• Journal of Korean Society of Forest Science
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• v.111 no.4
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• pp.482-489
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• 2022

This study aimed to determine the optimal planting density of Fraxinus rhynchophylla assessed from the early growth performance at various planting densities over the 7-year period after planting. The study site was in Pyeongchang County, South Korea, and seedlings of 2-year-old (bare-root seedlings) F. rhynchophylla were planted at four densities (3,000, 5,000, 7,000, and 10,000 trees ha^-1) in March 2015. The survival rate, root-collar diameter (RCD), and height (H) were measured from 2015 to 2021, and the H/D (H/RCD) ratio and stem volume were calculated. The survival rate (84-97%) and H/D ratio (54.5-59.2%) were not affected by the planting density during the study period, but the RCD, H, and stem volume were significantly higher for 7,000 trees ha^-1 than for other planting densities. Especially, the stem volume (cm³ tree^-1) at 7 years after planting was highest for 7,000 trees ha^-1 (1,356.1), followed by 10,000 trees ha^-1 (958.6), 5,000 trees ha^-1 (773.0), and 3,000 trees ha^-1 (579.5). As the planting density increased, F. rhynchophylla seedlings showed initial rapid growth due to light competition, but relatively low growth at excessive planting densities. In the future, use of a suitable planting density considering planting costs should provide outstanding growth performance of F. rhynchophylla on plantations.

• Journal of Environmental Science International
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• v.31 no.7
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• pp.579-592
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• 2022

Much controversy has been generated over whether the ecological restoration project in Korea is faithful to the basic approach of ecological restoration compared to projects aimed at creating parks or green spaces. This study was aimed at understanding the level of awareness of practitioners in the planting design method, which is recognized as relatively important in landscape architecture and ecological restoration. The proficiency of practitioners in planting design techniques for ecological restoration projects was investigated and analyzed in seven areas: overall planting design awareness, plant species selection method, planting tree sizes, planting density, use of native species, vegetation climatic zone, soil environment, and weed control. There was no statistically significant difference between the group who thought they were experts in the field of ecological restoration and the group who thought they were experts in the field of parks and green spaces. Moreover, there was no statistically significant difference between the degree of work performance, that is, the group whose main industry was ecological restoration, the group that performed relatively more ecological restoration work, and the group that rarely performed it. Therefore, to apply desirable ecological restoration techniques in the future and to clearly differentiate between the approach in the field of parks and green spaces, the appropriate tree size or planting density selected in the ecological restoration planting design stage must be chosen. To this end, the awareness of expert groups must be improved and related laws, systems, and guidelines must be revised.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.255-258
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• 2006

This study was carried out to find the effect of the pinching and planting density on yield of petal and grain in safflower (Caythamus tinctorius L.). The planting density was high effective branch number per $m^2$ compared with pinching, and effective flower bud was most in $270ea/m^2$ in three line planting density, but in case of pinching was few at $186{\sim}223ea/m^2$ Grain yield was increased with 231 kg/10a at double line planting density compared with in 220 kg/10a of control. Petal yield of double line and three line planting density was 25.4 kg/10a and 26.9 kg/10a, it was increased 15, 22% compared with 22.0 kg/10a of control, respectively.

• Korean Journal of Environmental Agriculture
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• v.27 no.4
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• pp.356-361
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• 2008

Chrysanthemum indicum L. (Gamgug) has been examined to study their flowering habits, yields and bioactive compounds under different planting densities and mowing dates. The planting density experiment revealed a significantly increasing stem diameter, number of flowers and branches with decreasing plant density in the $100\;cm{\times}30\;cm$ and $130\;cm{\times}30\;cm$ treatments as compared to $70\;cm{\times}30\;cm$ treatments, but not plant height, leaf and flower width. On the other hand, the mowing date experiment showed that growth characteristics of plants were similar to the control plants (not mowing) and June 20 treatment, but July 20 treatments had significantly smaller than the control. The weights (g $plant^{-1}$) of dry flowers were affected by the planting density and mowing date. The flower yield of $586\;kg\;ha^{-1}$ obtained at $100\;cm{\times}30\;cm$ density was 11% and 22% higher than that of $120\;cm{\times}30\;cm$ and $70\;cm{\times}30\;cm$ treatments, respectively. The yield of dry flowers in the control and June 20 mowing date ranged $495-508\;kg\;ha^{-1}$, which is 40-42% higher than the yield in the July 20 treatments. The amount of essential oil (g $plant^{-1}$) in medically valuable flowerheads of C. indicum L. was statistically different between mowing dates but not among planting densities. The study showed that planting density and the mowing date could increase yields of flowerheads. An optimum planting density of $100\;cm{\times}30\;cm$ and mowing date of on or before June 20 is recommended for C. indicum L.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.2
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• pp.95-99
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• 2001

Soybean [Glycine max (L.) Merr.) is known to produce the highest total digestible mutrients (TDN) yield among summer grain legumes in Jeju area but little is known about the effects of cultural practices on forage yield and quality. A determinate soybean cv. Baegunkong was planted on 5 June, 20 June, and 3 July and grown at four plant densities (30, 50, 70 and 90 plants $m^{-2}$ in 1998 in Jeju to evaluate the effects of planting date and plant density on the yield and quality of soybean forage. Days to flowering decreased from 47 to 38 days, average plant height from 61 to 51cm and main stem diameter from 6.31 to 5.00mm as planting was delayed from 5 June to 3 July. Average plant height quadratically increased from 45 to 62cm as plant density increased from 30 to 90 plants $m^{-2}$. Planting date did not affect the average dry matter, crude protein, and TDN yields. The average dry matter and TDN yields displayed a quadratic response to plant density and the optimum plant density for both dry matter and TDN yields was estimated about 60 plants $m^{-2}$. Plant density had no effect on crude protein yield. Planting date did not significantly influence forage quality. The crude protein content was not significantly influenced by plant density. Increasing plant density slightly increased acid detergent fiber content but slightly decreased TDN content.

