• Weed & Turfgrass Science
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• v.6 no.3
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• pp.262-271
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• 2017

This study was conducted to evaluate incorporation ratio of soil amendment 'Profile' to improve soil physicochemical properties and turfgrass growth. The soil amendment was added 0 (sand only), 3, 5, 7, and 10% to USGA Green-spec green sand soil. As incorporated with more 'Profile' amendment, soil electrical conductivity (EC), cation exchangeable capacity (CEC), capillary porosity and total porosity of root zone were increased than those of control, while bulk density and hydraulic conductivity decreased. Turfgrass index and clipping yield of creeping bentgrass grown in sand soil incorporated with 7% 'Profile' were improved than those of control. Correlation coefficient of turf color index and incorporation ratio of the soil amendment 'Profile' was found to show significantly positive correlation. These results indicated that application of the soil amendment 'Profile' to sand soil in golf course green improved turfgrass growth and quality by increasing CEC and porosity of root zone.

• Asian Journal of Turfgrass Science
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• v.25 no.2
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• pp.190-194
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• 2011

Potassium (K) is one of the essential nutrients for plants but is not a constituent of any plant compound. K is substances for activation of many enzymes and influences the process that the enzymes are involved in catalyzing. Although experimental results associated with the K effects with both benefits and no effects on turfgrass growth were reported, the limited research results of K effects on turfgrass among K sources are available in Korea. The objectives of the study was conducted to evaluate responses of Kentucky bluegrass (Poa pratensis L.) treated by fertilizer treatments with six K sources. There were six fertilizer treatments as K sources applied to Kentucky bluegrass which were potassium nitrate (13-0-44, PN), potassium chloride (0-0-60, PC), potassium sulfate (0-0-50, PS), polymer-coated potassium sulfate (0-0-45, PPS), potassium thiosulfate (0-0-25, PT), and potassium sulfate granulated with methylene urea (20-0-25, PSU). Potassium of $8g\;m^{-2}$ and N of $5g\;m^{-2}$ was applied 4 times giving a total 20 and $30g\;m^{-2}$, respectively. Although significant differences were found for turfgrass color, quality, chlorophyll index, and clipping dry weight, no consistent results among K sources were found during the one year study. Overall, K treatments didn't affect turfgrass growth in this study.

• Korean Journal of Environment and Ecology
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• v.30 no.4
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• pp.651-657
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• 2016

It is important to know know deleterious impact of deicing salt on plants for guidelines of planting along roads. The aim of this study was to determine the effect of calcium chloride ($CaCl_2$) on the growth and physiological characteristics of Liriope platyphylla and Pachysandra terminalis. The plants were grown from November of 2015 to March of 2016 in pots containing growing media with $CaCl_2$ at 0% (Control), 0.5%, 1.0%, 3.0%, and 5.0% (based on the weight). While plant growth and photosynthetic activity were significantly decreased in both plant species grown on the media with $CaCl_2$, the degree of sensitivity to $CaCl_2$ differed. The plant growth of Liriope platyphylla was considerably injured under higher than 3.0% of $CaCl_2$, whereas Pachysandra terminalis was all dead under higher than 1.0% of $CaCl_2$. This results indicate that Liriope platyphylla has higher degree of tolerance to the deicing salt than Pachysandra terminalis.

• Korean Journal of Agricultural and Forest Meteorology
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• v.12 no.3
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• pp.173-182
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• 2010

