• Journal of Plant Biotechnology
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• v.6 no.3
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• pp.193-197
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• 2004

In vitro multiplication of Curculigo orchioides was achieved by direct somatic embryogenesis in young leaf segments. Immature leaf segments of about 0.5 cm in length were cultured on MS medium supplemented with different concentrations of BAP (2-10 $\mu{M}$) or Kin (2-10 $\mu{M}$). Optimum response in terms of per cent cultures responding (89%) and the number of embryos per explant (16) were observed on MS medium supplemented with 8 $\mu$M BAP. The emergence of several somatic embryos on the adaxial side of the leaf segments was observed one month after the culture. Germinated somatic embryos were grown up to about 1.5 cm length before transferring to maturation medium. For maturation, the individual embryos were isolated and transferred to MS medium supplemented with BAP (5 $\mu{M}$) and NAA (0.5 $\mu{M}$). The plantlets emerged from the embryos were transferred to soil containing 1 peat: 1 sand with 90% success. The embryos were formed directly on the leaf segments without any callus phase. Direct regeneration of somatic embryos is important for the conservation of this endangered species, as rare somaclonal variants are likely to arise than from indirect regeneration.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.1
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• pp.49-53
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• 1998

Direct-seeding has major advantages such as labor and cost saving by eliminating preparation of seed bed and transplanting. But, it required increased input of fertilizers and pesticides because of the extended paddy period. Direct seeding in wet paddy (DSWP) gives faster growth and more uniform seedling emergence than direct-seeding in dry paddy. This research had an objective to develop an efficient N management practices for DSWP with split application of N fertilizer. A paddy field experiment was conducted to evaluate effects of starter N and N-topdressing which was delayed N application until 5-leaf stage, with comparison to transplanting (TP). Total amount of N application were two levels; 110kg and 77kg/ha. The N applications were split four times during rice growth stages; starter, topdressing at 5-leaf stage, top dressing at tillering stage, and topdressing at panicle initiation stage. DSWP had more tillers/$m^2$ than TP, but with the delayed heading. The DSWP plots which received N-topdressing at 5-leaf stage without starter N had higher leaf area index (LAI) and leaf greenness than the TP plot. Also, these DSWP plots had high leaf-N concentration at the heading stage, as calculated from leaf chlorophyll meter readings. Rice yield in DSWP with N-topdressing at 5-leaf stage was significantly higher than that in TP and in DSWP with starter N. Energy and N use efficiency were improved in DSWP with N-topdressing at 5-leaf stage. But, there were no significant differences in grain yield between the two levels of total amounts of N applications, 77kg and 110kg/ha. We concluded that starter N could not be used effectively by rice seedlings, but topdressing N at 5-leaf stage was an efficient N management for rice growth and yield in DSWP system.

• Journal of Ginseng Research
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• v.38 no.1
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• pp.73-77
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• 2014

Field and nutrient cultures of American ginseng (Panax quinquefolius L.) were used to establish foliar symptoms related to boron (B) concentration in leaves and soils, and to evaluate radish as a time-saving model system for B nutrition. Application of excess B, 8 kg/ha versus the recommended 1.5 kg/ha, to field plantings of 2-, 3-, and 4-yr-old American ginseng plants just prior to crop emergence caused, within 4 wk after crop emergence, leaf symptoms of chlorosis followed by necrosis starting at the tips and progressing along the margins. The B concentration in leaves of 2-4-yr-old plants receiving 1.5 kg/ha Bwas $30{\mu}g/g$ dry mass compared to $460{\mu}g/g$ dry mass where 8 kg/ha B was applied. Similarly, B concentration in soils receiving the lower B concentration was 1.8 mg/g dry mass and $2.2-2.8{\mu}g/g$ dry mass where the higher B concentration was applied. Application of 8 kg/ha B reduced the dry yield of 3rd-yr roots by 20% from 2745 kg/ha to 2196 kg/ha and 4th-yr roots by 26% from 4130 kg/ha to 3071 kg/ha. Ginseng seedlings and radish were grown under greenhouse conditions in nutrient culture with four B concentrations ranging from 0 mg/L to 10 mg/L. At 5 mg/L and 10 mg/L ginseng and radish developed typical leaf B toxicity symptoms similar to those described above for field-grown plants. Increasing B in the nutrient solution from 0.5 mg/L to 10 mg/L decreased, in a linear fashion, the root and leaf dry mass of ginseng, but not radish. Given the many similarities of ginseng and radish to B utilization, radish might be used as a timesaving model system for the study of B, and other micronutrients, in the slow-growing perennial ginseng.

