• Korean Journal of Agricultural and Forest Meteorology
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• v.14 no.2
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• pp.45-52
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• 2012

Enrichment planting is commonly used for increasing the density of tree species in secondary forests and one of forest rehabilitation programs in Lao PDR. This study aimed to determine the performance of five native species in enrichment planting using different canopy opening treatments, and to examine the suitable species and silviculture techniques applicable to a logged-over forest in Lao PDR. Results of the study showed that only crown height had significant difference among species and planting treatments. The survival rate and crown diameter were significantly different by species, but not by planting treatments. However, root collar diameter (RCD) and height of seedlings showed significant differences among planting treatments. Among the study species, Hopea odorata and Dalbergia cochinchinensis showed significantly higher survival rate and height growth, indicating their suitability in enrichment planting for rehabilitation of forest in Lao PDR. The results also suggested that 2 m width line planting stimulated RCD growth, but wider line planting, such as gap planting, promoted height growth of seedlings.

• Proceedings of the Korean Society of Crop Science Conference
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• 1989.02a
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• pp.110-111
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• 1989

• 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.

• Journal of Korea Foresty Energy
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• v.1 no.2
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• pp.1-19
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• 1981

In order to investigate biomass yield of one-year-old hyblrid poplars, Pripulusalba x P. glandulosa $F_1$ and Populus nigra var. italica x P. maximowiczii $F_1$clones, as energy and fiber resources, dry matter yield, leaf area, leaf area index, dry matter production ability, specific gravity and fiber length and width were measured. Dry matter yield was 1.89 ton/ha for Poplus alba x P. glandulosa $F_1$ and 3.63 ton/ha for Populus nigra via.italica x P. merximowiczii $F_1$ clones in the planting density of 20,000 trees/ha and in the planting density of 40,000 trees/ha was 3.87 ton/ha for Populus alba x P. glandulosa $F_1$and 5.64 ton/ha for Populus nigra var. italica x P. maximowiczii $F_1$ clones. Leaf area index was 1.24mtim2 in the planting density of 20,000 trees/ha and 2.45 m31m3 in the density of 40,000 trees/ha for Populus alba x P. glandulosa $F_1$ clones and it was 1.96 m21m2 in the planting density of 20,000 trees/ha and 3.36 m21m2 in the density of 40,000 trees/ha for the hybrid $F_1$ Populus nigra var. italica x P. maximowiczii clones. The average specific gravity of the hybrid poplars was 0..36 when bark and pith were included and 0.31 when bark and pith were removed in the plot of 20,000 trees/ha and in the 40,000 trees/ha plot showed 0.35 and 0.31 respectively, for Populus alba x P. glandulosa $F_1$clones. It was 0.36 when bark and pith were included and 0.32 when bark and pith were removed in the 20,000 trees/ha plot and in the 40,000 trees/ha plot was 0.34 and 0.31 respectively for Populus nigra var. italica x P. maximowiczii $F_1$clones. The average fiber length was 0.57 mm in the 20,000 trees/ha plot and 0.58 mm in the 40,000 trees/ha plot for Poplus alba x P. glandulosa $F_1$clones and was 0.60 in both plots of 20,000 trees/ha and 40,000 trees/ha for Populus nigra var. italica x P. maximowiczii $F_1$ clones. There is a big clonal variation among those clones studied, showing high selection potential in both species.

• Journal of Forest and Environmental Science
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• v.24 no.1
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• pp.35-39
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• 2008

The present study was conducted to analyze the soil environment of planted areas around Sudokwon Landfill Site, and drew conclusions as follows. Among the physical properties of soil, bulk density ranged between 1.11~1.59 $g{\cdot}cm^{-3}$, which was higher than the average bulk density (1.05 $g{\cdot}cm^{-3}$) of the B layer of forest soil in Gyeonggido, Korea. This is probably because of treading by heavy equipment used to prepare the ground for planting, and measures should be taken to improve bulk density for the growth of the root system of trees. Among the chemical properties of soils, the organic matter content was only 1/5~1/10 of 30 $g{\cdot}kg^{-1}$, the adequate level for landscape planting. In addition, cation exchange capacity (CEC) ranged between 1~3 $cmol{\cdot}kg^{-1}$, which was much lower than 6 $cmol{\cdot}kg^{-1}$, the least capacity for landscape planting. Therefore, these problems need to be solved.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.2
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• pp.162-166
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• 2014

This study was conducted to evaluate effects of planting densities ($60{\times}5cm$, $60{\times}10cm$, $60{\times}15cm$) and PE mulching (polyethylene film mulching, non- mulching) on growth and yield of foxtail millet in drained paddy field for 2 years. In PE plots, culm length, culm diameter and fresh weight were higher than control plot. Additionally, spike length, seed weight per hill and thousand seed weight were also higher in PE plot. The yield of foxtail millet were increased with 104% and 112% at PE plot. Culm diameter was highest at $60{\times}15cm$ plot with 8.90 and 8.06 mm, however, culm length was highest at $60{\times}5cm$ plot with 130, 142 cm in $1^{st}$ and $2^{nd}$, respectively. Plant height was higher by the increase of planting density. As plant density decreased, that spike length and seed weight per hill were increased. Yield of planting density were highest at $60{\times}10cm$ plot $298kg{\cdot}10a^{-1}$, $436kg{\cdot}10a^{-1}$ yearly, respectively that it were in order of $60{\times}10cm$ plot > $60{\times}5cm$ plot > $60{\times}15cm$ plot.

