• Korean Journal of Weed Science
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• v.31 no.1
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• pp.84-88
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• 2011

This study was established to investigate the effects of seeding depth and seeding time on the emergence, growth, and N production of Vicia tetrasperma and V. hirsuta in 2007 and 2008. All seeds of both species were gathered from Dangjin, Chungnam in late June of 2005 and stored for two year at room temperature. Both V. species began to germinate at the end of June, passed the winter with the seedling stage, rapidly increased their height in April and May, were in full bloom in May, and then withered after entering mid-June. V. hirsuta had higher emergence rate and growth compared to those of V. tetrasperma. The optimum seeding time and seeding depth for a cover cropping was from late August to early September and from 1 to 5 cm, respectively. V. tetrasperma and V. hirsuta had a satisfactory growth and provided 43.8 and $55.4kg\;ha^{-1}$of N, respectively.

• Korean Journal of Organic Agriculture
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• v.26 no.1
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• pp.57-72
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• 2018

Organic agriculture seeks sustainable agriculture. Organic agriculture is based on circulating agriculture of a family farm unit. However, as of the end of 2016, only 33 out of the total organic farming farms were implementing Crop-Livestock cycling organic farming. The reason seems to be a matter of income after all. The optimal size combination refers to the scale by which family farms can maintain their quality of life while engaging in farming activities. In other words. it is a farm scale that maintains optimal income through stable labor costs. In the meantime, there has been no previous study on the optimal economical combination of Crop-Livestock cycling farming. Choi (2016) analyzed whether the economies of scope (EOS) were realized in the combined production by using the management data of the farmers who practiced Crop-Livestock cycling organic farming for four years. As a result, it has been revealed that the EOS measurement value is 0 or more so the economies of scope are being realized. Therefore, the purpose of this empirical analysis is to identify farm incomes under this circumstance. It is assumed that the optimum production is achieved by balancing the total income curve and the total cost curve in the optimal scale production range. The results of the analysis are as follows. First, the income after the conversion to Crop-Livestock cycling farming was 44,789,280 won, the sum of the seedling-livestock sector, which was 17,873,120 won higher when the non-Crop-Livestock cycling farming was assumed. The same is true for 2014 and 2015. The reason for this is that pig droppings were composted from organic seedlings, and the cost of selling pork was 150,000 won/per pig more expensive even though the manufacturing cost of organic feeds was higher than the purchasing cost. Secondly, this study simulated the result that the economic index varies when the farm size combination is changed by the farm size of 100% standard (S100) as of 2014. S130 is the increase in size from 100% of 2014, whereas S30 is the result of 3ha crop and 66 livestock (pigs). As a result of this simulation, Crop-Livestock cycling farming income decreased more than non-Crop-Livestock cycling farming as the farm size decreased, whereas the income decreased as the farm size increased. When the size was reduced below S50, the income tended to decrease. In this situation, EOS changed in the same direction. The results showed that when the farming size was reorganized and reduced to 50% compared to 2014, the income and income difference was the highest. At the same time, economies of scope (EOS) were the highest at 0.12985. In other words, it was found that the income of farm houses in a family farm unit sector was the best in the combination of 1.5ha crop agriculture and 110 livestock (pigs).

• Korean Journal of Plant Resources
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• v.30 no.4
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• pp.364-371
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• 2017

Limonium tetragonum is a halophyte grown naturally in the coastal region in South Korea. This study was conducted to investigate the effects of salt concentrations on seed germination, seedling growth, and antioxidant capacity of L. tetragonum. Seeds were collected from naturally grown plants of L. tetragonum and those at full maturity were used in this experiment. All experiments were performed at 0%, 0.5%, 1.0%, or 2.0% of salt concentrations. Seed germination rate was highest as 86% at $20^{\circ}C$ and followed as higher in order of $25^{\circ}C$, $30^{\circ}C$ and $15^{\circ}C$. The germination rate was about 80% at 0% or 0.5% of salt concentration, but it was very low at the salt concentrations higher than 1%. Growth of L. tetragonum seedlings showed no difference in Hoagland solution containing NaCl in the range of 0% to 1.0% and seedlings survived at 2.0% of NaCl concentration. As the salt concentration increased, the content of $Na^+$ in the shoot increased, but that of $K^+$, $Ca^{{+}{+}}$, or $Mg^{{+}{+}}$ decreased. The antioxidant activity and the content of total polyphenol and total flavonoid in the shoot were similar at 0% and 0.5% of NaCl and were highest at 2.0% of NaCl concentration. In conclusion, performance of seed germination and plant growth of L. tetragonum was highest at 0% and 0.5% of NaCl concentration, and showed no difference in antioxidant activity, total polyphenol contents, and total flavonoid contents at the same salt concentrations.

