• 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.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.266-266
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• 2017

In recent years, adoption of the System of Rice Intensification (SRI) is spreading in most Asian countries, and more recently in Cambodia is one of the Asian countries with high adoptions of SRI. We conducted on-farm experiment to investigate the effects of SRI on rice growth and yield in the farmers' fields in rainfed region of southern Cambodia. The study was undertaken in rainfed lowland fields of Popel commune ($11^{\circ}$ 04' 67" N, $104^{\circ}$ 40' 79" E) of Tram Kak District in Takeo Province during the wet seasons in 2012, 2013, and 2015. A total of 32 on-farm experiments were conducted during the wet seasons for three years of 2012 (11 fields), 2013 (8 fields), and 2015 (13 fields). Across the three years of study, SRI produced significantly greater plant biomass and grain yield than Non-SRI. The yield increase was mostly ascribed for the increased number of grains per land area, which was due to the increased number of spikelets per panicle rather than the number of panicles per land area. With no significant difference between SRI and Non-SRI with respect to seedling age, the greater number of grains per panicle was accounted for by the reduced planting density and increased amount of manure application in SRI than Non-SRI fields. It was found that the greater manure application has increased soil nitrogen content in SRI and Non-SRI fields. While SRI did not increase the number of panicles per land area, it did increase the number of panicles per hill.

• Plant Resources
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• v.8 no.1
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• pp.32-35
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• 2005

This study was conducted to investigate the influence of $K_{2}O$ fertilizer application on growth, yield and lodging resistance of rice. Culm length and panicle length were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ plot but number of panicle, percentage of fruitful culm, $1{\ell}$ grain weights of paddy rice and brown rice, 1,000 grains weight of brown rice, brown rice ratio, yields of paddy rice and brown rice were highest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Bending moment, breaking strength and lodging index were lowest at the treatment of fertilizer level, $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a plot. Judging from the results reported above, an optimum fertilizer level of rice for lodging resistance is most likely be $N-P_{2}O_{5}-K_{2}O=16-8-8$ kg/10a treatment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.43 no.4
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• pp.250-253
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• 1998

Somaclonal variation was observed in the field on doubled haploid plants derived from single pollen of a rice cultivar "Hwaseongbyeo". The variations of seven quantitative traits including plant height and one qualitative trait (pubescence) in 436 lines ($R_2$ generation) were analyzed. The number of lines which fell beyond the boundaries of the 95% confidence intervals of the check variety, Hwaseongbyeo was checked for each quantitative trait, and of those fertility showed the highest variation frequency (85.6%), followed by plant height (77.5%), flag leaf length (66.5%), grains per panicle (42.2%), days to heading (34.5%), panicle length (30.7%) and panicles per hill (22.7%). And the variations of quantitative traits except days to flowering appeared to move in the negative direction compared to "Hwaseongbyeo". Variability within lines was also observed for quantitative and qualitative traits. Twenty-nine $R_2$ lines (7%) segregated for pubescence and 130 $R_2$ lines (30%) showed variation with regard to fertility. This suggests that mutations usually occur before diploidization. Twenty-nine $R_2$ lines representing a wide spectrum of variation were chosen for RAPD analysis. The number of lines showing DNA polymorphism compared to Hwaseongbyeo ranged 0 from to 10 according to the primer used and this seems to indicate that specific loci have highly mutable genomic site.utable genomic site.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.36 no.4
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• pp.305-309
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• 1991

This experiment was conducted to investigate the effect of shattered grain by combine harvesting at the previous year on rice plant emergence at different planting methods and plant characteristics, The results are follows : Combine harvesting greatly influence on shattered grain of Samgangbyeo as Tongil variety (49.5kg/10a) compared to that of Nagdongbyeo as Japonica variety(27.8kg/10a), while Nagdong-byeo showed higher germination rate than Samgangbyeo, whether transplanted and direct seeded. Emergence of volunteer and seed mixture were lower in transplanted than in direct seeded. In variety test. Japonica variety showed higher emergence of volunteer rice and seed mixture than Tongil variety. Generally, no significant difference in yield components were observed with different varieties by the volunteer rice. But the volunteer rice caused by combine harvesting decreased culm length, panicle length, spikelet number, panicle number and ripening ratio. except l000-grain weights.

