• Journal of Korean Society of Forest Science
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• v.86 no.4
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• pp.443-449
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• 1997

We examined the effect of pretreatments on seed germination, seedling growth, optimal seedling density of Phellodendron amurense. The seeds were carefully purified after collection in late Oct. from natural population at Mt. Chiri. For the evaluation of pretreatment effects, seeds were sowed in an experimental nursery after being stored in open ground($2{\sim}8^{\circ}C$) with soaking in 20% $H_2O_2$, 50-fold pon-pon solution, cold moist stratification in refrigerator($2{\sim}4^{\circ}C$) and dry storage in roam temperature($4{\sim}18^{\circ}C$), respectively, For the effect of growth density of seedlings, seedlings germinated in nursery were precisely controlled with 53, 104, 220, 380 seedlings per $m^2$. Among pretreatments for the promotion of germination rate, pon-pon treatment(68.8%) was highest, the others were higher than that in dry storage(2.3%), and these seed pretreatment methods were significantly different at 1% level. The height growth of seedlings showed the most vigor from Jun.12 to Jul. 8, and from Jul.20 to Aug. 2, and it reached to 72.8% of height growth. In case of 1-0 seedling, although seedling density per $m^2$ was increased, seedling growth was decreased. The optimal seedling density was 104 seedlings per $m^2$. The standard seedlings for plantation were above height 55cm, root collar diameter 8.1mm, and root length 21cm. These results demonstrated that seed of P. amurense requires stratification for the germination promotion.

• Journal of Bio-Environment Control
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• v.29 no.2
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• pp.130-140
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• 2020

This study was conducted in order to closely examine about optimum shading for superior seedling production a container seedling of Tetradium daniellii, which is being increased the demand for a seedling due to being used for alternative energy, ecological restoration and honey plant. The experiment of investigating the optimum shading on T. daniellii was carried out by using plastic container types (350 ml/cavity) for the forestry facility cultivation. The shading level was treated with full sunlight and with 35%, 55%, 75% of the full sunlight. As a result of having surveyed height and root collar diameter growth of a containerized seedling in T. daniellii, a case of the shading experiment showed a noticeably high value was indicated in the full sunlight. It was surveyed that the stronger shading level leads to the lower growth value. Root development was most active in full sunlight. Dry matter production, it was investigated to be the highest in full sunlight. It was surveyed to be the similar tendency to the outcome of height and root collar diameter growth. QI, which is index of showing the quality of a seedling, stood at 0.98 in full sunlight, thereby having been investigated to be the highest. As for the chlorophyll content in a seedling, the highest chlorophyll content was indicated in the 75% shading treatment with the relatively highest shading level. The photosynthetic rate and the water use efficiency were surveyed to be the highest in full sunlight with 8.48 μmolCO₂·m^-2s^-1, 1.40 μmolCO₂·mmolm^-1H₂O, respectively. As a result of surveying the whole experiment, optimum shading level for superior seedling production a container seedling of T. daniellii is determined in full sunlight (0%). It is expected that this will be used as a basic data for mass production.

• The Korean Journal of Ecology
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• v.24 no.6
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• pp.353-357
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• 2001

Differential response of genotypes to temporal environmental heterogeneity may contribute to the long-term persistence of these genotypes within a population. In this experiment, we experimentally tested whether groups by season interactions for germination and seedling growth can explain genetic variability within the population. To determine whether seeds collected during the four seasons respond differentially to temperature treatments, two-way ANOVA was performed. This study indicates that seasonal environments have large effects on demography. Groups within populations respond differentially to seasonal environments by influencing population growth that may in turn influence community composition. Most importantly, the study showed that temporal heterogeneity in the environment might functions as a mechanism that maintains within-population genetic diversity.

• Journal of Ginseng Research
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• v.20 no.1
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• pp.96-100
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• 1996

In this experiment, germination test of ginseng seed and growth test of two year old ginseng in soil incorporated with quinclorac (3,7-Dichloro-8-quinoline carboxylic acid) were conducted to evaluate phytotoxicity caused by quinclorac residue in soil. Ginseng seed germiilation was hardly affected, but growth of ginseng seedling was retarded by quinclorac. The phytotoxicity of quinclorac on ginseng seedling was expressed at the lowest level tested, 3.75 g a.i./10a (118 of recommended rate for rice cultivation). The representative phytotoxicity in ginseng were decreased root weight, shortened leaf width and leaf length, and weak lateral root Quinclorac residue decreased by 1/4 in pot soil after 2 months and below 2 ppm in the paddy soil applied at usual rate (30 g a.i./10a) after 1∼ 2 years. Below 2 ppd ginseng did not show any phytotoxicity symptom.

• The Korean Journal of Ecology
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• v.25 no.6
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• pp.395-398
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• 2002

Present paper showed allelopahtic effects of Tagetes minuta aqueous extracts on seed germination and root hair development. Allelopathy of aqueous extracts derived from T. minuta examined using two test plant species (Lotus comiculatus var. japonicus and Lactuca sativa). The seeds of test species were inoculated in petri dishes containing 0, 10,50 and 100% aqueous extracts from T. minuta. At day 5, the relative seed germination ratio to control was evaluated, and the development of seedling root hairs was observed through light microscopy. Seed germination of L. comiculatus var. japonicus was significantly inhibited proportional to the concentrations of aqueous extract, but that of L. sativa wasn't inhibited. The inhibitory allelopathic effect of T. minuta was found in the development and growth of seedling root hairs. It was concluded that the inhibitory allelophatic effects have been to be investigated using various bioassay, for the allelopathy of plant species shows species-specific and organ-specific.

