• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.226-230
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• 1986

Two near-isogenic lines with dark and pale green leaves, derived from the F$\_$7/ generation of wxl26 cross were compared on photosynthetic capacity, growth parameters, grain yield and yield-related characters. Dark green-leaved lines contained much greater content of chlorophyll a and b than pale green-leaved ones, but chlorophyll a to b ratio showed no difference between them. The photosynthetic nte per unit leaf area was higher in dark green-leaved lines than in pale green-leaved ones in the flag leaves at heading stage, but that per unit chlorophyll content showed reversed result. The crop growth rate from transplanting to heading was consistantly higher in the dark green-leaved lines, resulting from their greater net assimilation rate. Dark green-leaved lines produced greater number of panicles and spikelets per hill, out yielding pale green-leaved lines, but ripened grain ratio and 1000-grain weight showed no differences between those lines.

• Korean Journal of Soil Science and Fertilizer
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• v.18 no.1
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• pp.50-57
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• 1985

An attempt was made to determine the optimum levels of sewage sludge application for seogwangbyeo in the farmer's field. 1. Optimum amount of sewage slude application was 338kg/11a at the fertilizer (N-P-K) level of 15-10-10kg/10a, 430kg/10a at that of 7.5-10-10kg/10a and 544kg/10a at no fertilizer. 2. Number of tillers during all growing period were increased with amounts of sewage sludge and/or chemical fertilizers. 3. Panicles per hill was increased but percent ripeness was decreased with the application of increasing level of sewage sludge and/or chemical fertilizer. In particular, the decrease of ripeness among yield-related components sotood out as an important one to be solved for higher yield. 3. Panicles per hill was increased but percent ripeness was decreased with the application of increasing level of sewage sludge and/or chemical fertilizer. In particular, the decrease of ripeness among yield-related components stood out as an important one to be solved for higher yield. 4. Ripeness was remarkably decreased in high nitrogen content of soil and rice plant under heavy amounts of sewage sludge and/or chemical fertilizer. 5. Ripeness that had direct effect on yield showed significantly possitive correlation with the content of $SiO_2$ and $SiO_2/N$ in rice plant from 25 days after transolanting to harvesting stage. 6. Maximumutillzation of nitrogen and its production efficiency of absorbed nitrogen in sewage sludge were 16.6% and 31.9kg (Yield/kg, N) at the level 15-10-10kg/10a as fertilizer with amounts of sewage sludge application, and 19.0% and 31.8kg (yield/kg, N) at sewage sludge application without fertilizer.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.342-361
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• 2022

In order to evaluate the effect of nitrogen application levels on yield and quality of rice varieties, a field experiment was conducted at National Institute of Crop Science of Korea from 2018 to 2020. Five levels (0, 3, 5, 7, and 9 kg/10a) of nitrogen fertilizer were treated to 21 Korean rice varieties. Yield, yield component, appearance quality, and protein content in rice were analyzed. The average head rice yield for 3 years decreased by 28%, 22%, 11%, and 8%, respectively, when cultivated with 0, 3, 5, and 7 kg/10a nitrogen application compared to cultivation with a standard nitrogen application amount, 9 kg/10a. The number of panicles per hill increased as the amount of nitrogen application increased, but there was no significant change in the number of grains per panicle and 1000-grains weight, and the number of panicles per hill showed relatively small annual variation compared to other yield components. There was no significant difference in the head rice ratio according to the nitrogen application amount, the broken rice ratio slightly decreased, and the floury rice ratio increased. The protein content of rice decreased with increasing nitrogen application in 2018 and 2019, and was the lowest at 7 kg/10a of nitrogen application, and showed a tendency to increase again at 9 kg/10a. In the case of 2020, as the amount of nitrogen application increased, the protein content showed a tendency to continuously increase. In terms of varieties, 13 varieties, including Chilbo, seemed to be capable of low-nitrogen cultivation because loss of the head rice yield was less and the protein content could be lowered to 6% or less according to 7 kg/10a nitrogen application.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.4
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• pp.334-341
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• 1984

