• Journal of the Korean Society of Environmental Restoration Technology
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• v.16 no.3
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• pp.97-105
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• 2013

Kalopanax septemlobus (Thunb. ex Murray) Koidz. is natively distributed in Korea. The importance of this species has been increased not only for high quality timber but for medicinal and edible uses. However, increasing market demand of K. septemlobus with illegal cutting and overexploitation has resulted in its rapid depletion and destruction of natural habitat. This study was conducted to understand the survival rate and growth characteristics of planted K. septemlobus seedlings with treatment of root pruning, stem cutting and planting density. The survival rate and growth of height and root-collar diameter for one- and two-year old seedlings with different planting densities were investigated in the clear-cut area of a Pinus densiflora stand for five years. One-year-old seedlings were treated with or without root pruning and planted with three density levels (5,000 trees $ha^{-1}$, 10,000 trees $ha^{-1}$, and 40,000 trees $ha^{-1}$). Two-year-old seedlings were treated with and without stem cutting and planted with the density of 5,000 trees $ha^{-1}$. The survival rate of one-year-old seedlings with root pruning treatment in the density of 10,000 trees $ha^{-1}$ was 92%, while that without root pruning in the density of 40,000 trees $ha^{-1}$ was 67% after five years. The height of one-year-old seedlings has been significantly affected only by planting density in the $5^{th}$ year. The survival rate of the two-year-old seedlings with stem cutting was 75.5% and greater than control (67.3%) in the $5^{th}$ year but no difference in height was shown between the two treatments from three years after plantation.

• Journal of Bio-Environment Control
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• v.24 no.3
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• pp.173-177
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• 2015

This experiment was conducted to determined the optimum planting density for the production of high quality bitter gourd (Momordica charantia L.) adapted in spring cultivation with the unheated greenhouse condition. 'Erave' variety was planted at three different planting densities (235, 305, $380plants{\cdot}10a^{-1}$) on March 26. The training method was six lateral vines with pinching the main one. The light intensity was lower in the higher planting density than the lower one. Net photosynthetic rates of the bitter gourd leaves in the higher density were significantly lower (41 to 71%) than the lower one. There was no difference in the fruit characteristics among treatments. But the root weight was heavier in the lower planting density ($235plants{\cdot}10a^{-1}$) as 113.1g than 96.0g of the higher planting density ($380plants{\cdot}10a^{-1}$). The number of the harvested fruit also higher in the lower planting density ($235plants{\cdot}10a^{-1}$) with 60.7 than 39.9 of the higher planting density ($380plants{\cdot}10a^{-1}$). The average fruit weight was the highest in the plot of $305plants{\cdot}10a^{-1}$ as 338.7g and lowest in the lower planting density ($235plants{\cdot}10a^{-1}$) as 285.2g. The total yield of $305plants{\cdot}10a^{-1}$ density was $5,359kg{\cdot}10a^{-1}$, which was higher than $4,068kg{\cdot}10a^{-1}$ of the lower planting density ($235plants{\cdot}10a^{-1}$). Marketable yield was increased by 24% in the planting density of $305plants{\cdot}10a^{-1}$($4,767kg{\cdot}10a^{-1}$) as compared to the lower density in $235plants{\cdot}10a^{-1}$($3,629kg{\cdot}10a^{-1}$) and increased by 13% in the planting density as $380plants{\cdot}10a^{-1}$($4,137kg{\cdot}10a^{-1}$). Therefore, the planting density of bitter gourd was desirable in $305plants{\cdot}10a^{-1}$ density for the higher yield and quality in the protected cultivation.

