• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.4
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• pp.310-317
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• 2006

This study was conducted to investigate the influence of drought stress during the pod developing and seed filling stage on source-sink relationships of soybean (Glycine max). Drought treatments were imposed by withholding water at the full-pod stage, 19 days after flowering, and then limited watering was relieved at 15 days after the initiation of drought treatment. Soybean seed yield was reduced by 39% mainly due to decreased pod number under drought stress, but the 100-seed weight was relatively less reduced. In spite of the 15-day drought during the full-pod stage, soybean produced good seeds showing similar l00-seed weight, protein, starch and soluble sugar content to those from the well-watered. Although drought during the full-pod stage caused source limitations; i.e. accelerated leaf senescence and reduced leaf soluble sugars, it did not cause limitations of other source characteristics such as SGR and leaf starch level. This is because the reduction in size of sinks, such as pod and seed abortions compensated for source limitations, resulting in balanced source-sink as expressed by LAR and the ratio of leaf area to seed dry weight. Drought stress during the pod developing and seed filling stage did not disrupt the source-sink balance

• The Journal of Fisheries Business Administration
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• v.29 no.2
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• pp.143-161
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• 1998

The objective of this study is to analyze the effects of increase in the oyster hatchery on fishermen's income. The results of the analysis are as follows : \circled1 The necessary quantities of oyster seed are 18,000 thousand hanging line. The 29.4%, of that has been applied by ana-seed collection and 29.1% of that has been applied by proseed collection. The demage of oyster aquaculture business is estimated about 35 billion won or 83 billion won. \circled2 The production cost per hanging line of the oyster hatchery is 1,974 won. And if it is sold by 2,500 won, return on investment will be 31.9%. Therefore profitability of the oyster hatchery is very good. \circled3 There are four important determinant variables of profitability to the oyster hatchery. In the order of their effects, it is operation number, seed price, production cost, and quantity of production. \circled4 If differences of price between the artificial hardening oyster seed and the natural hardening oyster seed are more less 1,430 won, the former is better. \circled5 The necessarily quantities of the oyster hatchery are estimated 160 units in the scale of 10,000 hanging line production to one operation. \circled6 The effect of increasing income of fishermen are estimated about 85.3 billion won or 124.5 billion won from increase in the oyster hatchery.

• Journal of agriculture & life science
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• v.44 no.3
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• pp.1-6
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• 2010

The influence of sodium hypochlorite and ethephon on the germination of narrow-leaved purple coneflower (Echinacea angustifolia) was investigated. Treatment of seeds with ethephon (1 mM) for 2 h followed by soaking in 0.525% sodium hypochlorite greatly increased germination (>90%). The treatment of seed with a combination of sodium hypochlorite and ethephon shortened number of days required to reach 50% of the final germination ($T_{50}$) from 4.2 days in control to 1.1 days. Seedlings grown from ethephon-treated seeds had shorter and thicker hypocotyls and roots with higher dry weights compared to the control. The same trend was observed during seedling emergence from soil. Ethephon treatment longer than 2 h resulted in weaker seedlings, probably due to leaf senescence. Anthocyanin content in seedling leaves increased linearly from 0.04 mg/g fresh weight in control to 3.72 mg/g fresh weight in 24 h treatment as the time of seed exposure to ethephon increased. Seed treatment with bleach and ethephon may well be practiced to facilitate the establishment of E. angustifolia in the field.

• Journal of Korean Society of Forest Science
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• v.95 no.3
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• pp.316-322
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• 2006

This study was conducted to examine the changes of seed characteristics and germination properties and to determine the most suitable collection time in Ulmus davidiana var. japonica. Seeds were collected six times with the interval of seven days after April 21, 2005 at Jeong-seon. There were differences in seed characteristics and germination properties among seed collection times. The sizes of seed and fruit increased with the collection time, but seed moisture contents decreased with the collection time after increasing until May 5. The 1,000 seeds weight decreased with the collection time after increasing until May 12. Collection time showed high positive correlations (r=0.790, p<0.01) with seed size and negative correlations (r=-0.919, p<0.01) with moisture contents. Percent germination (PG) presented the highest value in seeds collected at May 5, and decreased with the collection time. Mean germination time(MGT), germination speed(GS), and germination performance index(GPI) also showed the highest values in seeds collected at May 5. PG, MGT, and GS had correlations with other seed characteristics except the 1,000 seed weight. The relative growth rate of height and root collar diameter of seedlings presented the highest values in seedling germinated from seed collected at May 5, and seedlings germinated from seeds collected at May 5 and 12 showed the highest values in chlorophyll contents. Consequently it will be possible to product a number of seedlings when the seeds of U. davidiana var. japonica are collected just before drying morphologically.

