제주지역에서 예취높이에 따른 (2, 4, 6, 8 및 l0cm)에 따른 양마의 생육특성, 수량성 및 사료가치를 구명하기 위하여 2001년 4월 13일부터 10월 8일까지 시험한 결과는 다음과 같다. 초장은 2cm 예취에서 157.7cm였던 것이 예취높이가 높아짐에 따라 점차적으로 커져서 10cm 예취에서는 180.2cm로 커졌다. 엽수, 분지수, 경직경 및 주당 무게는 초장반응과 비슷한 경향이었다. 생초, 건물, 단백질 및 TDN 수량은 2cm 예취에서

본 시험은 제주지역에서 양마의 적정질소시비 횟수를 구명하기 위하여 2001년 4월 13일부터 10월 8일까지 질소시비량을 240kg/ha 고정하고 30일 간격으로 1~5회 분시하여 양마의 생육특성, 사료수량성 및 조성분 함량 등을 조사하였다. 초장은 분시 횟수가 많을수록 증가하여 4회 분시구에서 최고인 201cm를 보이다가 5회에서 줄어들었다. 분지수, 엽수, 경직경 및 개체당 무게도 초장과 같은 경향으로 4회 분시에서 가장 우세하였다. 생초, 건물,

In order to determine the influence of nitrogen on agronomic characters, forage yield and quality, a Kenaf was cultured on the volcanic ash soil at the Experimental Farm of Cheju national University under the seven levels of nitrogen rates(0, 50, 100, 150

Background : The Kenaf (Hibiscus cannabinus L.) is an annual plant rich in phenolics compound and antioxidant activity. Particle size has an enormous effect on extraction of plant bioactive compound. Therefore, to evaluate the optimum particle size on extraction of bioactive compound from Kenaf was investigated. Methods and Results : Three kind of kenaf leaves; EF-1 and G-1 from Israel and Korea were collected in 2016 and the collected leaves were dried and pulverized are sorted by particle size. After adding 50 ㎖ of 100% ethanol per 0.5 ㎎ of the powder, the powder is extracted in an ultrasonic bath at 30℃ for 1 hour and then stirred for 1 hour at 250 rpm in the wise stirring. After extraction, the extract was filtered using filter paper. In the total polyphenol, flavonoid and antioxidant activity were higher in 100 to 200 ㎛ particle size of Gandae. On the other hand, phenolic compound, falvonoud and antioxidant were higher in 45 to 100 ㎛ particle size of EF-1 and G-1 Kenaf. Conclusion : Based on the results, the Israel varieties showed the best results compared to the Kenaf varieties of Korea. Among them, EF-1 had a particle size of 45 – 100 ㎛ Showed the higher antioxidant activity. It is believed that the smaller the particle size, the larger the specific surface area, which leads to an increase in the extraction efficiency of kenaf.

Background : The Kenaf (Hibiscus cannabinus L.) is an annual plant of African and Indian origin. and there are a lot of flavonoids in the leaves. To determine the most suitable method for extracting of Kenaf cosmetic ingredients, the data of changes in polyphenol, flavonoid contents and DPPH radical scavenging activities were analyzed, based on concentration of Extraction Methods. Methods and Results : 200 ㎖ of distilled water (100% ethanol in the case of ethanol extraction) was added to 20 g of the leaves of Kenaf; G-1 from Israel were collected in 2016 and the collected leaves were dried and pulverized, and five extraction methods were performed. The extraction method and conditions are as follows: pressurized high temperature extraction (AE: autoclave, 121 degrees, 15 minutes), ultrasonic extraction (UE: ultrasonic bath, 60 degree hot water, 1 hour), Hot water extraction (SE: spidulina mayina. 100 degrees 6 hours), Ethanol Extraction (EE: ethanol, spidulina mayina, 80 degrees 6 hours), room temperature stirring extraction (WSE: wise stirring, room temperature 250rpm 24 hours). After extraction, the mixture was filtered using a filter paper, and concentrated under reduced pressure at 40℃ for lyophilization. And diluted to 1,000 ppm with 80% ethanol. Conclusion : Based on the test results, EE method showed the highest results. In the case of using water as the solvent, the SE method showed the highest result. However, the results of the SE and AE methods are not significantly different from each other. Therefore, it is expected that if the extraction conditions of AE method are adjusted, the result of AE method will be higher than that of the SE method.

