• Korean Journal of Organic Agriculture
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• v.8 no.1
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• pp.89-99
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• 1999

To do mass multiplication of plug seedlings in potatoes, apical stem cuttings originated from virus-free microtubers were cut to one-two internodes and transplanted into the plug-tray. After 10days, we applied Chitosan and Wood Extraction on rooting and tuber formation of plug seedlings. To improve field adaptability of plug seedlings, rooted cuttings with a height of 20cm after 20days of cutting were transplanted ito the fields, We applied 500~2000ppm Chitosan on growth characteristics and tuber formation of that. The above and underground growths, such as plant height and number of leaves were significantly more vigorous after treatment with 500~1,000ppm Chitosan and 2,000ppm Wood Extraction, the spray treatment was carried out five times at intervals of four days after ten days of transplanting. T-N, K, P, Mg and Na, were higher as the concentrations of chitosan and Wood Extraction were higher. The growth and tuber yield in plug seedlings planting plot and seed potatoes planting plot were effectively highter as foliar application of Chitosan(500~2,000ppm) was done after planting the plot. T-N content in leaves and tuber was higher as the concentration of Chitosan was high. A similar tendency was shown in K, P and Mg. In the small tuber(under 30g), the number of tubers and tuber yield were relatively increased in the seed potatoes planting plot, but the large tubers(over 80g) yield was higher in the plug seedlings planting plot, and in order to increase tuber yield in plug seedlings it was necessary to add plant density to the field.

• The Korean Journal of Ecology
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• v.17 no.4
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• pp.523-531
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• 1994

Optimal conditions for the seed germination and growth of Hedyotis diffusa were studied. As photoperiod was increased from 12 hr to 24hr, the germination rate of Hedyotis diffusa was gradually increased. The photoperiod and temperature inflenced on the fermination synergistically. After the growth of 20 weeks under the natural condition (June~Oct.), the length of H. diffusa was $38.9{\pm}4.2cm$ (15.5~52.5cm), and total dry weight per $3.3m^2$ was $316.7{\pm}10.3g$. It is considered that H. diffusa could be cultivated in a part of inland. The anticancer effect of H. diffusa extract was examined. F-344 rats aged 6 weeks were divided into 3 groups and were given an I.P. of diethylnitrosamine at 200mg/kg body weight as a promoter, initially. And in two weeks after the beginnign of the experiment, group 1 was supplied iwth feed containing 0.02% 2-AAG as a promoter for 6 weeks. Group 2 was supplied with feed containing extracts of H.diffusa (0.02%) for two weeks. Group3 was supplied with only basal diet. All rats were sacrificed for partial hepatectomu, and the antipromoting effect was examined by the number 문 area per $cm^2$ of foci in river. In group 1, the number of hyperplastic nodule was $18.5{\pm}7.7$, but in group2, it was drastically reduced to $10.3{\pm}1.8$ rather thn those of group1. The total area of nodules $(mm^2)$ /whole liver $(cm^2)$ of group 1 and group2 were $19.2{\pm}7.7$ and $5.0{\pm}3.2$, respectively. These results indicate that extract of H.diffusa act as an anticancer agent at statistically significant level (p<0.001).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.334-339
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• 1995

Removal of apical ear after silking is a method to increase seed production in corn inbreds. Due to the phenomenon of apical dominance, the subapical ear would develope and produce seeds following the removal of the apical ear. This experiment was conducted to investigate the varietal difference in subapical ear development and seed production. Days to silking of subapical ears were delayed by about 4 days compared to normal apical ears. Cob length and filled ear length of subapical ears across seven inbreds tested were reduced by 21% and 36%, respectively. Those of inbred INV302 decreased less and subapical ear of inbred NC246 were barren, which incicated the varietal defferences. Number of kernel rows, kernels per row, and total kernels per ear also decreased. The mean reduction rates for those characters were 28%, 37%, and 47%, respectively. Weights of ears and kernels were reduced and showed different response among inbred lines. Coefficients of variations for cob and filled ear lengths, number of kernel rows and kernels were greater in subapical ears than in apical ears. Seed production of subapical ears was 40 ~ 80% of apical ears, depending on inbred lines when the apical ear is removed immediately after silking.

• Korean Journal of Food Science and Technology
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• v.43 no.3
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• pp.396-400
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• 2011

We examined the in vitro mutagenic and antimutagenic effects of hexane-extracted hemp (Cannabis sativa L. subsp. sativa var. sativa) seed oil (HO) with and without S9-mediated metabolic activation, using the TA98 and TA100 Salmonella Typhimurium strains. The MTT assay revealed no cytotoxicity in HepG2 cells for HO quantities $\leq400g$/mL. In the mutagenicity test, revertant colonies did not exceed spontaneous colonies in number. Colony numbers did not increase in either strain after HO treatment, with or without metabolic activation. HO showed no mutagenic effects and did not induce a mutation in either strain. In the antimutagenicity test, HO reduced the number of mutated colonies induced by 4NQO in both strains. The inhibition rates of HO (TA98, 21-91%; TA100, 21-85%) indicated a potent reduction in mutagenicity induced by 4NQO. HO showed no significant mutagenicity and may have antimutagenic effects, as assessed by Ames testing.

