• Korean Journal of Agricultural and Forest Meteorology
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• v.15 no.4
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• pp.210-218
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• 2013

The sea breeze shows different characteristics compared to land breeze, such as high wind speed and more rapider shift period. One of the major factors affecting plant early growth is wind speed. In the early growth stage, tree growth-rates rise with decreasing wind speed. Thus, the study was performed to identify wind break effects on wind characteristics and tree growth. The wind break used in this study was about 130 meters length and 3 meters height, made up with poly-ethylene (with 40% openness). We installed one vane and fifteen anemographs at three different heights (1, 2 and 3 meters) on the inner and outer wind break areas. The wind characteristic and plant growth data were collected from Jun. 2011 to Oct. over 2012. The wind rose of the Saemangum seawall area presented the north (21.5%) and it was followed by north-west (18.1%), east (14.9%) and north-east (13.7%) and the remainder with other directions. Wind speeds at height were different. The tree height was 159.6 cm at inside and 129.6 cm at outside. The diameter at root-collar was 36.9 mm at inside and 32.6 mm at outside from wind break.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.4
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• pp.392-402
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• 1987

To know the effect of presowing seed soaking with some growth substances (kinetin, IAA, ethrel and salicylic acid) on vegetative growth and yield contributing parameters in soybean [Glycine max (L.) Merrill] the investigation was undertaken. The salient features from the study are;-All the treatments showed the enhancement effect on vegetative growth, viz. seediling emergence, germination percentage, plant height, number of leaves and branches per plant as compared with control, whereas salicylic acid delayed the seedling emergence process and lowered the germination percentage.-Nodule initiation, number of nodules and nodule weight were hastened and increased respectively under all the treatments whereas IAA showed an opposite effect on all the parameters at the early stages of nodule development.-Kinetin, IAA and ethrel showed the significant enhancement effect on the levels of biochemical parameters throughout the time of seed development whereas salicylic acid and water showed the tendency similar to that of control.-Yield and its components, viz. number of flowers, pods and seeds per plant were significant increased under all the treatments but they didn't show any significant enhancement effect on number of seeds per pod and pod setting rate. One hundred seed weight was lower under all the treatments, indicating the dilution effect resulting from incapability of increased number and size of source to provide the increased size of sink with assimilates.

• Journal of Korea Foresty Energy
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• v.21 no.3
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• pp.46-53
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• 2002

The study was carried out to determine the growth and biomass production of deciduous trees including Betula pendula, Fraxinus rhynchophylla, Cornus controversa subjected to artificial shade treatment of three levels in nursery field. The results were as follows; The height growth of seedlings was no difference subjected to artificial shade treatment. The root collar diameters of the relative growth rates of seedlings grown in full sun showed 29-32% as compared with those subjected to the shade treatment of 7-10% light intensities of full sun. Corrus controversa of the root collar diameters of the relative growth rates were better in the seedlings grown in 26-34% light intensities of full sun. Total dry mass including the dry mass of leaves, shoot and root were as a whole decreased with shade treatment. The ratio of the dry mass of leaves and stem increased the dry mass of root. T/R ratio of the seedlings increased by decreasing the relative light intensity. And the T/R ratio of 7-10% light intensities of full sun was ranged from 1.00~2.27 were greater in the full sun light was ranged from 0.51~l.13. Light intensity by artificial shade treatment decreased in deciduous trees when compared on the whole, it showed tendency that SLA increases, increased that seeing resemblant tendency in LAR and LWR and changed of light intensity is strong, it increased that showed difference as statistical.

• Journal of Life Science
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• v.31 no.5
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• pp.511-519
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• 2021