Background : The Kenaf (Hibiscus cannabinus L.) is an annual plant of African and Indian origin. and there are a lot of flavonoids in the leaves. To determine the most suitable method for extracting of Kenaf cosmetic ingredients, the data of changes in polyphenol, flavonoid contents and DPPH radical scavenging activities were analyzed, based on concentration of surfactants and Extraction Methods. Methods and Results : The effect of autoclave extraction (AE) and ultrasonification extraction USE) with hydrophilic surfactant that is Brij35 diluted 15, 25 and 35 mM with water on antioxidant activity of Kenaf was investigated. The leaves of Kenaf; R from Israel were collected in 2016 and the collected leaves were dried and pulverized. The highest polyphenol content of Kenaf extracted was 47.54 ㎎/㎖ as Brij35 20 mM extract from AE after USE. The highest flavonoid content of Kenaf was 20.01 ㎎/㎖ as Brij35 25 mM extract from AE. The Brij35 20 mM extract from AE after USE showed higher DPPH radical scavenging activity than that of the other treatments. Conclusion : Based on the test results, the extracts obtained by AE or AE after USE showed excellent antioxidant activity and effective component than extracts by USE. The results of the DPPH radical scavenging activity and total polyphenol content of the extracts obtained by AE after USE than AE were slightly improved, but there was no significant difference. Therefore, it is considered that the extract obtained by autoclave extraction most effective for use as a cosmetic ingredient.

Background: The present study assessed the response of kenaf (Hibiscus cannabinus L., Jangdae) seed to NaCl and the effects of polyethylene glycol (PEG) on kenaf seed germination and vigor. Methods and Results: Seed germination ranged from 11.3% to 58.8% after 24 hours of immersion in NaCl concentrations from 0% to 0.5%. The priming treatments had lower electrical conductivity (EC) values for the seeds than for the control and a deteriorated palisade layer. Priming in 10% PEG for 48 hours increased the germination upto 96.3% in H2O solution and 98.8% in 0.3% NaCl solution compared to that of the control (78.8%). Germination synchronization, and shoot and root growth of the primed seeds were greater than those of the control. The T50 of the control in H2O and 0.3% NaCl solution was 22 and 28 times, respectively. After priming, nine times was sufficient to reach T50 in both solution. The mean number of days to germination (MDG) decreased from 1.43 days for the control to 0.55 days for 0% PEG in H2O solution and from 1.57 days for the control to 0.56 days for 0% PEG in 0.3% NaCl solution. The dry weight after the 10% PEG treatment was higher than that of the control. Conclusions: Taken together, 10% PEG treatment for 24 hours is recommended for kenaf seed invigoration before planting.

The main objective of this study was to increase the germination percentage of kenaf seeds with less number of times under non-saline and saline conditions. Therefore, the first goal was to assess the response of kenaf seeds to NaCl. The second goal was to evaluate the effects of KNO3 on kenaf seed germination. The germination percentage exhibited a decreasing tendency in germination rate. Plant dry weight was approximately 0.2 g in all treatments at 5 days after germination. As time passed, the electrical conductivity (EC) value of hydro-priming (HP) consistently increased by 8.7 mS/cm at 24 hours of immersion. However, seeds primed with KNO3 showed no difference in EC values even as times passed. Regarding the priming effect, priming in 100 mM KNO3 concentration for 12 hours increased germination up to 85% in H20 solution and in 0 mM KNO3 concentration upto 73.8% under 0.3% NaCl solution, compared to that of Control. Germination synchronization, shoot length, and leaf unfolding of primed seeds were greater than those of the Control. In addition, main root and hair roots appeared more rapidly in the treated seeds and were more abundant compared to that of the Control. The T50 (times to reach 50% of the final germination percentage) of the Control in both H20 and 0.3% NaCl solutions was 18 and 22 hours, respectively. However, when treated KNO3 priming (0 to 100 mM) in H20 and 0.3% NaCl solution, 9 hours was sufficient to reach T50. Primed (hydro-priming and KNO3) seeds had a lower MDG (mean days untill germination; 0.6-0.62) compared to that of the Control (1.13-1.31) in H20 and 0.3% NaCl solutions. Regarding dry weight of plants after priming, an increasing tendency after the priming treatment in the H20 solution was observed. Furthermore, no significant difference in plant dry weight under 0.3% NaCl stress was observed between the Control and primed seeds. Taken together, the results suggest that 50-100 mM KNO3 priming for 24 hours optimize seed germination rate in less number of times of exposure with great vigor. Therefore, it is recommended for kenaf seed invigoration before planting.