• Korean Journal of Medicinal Crop Science
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• v.23 no.1
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• pp.8-12
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• 2015

Characteristic of seed for Sageretia thea fruits collected from the habitat of harvest season in Jeju and their germination ratio in different temperatures were considered. The average weight was 0.2 g, average diameter was 7.2 mm, average length was 6.5 mm, and size distribution range was 5.1 ~ 10.0 mm. The number of seeds per fruit was 1.8, and 1000 grain weight was 7.77 g with diameter of 3.7 mm and thickness of 1.7 mm in size. The fruit maturation was investigated to be from April 27 to June 1, when the best maturation period was about a week, May 11 to May 18. Also, the fruits grown on May 4 to May 11 were seen to have the bigger in transverse size and weight with a tendency of the earlier maturation date has the greater the number of seeds. S. thea seeds pretreated for 24 hours at $50^{\circ}C$ were not germinated, while most of those pretreated for 24 hours at $4^{\circ}C$ were successfully germinated at any degree of temperature (except at a temperature of $10^{\circ}C$). Particularly, the highest germination rate of 55% was made at $15^{\circ}C$, and plumule and radicle were best grown within the temperature range of $25^{\circ}C$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.431-435
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• 1987

Terminal bud removal has been thought as a useful practical management of soybean cultivation in Korea, and such cultivating method has been recommended till recent times. Many experiments about the effect of bud removal have been made, but it is not certain yet. This study was conducted to determine if source potential and seed yield would be affected by bud removal in 4 determinate soybean varieties. Terminal bud was removed by hand at the 5 trifoliolate stage of growth. Data were collected on leaf area and leaf dry matter weight from 58 to 101 DAP by nearly every 10 days and some agronomic characteristics and seed yield after maturity. Removing the apical bud did not increased leaf area and leaf dry matter. Number of modes and pods per a plant was increased by bud removal, but number of seeds per a pod was decreased, and seed yield was unchanged by such offsets. From the data, we concluded the source potential of soybean plants was not increased by terminal bud removal under the planting density, 22,000 pit/l0a, however it would be a useful way to reduce the lodging or over-growth.

• The Korean Journal of Ecology
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• v.17 no.2
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• pp.203-211
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• 1994

The establishment by seeds and the maintenance by ramets of the autumn olive (Elaeagnus umbellata) population were investigated in the Namhansansung Provincial Park, Jungbu-myun, Kwangju-gun, Kyunggi-do. Seed production and germination rate were 3, 300 $seeds{\cdot}m^{-2}{\cdot}yr^{-1}$ and 52%, respectively. The ramet formation in the population was classified into 4 types: stump type, creeping root type, lateral root type and secondary creeping root type. The subterranean creeping roots were 0.1~1.0 m in length, 4.5~14.0 mm in diameter and 0.06~0.2 m in soil depth. The number of ramets formed from a node was 1~21. The subterranean roots spread $5~509cm^2{\cdot}plant^{-1}{\cdot}yr^{-1}$, which began to be produced from 7~9 year-old individuals. The number of stems was 1~67 per stump, which was reduced by self-thinning from 2 to 14 year-old trees. The frequency distribution of stem diameter$(D_{30})$ showed a reverse J-shaped curve, suggesting that this population be maintained perpetually by their own ramets.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.10 no.5
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• pp.67-75
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• 2007

The purpose of this study was to pelletize to calendula and salvia seeds with peat moss as basic material for the efficient greening and vegetating of slopes and damaged areas. Also the pelletizing was compressed by spherical types that mixed basic fertilizer of N.;300 mg/l, P.;200 mg/l, K.;400 mg/g and plant growth regulator of A and NAA each 300PPM. Soil and soil surface seeding methods were researched to find the growing state of germination percent, germination date, germination force, length of leaf, number of leaf, width of leaf, length of plant, and etc. Comparing with controlled pelletizing, peat moss and +GA pelletizing treatments resulted in higher from two to three times as following growing states : length of leaves, number of leaves, width of leaves, length of plants, length of roots, fresh weights, and ratio of germination. Especially the two treatments above showed four more times effects than the +NNA treatment. Also their germinating date germinating force were earlier and stronger. The surface seeding method was superior to soil seeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.134-137
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• 1999

An experiment was carried out to determine the effects of priming and growth regulator treatment of seeds on the emergence and seedling growth of rice, Oryza sativa L. (cv. 'Ilpumbyeo'). Normal seeds were primed in a -0.6 MPa polyethylene glycol solution at 15$^{\circ}C$ for four days with air-bubbling. Then both primed and non-primed seeds were soaked in water, 100 ppm GA$_3$, 2 ppm ABA, and 10 ppm kinetin solutions for 24 hours. The seeds were planted in soil at 3 and 5 cm depths and allowed to germinate in a growth cabinet at 2$0^{\circ}C$. Generally, the emergence rate at the 3 cm seeding depth was higher and emerged faster compared with the 5 cm seeding depth. The emergence rate of primed seeds was higher and emerged faster compared to non-primed seeds. GA$_3$ and kinetin treatments were the most effective to improve the emergence rate of non-primed seeds. Coleoptile length at the 5 cm seeding depth was longer than that at the 3 cm seeding depth. Leaf number, plant height, and root length of primed seedlings were higher compared with non-primed seeds. GA$_3$ promoted the elongation of plant height and mesocotyle length.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.305-309
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• 1991

This experiment was conducted to investigate the effect of shattered grain by combine harvesting at the previous year on rice plant emergence at different planting methods and plant characteristics, The results are follows : Combine harvesting greatly influence on shattered grain of Samgangbyeo as Tongil variety (49.5kg/10a) compared to that of Nagdongbyeo as Japonica variety(27.8kg/10a), while Nagdong-byeo showed higher germination rate than Samgangbyeo, whether transplanted and direct seeded. Emergence of volunteer and seed mixture were lower in transplanted than in direct seeded. In variety test. Japonica variety showed higher emergence of volunteer rice and seed mixture than Tongil variety. Generally, no significant difference in yield components were observed with different varieties by the volunteer rice. But the volunteer rice caused by combine harvesting decreased culm length, panicle length, spikelet number, panicle number and ripening ratio. except l000-grain weights.