This study was conducted to investigate ozone sensitivity of physiological indicators and the difference in ozone tolerance of 8 families of Sophora japonica seedlings on the basis of the standardized physiological indicators. After ozone treatment, photosynthetic parameters, photosynthetic pigments and malondialdehyde (MDA) content, and antioxidative enzyme activities were analyzed from the leaves of S. japonica seedlings. Ozone tolerance indices among 8 families were calculated with the standardized physiological parameters. In addition, the reduction of carboxylation efficiency and apparent quantum yield were observed in the leaves of seven families, except for family No. 6 and 7, respectively. The apparent quantum yield varied from -27% to -61% of the control seedlings. Photosynthetic pigment content differed significantly among 8 families, but was not affected significantly by ozone treatment. Superoxide dismutase (SOD) activity increased from 7% to 64% after ozone exposure, and significant difference existed among 8 families. Ascorbate-peroxidase (APX) activity of 8 families increased by ozone treatment, and the activity of family No. 7 showed the highest increase (218%) in comparison to their respective control plants. On the basis of the standardized indices, family No. 6 showed the lowest tolerance by indicating higher reduction of both photosynthetic parameters and pigment content and lower increase of antioxidative enzyme activities. On the contrary, family No. 7 showed the highest tolerance as indicated by lower reduction of photosynthetic parameters, higher amounts of photosynthetic pigments, and higher enzyme activity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.28 no.4
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• pp.439-444
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• 1983

Effects of temperature and soil moisture on the growth and grain-filling of two wheat cultivars were investigated. Two levels of temperature; day 3$0^{\circ}C$/night $25^{\circ}C$ and day 2$0^{\circ}C$/night 15$^{\circ}C$ and two levels of soil moisture; stressed (45-50% of F.C.) and non-5tressed (50-60% of F.C.) were imposed in the green house from heading date to the maturity and grain weight, chlorophyll content of flag leaf and leaf area index(LAI) were observed at weekly interval. Grain maturation was faster in the high temperature than those in the lower temperature. Chlorophyll content of flag leaf and LAI decreased rapidly in the high temperature and chlorophylls disappeared at the 20 days after heading. In lower temperature condition, slower decrements were shown in chlorophyll content and it remained until 45 days after heading. Grain weights in the high and optimum temperature conditions reached to maximum values at 29 days and 45 days after heading, respectively. Differences of grain weight and chlorophyll content of flag leaf were not significant between stressed and non-5tressed soil moisture condition.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.136-142
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• 2008

We conducted this study to compare physiological response according to growing conditions between superior and inferior family of Pinus densiflora. In 1981, open-pollinated (OP) progenies of P. densiflora were planted in Chuncheon (CC) and Naju (NJ). We selected KW2 as a superior family and KW23 as a inferior family based on volume index among 30 OP progenies. We calculated general combining ability of each 30 OP progenies in each sites, and compared family growth rank. We collected needles of selected families in CC and NJ, and analyzed chlorophyll content, nitrated reductase (NR) activity, nitrogen content, and superoxide dismutase (SOD) acitivity. In CC, chlorophyll content and nitrogen content were more in needles of KW2 than those of KW23. In NJ, KW2 showed higher NR activity than KW23, and according to site, families in CC showed higher NR activity than those in NJ. SOD activities of both families were higher in NJ, and KW23 showed higher activity than KW2 in both sites. Consequently, inconsistency of the growth performance of two families was caused by different genetic and physiological responses.

• Journal of Korean Society of Forest Science
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• v.112 no.2
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• pp.136-144
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• 2023

This study aimed to determine the optimal fertilization level for the production of Hovenia dulcis Thunb. seedlings. The height, root collar diameter, biomass, seedling quality index, and chlorophyll content of Hovenia dulcis container seedlings (1-0) according to six fertilization treatments (control, 0.5, 1.0, 1.5, 2.0, 2.5 g·L^-1) were investigated. The height, root collar diameter, and biomass of Hovenia dulcis container seedlings increased with increasing fertilization, but there were no significant differences among the ≥1.5 g·L^-1 treatments, and the 2.5 g·L^-1 fertilization treatment was associated with significantly lower height growth. The seedling-quality index showed a high but non-significant difference in the ≥1.5 g·L^-1 treatment range, and the chlorophyll content was highest in the 1.5 g·L^-1 treatment group. Considering the environmental and cost aspects of fertilization, the appropriate level of fertilization required for superior container seedling production of Hovenia dulcis was 1.5 g·L^-1, and a minimum fertilization treatment of ≥0.5 g·L^-1 should be applied to meet the minimum seedling specifications. These results are expected to be used as basic data for establishing an efficient seedling-production system and stable supply of Hovenia dulcis, which is used as a medicinal and honey plant.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.4
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• pp.398-404
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• 1985