최근 건설현장에서 작업자의 고령화 및 숙련공 부족 현상이 중요 문제로 부각되고 있으며, 또한 최근 건설구조물이 점차 고층화, 대형화됨에 따라 부재의 형상이 복잡해지고 있다. 이러한 건설 환경의 변화에 따라 국내 및 국외에서 고유동 콘크리트에 대한 연구 및 개발이 증대되고 있다. 고유동 콘크리트는 재료분리 없이 굳지 않은 콘크리트의 유동성을 개선시켜 다짐 작업 없이 자기 충전이 가능한 콘크리트를 말한다. 하지만 고유동 콘크리트는 인장 및 휨 강도의 저하와 균열 등의 문제점을 가지고 있다. 따라서 본 연구에서는 문제점을 해결하기 위하여 고유동 콘크리트에 양마섬유를 혼입하였다. 양마섬유의 경우 천연섬유로 친환경적이며 이산화탄소의 흡수량이 많아 콘크리트 생산과정에서 배출되는 이산화탄소의 양을 상쇄시킬 수 있을 것으로 보인다. 또한, 기존 콘크리트의 섬유 보강재로 사용되었던 황마와 유사한 특성을 지녔으며 짧은 생육 기간으로 대량생산이 가능하여 경제적이다. 양마섬유는 섬유 표면이 거칠어 콘크리트와의 부착력이 뛰어나고 섬유의 인장력이 우수하여 콘크리트의 인장강도 증진과 균열 저감 효과가 있을 것으로 사료된다. 또한, 산업부산물의 일종인 플라이애쉬와 고로슬래그를 혼입하여 탄소저감 효과와 폐기물의 처리로 환경적인 측면에서 긍정적인 효과가 기대된다. 따라서 본 연구에서는 이와 같은 재료로 시멘트의 일부를 대체하여 양마섬유를 혼입한 고유동 콘크리트의 강도 특성을 알아보고자 하였다.

Background : Kenaf (Hibiscus cannabinus L.) is a member of the malvaceae family and has been prescribed in traditional folk medicine in Africa and India. It showed broad biologicas activities such as hepatoprotective activity, antioxidative activity and haematinic activity. Kenaf leaves contain a lot of vegetable calcium, protein, iron and vitamins, so have high potential as functional food. Thus, the present study purposed to analyze useful substances contained in kenaf leaves and their activities and look for their possibilities as the materials of food and medicine. Methods and Results :　We sowed the seeds of three varieties of kenaf, namely, Dowling, Everglade-41 and Tainung-2 at planting space of 20 × 20㎝ on the field and collected plants on the 98th , 127th and 141st days from sowing. The total polyphenol content was measured using a slightly modified Folin-Denis method, which uses the phenomenon that a phenolic substance turns blue by reaction with phosphomolybdate. Conclusion : We analyzed SOD enzyme activity related to the scavenging of superoxide anion radical (․O2-) through NBT reduction. As for the SOD activity of leaf extract by variety, the activity was 92.6%, 91.0% and 92.6%, respectively, in Tainung-2 on day 98, 127 and 141 from sowing, slightly higher than those in the other two varieties but not significantly different. The activity was slightly higher in the middle period of growth than in the harvest period, but not much different according to harvest time. As for the DPPH radical scavenging activity of leaf extract by variety, the activity was 80.87% and 80.71%, respectively, in Tainung-2 on day 98 (30th of October)and day127 (28th of September), slightly higher than the other two varieties.

Background : Kenaf (Hibiscus cannabinus L.) is a member of the malvaceae family and has been prescribed in traditional folk medicine in Africa and India. It showed broad biologicas activities such as hepatoprotective activity, antioxidative activity and haematinic activity, Recently, immunomodulatory effect of kenaf extract has been elucidated. However, depigmenting activity from kenaf extract has not been evaluated. In the present study, the tyrosinase inhibitory effect of kenaf leaf extract was investigated before and after subjecting the extract to together with infrared(FIR) irradiation. Methods and Results :　FIR irradiation involves electromagnetic waves with wavelengths ranging from 4 to 15 μM. It has been hypothesized that FIR treatment during extraction of polyphenols from plant cells stimulates exudation of chemical components in cells without destroying the cells by radiant heat and breaks covalent bonds of polymerized polyphenols resulting in the release of active, natural antioxidants with a low molecular weight. The purpose of this study was to evaluate not only the changes in antityrosinase activity but also the chemical transformation of kenaf extract exposed to FIR(Scheme 1). Conclusion: The tyrosinase inhibitory activity of kenaf xtract was evaluated after far-infrared (FIR) irradiation. The ethanol extract of kenaf was prepared and its main component was analyzed as a kaempferitrin (kaempferol-3,7-O-a-dirhamnoside). Inhibitory activity of kenaf extract was not detected in tyrosinase assay. However, tyrosinase inhibitory activity was observed in kenaf extract treated with FIR irradiation. After 60 min of FIR irradiation onto kenaf extract at 60oC, a ethanolic extract was prepared and it showed significant tyrosinase inhibitory activity (IC50=3500ppm). According to HPLC analysis, kaempferol, afzelin and minor product were detected(. The inhibitory activity may be due to the existence of kaemperol, afzelin and minor product. This study showed that FIR irradiation method can be used as a convenient tool for deglycosylation of flavonoid glycoside.