• The Korean Journal of Ecology
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• v.21 no.6
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• pp.805-808
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• 1998

The methanolic crude leaf extract of Acacia melanoxylon shows inhibitory effects on seed germination, shoot growth, root growth and biomass of black gram (Phaseolus mungo L. Co 1) and weeds (Cassia occidentalis L. and Cyperus rotundus L.). The post emergence treatment was given on the 8th day after sowing and 4-6 days after seedling emergence. After postemergence treatment with 20% extract concentration, wilting symptoms appeared in P. mungo and C. occidentalis while necrosis occurred in C. rotundus. The seedling growth was inhibitory at all concentrations (5%, 10%, 20%) as compared to control plants. This inhibitory effect may be due to the presence of allelochemicals like phenolics in the A. melanoxylon leaves. Different types of phenolic acids were identified.

• The Korean Journal of Ecology
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• v.15 no.3
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• pp.297-309
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• 1992

The growth of digitaria adscendens and eleusine indica, annual weeds common in japan, was experimentally analyzed under varying untrient conditions. compared with e. indica, d. adscendensshowed a higher the two under high nitrogen availability. Higher net assimilation rate(nar) in d. adscendens than e. india was responsible for high RGR in D. adscendens under the low nitrogen availability. The different of NAR in the two species was induced not by leaf nitrogen content but by nitrogen use efficiency. Under unfertilized conditions nitrogen uptake rate(nur) was greater in d. adscendens than e. indica. Specific absorption rate in two species was similar, but root mass was greater in d. adscendens than e. indica.d. adscendens allocated more dry matter to roots than e. india earlier stage of seedlings. The contributed to higher rot mass and in turn resulted in higher nur in d. adscendens than that in e. india. It is concluuded that the larger allocation of dry matter to roots at early seedling stage in d. adscendens plays an important role in obtaining nitrogen for the continuation of growth under low nitrogen availability.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.418-421
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• 2002

This study was carried out to clarify the effect of sowing method in four planting densities on growth and root yield of Cynanchum wilfordii. vine diameter, number of branches, number of branched roots, and root length, were greater in seedling transplanting than in direct sowing. In planting densities, main vine length, number of branches, and number of tillers were increased at higher planting density, but vine diameter, leaf length, leaf width, root length, and root diameter were increased at lower planting density. fresh root yield was greater in seedling transplanting than in direct sowing. In seedling transplanting, it was 53% higher in 27 plants per unit area than 1,680 kg/10a in 17 plants per unit area. Therefore, seedling transplanting in 27 plants per unit area showed most effective for increasing root yield of Cynanchum wilfordii.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.3
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• pp.194-198
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• 1998

An experiment was carried out to find out the priming effects of rice seeds, Oryza sativa L. (cv. Ilpumbyeo) on. the seedling establishment and early emergence under excess soil moisture conditions. Seeds were primed by soaking in -0.6 MPa polyethylene glycol (PEG) solution at $25^{\circ}C$ for 4 days. The primed seeds were sown in soils with various soil moistures (60, 80, 100, 120, and 140% field capacity) at 17 and $25^{\circ}C$, respectively. Germination and emergence rates, plumule height, and radicle length of primed seeds were higher than those of untreated seeds at any soil moisture and temperature examined. The time from planting to 50% germination ($T_{50}$) of primed seeds was less than that of untreated seeds by 0.9～3.7 days. Germination rate, emergence rate, plumule height, and radicle length were highest at the soil moisture of 80% field capacity among the soil moistures. Priming effects of rice seeds on germination and emergence rates were more prominent under the unfavorable soil moistures (60, 100, 120, and 140% field capacity) than those under the optimum soil moisture condition (80% field capacity). However, priming effects on seedling growth were greater at near optimum soil moisture compared with too lower or higher soil moistures. Therefore, these findings suggest that priming of rice seeds may be a useful way for better seedling establishment under the adverse soil conditions.

• The Korean Journal of Malacology
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• v.29 no.3
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• pp.197-205
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• 2013

Even though seedling production of Haliotis discus hannai has fully developed, the culture of benthic diatom as a live food for larvae is still a barrier to solve in commercial hatchery. The farmer depends on mixed microalgae which are non-selectively attached on the plate by flowing of natural seawater. The adequate diatom on the plate for the larvae in terms of quality and quantity is always significant bottleneck in the hatchery. In this study, two benthic diatom species, Caloneis schroederi and Rhaphoneis sp. were separately cultured in mass and inoculated to four tons' settlement tank of the larvae. And the larvae and the spats were cultured for nineteen and nine weeks, respectively. The result on seedling production of H. discus hannai with this method was compared to that of the farmer's traditional method as a control. With regard to variation of species composition of benthic diatom on the plate, C. schroederi and Rhaphoneis sp. were dominant for first three weeks after inoculation. But the diverse diatoms mainly, Navicula, Amphora, Cylindrotheca, Licmophora, Pleurosigma began to attache on the plate from the 4th week. The larvae attached 2.5 times more in C. schroederi tank than in the control tank. The final total biomass of the seeds in Rhaphoneis sp. tank was 3.2 times more than that of the control tank. The retared-spats in the seedling production also showed significantly higher growth and survival in the spat fed Rhaphoneis sp. or C. schroederi than those in the control group. We suggest that C. schroederi is proper for settlement of the larvae and Rhaphoneis sp. is appropriate for the growth of the larvae and spats in the commercial hatchery of H. discus hannai.