• Korean Journal of Plant Resources
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• v.30 no.3
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• pp.318-322
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• 2017

The study was carried out to determine the changes of growth characteristics, anthocyanidin, and brown rice yield grown at coast and inland areas apart from the east coastline of Gyeongsangbuk-do province. Number of spikelets per panicle was much more increased in inland area. Regional difference in number of spikelets per panicle was observed in Jeongjinju cultivar. Among these red rice cultivars, the highest brown rice yield was Jeongjinju rice cultivar having 702 kg in inland area and 692 ㎏ in coast area, respectively. Anthocyanidin content ranged 524 to $610{\mu}g/g$ dry weight basis. Cyanidin content was 11.4 to 14.0 times higher than that of delphinidin under coast and inland area. Anthocyanidin content was higher in rice cultivar grown at coast area. Highest head brown rice rate was only observed in Geonganghongmi to 95.2 at coast area and 95.4 inland area. In considering brown rice yield and pigment content, Hongjinju rice cultivar was recommended in optimal pigment rice cultivar in eastern coast of Gyeongsangbuk-do Province.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.25 no.1
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• pp.25-30
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• 1980

Lowland and upland rice were grown concurrently under the both lowland and upland conditions. Yield and its components such as one liter weight, 1, 000 grain weight, number of grain per panicle and number of panicle per hill were compared between varieties and between cultural conditions. Variations of rice quality were also observed about amylose content, alkali digestion value and protein content between varieties and cultural conditions. Most of lowland varieties showed high growing vigour and yielding ability in lowland culture, and they also showed high variations between the lowland and upland cultures compared to upland variety. Upland varieties were revealed higher adaptability in productivity to the lowland condition than upland condition.

• Journal of agriculture & life science
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• v.51 no.3
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• pp.19-27
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• 2017

This study was conducted to investigate the optimum transplanting method for increasing the rice yield and quality by early transplanting cultivation in Gyeongnam plain area. This examination used of the transplanting method of planting distance($30{\times}14$ and $30{\times}18cm$) with number of seedlings(3, 5 and 7 plants). In high planting density($30{\times}14cm$), the number of tillers was increased while plant height was decreased as the planting number increases. On the other hand, the plant height and number of tillers were increased as planting number increases in low planting density($30{\times}18cm$). However, the number of grain per panicle was increased while the number of panicle was decreased as the planting number decreases. The number of panicle and the number of grain per panicle was increased as the planting distance increase. The yield of rice, when transplanted in the distance of $30{\times}14cm$ with 3 plants, was higher than the other treatment. Head rice ratio and head rice yield was the highest when transplanted in the distance of $30{\times}18cm$ with 3 plants(403 kg/10 a). The protein content was decreased and Toyo taste value was improved when transplanted in the distance of $30{\times}18cm$. Taken together, the best transplanting method for early transplanting cultivation was low planting density($30{\times}18cm$) with 3 plants in Gyeongnam plain area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.3
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• pp.236-241
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• 1988

The responses of GA$_3$ treatment on the culm length, internode elongation, number of internodes elongated and on the panicle length of 115 Japonica rice cultivars were studied. One spray with 50 ppm GA$_3$ was made at about 30 days before heading. Generally short culm cultivars showed better elongation responses than taller ones and a few taller cultivars showed reduced culm length. The internode length of 1st, 5th, 6th and 7th were increased, but, 2nd, 3rd and 4th internodes were reduced. Especially the reduction of 3rd internode elongation and the increase of 5th internode length was prominent. Most of the tested cultivars showed no changes in the number of internodes elongated, but, in some cultivars it was increased and in a few ones it was reduced. The effect on the panicle length was variable depending cultivars. No significant correlation was found between the culm length elongation and the elongation of panicle length, implying that the response of GA$_3$ on the culm and on the panicle is independent of each other. According the response of culm length elongation tested cultivars were grouped into 6 ; Significantly reducing, slightly reducing, less sensitive, slightly elongating, largely elongating and extremely elongating.

• Korean Journal of Soil Science and Fertilizer
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• v.29 no.1
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• pp.3-7
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• 1996

Effects of the nitrogen application time and amounts on the nitroger. uptake and recovery of fertilizer nitrogen applied at panicle formation stage was investigated in connection with the growth and yield of rice drill-seeded in puddle-soil. silt loam of Jeonbuk series. Urea was applied as nitrogen source. Nitrogen uptake and recovery of fertilizer nitrogen by rice plant was highest in the treatment applied nitrogen at 20 days before heading. Culm length, internode length (4th and 5th) and lodging index were increased by earlier application time and higher level of nitrogen. but filled grain ratio and 1,000 grain weight showed the opposite trend Panicle number per square meter and grain number per panicle was significantly decreased in nitrogen application at 10 days before heading. Rice yield was the highest in 33kgN/ha(conventional amount at 20days before heading, and yield in 26kgN/ha(80% of conventional amount) at 20 days before heading and in 33kg/ha at 15days before heading were nearly the same as conventional treatment.