The Perilla frutescens var. japonica HARA is widely cultivated in Korea for vegetable leaves and oil seeds. Perilla species have been used for food and medicine and are known to contain many functional compounds. In this study, we investigated the functional compound contents of Perilla during its growth stages to analyze the optimal harvest time and conditions. The contents of the Perilla sprouts were analyzed according to culture environment and days of growth. Sprouts grown in soil under natural light conditions showed high rosmarinic acid (23.19±0.16 mg/g) and GABA (0.55±0.05 mg/g) content. Therefore, the results suggest that 6 to 8 days after sowing in soil under natural light conditions was the optimum harvest condition for sprouts. Also, the functional compounds of Perilla were analyzed according to growth stage and plant part. As a result, caffeic acid and rosmarinic acid exhibited the highest content in the stage from vegetative growth to reproductive growth (0.28±0.03 ~ 0.30±0.07 mg/g rosmarinic acid and 20.60±7.02 ~ 19.37±3.18 mg/g caffeic acid), and luteolin and GABA showed the highest content in the reproductive growth stage and in the early stages of vegetative growth, respectively (31.11±2.98 ~ 22.35±1.64 ㎍/g luteolin and 0.42±0.09 ~ 0.37±0.04 mg/g GABA). It was confirmed that the content of caffeic acid (0.34±0.03 mg/g), rosmarinic acid (55.22±9.33 mg/g) and luteolin (1,044.89±6.72 ㎍/g) was the highest during the bolting stage. Overall, we identified the timing of the highest level of functional compounds in the sprouts and mature leaves of Perilla. These results suggest a suitable harvest time and conditions for sprouts and leaves for the use of Perilla as a functional material.

• Korean Journal of Environmental Biology
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• v.19 no.1
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• pp.7-17
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• 2001

Growth optima and tolerance ranges of marine algae species nay vary greatly during the developmental stage. The establishment stage is clearly of great importance for each generation, affecting the performance of the adult population. The present study was aimed to determine the effect of various concentrations of inorganic nutrients and heavy metals on germination and germlings of Ulva pertusa Kjellman (Chlorophyta). Percent germination increased rapidly as irradiance level increased, reaching the maximum at 100 ${\mu}$mol m$\^$-2/s$\^$-1/ in both east and west seawater. Percent germination in the east seawater was higher than that in the west seawater at irradiances lower than 30 ${\mu}$mol m$\^$-2/s$\^$-1/, and there was no difference in percent germination between the two different seawaters at irradiances higher than 60 ${\mu}$mol m$\^$-2/s$\^$-1/. Germling growth increased in the both cases with increasing irradiances but no growth was found in the dark. Overall germling area was larger in the east seawater than in the west seawater. Number of cell increased with increasing irradiance and became light-saturated at 100 ${\mu}$mol m$\^$-2/s$\^$-1/ in the both cases. Germlings grown in the east seawater had more cells than those cultivated in the west seawater at irradiances lower than 60 ${\mu}$mol m$\^$-2/s$\^$-1/. In various combinations of nitrate and phosphate, percent germination increased with increasing nitrate concentrations irrespective of phosphate concentrations. At 3 days after inoculation, nitrate concentration of 2.5 ppm with all phosphate concentrations promoted germination. Area and number of cell of germlings increased with increasing nitrate concentrations in all phosphate concentrations. In various combinations of copper and lead, germination was delayed as copper concentrations increased in all lead concentrations. Percent germination was severely reduced at 1 ppm Cu$\^$2+/. Area and number of cell of germlings decreased with increasing copper concentrations in all lead concentrations. The highest copper concentration (1 ppm) clearly suppressed the germling growth in U. pertusa.

• Korean Journal of Environmental Biology
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• v.29 no.4
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• pp.274-279
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• 2011

In order to know the effect of seed size on the early plant life history, we measured the rate of germination, early growth and winter survival of four oak species with different acorn size (large, medium and small). The mean germination rate was higher in the larger seed species ($Q.$ $acutissima$ and ($Q.$ $variabilis$) than those of the smaller seed species ($Q.$ $aliena$ and $Q.$ $serrata$). Within $Q.$ $variabilis$, the germination rate decreased with larger acorn size class but that of rest other species was not significantly affected by the acorn size. The early mean growth rate decreased with acorn size in the order of $Q.$ $acutissima$, $Q.$ $variabilis$, $Q.$ $aliena$ and $Q.$ $serrata$. The early mean growth rate was higher in large or medium size than in small size of $Q.$ $acutissima$ and $Q.$ $variabilis$, but it showed no difference with acorn size in $Q.$ $aliena$ and $Q.$ $serrata$. Survival rate in winter was the highest in the medium acorn size among 4 oak species, the seedling of $Q.$ $serrata$ and $Q.$ $variabilis$ did not survive in both large and small acorn size. These results indicate that seed size influences a different effect on the early plant life history stage.