• Journal of The Korean Society of Grassland and Forage Science
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• v.25 no.4
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• pp.239-244
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• 2005

This study was conducted to investigate the effect of the planting densities and nitrogen levels on the growth characteristics, dry matter yield and nutritive value of corn for silage in alpine area(altitude 800m a.s.1.) of National Livestock Research Institute from 2001 to 2002. The experiment was arranged in a split plot design with three replications. Main plots consisted of three planting densities, low(67,000 plants/ha), medium(89,000 plants/ha) and high(95,000 plants/ha). Sub plots consisted of three nitrogen levels, 150 kg/ha, 200 kg/ha, and 250 kg/ha. Tassel height of corn was increased with decreasing planting density, and nitrogen level of 200 kg/ha in all main plots. Ear height of corn was decreased with increasing planting density, and 150 kg/ha of three nitrogen levels. But there were no significant differences among treatment in tassel and ear height. Although dry matter ear ratio of whole com was increased with decreasing planting density, there were no significant differences among treatments. But there were significant differences among nitrogen levels(P<0.05). Dry matter yield of com was high with increasing planting density, but there were no significant differences among treatments. And DM yield of corn was significant difference among nitrogen levels(P<0.05). Crude protein content of corn was the highest with high planting density and low nitrogen level. NDF and ADF content of com was the highest with low planting density and nitrogen levels of 200 kg/ha in all main treatments. These results indicate that low planting density(67.000 plants/ha) and nitrogen of 150-200 kg/ha would be the optimum level fur dry matter yield and nutritive value of silage com in alpine area.

• Korean Journal of Environmental Agriculture
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• v.42 no.3
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• pp.239-252
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• 2023

Most apple trees in South Korea are grafted on M.9 and M.26 rootstocks; however, these rootstocks are susceptible to fire blight. Although M.7 rootstocks are moderately resistant to fire blight, they tend to exhibit excessive vigor, which is unsuitable for high-density planting, unless weak cultivars are used. This study investigated the vegetative growth, yield, and fruit quality of apple trees grafted onto M.7, M.9, or M.26 rootstocks to assess the feasibility of establishing high-density apple orchards domestically using the M.7 rootstock a period of seven years (1-7 years after planting). Rootstocks were tested using three cultivars with contrasting induced vigor and harvesting times: vigorous and late-maturing 'Fuji,' moderate vigor and middle-maturing 'Hongro,' and low vigor and early-maturing 'Sansa.' The planting density was maintained constant, with 190 trees per 10 a. Primary thinning (leaving only the king fruit on clusters) was performed, whereas secondary thinning (controlling crop load) was not. Vegetative growth, accumulated yield per 10 a, and yield efficiency varied depending on cultivars and rootstocks; however, the cultivars had a more notable effect on fruit quality than the rootstocks. Biennial bearing often occurred in the M.26 rootstock. 'Fuji'/M.7 was overly vigorous for high-density planting. The fruit quality and accumulated yield per 10 a of M.7 were similar to those of M.9 with the 'Hongro' and 'Sansa' cultivars. In particular, 'Hongro'/M.7 did not show tree vigor reduction due to heavy crop load, and the degree of biennial bearing in 'Sansa'/M.7 was not particularly high. These results indicated that high-density apple planting using the M.7 rootstock was achievable using the 'Hongro' and 'Sansa' cultivars.

• Korean Journal of Plant Resources
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• v.20 no.4
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• pp.304-308
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• 2007

In order to find out the optimum fertilizer level and planting density of high yielding variety, $Okayma^{#2}$, this experiment was conducted with 3 compositions of fertilizer levels and a different plant density at the experiment paddy field of mat rush in Mokpo Experiment Station, National Institute of Crop Science, RDA. $Okayma^{#2}$, mat rush variety was grown under different fertilizer level and planting density with the highest yielding. Yield components such as stem length, number of stem were highest at the plots with fertilizer level (kg/10a), 80-20-40 and planting density, 20 ${\times}$ 10cm. Judging from the results reported above, at optimum fertilizer level and planting density of mat rush seemed to be 80-20-40kg/10a fertilizer and 20cm row spacing and l0cm or I5cm planting spacing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.1
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• pp.73-82
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• 1990

