• Journal of Life Science
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• v.32 no.8
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• pp.633-640
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• 2022

Recently, kenaf (Hibiscus cannabinus L.) has been highlighted due to its rapid growth in dry, infertile land and its versatile applications in textiles, paper, feed, food, medicine, and phyto-remediation. In Korea, a new cultivar, 'Jangdae', which has the merit of feasible seed-gathering, was established in 2013. However, most of the kenaf seeds used are still imported, and a comparison study of useful bio-activities between Jangdae and imported seeds has not been conducted. In this study, anti-thrombosis, antioxidant and anti-diabetic activities of the ethanol extracts of the Jangdae seed (E-JS) and 8 imported cultivar seeds (E-ICS) were investigated. The E-JS has 14.4 mg/g of total polyphenol and 5.3 mg/g of total flavonoids, whereas the E-ICS has 5.9~8.7 mg/g and 0.7~1.5 mg/g, respectively. Among the 9 kenaf seed extracts, IT 181215 and IT 207877 seed extracts showed 1.92 and 1.88-folds extended thrombin time (TT), and IT 207886 seed extracts showed 3.04-folds extended activated partial thromboplastin time (aPTT). All extracts, except Hong-ma seed, showed 1.36~1.56-folds extended prothrombin time (PT). The E-JS showed strong anti-thrombosis activities with 1.46-folds (TT), 1.38-folds (PT) and 2.37-folds (aPTT) compared to those of solvent controls. The E-JS has the strongest antioxidant activities among the seed extracts, with 0.48 mg/ml of RC₅₀ for ABTS cation and 0.27 mg/ml of RC₅₀ for nitrite scavenging. Meanwhile, the E-JS and IT 181215 extracts showed strong inhibition against α-glucosidase with 10.3~10.6% inhibition at 0.5 mg/ml. Our results suggest the E-JS has potential as an anti-thrombosis, antioxidant and anti-diabetic agent.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.511-520
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• 2014

Kenaf (Hibiscus cannabinus L.) was recognized as a potential source of forage. To reduce the production cost, we should insure large cultivation area. The one of the best candidate places to expand the useful kenaf production was 'Saemangeum' reclaimed land. To confirm the possibility of kenaf growth in reclaimed land, we seeding and cultivated the kenaf in 'Saemangeum'. The germination percentage of kenaf on 5.0 dS/m soil salinity was 18%. It is less 66% than that of 4.0 dS/m soil salinity and at 6.0 dS/m, the germination percentage of kenaf was under 10%. The growth and development of kenaf in reclaimed land grew worse with increasing soil salinity. The stem diameter which the most important factor that decide the value and yield of product was upper 2.6 cm when soil salinity maintained under 4.0 dS/m, but if soil salinity marked over 4.0 dS/m, the stem diameter of kenaf was drop under 2.0 cm and it deteriorate the number of leaves per plant by 20~46%. The necrosis on older tip and marginal leaves were noted approximately first month after seeding which was correlated directly with the salinity levels of reclaimed soil. Reduction of total yield was coincide with increasing levels of EC. If soil salinity over 5.0 dS/m, the amount of decreased by soil salinity was 51% than that of non-reclaimed region. The allowable soil salinity level of which could be maintained within 20% reduction rate was 4.2 dS/m. Consequently kenaf can be grown successfully with moderately saline soil condition. However, salt levels in excess of 4.2 dS/m severely have restricted plant growth and development and will result in significant yield reduction.

• Journal of the Korean Wood Science and Technology
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• v.35 no.6
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• pp.43-49
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• 2007

Anatomical properties of Kenaf (Hibiscus cannabinus L.) planted in a reclaimed-land of Korea were examined to understand the growth characteristics by an optical and scanning electron microscopy. The samples of kenaf were taken from four positions of the stem (3, 35, 70, 105 cm above from the ground) in four growth periods (July. August, September, October) from seeding planted in the middle of May. Bast fiber, phloem rays, cortex parenchyma cells and sieve tube members were observed in phloem, and vessel elements, fibers and rays in xylem. Solitary and multiple radial pores existed in xylem. The cell types of ray parenchyma in radial section were procumbent, upright, and square. The intervascular pitting showed an alternate type. Xylem proportion, the number of bast fibers and dimension of phloem rays increased with increasing growth period, and decreased with increasing stem height. The proportion of multiseriate rays was higher than that of uniseriate and biseriate rays in xylem with increasing growth period. On the other hand, The proportion of multiseriate rays was lower than that of uniseriate and biseriate rays in xylem with increasing stem height.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.35 no.4
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• pp.68-74
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• 2003