• Korean Journal of Environment and Ecology
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• v.35 no.6
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• pp.621-631
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• 2021

The purpose of this study is to survey and analyze acorn production and characteristics of the Quercus acuta Thunb. according to the need for information on seed supply and seedling cultivation during the restoration of warm broad-leaved forests. For the survey, a total of 30 seed traps with a surface area of 1 m² were set up, 3 in each of 10 quadrats (8 in Wando, 1 in Haenam, and 1 in Jindo). The acorns that fell in the seed trap at the end of each month were collected from August to December each year between 2013 to 2016. The collected acorns were then classified into sound, damaged, decayed, or empty grade, and the number of acorns produced was calculated. In the case of sound acorns, acorn traits, such as length, diameter and weight of acorns without cupule, were measured. Duncan's multiple tests of acorn production and characteristics were conducted for comparative analysis of the annual average values with the values by year, stand, month, and treatment plot. The annual number of acorn dropped into the seed traps in each quadrat from 2013 to 2016 was 5-350 acorns/3 m² in 2013, 17-551 acorns/3 m² in 2014, 5-454 acorns/3 m² in 2015, and 14-705 acorns/3 m² in 2016. There was a large difference in acorn production between the quadrats, presumably attributed to the difference in the amount of light received due to the density of trees in the square. Annual acorn production per area was 335,000 acorns/ha in 2013, 932,000 acorns/ha in 2014, 556,000 acorns/ha in 2015, and 1,037,000 acorns/ha in 2016. That was a sharp variation of acorn production in the two-year cycle. As the fluctuation in the production of Q. acuta showed simultaneity between stands, it is judged that Quercus acuta Thunb. had a clear cycle of fruitfulness and fruitiness between forest objects. September showed the biggest amount of fallen acorns and largest damage from insect pests, indicating that preventing early fall of acorns could increase the fruiting period and enable mass production of sound acorns. There was no significant difference between annual average acorn length in each region. In the case of the acorn diameter and weight, the average values of acorns from Haenam were significantly higher than those from Wando and Jindo. There was no significant difference in the average annual acorn characteristics by month, and the average annual acorn length, diameter, and weight in November were 19.72mm, 12.23mm, and 1.64g, respectively, the highest between August and November.

• Journal of Korean Society of Forest Science
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• v.90 no.4
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• pp.565-572
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• 2001

The spatial genetic structure of Needle fir(Abies holophylla Max.) seedlings on forest gap within a Needle fir forest at Mt. Odae in Korea was analyzed on the basis of ISSR(inter-simple sequence repeats) marker analysis. The gap size was $1,500m^2(50m{\times}30m)$, and we sampled 416 one- or two-year-old seedlings by 2m intervals. Some trees at the upper crown layer except Needle firs and all trees at the middle and lower crown layers were removed, and Needle firs at the upper crown layer showed very weak growth strength or to be withering to death. The results of spatial autocorrelation using 31 polymorphic ISSR markers revealed that it was genetically homogeneous within spatial distance of 15.6m and the randomness of genetic distribution was from 15.6m to 31.2m. The genetic patch size of seedlings in forest gap might be restricted by the density of mother trees, making allow for the average height of adult Needle firs, the seed dispersal area, and the average distance between adults. For the directionality of seedling distribution, we investigated the variography using 'genetic configuration' which was the value of configuration in Multidimensional Scaling by genetic distance. In directional variogram, the increment of spatial distance from East to West direction was inversely proportional to genetic homogeneity. We presumed that this anisotrophy of seedling distribution at this forest gap resulted from the directionality of seed dispersal rather than the difference of fecundity between mother trees or the microhabitat variation, taking the evenness of forest floor condition, a vast seed production and the random distribution of seedlings at the studied site into consideration.

