• KOREAN JOURNAL OF CROP SCIENCE
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• v.7 no.1
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• pp.71-78
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• 1969

To study the varietal differences of vegetative organs, yield and yield components along the periodical changes of rice variety in korea, this experiment was conducted in 1968. Eighteen used varieties were grouped into 6 varietal groups by the cultivated period as follow.: 1) Group I - Korean local varieties cultivated about 1907, 2) Group II - introduced varieties cultivated in 1907 - 1930, 3) Group III - introduced varieties cultivated in 1930-1960, 4) Group IV - improved varieties cultivated in 1930-1960, 5) Group V - introduced varieties cultivated after 1960 and 6) Group VI - improved varieties cultivated after 1960. 1. Varietal Group I showed the longest leaves, the largest leaf area, the lowest value of leaf area index and the highest value of flag leaf angle. Along the periodical changes of rice varieties the leaf length, the total leaf area and the flag leaf angle were decreased, and the leaf area index was increased. 2. Varietal Group I showed higher value of the length and the weight of leaf sheath than those of Group II, III, IV, V and VI. The length of every internode was longer in Group I than in the other varietal groups. The weight of every internode was shown higher value in Group 1. The length and the weight of every internode were decreased along the periodical changes of rice variety. 3. Varietal Group I and Group III showed the higher value of culm length, panicle length and the number of grain per panicle length and groups. Group IV, V and VI had the higher value of the number of panicle, the maturing rate and the 1, 000 grains weight. Varietal Group V and VI which are cultivated in recent years showed shorter culm and panicle length, higher value of the maturing rate and the 1, 000 grains weight, and intermediate in the number of panicle and the number of grain per panicle. 4. The lowest value of straw weight was found in Group I. The highest value of grain yield was shown in Group VI, intermediate in Group II, III, IV and V and lowest in Group I. Grain-straw ratio was shown highest in Group VI.

• Journal of Korean Society of Forest Science
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• v.13 no.1
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• pp.79-84
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• 1971

This study is, by correlation and regression analysis, on the correlation between culm height and other growth factors which are circle at eye height and length of internode. The samples were come by in Tamyang district, To sum up, the results are as follows; 1. Two growth factors are much more correlative to culm height; both simple correlation and multiple correlation between the former and the latter are significant. ($r_{yx}=0.91$, $r_{yz}=0.78$, $r_{yx{\cdot}z}=0.84$, $r_{yz{\cdot}x}=0.55$, $R_{y{\cdot}xz}=0.94$) Seeing above significance, circle at eye height is more highly correlative than length of internode. 2. The following regression equation was derived from regression analysis. y= -0.687+0.335x+0.206z. y ; culm height. x ; circle at eye height. z ; length of internode. 3. By testing of the equation, regression coefficients are as follows; ${\beta}{\neq}O$, ${\gamma}{\neq}O$, ${\beta}{\neq}O{\neq}{\gamma}$ 4. The results tested the precision of the empirical formula, standard error of standard error by percentage are as follows. $Sy{\cdot}xz=0.89$, $Sy{\cdot}xz(%)=8.14$.

• Korean Journal of Weed Science
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• v.12 no.1
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• pp.31-38
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• 1992

This study was conducted to investigate the effect of plant growth retardants on the growth and characters related with lodging in rice. The results are summarized as follows. Plant height which is closely related to lodging was significantly inhibited by the application of inabenfide, paclobutrazol, and uniconazole. Among the tested application times, inabenfide, paclobutrazol, and uniconazole were the most effective in inhibiting plant height at 30, 20, 20 days before heading respectively. Inabenfide was markedly effective in reducing the lower (4th) internode length, whereas paclobutrazol and uniconazole were more effective in reducing the upper (3rd and 2nd) internode length. Internode wall of rice plant treated with chemicals was tended to be thickened as compared with control. Heading date was not influenced by inabenfide, but paclobutrazol and uniconazole were inhibited 1 or 2 days in heading date as compared with control. Lodging index was the most reduced when inabenfide was applied 30 days before heading with 160g ai whereas paclobutrazol and uniconazole were applied 15 days before heading with 12, 1.2g ai per 10a, respectively. All the treatments inhibited the lodging of rice but control was completely lodged. Yield treated with these chemicals was prevented by 10-12% of yield decrease occurred by lodging. As a conclusion, inabenfide with 120 or 160g ai at 40 or 30 days before heading, paclobutrazol with 12g ai at 15 days before heading, arid uniconazole with 1.2g ai at 15 days before heading appear to be the most practical application time and rate for preventing lodging in paddy rice.