Kenaf(Hibiscus cannabinus L.) cultivar, Tainung 2, had been grown for 152 days at the experimental farm of Jinju National University, Gajoa-dong, Jinju-si, Kyongnam, Korea. The planting, growth rate, fertilization and structural characteristics as well as the cultivation and growth characteristics of kenaf, and the product usage were investigated. The narrowest diameter at kenaf bottom was 10 mm, the widest 42 mm and the average about 28 mm, and the shortest height 150 cm, the tallest 480 cm and the average about 350 cm. The weight of a core fraction was 68.1％ and a bast fraction 31.9％. The weight ratio of core material to bast fiber was 2.31. The weight ratio of dry stem was 73.5％ and that of leaves 26.5％. The weight of dry plant produced in 1 $m^2$ was 1,467 g, and about 1,052 g of stem could be used for the commercial purpose, The application of fertilizers resulted in the increase of the growth rate of the diameter at plant bottom and the height. Bast fiber, phloem ray and cortex parenchyma cell were observed in bast, and vessel, wood fiber and ray in core.

• Journal of the Korean Wood Science and Technology
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• v.36 no.4
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• pp.11-18
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• 2008

Anatomical characteristics of volumetric composition, fiber length, vessel diameter, and crystalline properties of cellulose in kenaf (Hibiscus cannabinus L.) planted in the reclaimed land of Buan-si, Korea were examined to understand the growth characteristics using a light microscopy and an X-ray diffraction method. The samples of kenaf were taken from six positions (3 cm, 35 cm, 70 cm, 105 cm, 280 cm, and 320 cm) of each stem over the growth period (July, August, September, and October) after seeding in the mid-May. In the kenaf stem, phloem constituted 10 to 15 %, xylem 66 to 82%, and pith 7 to 19%. The ray, bast fiber, and remainder comprised 50%, 20%, and 30% of the phloem, respectively. The volume of vessel, ray, and fiber in the xylem was approximately 10, 15, and 75%, respectively. The proportion of cell wall was 30.92% at the base of stem and 46.40% at the top of stem, respectively. The average length of bast fiber and xylem fiber was about 2.8 mm and 0.9 mm, respectively. Radial and tangential diameters of vessel increased with the increase of growth period, while they decreased with increasing the stem height. Relative crystallinity ranged from 70 to 79% in phloem and from 50 to 56% in xylem. Cellulose crystallite width was about 3 nm both in the phloem and xylem. Thus, the volumetric composition and cell dimensions in the phloem and xylem appeared to be varied with the growth period and the stem height.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.1
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• pp.64-71
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• 2018

To improve the soil of reclaimed land, we added organic materials at a level of 3,000 kg/10 a. As a result, the electrical conductivity (EC) value of reclaimed soil decreased by 58%, the organic material content increased from 6.7 to 16.0 g/kg, the porosity increased from 1.57 to 1.31%, the soil hardness decreased from 20.2 to 17.9 mm and the plow layer was deepened from 19.8 to 26.8 cm. After these physiochemical improvements to the reclaimed soil, the growth phase of crops was improved compared to that of non-treatment crops. The height of kenaf (Hibiscus cannabinus L.) cultivated in the reclaimed land containing organic materials was increased by 18.8%. Especially, the improvement effects of pellet type manure compost and rice straw on kenaf were more preferable than those of other organic materials. When the kenaf was cultivated in the reclaimed land containing organic materials, the yield increased. The average yield of the treatment crops was 9,218 kg/10 a, 2.1 times higher than that of non-treatment crops. The most effective treatments to increase the yields were pellet type manure compost (10,848 kg/10 a, 148% increase), rice straw (120% increase) and chopped kenaf (95% increase). To increase the physicochemical enhancements to the reclaimed land soil and most improve yields, the most effective type of organic materials was the pellet. The organic material types that maintained a better growth phase and most increased the yield were the liquid and pellet types. When we used pellet type organic material, the plant height of kenaf was increased by 41% in comparison with that of the non-treatment crops and yield was increased by more than 122%. Additionally liquid type organic material improved the yield (by 127%).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.1
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• pp.87-96
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• 2021

Information and Communication Technology (ICT) remote soil moisture control system including soil sensing, automatic water supply chain, and remote alarming system was established on reclaimed land and operated stably. The system was operated using river water around the reclaimed land without fertilizer. On applying this system to control soil moisture, the kenaf germination rate was improved up to two times. Kenaf biomass was 4,748 kg/10a and was higher than that of untreated soil moisture management. When the nutritious liquid fertilizer was used, kenaf yield reached 8,390 kg/10a, which was lower than 10,848 kg/10a of the non-reclaimed land treated with standard chemical fertilizers. As the soil moisture was managed stably through the ICT remote soil moisture control system, the quality of the kenaf crop was improved, resulting in a 7% increase in dry weight, and a 11.5% increase in plant hardness. The estimated kenaf yield was 5,039 kg/10a when 800 tonnes of water were supplied by the ICT remote soil moisture control system with the stream water around Saemangeum reclaimed land without chemical fertilizers and organic matter.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.10
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• pp.1598-1603
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• 2018