The experiment was carried out to study the influence of planting space and fertilizer application levels on some agronomic characters and yield in newly released semi-dwarf soybeans, Paldalbong and Dankyungkong. The number of branches per plant was not reduced by planting space from 60${\times}$10cm 30${\times}$15cm. These Semi-dwarf soybeans had good adaptability on high planting density. The number of pods per node on the main stem was different according to the planting space in Dankyungkong, but it was similar in Paldalkong except planting space 20${\times}$10cm. Regardless of planting densities and varieties, the number of grains per pod on upper node of the main stem was large. Coefficient of variation of pods and grains per node in the middle part of the main stem was small. The number of grains per plant was decreased in high planting density compared to low planting density, but the number of harvested plant per unit area was increased. Optimum planting space was 25${\times}$10cm in both varieties. The ability of nodulation was bigger in Dankyungkong than in Paldalkong.

• Plant Resources
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• v.4 no.1
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• pp.6-12
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• 2001

Growth and yield of licorice were investigated under the different conditions of ridge height, planting density, and irrigation in order to establish its cultural practices for the domestic production with the aim to substitute the import. Seedlings were grown under low ridge(20cm) and high ridge(40cm) in low density plot(60$\times$30cm) and high density plot(40$\times$30cm), respectively. The low ridge cultivation of large seedlings increased plant height and root length under low density, and stem and root diameter under high density compared to the high ridge cultivation. In the high ridge cultivation, high density plot was 1.1 to 1.3 times in plant height, root length, stem and root diameter as high as low density one. Fresh and dry weight of plant and root in high ridge were 1.3 to 1.5 times as high as those in low one. The growth of small seedlings(4~10g) were generally poor compared to that of large seedlings. High density plot in low ridge showed the good growth characteristics including plant height, root length, stem and root diameter, and number of branch. High density plot was 1.4 to 1.6 times in fresh and dry weight of plant and root as high as low density plot. In the seasonal changes of growth under various irrigation regimes, the twice irrigation a day produced the more number of leaf than the other regimes since around 46 days after transplanting. The former irrigation resulted in 1.2 to 1.4 times in plant height as long as the other irrigations around 26 days after transplanting and then the difference was increased to 1.6 to 2.0 times around 64 days after transplanting. Under the twice irrigation a day, plant height, root length, stem diameter, root diameter, number of leaf, fresh plant weight, dry plant weight, fresh root weight, dry root weight were 1.6 to 2.0, 1.1, 1.2 to 1.6, 1.3 to 1.8, 1.9 to 2.7, 1.7 to 8.0, 1.6 to 2.8,2.0 to 3.0, 1.6 to 2.7 times as high as those under the other irrigation regimes, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.214-220
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• 1999

Rice production in Korea has markedly increased during the last two decades due to newly developed high yielding varieties and improved production technology. This experiment was conducted to determine the potential of tropical japonica germplasm in enhancing the yield of temperate japonica. The yield performance of two tropical japonicas (IR 65597-29-3-2 and IR66154-52-1-2) and one temperate japonica (Dongjinbyeo) was compared at different plant densities and nitrogen levels under Korean environmental conditions. Although tropical japonicas showed low tillering habit and large panicles, they had similar leaf area index and dry weight at heading stage to Dongjinbyeo of the high tillering type indicating that there was not much difference between tropical and temperate japonica in terms of biomass production. The highest milled rice yield of 6.15 t/ha was obtained from Dongjinbyeo at a high nitrogen level with less planting density (220 kg N/ha and 30 $\times$ 15 cm). However, those of the two tropical japonicas were 5.36 t/ha at the condition of 165 kg N/ha and 30 x 10 cm planting density and 5.06 t/ha at the condition of 165kgN/ha and 15 x 15 cm planting density, respectively. Ripened grain of tropical japonicas ranged from 65 to 87%, while that Dongjinbyeo ranged from 82 to 97% under Korean conditions.

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.50-51
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• 1992

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.02a
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• pp.114-115
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• 1989