• Korean Journal of Fisheries and Aquatic Sciences
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• v.32 no.5
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• pp.654-658
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• 1999

To investigate an efficient microalgal feed for lariat culture of the Pacific oyster Crassostrea gigas, we prepared three types of Isochrysis aff, galbana (T-iso) : 1) freshly Harvested feed, 2) concentrated feed and 3) freeze-dried feed. The chemical compositions and fatty acid content of these feeds were evaluated and survival rate and lipid content of oyster larvae fed by these feeds were also determined. There was no significant difference in all types of feed in the gross biochemical compositions, In the fatty acid composition, the freeze-dried feed showed a significant increase in the level of polyunsaturated fatty acid (PUFA), eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) than freshly Harvested feed, especially EPA was 7.35-fold higher than freshly Harvested feed. The survival rate of the oyster larvae was the highest when the larvae were fed with a diet of $10\%$ freeze-dried and $90\%$ concentrated feed; it was 2.1-fold higher than that fed with freshly Harvested food alone. Thereafter, the survival rate decreased with the increased substitutions of freeze-dried food, finally equalling that fed $100\%$ freshly harvested feed at the $30\%$ substitution. Larval lipid content of the oyster was also the highest when the larvae were fed with a diet of $10\%$ freeze-dried and $90\%$ concentrated feed. This increase was by 1.6-fold ver that fed $100\%$ freshly Harvested cells. Thus feed produced during slack times, on a seedling aquaculture farm, and preparedas a freeze-dried diet can be used, mixed with concentrated feed, to supply diets more efficiently and to improve the larvae survival rate of Pacific oyster.

• Journal of Korean Society of Forest Science
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• v.105 no.1
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• pp.63-72
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• 2016

A study was conducted to evaluate the effect of collected region(Bongpyeong in Gangwon, 690 m, Mt. Halla in Jeju, 1,085 m), pre-treatment (stratification, soaked in distilled water or $GA_3$) and shading (control, 50%, 80%) on seed emergence and seedlings growth of Ligularia fischeri. The result showed that seed emergence (%) of L. fischeri were 6.9~75.5% (Gangwon : 6.9~32.8%, Halla : 22.2~75.5%). Maximum seed emergence (%) of 32.8 (Gangwon) and 75.5 (Halla) were achieved for seeds were stratified, soaked in distilled water, and under non-shading for L. fischeri (Gangwon), whereas seeds were stratified, soaked in $GA_3$ 100 ppm, and under 80% shading for L. fischeri (Halla). In this study, the best seedling vigor index (SVI) of L. fischeri (Gangwon) and L. fischeri (Halla) were obtained when seeds were stratified, soaked in distilled water, and under 50% shading. The survival rate of potted seedlings for L. fischeri (Halla) were 100% of all shading conditions, but there were decreased by 77.8%, 61.1%, 55.6%, as an increasing shading rate (con, 50%, 80%) for L. fischeri (Gangwon). Therefore, good seedlings were obtained when seed (Mt. Halla) of L. fischeri were stratified, soaked in distilled water, and under 50% shading, and then seedlings were transferred in pot.

• Korean Journal of Environment and Ecology
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• v.7 no.1
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• pp.10-21
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• 1993

Artificial acid rain (pH 3.0, 4.0 and 5.0) and ground was treated on the seeded pots of 4 species to examine its effects on germination and survival rate, seedling growth and contact angles on needle surface. Artificial acid rain was prepared by diluting sulfuric acid with ground water and ground water (pH 6.5) was used as control. Artificial acid rain was sprayed to seeded pots two or three times per week for growing season, one times per week for winter seasons. About 5mm of artificial acid rain was treated each time from early April, 1991 to early October, 1993. Germination and survival rate, soil acidity, seedling growth and contact angles on the needle surface were measured and compared among the treatments. The results were summarized as follows ; Artificial acid rain might have positive effects on growth-related characteristics of the seedlings in the first and second year of acid rain treatment, and the effects were differed among four species. All growth-related characteristics of the seedlings in third year, however, decreased with decrease of pH values of artificial acid rain. This was considered to the results of acidic accumulation over soil buffer capacity. Needle injury and biomass (defoliation) was correlated with the pH values of artificial acid rain, and this character might be a good criteria for early diagnosis of acid rain injury. The differences of soil acidity were significant among the treatments for all species. Contact angles between needle surface and water droplet decreased with decrease of pH values of artificial acid rain. Measuring and comparing contact angles might be very good criteria for early diagnosis of acid rain injury.