• Journal of Aquaculture
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• v.20 no.1
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• pp.7-13
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• 2007

The seed production of Ecklonia stolonifera Okamura was studied under laboratory conditions through the embryonic sporophyte stage and the field cultivation was conducted in eastern coast of Korea. The germination of zoospores occurred within 3 days and the growth of gametophytes was most rapid at $25^{\circ}C$ and $20\;{\mu}mol{\cdot}m^{-2}s^{-1}$. Sporophyte growth was highest at $20^{\circ}C$ and $20\;{\mu}mol{\cdot}m^{-2}s^{-1}$ and lowest at $25^{\circ}C$ and $80\;{\mu}mol{\cdot}m^{-2}s^{-1}$. In the nursery culture of E. stolonifera lasting for 2 weeks in January, the initial blade length of E. stolonifera (about $500\;{\mu}m$) grew to $526.3{\pm}176.0\;{\mu}m$ at water temperature of $12.05^{\circ}C$. The blade length and width reached their maxima in July, after which the ends of blade and stem began to degrade with the increase in water temperature. The degraded end of the blade started to regenerate in October, when water temperature began to decline. This species can be considered a potential candidate for aquaculture, increasing in the availability of raw material and aiding in recovery of seaweed bed.

• Korean Journal of Remote Sensing
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• v.40 no.3
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• pp.275-284
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• 2024

Monitoring crop growth changes and water content is crucial in the agricultural sector. This study utilized drones equipped with Short Wavelength Infrared (SWIR) sensors, sensitive to moisture changes, to observe soybeans' growth and water content variations. We confirmed that as soybeans grow more vigorously, their water content increases and differences in irrigation levels lead to decreases in vegetation and moisture indices. This suggests that waterlogging slows down soybean growth and reduces water content, highlighting the importance of detailed monitoring of vegetation and moisture indices at different growth stages to enhance crop productivity and minimize damage from waterlogging. Such monitoring could also preemptively detect and prevent the adverse effects of moisture changes, such as droughts, on crop growth. By demonstrating the potential for early diagnosis of moisture stress using drone-based SWIR sensors, this research suggests improvements in the efficiency of large-scale crop management and increases in yield, contributing to agricultural production.

• Journal of Korean Society of Forest Science
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• v.99 no.1
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• pp.68-74
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• 2010

The present study was conducted to investigate growth performance and ascorbic acid contents of Allium victorialis var. platyphyllum, Ligularia fischeri, and L. stenocephala growing under four different light intensity regimes (full sun, and 64~73%, 35~42%, 9~16% of full sun). The leaf area and total biomass of Allium victorialis var. platyphyllum were highest in 35~42% of the full sun. However, the leaf area and total biomass were highest in 64~73% of the full sun in Ligularia fischeri, and L. stenocephala. The leaf thickness decreased with increasing shading in all three wild vegetables. The growth of root comparing to that of shoot decreased as shading increased, and as the result, the ratio of shoot biomass to root biomass increased. Ascorbic acid contents were higher in Allium victorialis var. platyphyllum than in Ligularia fischeri and L. stenocephala. Allium victorialis var. platyphyllum showed the highest contents of ascorbic acid in 35~42% of full sun. Whereas Ligularia fischeri and L. stenocephala showed the highest in 64~73% of full sun.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.2
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• pp.185-191
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• 1981

The purpose of this paper is to define and describe a series of growth stages for maize. cv. MTC-l (early) and Suweon No. 19 (late) that are easily identifiable by both professional agronomists and farmers. Plants were grown at a density of 60cm row with plant spacing of 15cm at six different seeding times in 1980. Leaf development indices with ten grades (LDI) were identified and defined in accordance with the development of a leaf blade. Leaf appearance rate (LAR) was ca. 3 days and it was not influenced by the variety or seeding time. The elongation of the first internode above the ground level began in a month after emergence and it corresponded to the 8th or 9th leaf stage. Internodes elongated in regular sequence of node position. The morphological change of silks related closely with the development of kernel. The duration of generative development was not influenced by varieties and seeding time but that of vegetative growth was influenced. A new scheme for the maize which was made by the developed leaves, visible nodes above ground level, morphological change of silks and development of kernel was proposed.