been reused for one year increased the number and area of leaves, but not as much as the substrate that had been reused for two years. One- and two-year reused coir substrates increased the weight of strawberries produced relative to the unused substrate, but the difference was not statistically significant. The plants grown in two-year reused substrates were longer and wider, as well. Also, the number of fruits per plant was higher when substrates were reused. Specifically, the number of fruits per plant was 28.7 with a two-year reused substrate, but only 22.2 with a fresh substrate. The fruit color indices (as represented by their Hunter L, a, b values) were not considerably affected by recycling of the coir substrate. The Hunter L value, which indicates the brightness of the fruit, did not change significantly when the substrate was recycled. Neither Hunter a (red) nor b (yellow) values were changed by recycling. In addition, there were no significant changes in the hardnesses, acidities, or soluble solid-acid ratios of fruits grown in recycled substrates. Thus, it is thought that recycling the coir substrate does not affect measures of fruit quality such as color, hardness, and sugar content. Overall, reuse of coir substrates from hydroponic culture as high-bed strawberry growth substrates would solve the problems of new substrate costs and the disposal of substrates that had been used once.

Effect of Waterlogging on Growth and Morphological Characteristics of Roots of Maize Inbred Lines (담수 처리에 따른 옥수수 자식 계통의 지상부와 뿌리의 생육 및 형태적 특성)

  • Lee, Jihyun;Shin, Myeong-Na;Jung, Gun-Ho;Kim, Jung Tae;Cha, Jungeun;Shim, Kang-Bo;Lee, Jae-Eun;Son, Beom-Young;Kim, Sang-Gon;Ku, Bon-Il;Lee, Seukki;Jeon, Weon-Tai
    • Journal of The Korean Society of Grassland and Forage Science
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    • v.40 no.4
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    • pp.227-235
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    • 2020
  • This study was conducted to investigate the growth characteristics of the shoot and roots and to analyse the morphological characteristics of roots of waterlogging resistant and susceptible maize inbred lines. Six maize inbred lines were treated with waterlogging for 10 days at V3, and the degree of leaf senescence was evaluated for waterlogging resistance. As a result of waterlogging resistance evaluation, KS85 was the most damaged inbred line with 3.33 senescence leaves and 5.54 degree, and KS141 was the least damaged inbred line with 1.33 senescence leaves and 3 degree. At 20 days after treatment, the effect of waterlogging stress on the shoot dry matter accumulation of KS85 and KS141 were decreased by 86.1% and 77.0%, respectively, compared to the control. Similarly, root dry matter accumulation of KS85 and KS141 were decreased by 77.6% and 65.0%. As a result of SEM photographs of the nodal roots of the two maize inbred lines, the thickness of cortex of KS141 was thicker than that of KS85, and the distortion of the cortex was observed in KS85 at 20 days after waterlogging. It was concluded that the thickness of cortex was related to maize waterlogging resistance.

Ethanol extract of Aster glehni exhibits anti-inflammatory and anti-oxidant effects in RAW 264.7 cells and Caenorhabditis elegans (섬쑥부쟁이 에탄올 추출물이 대식세포와 예쁜꼬마선충에서의 항염증 및 항산화 효과 )

  • Mi-Kyung Seo;Han-Na Chu;Da-Bin Lee;Haeng-Ran Kim;In-Seon Hwang;Yong-Jin Jeong;Sung-Ran Yoon;Seok-Seong Kang;Kyeong-A Jang;Min-Sook Kang
    • Food Science and Preservation
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    • v.30 no.6
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    • pp.1095-1106
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    • 2023
  • This study investigated the anti-oxidative and anti-inflammatory effects of Aster glehni (AG) extract in RAW 264.7 cells and Caenorhabditis elegans. The total polyphenol and flavonoid contents were higher in the ethanol extracts than in the hot water extracts. As a result of measuring the moisture contents (%) and extraction yields (%) of AG and drying A. glehni for processing (DAG), 70% ethanol, which has the highest percentage of extraction yield, was selected as the final solvent. DPPH radical scavenging activity showed higher antioxidant activity of ethanol extracts of DAG than AG. The cytotoxicity assay of the AG or DAG ethanol extracts was treated at different concentrations (25, 50, and 100 ㎍/mL), and cell viability rates were higher than 80% at all concentrations. The LPS-stimulated nitric oxide (NO) production in RAW 264.7 was significantly reduced at all concentrations of AG and DAG groups. As a result of measuring the gene expression of iNOS, which induces NO production, the AG or DAG group decreased by 33% and 32%, compared with the phosphate buffer saline (PBS) group. Under inflammatory stress conditions, the survival rate of C. elegans treated with AG or DAG ethanol extract with LPS showed concentration-dependent improvement in survival rate compared with the PBS group. Considering these results, AG could potentially be developed as an antioxidant and anti-inflammatory functional food material.