• Korean Journal of Medicinal Crop Science
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• v.6 no.2
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• pp.160-164
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• 1998

Angelica gigas has been a major medicinal crop in Korea for a long time. This study was to determine optimum seeding time and bolting response by shifting seeding time between November 10, 1993, and August 10, 1994 using promising line, Suwon 2. Days to emergence were similar among seeding times from April 10 to August 10 in Suwon. Seedling duration was shortened 92 days when seeded on July 10 compared with the conventional seeding time of April 10. Productivity of seedling ranging from 0.31 to 0.70cm in diameter was highest of 730 plants per $m^2$ in July 10 seeding. When seeded in July 10, bolting rate was 2.4 percent as compared with 2.6 percent in conventional seeding (April 10). The optimum seeding time was July 10. Seedling quality, survival rate after planting in field, and root yield were greatly influenced by seeding time.

• Journal of Aquaculture
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• v.11 no.2
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• pp.183-191
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• 1998

To substitute fromzed and freeze-dried food for live food in the development of the artificial seedling production of bivalve larvae, the dietary value of live T. suecica was compared with those of freeze-dried T. suecica, frozed T. suecica, live T. suecica (50%)+frozen T. suecica (50%), and live T. suecica (50%)+freeze-dried T. suecica (50%) in the rearing of oyster (Crassotrea gigas) and hen clam (Mactra chinensis) larvae, and manila clam (Tapes philipninarum) spats. Oyster larvae fed live T. suecica showed the highest growth (shell hight $231.9^{\mu}$m) and survival rate (72.6%) and those fed freeze-dried T. suecica showed the lowest growth (shell height $168.9^{\mu}$m) and survival rate (35.3%). However, in the hen clam larvae, there were not significantly different among diet group in growth and survival rate. The small spats of manila clam fed live t. suecica or live T. suecica (50%)+freeze-dried T. suecica (50%) showed higher growth and survival rate than those fed other diet group. In the case of large spats of manila clam, live T. suecica and live T. suecica (50%)+frozen T. suecica (50%) showed better growht. But, survival rates were not different among diet groups. Dietary valuse of frozen and dried T. suecica were different on species and growth stage, and frozen and freeze-dried T. suecica can be partially used as substitute food for T. suecica live T. succica in shellfish hatchery.

• Journal of Bio-Environment Control
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• v.22 no.4
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• pp.335-340
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• 2013

This research was conducted to know the appropriate leaf number of scion for tube grafting in context with survival rate and quality of seedlings, and early yield of $1^{st}$ and $2^{nd}$ cluster of cherry tomato plants. Scions were grafted when having leaves 1~2 (LF-2), 2~3 (LF-3), or 3~4 (LF-4). The treatment LF-3 showed the highest survival rates and the best results in 6 factors among 12 seedling quality factors. In case of early yield, the treatment LF-2 showed higher yield than others with the big difference. Economic analysis showed that LF-3 is desirable in case of nursery while LF-2 is better in case of farmers. The compromising solution is that farmers buy a little expensive seedlings grafted at the leaf stage of 1~2 from nurseries in terms of win/win strategy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.139-144
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• 1969

1. In order to obtain useful mutants such as early maturity, resistance to lodging, high protein and oil content, and capability of high yield, dormant seeds of two soybean varieties, Jang Dan Baik Mok and Clark, were treated with ${\gamma}$-ray, Ethyl Methane Sulfonate(EMS), Ethylene Imine(EI)and combinations of ${\gamma}$-ray and EMS or EI. 2. The germination rate and survival rate in a variety Jang Dan Baik Mok were significantly decreased with ${\gamma}$-ray treatment while it was not the same in the Clark variety. A significant decrease for seedling height measured at 14 and 21 days after sowing was found with the increase of ${\gamma}$-ray dose in both varieties. 3. Germination rates in both varieties were significantly decreased as EI concentration increases, particularly severe damage in germination was observed at 0.008 Mo. concentration. Germination rate damages were found with EMS concentration increases in the variety Jang Dan Baik Mok while no regular responses in seedling height were observed in the variety Clark. 4. Germination rate was significantly lowered with the combined treatment of EMS and ${\gamma}$-ray 24KR than that of EMS alone. In the treatments of ${\gamma}$-ray with three levels of EI concentration, the combined treatments except 24KR+EI 0.002 Mol. resulted in better germination than of EI alone. In both varieties, significant reduction in seedling height was observed in the combined treatments of ${\gamma}$-ray with various concentrations of EMS, whereas stimulation effect on seedling height was found with treatment of ${\gamma}$-ray EI +0.08Mol. 5. Germination rate, survival rate, and plant height as criteria of radio sensitivity, variety Jang Dan Baik Mok is moze sensitive to ${\gamma}$-ray, EMS, and EI than the variety Clark, and the varietal difference in responsibility to mutagen may be due to the genetic-constitution of the varieties.