• Horticultural Science & Technology
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• v.31 no.4
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• pp.490-495
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• 2013

Two chrysanthemum varieties, 'ARTI-purple' and 'ARTI-queen', were chronically irradiated with doses of 30, 50, 70, and 100 Gy for four weeks in gamma-phytotron, a long term irradiation facility. We investigated the growth, responses of antioxidant enzymes (ascorbate peroxidase, APX; catalase, CAT; peroxidase, POD; superoxidase dismutase, SOD) and malondialdehyde (MDA) contents under different doses of chronic-irradiation. The five plant growth measurements including plant height, number of leaves, internode length, stalk diameter and leaf thickness were investigated immediately after four week irradiation. The plant height (p<0.001), internode length (p<0.01), the number of leaves (p<0.001) and stalk diameter (p<0.05) were significantly decreased an increasing doses of gamma-ray. Among them, especially, the internode length was remarkably decreased showing the RD50 (Reduction Dose 50) at approximately 65 Gy. The antioxidant response after four weeks of recovery period, ascorbate peroxidase (APX) (p<0.01), superoxide dismutase (SOD) (p<0.01) and peroxidase (POD) (p<0.001) were significantly increased with an increasing dose of gamma-ray. And malondialdehyde (MDA) (p<0.01) contents showed the significant increase at the 70 and 100 Gy which means the oxidative stress was lasting for a considerable period. In this study, the 50 Gy irradiation as optimal dose showed higher growth than the $RD_{50}$, it also showed insignificant differences on the antioxidant responses and MDA contents. However, the 100 Gy dose showed lower growth than $RD_{50}$.

• Horticultural Science & Technology
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• v.19 no.4
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• pp.579-584
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• 2001

This experiment was conducted to investigate the effect of soil moisture content on cut flower quality of Gypsophila paniculata L. 'Bristol Fairy' in spring and autumn cultivations. The soil moisture potential (SMP) set point for irrigation was either -3.2 or -10.0kPa in the vegetative growth stage, and -10.0, -31.6, or -79.4kPa after the budding stage. When soil moisture reached at each set SMP point, 10 mm water was drip-irrigated. Tendency of flowering was earlier as SMP set point was lower in both vegetative growth and after budding stages. No other flower characteristics were found among other treatments. In both spring and autumn cultivations, as SMP set point was lower, the low primary branch length and upper internode length were decreased, the stem firmness was increased, and curvature of cut flower stem was decreased. Especially, in autumn, the higher the SMP set point, the higher the low primary branch than the apex, thus the paniculate inflorescence was deeply destroyed. Yield in spring cultivation was not significantly different among treatments, while that in autumn cultivation increased as the lower the SMP value. It is thought that optimal imgation points during vegetative growth and after budding stages to produce high quality cut flowers are -10.0 and -79.4kPa, respectively.

• Korean Journal of Plant Resources
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• v.26 no.6
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• pp.701-708
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• 2013

To test the quality change of seedlings of three domestic medicinal plants raised in plug trays, a short term storage experiment was conducted. Seedlings were kept in growth chambers for two weeks at 4 or $8^{\circ}C$ temperature combined with 0 or $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. Quality of glasshouse-raised seedlings was assessed after two weeks of cold storage in the growth chamber and one week of acclimation in the greenhouse. After two weeks of storage in the growth chamber of Perilla frutescens var. acuta Kudo, plant height was the greatest in the treatment $8^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. Internode length of P. frutescens var. acuta Kudo was the greatest in the treatment of $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD. After one week of acclimatization in a glasshouse, the growth and development, such as plant height, internode length and leaf size, were greater in the $8^{\circ}C$ combined with $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD than in the other treatments. After two weeks of storage in the growth chamber of Sophora tonkinensis, plant height increased more in the treatment of $4^{\circ}C$ than $8^{\circ}C$. After one week of acclimatization in a glasshouse, number of leaves did not change in the treatment of $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD, but it increased in the other treatments. Leaf width increased more under the dark than light condition. Leaf length did not observably change in any treatments. After two weeks of storage in the growth chamber, plant height of Angelica gigas Nakai was the greatest in the treatment of $8^{\circ}C$. Number of leaves was the greatest in the treatment of $8^{\circ}C$. Leaf growth was greater under dark than light condition. These results suggested that optimal storage environment was $8^{\circ}C$ combined with $5{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD for P. frutescens var. acuta Kudo, and $4^{\circ}C$ combined with $0{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ PPFD for S. tonkinensis and A. gigas Nakai. Hence, proper combination of temperature and PPFD were necessary for better storage, and acclimatization and growth, thereafter, of the plug seedlings of theses plant species.