Kenaf (Hibiscus cannabinus L.) is an annual herbaceous crop of the Malvaceae family. Recently, kenaf is being used in many diversified applications such as pulp, animal feed, bioplastics and cellulosic biofuel etc. A new cultivar 'Jangdae' was developed by mutation breeding using irradiated with 300 Gy gamma-rays. Jangdae has a few distinguishable characteristics such as early flowering, high seed yield and palmate leaf, compared to wild type (Jinju). The fresh matter (FM) and dry matter (DM) yield of Jangdae are similar to those of Jinju, their seed yield (833.3 kg/ha) is approximately 4 times higher than that of Jinju. In addition, the FM and DM yield of Jangdae are 40% higher than those of early-maturing cultivar (C11). We performed the nutritive value of four kenaf cultivars (Jangdae, Jinju, C11 and Hongma300) at 100 day after seeding. The crude protein content of Jangdae, Jinju, C11 and Honma300 were 10.5, 11.0, 9.4 and 10.6%, respectively. The crude fiber, neutral detergent fiber and acid detergent fiber contents were no significant difference among the cultivars. Jangdae, which afforded both a high biomass and seed yield in South Korea, may be useful as potential source of feed and industrial materials.

This study was carried out to determine the amount of lignin, cellulose, and hemicellulose in six kenaf cultivars during different harvesting stages. Three mutant cultivars (Jangdae, Jeokbong and Baekma), two original cultivars (Jinju, C14), and one Chinese cultivar (Auxu) were planted on May 14, 2013. Four harvesting times were made at intervals of 20 days from 15 July to 16 September, 2013. The overall growth characters of mutant cultivar ‘Jeokbong’ such as plant height, stem diameter, flowering time, and dry mass were similar with those of the original variety. The mutant cultivar ‘Baekma’ occurred 10-day late flowering in comparison with the original variety and also displayed higher dry mass than the original variety. Jinju, Auxu and Jangdae, mid-late maturing kenaf cultivars, had high dry weight compared to early maturing cultivars such as Jeokbong, Baekma and C14. In all cultivars, the lignin contents were increased by a late harvest. The Mid-late maturing kenaf cultivars showed high lignin content in comparison with those of the early maturity cultivars. There were no significant differences of cellulose, and hemicellulose content between the cultivars, however cellulose content in stems of these kenaf cultivars were significantly decreased by a late harvest. These results may provide valuable information to assist the parental selection of kenaf breeding.

Kenaf (Hibiscus cannabinus L.) native to Africa can be used as fiber, food, feedstock and bio plastic. This study was carried out to evaluate the mineral, amino acid and vitamin contents of six selected kenaf cultivars which are enable to produce seed under Korean circumstance. The leaves of three mutant cultivars (Jangdae, Jeokbong and Baekma), two original cultivars (Jinju, C14) and one Chinese cultivar (Auxu) were harvested at flowering time. Mineral components of kenaf leaves, such as calcium, potassium, and mineral, did not showed significant differences among the cultivars. As major amino acids including proline and phenylalanine, significant differences were found in these kenaf cultivars. The Auxu cultivar contained the highest amount of essential amino acid (Phenylalanine, Leucine, Isoleucine, Valine, Methionine and Lysine). The amount of vitamin displayed significant differences such as vitamin E and vitamin K among these cultivars. Especially, Jangdae cultivar contained the highest amount of vitamin E and vitamin K. Thus, these data suggested that Jangdae and Auxu is the most desirable cultivar containing high amount of vitamin and amino acid.