• Journal of Korean Society of Forest Science
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• v.110 no.3
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• pp.295-307
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• 2021

This study proposed a field-applicable natural regeneration method using natural seeding to afforest a secondary growth forest after felling in Larix kaempferi plantations. In 2016, an experimental site was established usingseed-tree and clear-cutting methods in Gapyeong, Gyeonggi-do, South Korea. Characteristics of seed fructification and inflow in the natural regeneration site were analyzed along with an experimental site in Bonghwa, Gyeongsangbuk-do, which was established in 2014. As a result, the number of seeds per individual tree of V age class L. kaempferi was 690,340 seeds in a good year, with an estimated 13.8 million seeds per ha fruited in natural regeneration sites of L. kaempferi with 25 seed-trees per ha. Seed dispersal began in September and germination rates of seeds dispersed until November were greater than 40%. Reserved seed-tree sites showed the highest amount of seed inflow, followed by the seed-tree site and clear-cut site in descending order. The reserved seed-tree method performed better than other methods for evenly scattering seeds. Therefore, the timing of logging and seedbed generation for natural regeneration of L. kaempferi is estimated to be most effective before September when seeds are purposefully scattered using the reserved seed-tree method as an effective method for uniform seed supply.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.167-172
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• 1986

This experiment was carried out to obtain some information about the growth habit and morphological and anatomical characteristics of fasciated soybean, var. Buchai-kong. The results obtained are summarized as follows: 1. Main stern of fasciated soybean, var. Buchai-kong was gradually broadened and became flat, on which leaves emerged irregularly compared with normal soybean, var. Danyeop-kong. The number of leaves on main stern was more in Buchai-kong, but the total number of leaves per plant was not considerably different each other. 2. The degree of fasciation (max./min. in diameter at the broadened part) in main stern of Buchai-kong was about 3.1, and was related to the amount of growth of main stern and branches of Danyeop-kong. Stern fasciation types found in Buchai-kong were linear (the most common) and bifurcated with regard to branching of main stern tip. 3. The number of branches per plant was much less in Buchai-kong than in Danyeop-kong. There were fas-ciated branches and fasciated petiole in Buchai-kong. 4. About 75 percent of pods of Buchai-kong were concentrated on the top of stern, which showed strong pod clustering. 5. Seed yield per plant of Buchai-kong was about 60 percent of that of Danyeop-kong, and the decrease in seed yield was mostly affected by the decrease in seed weight and seeds per pod. 6. The number of vascular bundles of transection of mature stern was more in Buchai-kong, but Danyeop-kong developed the better vascular bundle.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.121-124
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• 2001

Potato (Solanum tuberosum L.) tubers of 10, 20, 30, 40, and 50 g were planted in plug trays with vermiculite-based root medium on 10 August 2000 and grown for 15 days in a glasshouse to determine the effects of mini-tuber size on plug seedling growth and field performance of plug seedlings. For a control, common potato tubers weighing 50 g were also planted. As size of seed tubers planted increased from 10 to 50 g, seedling height decreased from 24.6 to 20.0cm while shoot number per seedling increased from 2.0 to 3.5, main stem diameter from 4.3 to 6.1mm, and fresh weight of root + top from 9.3 to 19.4 g/seedling. At 90 days after transplanting plug seedlings, the total number of tubers per plant increased from 3.62 to 4.72, average tuber weight from 62.9 to 72.8g, and total tuber yield 20.5 to 23.6 t/ha with increase in seed tuber size. Plug seedlings raised from 50g tubers produced 22% more tubers per plant and had 21 % higher＞80g tuber yield than the directly planted potatoes.

• Korean Journal of Plant Resources
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• v.9 no.3
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• pp.249-253
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• 1996

The study was conducted to investigate the effect of the culture with trickle with trickle irrigation in transparent vinyl house on the seed productivity of onion. Growth, number o tiller and leavers, plant height, leaf sheath length, flowering rate, diameter of flower wheel, number of little flower per flower stalk and fertilization rate are best in the case of the seed production under the culture with trickle irrigation in transparent vinyl mulching house, catch in the rain with vinyl from February to March, so it is found that it is appropriate to plant the onion mother bulb under the culture with trickle irrigation in transparent vinyl mulching house, catch in the rain with vinyl from February to March in the Southern areas of Korea.