This study was conducted to define the seasonal differences in the morphological characteristics, the photosynthetic abilities and the dark respirations of the 4-year old ginseng leaves. Chlorophyll-a content in the ginseng leaf was significantly decreased at September than at June but content of chlorophyll-b was not showed seasonal difference. At June, the amounts of chlorophyll a and b in the ginseng leaves grown in the back row were rather abundant than those grown in the front row, but no significant differencies were detected between rows at September. The estimated optimum light intensity for the photosynthesis of ginseng leaves was higher at June than at September and higher in the front row than the back row but was significantly decreased by air temperature above 25$^{\circ}C$. The light compensation point was elevated in higher temperature and at September than June. The amount of photosynthesis was significantly increased in the ginseng plant grown in the front row than the back row at June but the reverse was significant at September. The highest photosynthesis was observed in temperature range of 20 - 25$^{\circ}C$ at June and range of 15 -20$^{\circ}C$ at September. The optimum temperature range of photosynthesis was 21$^{\circ}C$ to 25$^{\circ}C$ at June and 14$^{\circ}C$ to 21$^{\circ}C$ at September, and that was higher in the back row than the front row. High temperature significantly stimulated the dark respiration of ginseng leaves and the respiratory quotients(Q$\_$10/) of the ginseng leaves showed a significant seasonal variation.

• Weed & Turfgrass Science
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• v.4 no.3
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• pp.268-277
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• 2015

Organic fertilizer preparation was developed with organic materials to improve growth and qualities of cool-season turfgrass species. Organic fertilizer preparation were contained with essential macronutrient elements and organic matter for growth of cool season turfgrass. Four preparations of organic fertilizers were tested on creeping bentgrass (Agrostis palustris Huds) cultivar Penn-A1 and Kentucky bluegrass (Poa pratensis L.) mixed cultivars (Midnight 33%, Moonlight 33%, and Prosperity 33%) by one time application on fifty days after sowing. Two species of cool season turfgrasses were evaluated on turfgrass coverage, growth on NDVI (Normalized Difference Vegetation Index) and qualities from fall season to spring season in sod producing farm. It were found significantly difference found on turfgrass coverage, turf color, chlorophyll contents and growth increase on two species of cool season turfgrasses. Turfgrass coverage, chlorophyll content, turf color and growth increase of organic fertilizer preparation were significantly increased on creeping bentgrass cultivar and Kentucky bluegrass mixed cultivar for six time investigation in spring season. These results may indicate that the use of some preparation is beneficial for sod producing sod and turfgrass management.

• Journal of Korean Society of Forest Science
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• v.110 no.2
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• pp.189-197
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• 2021

This study aims to optimize the appropriate concentration of fertilizers for Sageretia thea by analyzing growth performances (height and root collar diameter) and physiological characteristics (photosynthesis, chlorophyll contents, and chlorophyll fluorescence reaction). As fertilizer concentration was increased to 1.5 g·L^-1, growth increased, but it decreased at 2.0 g·L^-1 treatment. Root collar diameter growth was reduced because of higher fertilizer concentrations. Photosynthesis reactions showed the highest CO₂ reaction curves, maximum photosynthesis rate, and maximum carboxylation rate in the 1.5 g·L^-1 fertilizer treatment. The chlorophyll fluorescence reaction and SPAD values revealed that fertilizer treatment improves photosynthesis efficiency and robustness compared with untreated control. Therefore, the appropriate fertilizer concentration for producing good seedling quality of Sageretia thea is 1.0~1.5 g·L^-1.