우수한 사료자원으로 평가되는 케나프의 생산단가를 낮 추기 위하여 새만금 간척지 시험포에서 염농도 단계별 생육 및 수량을 관찰한 결과 케나프는 중·상정도의 내염성을 보 유한 작물로 평가할 수 있으며 충분한 제염이 이루어진다고 하면 간척지에서의 재배 가능성도 충분할 것으로 평가할 수 있었다. 염농도별 케나프의 발아력을 조사한 결과 토양 염 농도가 4.0 dS/m (=0.26%) 일 때 84%이던 케나프 발아율 이 5.0 dS/m (=0.32%) 에서는 18%로 급격히 떨어졌으며 6.0 dS/m (=0.39%) 에서는 발아율이 10%를 넘지 못하였다. 또한 생육 상황도 토양 염농도에 비례하여 급격히 떨어졌는 데 케나프는 줄기직경을 2.6 cm 이상으로 유지할 수 있을 경우 엽수가 유의할 수준으로 늘어나고 줄기부분에 대한 상 대적 무게비율이 증가하는 결과를 얻을 수 있었다. 이는 잎 의 분열을 촉진시킬 수 있는 충분한 생장량 확보가 줄기직 경 2.6 cm 이상에서부터 가능하다는 것을 의미하는데 새만 금에서는 토양 염농도 4.0 dS/m (=0.26%) 이하에서는 케나 프의 줄기직경을 2.6 cm 이상으로 유지하는 것이 가능하였 으나 염농도가 5.0 dS/m (=0.32%)를 넘어서게 되면 줄기직 경이 2.0 cm 이하로 엽수도 20~46% 감소하였다. 생육장해는 파종 후 1개월 경과부터 본격적으로 나타나기 시작하였 는데 엽 정단이 고사하고 주변 잎 들이 급격하게 황화 낙엽 되는 현상이 발생하였다. 케나프의 토양 염농도에 대한 수 량성을 분석한 결과 토양 염농도 4.0 dS/m (=0.26%) 까지 는 비간척지에 비해 수량이 최대 19% 하락하였으나 염농도간 차이는 크지 않았다. 그러나 토양 염농도가 4.0 dS/m (=0.26%) 를 넘어서는 5.0 dS/m (=0.32%) 에서는 비간척지의 51% 수준을 유지하는데 그쳤으며 토양 염농도 4.0 dS/m (=0.26%) 일 때의 수량에 비해서도 38% 감소하였다. 통계분석을 통 하여 간척지에서 수량성 감소를 80% 이내로 유지 할 수 있 는 토양 염농도를 산출해본 결과 토양 염농도가 4.2 dS/m 이내로 유지될 경우 케나프의 생산성은 80% 이상을 유지할 수 있었다.

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. But the domestic cultivation techniques are not set standards yet. So we tested the basic culture techniques during 2012~2013 for getting a high yield and good grade forage production system. The best seeding method for mechanized planting (corn planter used) was hill seeding with 20×20 cm seeding distance. When we treated hill seeding with 20×20 cm, the yield what we could get was 13,641 kg/10a and it was 32% more than that of conventional practice hill seeding with 20×30 cm seeding distance. The proper seeding date for getting high yield was May 1. In May 1, the yield per 10a was reached 13,423 kg, and it was 30% more than that of seeding at May 30. More over the crude protein content which was important factor for determinating forage nutritive value was 12.7% and it was higher 1.8% (relatively 16.5% high) than that of May 30 seeding. The most effective herbicide for kenaf was Fluazipof-p-butyl. It’s herbicidal rate was 97% and phyto-toxicity was less than 5%. Regional adaptability for Jeollabuk-Do including Imsil Gun, Kochang Gun and Sunchang Gun were identified that the stable cultivation were possible in these area with average yield 12,400 kg/10a and it was about 1.7 times as compared to corn harvest.

This study was carried out to determine the effects of different harvesting stage on nutritive value and the quality of ensiled kenaf after fermentation among six kenaf cultivars. Six kenaf cultivars including two different maturity groups, mid-late maturing (Auxu, Jangdae and Jinju) and early-maturing (Baekma, Jeokbong and C14), were planted on May 14, 2013. Four harvesting times were made at intervals of 20 days from 15 July to 16 September, 2013. In all cultivars, the CP (crude protein) contents were decreased by a delayed harvest; the CP contents of kenaf silage were ranged from 92 to 184 g kg-1. Interestingly, there were no significant difference of NDF (neutral detergent fiber) and ADF (acid detergent fiber) content between the cultivars, however NDF and ADF content of kenaf silage were significantly increased by a late harvest. The silages of all cultivars displayed a low pH ranges less than 4.0, which is sufficient for stable storage. The lactic acid contents in Auxu were from 2.57 to 3.21%, which is higher than other cultivars. The harvesting stages did not affect to the concentrations of butyric acid and acetic acid in all cultivars. These results indicate that the harvesting stage is more important for the quality of kenaf silage than cultivar differences. And kenaf silage could be also used as fodder for ruminants.