• Korean Journal of Plant Resources
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• v.8 no.2
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• pp.209-215
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• 1995

This experiment was carried out to elucidate the effect of row width and hill space on growth and yield in cynanchum wilfordii on experimental fields of chungbuk Provincial Rural Development Administration. Emergence date was May 25 and had no differences between planting density. Vine length was 219cm with row 40cm, 220cm, with 50cm and 225cm with 60cm, and in hill spaces, it was 225cm with hill space 10cm, 219cm with 15cm, and 218cm with 20cm. No. of leaves was same tendencies to vine length and was more increased as the hill space was narrower. Root length was longer about 0.9cm to 1.4cm as the hill space was wider, and no. of root had no difference between planting tensity. Yield was more increased row width was wider and was decreased hill space was wider. And the profitalble planting density was row width 50cm and hill space 10cm in the cultivation cynanchum wilfordii.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.363-369
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• 2010

This study was carried out to investigate proper planting density and depth of tissue-cultured oriental lily bulblets for bulb production. Planting densities of bulblets were 200, 400, 600, 800, 1,000 bulblets/ $m^2$, and planting depths were 1, 3, 6, 9, 12 cm. Proper planting density of tissue-cultured 'Siberia' bulblets was 400 bulblets/ $m^2$ with 87.3% of survival rate, 6.4 cm of bulb circumference, and 8.3 g of bulb weight. For 'Sorbonne', it was thought to be 400 bulbs/ $m^2$ with 88.8% of survival rate, 5.0 cm of bulb circumference, and 7.1 g of bulb weight. Proper planting depth of tissue-cultured 'Siberia' bulbs was 3 cm with 77.8% of survival rate, 5.9 cm of bulb circumference, and 7.9 g of bulb weight. For 'Sorbonne' bulbs, it was 3 cm with 87.1% of survival rate, 5.1 cm of bulb circumference, and 6.5 g of bulb weight.

• Korean Journal of Plant Resources
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• v.24 no.5
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• pp.507-513
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• 2011

This study was conducted to evaluate the effect of mulching material and planting density on growth and bulb development of shallot. The transparent PE film was better than black PE film as a mulching material for the overwintering shallot crop. Transparent PE film mulching promoted plant growth and increased marketable yield by 21% as compared with that of the black PE film-mulched crop. However, the bulb size was not significantly affected by the type of mulching film. The height and width of ridge and planting density significantly affected the growth and bulb yield of the moisture sensitive shallot. Bulb yield of the shallot planted in five rows in 120 cm wide ridges (20,833 plants per 10 a) was 1,332 kg per 10 a, which was 1.7 times as high as that by the crop grown in three rows in 120 cm wide ridges (12,500 plants per 10 a). In conclusion, the shallot crop is recommended to be cultivated in five rows in 120 cm ridges mulched with the transparent PE film.

• Korean Journal of Plant Resources
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• v.10 no.2
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• pp.140-144
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• 1997

This experiment was carried out to investigate the proper planting method of Rehmannia glutinasa Liboschitz. A Chungbuk local cultivar was sown on the seed bed of 200cm with the planting density of 30cm(6 rows) $\times$ 8.5cm(30 rhizome per $\textrm{m}^2$). The experimental design was randomized block design with 3 replications. And the result was summarized as follows. The emergence date of level Planting(control : 0$^{\circ}$) was May 23, but the emergence dates of Oblique planting(45$^{\circ}$) and Upright planting(90$^{\circ}$) treatments were later than the control by 2~4 days. And the leaf length and the ratio of leaf length/leaf width were not significantly different. As compared with the 29.2cm and 10.0mm of the rhizome length and the rhizome diameter of level planting treatment, the rhizome length of Oblique planting treatment was decreased by 3.4cm and 0 mm. The length and diameter of rhizome of the Upright planting treatment was decreased by 2.8cm and 1.0mm. And the order of sugar content was level Planting > Oblique planting > Upright planting. The total yields were decreased by 9% in the Oblique planting and by 15% in the Upright planting compared to 1,203kg/10a in the control, and the commercial yields showed the same tendency. The level planting treatment was found to be most proper for sowing of Rehmannia glutinasa Liboschitz in the middle inland region of Korea.