• Korean journal of applied entomology
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• v.31 no.2
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• pp.174-181
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• 1992

Early, mid, and late maturing soybean varieties were artificially infested with larvae of Delia platura at seeding, and then later development and productivity of soybeans were studied. In addition, in hope to utilize as possible tactics in the management of D. platura in soybeans, cultural factors such as contents of organic matter in soil, soil types, and the use of plastic mulching on the degree of damage to soybean plants by D. platura were examined. Primary leaf damage by the larva delayed the forthcoming vegetative growth but not the blooming which is initiated by the change in day length. Degree of delay in growth was more severe where leaf damage was induced by insect infestation than where artificially excised, apparently owing to simultaneous damage in stems and roots besides primary leaves. Productivity of soybeans also dropped significantly in plants with 25 % or more loss in the primary leaf area by the larva. Both transparent and black plastic mulchings shortened the period from seeding to emergence of soybean thus reducing the chance of possible attack by the larva. Soybean seedlings grown in clay loam or clay were attacked less by the larva than those in other types of soil. High organic matter content in the soil enhanced speed of emergence resulting in less larval damage to the seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.1
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• pp.115-120
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• 1981

Effect of soil water on the growth of Panax ginseng(2 years old) was investigated through pot experiment. the results were as follows. 1. Optimum soil moisture content for root yield appeared to be 65.5% of field capacity(22.1% fresh weight basis) and at 31.5%(10.7% fresh weight basis) relative growth rate was nil. 2. Under suboptimum condition of soil moisture, emergence of shoot and leaf unfolding was delayed. The rate of emergence of shoot and leaf area was also decreased while missing shoot rate was increased. 3. Root yield was positively correlated with leaf area per plant(r=0.91 **), stem diameter (r=0.73**), stem length(r=0.71 **) fresh top yield(r=0.93**) and negatively with missing shoot rate(r=-0.77**). 4. Fresh root weight showed negative correlation(r=-0.80**) with water content of root indicating that tissue is more compact when grown at sufficient water.

• Korean Journal of Plant Resources
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• v.20 no.1
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• pp.43-49
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• 2007

This study was conducted to examine the pattern and characteristics of flowering and leaf emergence for twenty two kinds of the genus of Lycoris sp. One species of Lycoris was flowered on July to August, twelve species on August, and nine species on September. Shape of flowers were as follows : Nine species belong to L. radiara-shaped flower, seven species L. squamigera-shaped flower, and seven species the intermediate type. Flower color of three kind were an order of descent red and pink. seven kind white, four kind yellow, three kind orange, and two kind purple colors. Ten Lycoris species were good fertile, and two kinds were poor fertile. The average length of pollen grain was ranged from $48.53\;to\;88.62{\mu}m$, and the width from $22.87\;to\;33.67{\mu}m$. Eleven kinds were spring-leaf emergence type, and ten kind autumn-leaf emergence types. Hunter values in leaves were as follows : $L^*$ value was ranged from 31.6 to 45.2; $a^*$ values from -6.74 to -17.46; $b^*$ values from 6.19 to 21.89 Leaf width was ranged from 0.90 to 2.35cm, and its shape was oblong. The length of epidermal cells was 0.33 to 0.75mm, and the width was $38.53\;to\;90.00{\mu}m$. Most of stomata were distributed in the back side of leaves. The length of stomata was ranged from $67.12\;to\;104.89{\mu}m$, and its width was from $14.90\;to\;71.52{\mu}m$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.48 no.6
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• pp.460-464
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• 2003

White spunbonded fabrics has been utilized toy covering in rice seedling nursery. This study, therefore, was carried out to examine the effect of light quality on seedling emergence, growth, morphology, chlorophyll content and photosynthesis to get the information on the color of the fabrics. Blue, red and far-red lights were treated immediately after sowing seeds of three cultivars, Dongjinbyeo, Ilmibyeo and Daesanbyeo. Seedling emergence, growth and morphology, chlorophyll content and photosynthetic rate were measured. Seedling emergence rate of Dongjinbyeo and Daesanbyeo was low under far-red light treatment compared to those under blue and red light ones. Although the rate of Ilmibyeo was not different from three light treatments. Far-red light treatment showed similar response in plant height and leaf length, but yee light increased number of roots. Shoot and root dry weight was the highest in blue and red light treatments, respectively. Total dry weight, however, was the lowest under far-red light treatment. While chlorophyll content and photosynthetic rate of the three cultivars did not showed consistent response, those were the greatest under red light treatment, and were decreased in order of blue and far-red light treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.13 no.2
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• pp.132-138
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• 1993