• 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.

• Korean Journal of Environment and Ecology
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• v.28 no.2
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• pp.150-160
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• 2014

In this study, the analysis carried out on characteristic of planting species and planting density of parks and green spaces in downtown city of Haengjeong-dong in Wonju, Gangwon Province. We found that 8,050 coniferous trees (19 species), 6,037 deciduous trees (61 species) and 77,609 shrubs 103 species were planted in the parks and green space in Haengjeong-dong. However, a conifer Pinus strobus is highly concentrated in all four kinds of places which are neighborhood park, children's park, green buffer zone and landscape green space regardless of their period of construction and usage of surrounding land and other trees were planted in order of Pinus koraiensis, Prunus yedoensis, Acer palmatum, Zelkova serrata, Pinus densiflora. Average planting density of parks and green spaces is $0.03tree/m^2$ for a tall tree and $0.18tree/m^2$ for a shrub, which shows low planting density in most parks and green spaces of Wonju. Also, understory vegetation was not planted enough. Since area of lawn is wide in green spaces, planting density is needed to be increased and tall trees should be planted more. Therefore, we suggest planting more trees in an area where trees are not planted, multi-layered vegetation and increasing in planting density through shrub planting etc., by identifying spaces for trees to be planted within parks and green spaces.

• Korean Journal of Plant Resources
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• v.17 no.2
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• pp.102-106
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• 2004

To determine the optimal planting density of wanggol in southern areas of Korea, Gangsan early local, the highest yielding variety was grown under four different plant density. Yield components such as stem length, number of tiller, stem diameter were highest at the plots with 18 cm row spacing and 18 cm plant spacing. Dry cortex and medulla yield were highest at the plots of 18 cm row spacing and 18 cm plant spacing. Judging from the results reported above, at optimum planting density of wanggol seemed to be 18 cm row spacing and 18 cm plant spacing.

• Journal of the Korean Institute of Landscape Architecture
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• v.37 no.2
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• pp.114-123
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• 2009

To investigate the possible use of plants for landscaping in reclaimed soil, a planting pilot system experiment was performed over the course of four years in reclaimed dredging area with four species: Alnus firma, Alnus hirsuta, Pinus thunbergii, and Pyrachantha angustifolia for 4 years. The physicochemical characteristics of the tested soil showed that it was sandy through coming from a reclaimed dredging area. The average pH of the tested soil was 7.16(slight alkali), and electric conductivity(EC) was relatively low, $294{\mu}S/cm$, even though it came from a saltwater area. To test the effect of planting density vs. phytomass by plant specie from a planting basin, the experiment was designed using four plant species with high and low planting densities over 4 years. The planting conditions of the growth of landscape tree species exhibited growth height as follows: A. hirsuta, A. firma, P. thunbergii, and P. angustifolia, whill the DBH followed the order of A. hirsuta, A. firma, and P. thunbergii. The total phytomass of each plant was higher at low density planting areas than high density planting area in terms of total phytomass production and growth distribution in the reclaimed dredging area. Total phytomass per unit area increased as follows: A. hirsuta, A. firma, P. thunbergii, and P. angustifolia. The total phytomass per each tested plant was 2 times higher in low density planting areas than high density planting areas. Total phytomass per unit area, however, was similar or slighty higher in high density planting areas compared to low density areas. Among the tested plants, A. hirsuta showed the highest phytomass, implying that A. hirsuta adapted very well to the reclaimed area and has the capability of a fast growth, nitrogen fixation tree, and utilizing insoluble nutrients through inoculated root nodule bacteria. The yield of phytomass per individual in low density Alnus species was greater than that of the high density. However, those per unit areas had no difference in the density-dependent planting. The ratio of belowground to aboveground was $0.21{\sim}0.26$. Thus, it could be concluded that the Alnus species are potential candidates for ornamental tree species in reclaimed dredging areas. This study offers baseline data for the use of ornamental tree species in reclaimed dredging areas. Additional research is required for different ornamental species in order to increase phytomass of a planting conditions based on reclaimed dredging areas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.33-39
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• 2019

The goal of this study was to investigate how the characteristics of growth and yield are affected by various planting densities in wide-row drill seeding cultivation suitable for mechanized harvesting. Two cultivars ('Hwanggeum' and 'Leebackchal') of proso millet (Panicum miliaceum L.) were planted at varying planting densities [row spacing (20, 30, and 50 cm) and plant spacing (3, 5, 10, and 15 cm)]. The culm length was highest at the planting density of $50{\times}3cm$ and $50{\times}5cm$ for 'Hwanggeum' and $20{\times}3cm$ for 'Leebackchal'. The culm diameter became thinner as the planting density increased. The number of tillering and panicle length showed the same tendency to increase in quantity or length as planting density decreased and was highest at $50{\times}15cm$ when the planting density was lowest. The number of seeds per individual increased as planting density decreased. The thousand grain weight showed no significant differences among treatment plots. The greatest yield of 'Hwanggeum' was obtained at a planting density of $50{\times}3cm$ ($314.9kg{\cdot}10a^{-1}$) and that of 'Leebackchal' was obtained at $50{\times}3cm$ and $50{\times}5cm$ ($358-356kg{\cdot}10a^{-1}$).