• Journal of Korean Society of Forest Science
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• v.106 no.4
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• pp.465-472
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• 2017

In this study, containerized seedlings of Pinus densiflora (2-0) were planted in Iso-ri, Hwadong-myeon, Sangju-si, Gyeongbuk on April, 2015. It was planted by lightweight planting auger that Kyungpook University has developed and mattock which is the general planting method of containerized seedlings. With the square planting method ($1.8{\times}1.8m$), 225 trees were planted respectively and about 2 years of initial growth, survival rate and seedling quality index (SQI) were analyzed and investigated. According to the analysis result, the average root collar diameter (mm) of planted containerized seedlings that used lightweight planting auger and mattock reached 3.77 and 3.94 in 2015, 18.73 and 15.32 in 2016, and 27.8 and 23.9 in 2017 respectively. In addition, the average height of containerized seedlings rated 33.4 and 33.4 in 2015, 89.8 and 74.7 in 2016 and 120.7 and 97.9 in 2017. It turns out that the height of initial growth of containerized seedlings that are planted by lightweight planting auger were much higher than mattock. The survival rate of the containerized seedlings that used lightweight planting auger was also higher by 10% than that used mattock. Also, H/D rate (healthiness) and T/R rate were almost the same, however, for the SQI, 0.60 was for lightweight planting auger and 0.24 for mattock. It seems like the lightweight planting auger is more advantageous than mattock in initial growth.

• Journal of Bio-Environment Control
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• v.6 no.4
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• pp.258-263
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• 1997

The result was summarized of basic test and field test to find what quantity of irrigation, what state of compaction and what size of transplanting hopper could induce the optimum taking root in the transplantation of plug seedling by transplanters, and thus acquired the basic data for the development of the related transplanters and the optimum growth and development control. Livability of vegetables after transplanting had no significant difference with respect to for the size of hopper, but was greatly affected by the length of seedlings. The longest possible length of seedling for transplanting and optimal length were found to be 30cm and 28cm, respectively. For irrigation when transplanting red pepper or Chinese cabbage it was thought that large-sized hopper was appropriate. The livability of plug seedling 10 days after transplantation was mainly affected by soil moisture content. Consequently it was thought no irrigation would be needed when transplanting at the soil moisture content of more than 18% ; irrigation of more than 50cc would be needed at the soil moisture content of 13% : initial irrigation of more than 100cc and subsequent irrigation would be needed at the soil moisture content of less than 3.8%. The improvement of soil compaction method (left and right side compaction) with conventional semi-automatic transplanter was not necessary, since there was no difference in livability depending on the compaction methods, left-right side compaction or back-forth-left-right side compaction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.228-234
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• 1993

Seedling emergence of 15 rice varieties (Gayabyeo, Chilseongbyeo, Samgangbyeo, Yeongsanbyeo, Yeongdeugbyeo, Hwajinbyeo, Palgongbyeo, Seomjinbyeo, Tamjinbyeo, Milyang 95, M 101, M 202, Newbonnet, Tebonnet, and Lemont) were tested at different soil moisture regimes and seeding depths. Submergence for four days immediately after seeding did not reduce emergence rate in all varieties. Under the flooded condition, the percentage of emergence of all varieties at 1.5cm seeding depth ranged 0～40%, it is much lower compared to uncovered control, and percentage of seedling survival ranged 0～24% due to death of some emerged seedlings. Under the field condition, one time flooding up to 10cm above the soil surface after seeding did not reduce the percent emergence of seedlings. The pF value of soil was 0 for few days after flooding or raining and Eh of soil ranged 443-453m V.