Yield and plant constituent responses of forage sorghum cultivars have usually been compared in uniform defoliation management test. However the influence of harvest time on differential response of cultivars needs more precise definition. Therefore this study with sorghum-sorgo-sudan hybrid cv. NC+Sweet Leaf, and Super Su 22 and Sorghum-Sorghum hybrid cv. Pioneer 931 was carried out under two defoliation regimes, namely defoliation at heading stage of each variety and defoliation on the same calendar date in response to heading stage of early variety. The results are summarized as follows; 1. Three harvests were taken by early variety with 80 days and two harvests by late variety with 94 days from sowing to heading. 2. Dry matter and TDN yield tend to be higher when the plants are cut at ear emergence stage of late variety. 3. Crude protein content was similar for the same growth growth stage of 1st growth and 1st regrowth, and rather big different between varieties. 4. Considering only dry matter and TDN yield, it is recommendable to cut two times at ear emergence stage of late variety and also three times at ear emergence stage of early variety in view point of utilization period extension and distribution of forage products.

• Journal of Environmental Science International
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• v.33 no.5
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• pp.305-322
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• 2024

The aim of this study was to investigate the effects of artificial light sources on the germination and seedling vigor of lettuce, aiming to identify the optimal artificial light source for producing high-quality seedlings. Lettuce cultivar of 'Tomalin' and 'Seonpunggold' exhibited the highest seed emergence in the Metal halide(MH) lamp and High-pressure sodium(HPS) lamp treatment group, while the emergence rate parameter, T50, was the fastest in the HPS lamp treatment group. Both cultivars showed good growth characteristics such as number of leaves, root length, and stem diameter under RGB-LED, and their seedling vigor was excellent as well. The plant height was smallest in the Red + Green + Blue LED treatment, but the leaves were round and thick, resulting in higher biomass and dry weight. Single light sources of Red LED and Blue LED led to reduced growth compared with that under the mixed light treatments. Chlorophyll content in lettuce varied with the type of artificial light, with both cultivars exhibiting the highest chlorophyll content in the Red + Green + Blue LED treatment. The most suitable artificial light for lettuce seedling growth was the Red + Green + Blue LED treatment.

• Journal of The Korean Society of Grassland and Forage Science
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• v.7 no.3
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• pp.146-152
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• 1987

Sorghum cv. Pioneer 93 1, sorghum-sudangrass hybrid cv. Sioux and maize plant cv. Blizzard were assayed for toxic concentrations of nitrate-nitrogen ($NO_3$-N) and their relationship to morphological characteristics and environmental temperature in a field and phytotron trial. In the phytotron, sorghum and maize plants ranging from emergence to heading stage, were grown under different day/night temperatures of 30125, 25/20,28/18 and 1818 degree C. Nitrate-nitrogen in sorghum and maize plants was accumulated mainly in stems. Therefore nitrate concentration in the young plants was increased as development of stalks advanced and was highest at the stage of 3-4 leaves, when the plants had a leaf weight ratio 0.78-0.80 g/g plant weight. However, nitrate concentrations of the plant decreased as morphological development progressed, especially from the stage of growing point differentiation. Correlation coefficients showed a positive correlation of nitrate concentration with leaf weight ratio, leaf area ratio and specific leaf area, while plant height, dry matter percentage and absolute growth rate showed a negative association with TEX>$NO_3$-N ($P{\le}0.1$%). Cyanogenic glycosides, total nitrogen and crude protein were close associated with nitrate accumulation, and positively significant ($P{\le}0.1$%). High temperature over 30/25^{\circ}C.$ for 3 weeks increased N-uptake and dry matter accumulation, but reduced nitrate concentration. Under cold temperature below 18/8^{\circ}C.$ concentration of nitrate-N was increased in spite of its limited nitrogen uptake and plant growth.