• Horticultural Science & Technology
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• v.34 no.5
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• pp.727-735
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• 2016

This research was conducted to investigate the influence of various pre-planting $NO_3:NH_4$ ratios in the coir dust+peatmoss+perlite (3.5:3.5:3, v/v/v) medium on the growth of tomato plug seedlings (cv. Dotaerang Dia), changes in chemical properties of root media, and tissue nutrient contents. With the fixation of N concentration to $300mg{\cdot}L^{-1}$, the $NO_3:NH_4$ ratios were adjusted to 100:0, 73:27, 50:50, 27:73, 0:100. Then, root media containing various $NO_3:NH_4$ ratios and equal concentration of other essential nutrients were filled into 50-cell plug trays and the seeds of 'Dotaerang Die' tomato were sown. The investigation of seedling growth and tissue analysis for mineral nutrient contents based on the dry weight of above-ground tissue were conducted 6 weeks after sowing. As seedlings grew, the EC decreased quickly and pH increased gradually in the all treatment media. The plant height, fresh weight and dry weight of seedlings in the treatment of 50:50 ($NO_3:NH_4$) were 29.0 cm, 13.7 g, and 1.21 g, respectively, which were the highest among treatments tested. However, the seedlings in the treatment of 0:100 ($NO_3:NH_4$) had 26.5 cm, 11.2 g, and 0.92 g in plant height, fresh weight and dry weight, respectively. These were the poorest among the treatments tested. The tissue contents of N were 2.77 to 3.22% in all the treatments. The treatment of 27:73 ($NO_3:NH_4$) had the highest contents of Fe, Mn and Zn and that of 0:100 ($NO_3:NH_4$) had the lowest contents of Mg, Na, Cu, Mn and Zn among the treatments tested. The results indicate that $NH_4$ ratio should be lower than 50% in the coir dust+peatmoss+perlite (3.5:3.5:3, v/v/v) medium for seedling growth of tomato and the optimum ratio will be used to draw up guide lines for plug seedling production.

• Journal of Bio-Environment Control
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• v.27 no.1
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• pp.13-19
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• 2018

This study was conducted to examine the germination and growth during seedling period of Codonopsis lanceolata and Astragalus membranaceus as affected by different media. The seeds were sown in commercial medium (Tosilee), coir, rockwool, and urethane sponge. The seeds were germinated for 22 days in a closed-type plant production system, and seedlings were grown for 35 days after sowing in the venlo-type glasshouse located on Gyeongsang National University. Nutrient solution was supplied by the sub-irrigation as EC $1.0dS{\cdot}m^{-1}$ and pH 6.5 every second day. Final germination of Codonopsis lanceolata was the significantly highest in the coir and rockwool media as 68.5% and 67.9%, respectively. Mean daily germination was also the highest in the coir and rockwool media as 4.2 and 4.1, respectively. The germination rate of Astragalus membranaceus was not significantly difference in the media types. Plant height and leaf area of Codonopsis lanceolata were the significantly highest in the rockwool medium as 11.5 cm and $11.3cm^2$, respectively. Longest root length and fresh weight of root were the greatest in the coir medium as 5.8 cm and 0.07 g, respectively. Plant height and leaf area of Astragalus membranaceus were the significantly highest in the coir medium as 14.0 cm and $16.9cm^2$, respectively, and fresh and dry weights of root were the highest in the urethane sponge medium as 0.34 g and 0.03 g, respectively. Therefore, these result suggest that the rockwool and coir media were suitable for the germination and growth during seedling period of Codonopsis lanceolata and Astraglus membranaceus.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.34 no.4
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• pp.299-308
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• 2001

We examined the growth variation with water depth, interval between suspended lines and locality of seedling production of sea squirt. Halocpthia roretzi, measuring approximately $10.1\~15.3$ mm in tunic height, was cultured at the farm near Guryongpo, Pohang city from 7 January to 6 December 1998 (333 days). Growth condition depending on culture depth was most favourable at the depth of $10\~12$m, It was concluded that nutritional conditions were better at the depth since there was a greater mount of phytoplankton than at any other depth in the water column. Growth condition depending on distance between suspended lines was most favourable at the interval of 2 m and 2.5 m than at the interval of t m and 1.5 m, There was no significance difference in growth variation with locality of seedling. The seasonal variations in growth of tunic height, meat and total weight were correlated with temperature and chlorophyll a, In the depth of $10\~12m$ the rate of increase in tunic height was generally greatest in the growth period II ($244{\mu}m/day$) and IV ($338{\mu}m/day$), lower in the period I ($108{\mu}m/day$), and slightly increased during the period III ($185{\mu}m/day$). The water column have showed a typical seasonal pattern with temperature ranged between $12.07{\sim}24.14^{\circ}C$ and over $20^{\circ}C$ between July and September.