Objective: The goal of this study was to evaluate kenaf as a roughage source in vitro and its effects on meat quality of Hanwoo (Korean native) cattle. Methods: Three roughage materials, rice straw silage, ryegrass silage, and kenaf silage, were tested in a batch culture and feeding trial. Rumen fermentation parameters, including gas, pH, volatile fatty acid (VFA), and ammonia were analyzed. In the feeding trial, Hanwoo steers ($373.5{\pm}5.1kg$, n = 36, 11 month of age) were divided into three feeding groups (n = 12 each). Animals were fed with each silage and concentrate until the fattening stage. Results: Crude protein, ether extract, and non-structural carbohydrates were greater in kenaf silage. Total gas production was higher in ryegrass silage, followed by kenaf silage and rice straw silage (p<0.05). Total VFA and individual VFA (acetate, propionate, and n-butyrate) were greater in kenaf silage than rice straw silage (p<0.05). In vitro dry matter digestibility showed a similar trend to that of total gas and VFA production; it was higher in ryegrass silage and lower in rice straw (p<0.05). Throughout the feeding trial, the rice straw silage group showed significantly greater average daily gain than did the others (p<0.05). The feed conversion ratio in the group fed kenaf silage was significantly greater than that of others (p<0.05). No significant differences were observed in yield or quality traits, including carcass weight, ribeye area, backfat thickness, and scores for marbling, meat color, and fat color (p>0.05). Conclusion: The results indicated that no negative effects on growth performance and carcass characteristics occurred across treatments. Therefore, kenaf could be substituted for rice straw, which is most widely used as a roughage source in Korea.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.1
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• pp.15-22
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• 2002

This study was conducted from April 13 to October 8, 2001 in Jeju to determine the influence of cutting height (2, 4, 6, 8 and 10 cm from the soil surface) on growth, forage yield and chemical composition of kenaf (Hibiscus cannabinus L.). As cutting height was increased from 2 to 10 cm, plant height averaged across two cuttings increased from 157.7 to 184.7 cm. This pattern held fir the number of leaves and branches per plant, stem diameter and plant weight per plant. As cutting height increased from 2 to 10 cm, fresh forage, dry matter, crude protein and TDN yields increased from 85.5 to 113.7MT/ha, from 11.97 to 15.63 MT/ha, from 1.63 to 2.72, and from 4.95 to 7.54 MT/ha, respectively. As cutting height was increased from 2 cm to 10 cm, crude protein, ether extract, nitrogen free extract, and TDN contents increased from 14.2 to 17.6%, 2.9 to 3.9%, 24.2 to 25.8% and 43.1 to 48.5%, respectively, while crude fiber and crude ash contents decreased from 35.5 to 30.4 % and 9.9 to 8.1 %, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.6
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• pp.439-442
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• 2001

This study has been conducted from April 25, 1999 to June 25, 1999 in Jeju Province in order to determine the influence of seeding date on growth, yield and chemical composition of Kenaf (Hibiscus cannabinus L.) Delaying the seeding date from April 25 to June 25 decreased the plant height of Kenaf from 278.5 cm to 205.7 cm. As for the number of leaves, number of withering leaves, number of branches, and stem diameter decreased as the seeding date was delayed. As the seeding date was delayed, fresh forage yield decreased from 98.5MT/㏊ to 45.9MT/㏊, dry matter yield from 20.7MT/㏊ to 8.2MT/㏊, crude protein (CP) yield from 2.9MT/ha to 1.3MT/ha and total digestible nutrients (TDN) yield form 1l.6MT/㏊ to 5MT/㏊. However, both leaf yield and stem yield were nearly the same tendency. Delaying the seeding date from April 25 to June 25 increased crude protein contents of leaves from 21.5％ to 24.4％, crude fat contents from 5.2％ to 6.1％, nitrogen free extract (NFE) contents form 39.9％ to 41.2％ and TDN contents from 64.3％ to 69.7％. However, delaying seeding date decreased crude fiber contents from 20.8％ to 17.5％, and crude ash contents from 7.9％ to 7.0％. Based on the these findings, optimum seeding date for forage production of Kenaf seems to be about 25 April in atmospheric phenomena and volcanic ash soils of Jeju island.