• Korean Journal of Agricultural Science
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• v.12 no.2
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• pp.183-190
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• 1985

To determine anti-lodging effect of paclobutrazol and its influence on yield of rice, paclobutrazol was applied at 12 and 18g ai/10a to cv. Nakdongbyeo and cv. Seomjinbyeo 20, 15, and 10 days before heading under 12 and 20kg/10a nitrogen conditions. 1. Paclobutrazol reduced internode length of rice, especially internode N3. Higher suppression of stem of both cultivars and reduction of ear length in cv. Nakdongbyeo were observed when paclohutrazol was applied at 18g ai/10a 15 and 20 days before heading. 2. Paclobutrazol increased culm cross-section area, culm diameter, linear density and stem flexure resistance which affected anti-lodging efficacy. Although actual lodging was not occurred in field, less stem inclination was observed at paclobutrazol treated plots. 3. There were significant correlation between stem flexure resistance and culm cross-section area, culm diameter and linear density, and negative correlation between straw inclination angle and culm cross-section area and culm diameter. 4. Slight yield reduction was observed when paclobutrazol was applied at 18g ai/10a 20 days before heading. However, when paclobutrazol was applied at 12g ai/10a 10 and 15 days before heading, rice yield was not decreased compared to untreated control.

• Korean Journal of Environmental Agriculture
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• v.20 no.4
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• pp.232-237
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• 2001

This study was conducted to clarify the effects of physical stimulation to the rice plant by free-ranging ducks (Chinese native ducks) on growth, lodging resistance and yield of the rice plants in a rice-duck farming system. Two paddy fields were used for this experiment, one exposed to physical stimulation (PS) and the other with no physical stimulation (NPS). Fifteen days after ducks were introduced into the paddy plot, rice plants in the PS field were significantly (P<0.05) shorter than those in the NPS field. Measurements of lodging characteristics showed that, the 3rd internode was significantly (P<0.05) shorter in the PS treatment than in the NPS treatment, but neither the 4th internode length nor the center of gravity of the rice plants differed between treatments. The breaking strength of $N_4$ in PS rice was significantly (P<0.05) higher than in NPS rice, however the bending moment and the lodging index of $N_3$ (distance between fulcra - 5 cm) was significantly (P<0.05) lower in PS than in NPS. The number of panicles per $m^2$ was significantly (P<0.05) greater in PS rice than in NPS, but there was no such difference in spikelet number per panicle, percentage of ripened grain or weight per 1000 kernels. Paddy rice yield per $m^2$ in the PS treatment was significantly (P<0.05) higher than that in the NPS treatment.

• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.9-15
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• 1972

Comparative analyses of canopy structure were conducted using newly bred high yield rice cultivars (IR 667-Suwon 213 and 214) and commercial varieties (Jinhung and Paldal) under the field condition. "Canopy score" as criteria of canopy structure was proposed. The results were summerized as follows: 1. IR667 line (IR8${\times}$Taichung Native 1${\times}$Yukara) showed lower canopy height, greater tiller openness, smaller leaf openness and leaf length ratio (flag leaf/3rd), shorter 4th and 5th internode length, greater diameter of 5th internode, consequently greater leaf area index, panicle weight and leaf weight ratio (leaf/leaf sheathculm) as merits, and greater leaf width, smaller leaf number(number of leaf/$m^2$)and specific leaf area($cm^2/g$) and faster destruction of canopy by senescence as demerits comparing with commercial varieties. 2. IR 667 line showed much higher "Canopy score", subsequently higher yield. 3. The quality of individual leaf was better in the commercial varieties indicating that the best combination for the better yield would be the leaf of commercial varieties with the structure of IR667 line.

• Current Research on Agriculture and Life Sciences
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• v.6
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• pp.19-24
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• 1988

The present experiment was undertaken to study the influence of light intensity on plug establishment of zoysia-82, chewings fescue and red fescue. The results obtained are summarized as follows : In chewings fescue and zoysia-82, plant height and leaf length were increased and leaf width was decreased by reducing light intensity. But in red fescue, plant height and leaf length measured at 90 and 120 days after plugging under 9% of incident light were shorter than those under 30% of incident light. Percent ground cover was decreased by reducing light intensity in chewings fescue, red fescue and zoysia-82. Each part of dry weight in three species was getting lighter by reducing light intensity. Decrease of light intensity in zoysia-82 causes increasing chlorophyll a, b, and total chlorophyll content. But red fescue and chewings fescue had the most plentiful chlorophyll under 30% of incident light. Chewings fescue and red fescue had the lowest concentration of chlorophyll a/b under natural light intensity. But zoysia-82 had the lowest concentration of chlorophyll a/b under 30% of incident light. Tillering number of chewings fescue and red fescue was decreased by reducing light intensity. Internode length of zoysia-82 was longer in the order of : 1) 30% of incident light, 2) natural light, 3) 9% of incident light. And internode diameter was decreased by reducing light intensity.