• Journal of Bio-Environment Control
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• v.23 no.2
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• pp.144-147
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• 2014

It was intended to closely examine an effect that a change in the concentration of culture medium had on the potato(Solanum tuberosum L.) plantlet growth in the microponic system so as to mass-produce the virus-free plant of new variety 'Saebong' for potato processing. The adjusted concentration of potato culture medium was 0.2, 0.6, 1.0, 1.4, 1.8, and $14.0dS{\cdot}m^{-1}$. And potato seedling was cut into pieces of 1.5 cm in length, which included 2 growth points and leaves. And each was explanted in glass vial of 50 mL. And experiments were carried out twice for 18 days or 21days. Culture medium of 2ml was put in the container respectively. And 1 mL was added after 10 days. And in terms of cultivation environment, the experiment was carried out at the day length of 16 hours at the temperature of $23{\pm}1^{\circ}C$ under the white LED light of $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. The concentration of culture medium in the experiment I was EC 0.2, 1.0, $14dS{\cdot}m^{-1}$ and was adjusted to 0.6, 1.0, 1.4, $1.8dS{\cdot}m^{-1}$ in the experiment II. The results showed that the survival rate of plantlet was 90% at $0.2dS^2m^{-1}$, 100% at $0.6dS^2m^{-1}$, 100% at $1.0dS^2m^{-1}$. 0% at $1.4dS{\cdot}m^{-1}$, 0% at $1.8dS{\cdot}m^{-1}$. and 0% at $14.0dS{\cdot}m^{-1}$ after 7 days. With regard to the explanted potato seedling, in case of the treatment where the electrical conductivity of culture medium was adjusted to $1.0dS{\cdot}m^{-1}$, root developed 2 days after transplantation. And the plantlet vigorously grew into strong plant that had 7 leaves, length of 5cm, and fresh weight of 0.5 g after 18 days. In case of the treatment where the concentration of culture medium was adjusted to $0.6dS{\cdot}m^{-1}$, the root plantlets developed 4 days after transplantation. And those grew into plant that had 7 leaves and fresh weight of 0.2 g after 21 days. Therefore, we found that it is effective to control potato culture medium by adjusting its electrical conductivity to $0.6{\sim}1.0dS{\cdot}m^{-1}$ for the mass production of virus-free potato seedling in the microponic system.

• Journal of Bio-Environment Control
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• v.26 no.4
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• pp.368-377
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• 2017

This study investigated the possibility of application of the recently introduced cylindrical paper pot seedlings in hot pepper (Capsicum annuum L.) cultivation. The seedling growth, initial rooting after planting and accumulated fruit yield were investigated with the treatments of tray type (paper pot and plug) as a main factor, tray cell number (40 cell and 50 cell) as a sub-factor, and fertigation method (continuous fertigation and fertigation after 35 days sowing) as a sub-sub factor, respectively. The growth of pepper seedlings was significantly affected by tray type and fertigation method showing the highest value at 50 cell plug tray with continuous fertigation, and the effect of fertigation was greater than that of trays. 'Cheongyang', 'Daekwonseoneon' and 'Longgreenmat' cultivar showed all the same pattern in seedling growth. These three-cultivar seedlings were planted in plastic house and in open field in Jeonju area, respectively, and another 'Daekwonseoneon' seedlings raised Yeongyang local area was also planted at the same area. There was no difference in the rooting of 'Cheongyang' pepper at 2 weeks after planting in plastic house. The accumulated fruit weight was not significantly different between paper pot seedlings and plug seedlings in three cultivar grown in plastic house. However, that of 'Cheongyang' pepper showed higher at paper pot seedlings than plug seedlings and the other two cultivar were higher at plug seedlings in open field. 'Daekwonseoneon' pepper yield grown in open field in 'Yeongyang' area was not significant between paper pot seedlings and plug seedlings. In conclusion, the pattern of seedlings growth grown in the cylindrical paper pot was the same as those of the conventional plug seedlings and also fruit yield was similar between paper pot seedlings and plug seedlings even though minute difference among cultivars. These results suggest that pepper seedlings grown in paper pot should be highly applicable to pepper cultivation.