• Journal of the Korean Institute of Landscape Architecture
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• v.23 no.2
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• pp.113-123
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• 1995

This study was conducted to find out appropriate rates of seed mixture of both native and foreign plants in order for stabilization of early afforestation and proper vegetation on road slope. The results are summarized as follows: 1. Characteristics of germination : After seeding, 2 weeks for both Lespedeza bicolor and Lespedeza cuneata, and 4 weeks for both Arundinella hirta and Zoysia japonica were needed for vigorous germination, and 1-4 wee17s for 3 cool-season grasses were spent for gradual germination. 2. Plant height : There was no difference between Lespedeza cuneata and Lespedeza bicolor in plant height by 7 treatments. As mixture rates of cool-season grasses were lowered, plant height of Arundinella hirta became longer. Descending order of co81-season grasses for plant height was Tall fescue, Perennial ryegrass and Creeping redfescue. 3. Number of tillers : The number of tillers tended to increase in the experimental plots where competition was low. 4 Ground cover rate : Ground cover rate was the highest in Mixture IV (96.7%) and was fluctuated from 13.3% on Sept. 13 to 45% on Nev. 3 in Mixture III. Descending order of gronud cover rates in 7 treaments was Mixture IV, Mixture III. Mixture II, Mixture Ⅶ, Mixture V, Mixture Ⅵ, Mixture I, and Mixtur III when measured on Oct. 13 5. Visual assessment: High preferences were observed on Mixture IV and Ⅶ In sun the best seed mixtures were Mixture IV and Ⅶ. It meant that (1) either mixture of 70% the native plants with 30% cool-season graaes or (2) mixture of 80% the native plants with 20% cool-season glasses was best for this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.599-607
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• 2006

The experiments were carried out to develop simulation model for estimating the yield of soybean in upland and paddy field condition. Field experiments were done at National Institute of Crop Science in 2005. The evaluated soybean cultivars were Taekwangkong, Daewonkong, and Hwangkeumkong. Soybean seeds were planted by hill seeding with 3-4 seeds and row and hill spacing were $60{\times}10cm$ in upland and $60{\times}15cm$ in paddy field. Seeds were sown on row (without making ridge) and on the top of ridge in upland and paddy field, respectively. Field parameters were measured yield components ($plants/m^{2}$, pod no./plant, and 100-seed weight, seed yield and growth characteristics (stem length, leaf area at each stage, and dry weight of shoot) and after measuring they were compared the relationships with seed yield and yield components and seed yield and growth characteristics. Seed yield of soybean was affected by cultivars and planting density. Seed yield was higher in upland than paddy field due to the higher planting density in upland field. The upland soybeans generally had lower 100-seed weight than that of paddy field. Seed yield of soybean in a paddy field was greatest in Taekwangkong and followed by Daewonkong and Hwangkeumkong. The harvest index of taekwangkong and Hwanggumkong was higher in upland than paddy field, however, it was higher in paddy field than upland in Daewonkong. Seed yield was greatest in Daewonkong in both experimental fields. The greatest stem length was observed in taekwangkong and Hwanggumkong (R6) in late growth stage in paddy field. Dry weight of shoot and pod, pod number, stem length, and stem diameter were higher grown in paddy field than grown in upland. Crop growth rate (CGR) of cultivars was higher in paddy field after 8 WAS(weeks after sowing) and it was greatest at 13 WAS in Daewonkong among the cultivars. In upland field, CGR was greatest in Taekwangkong and then followed by Daewonkong and Hwanggumkong during 12 and 15 WAS. There was no significant relationships between 100-seed weight and seed yield in both experimental fields. A significant positive relationship was observed between seed number and seed yield. The correlation coefficients between leaf area and shoot dry weight were about 0.8 during the whole growth stage except 5 WAS and 4-5 WAS in paddy field and upland, respectively. This experiment was done just one year and drained paddy field condition was not satisfied drained condition successfully at 7th leaf age of soybean by the heavy rain, so we suggest that the excessive soil water reduced seed yield in paddy field and the weather condition should be considered for utilizing of these results.