Yield response of 30 rice varieties widely grown during the past 70 years in Korea was examined at the six transplanting dates from May 10 to June 29 at the 10 day intervals in 1982. Early japonica varieties grown before 1960s showed the highest yield at the June 9 and 19 transplantings and yields decreased with earlier or later transplantings except the earliest transplanting of May 10. However, yield of recent japonica varieties grown after 1960s was similar among the transplanting dates from May 10 to June 19, but yield was lower at the June 29 transplanting. In the indica/japonica varieties grown after mid- 1970s, yield was highest at the May 10, 20, and 30 transplantings and it decreased with further delay of transplantings largely due to the decreased panicle number, percent ripened grains, and 1,000 grain weight. This may indicate that recently developed varieties may be more adaptable toearly transplanting than older varieties. The number of panicles per hill was variable among the transplanting dates in all varieties, but it decreased as transplanting dates delayed after June 9. In japonica varieties the number of spikelets per panicle, percent ripened grains, and 1,000 grain weight increased as transplanting was delayed. However, in indica/japonica varieties the number of spikelets per panicle was similar among the transplanting dates and percent ripened grains and 1,000 grain weight decreased as transplanting date was delayed after June 9. The percent ripened grains of japonica varieties decreased with increase in the number of spikelets per hill but increased as heading date delayed. However, in indica/japonica varieties the percent ripened grains was not affected by both the number of spikelets per hill and heading date except that of June 29 transplanting of which percent ripened grains was extremely low because of delayed heading although the number of spikelets per hill was low. Grain/Straw ratio was not affected by heading date in japonica varieties, but it decreased significantly as heading date was delayed in indica/japonica varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.1
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• pp.1-8
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• 2022

In order to manufacture feed suitable for consumer use and provide feed value information, we analyzed the feed components of the four main forage rice varieties by plant parts harvested 30 days after heading. The contents of the six feed ingredients were significantly different (p<0.05) among harvested parts. In the panicle, the crude protein (CP) (6.97%) and lignin (3.11%) were the highest, while the crude ash (CA) and neutral detergent fiber (NDF) contents were significantly lower, resulting in a total digestible nutrient (TDN) content of 77.29%, which is higher than that of the stem (64.82%) and leaf blade and sheath (LBS) (63.57%) (p<0.05). In contrast, the content of crude fat (CF) did not differ significantly among parts (p<0.05). In panicles from 'Jonong', 'Nokyang' and 'Yeongwoo', the TDN content of each cultivar was 78.48-79.07%, with no significant difference among the varieties. In 'Mogwoo' (Mw), the CP content was 8.70%, which was much higher than that of other varieties (p<0.05). In particular, the Mw TDN content was slightly lower in the panicle (72.95%) but higher in the stem (75.37%) and LBS (66.49%) than in the other varieties. The CA, NDF, acid detergent fiber (ADF), and lignin contents were also very low compared to other varieties; therefore, the feed value of the stem and LBS was excellent. In addition, the total dry matter weight (DMW) was 123 g per hill, which was much higher than 82-105 g per hill for other varieties. The distribution of DMW by part was LBS (56.9 g), stem (36.8 g), and panicle (29.3 g), and because the parts, except the panicles, were much higher than the 43-57% of other varieties (grain straw ratio: 76%), rice straw is advantageous in terms of quantity and feed value when used as forage on farms. The relative feed value (RFV) of the four cultivars ranged from 86.79-403.74 across all parts, and hay of grade 3 or higher with an RFV of 100 or more increased with delayed heading in both stems and LBS. This is due to the accumulation of starch into grains during ripening, which supports the observation that the RFV of the early flowering 'Jonong' and 'Nokyang' panicles increased.

• Korean Journal of Soil Science and Fertilizer
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• v.10 no.1
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• pp.49-53
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• 1977

In order to know the effect of lime application on the phosphorus and silicate, lime and phosphorus were applied in the soil where phosphorus concentration was low and pH 5.4 The results are as follows 1. The filled grain ratio increases by applying the lime in moderate quantity, conversely the large amount of lime reduced the number of panicles per hill and number of spikelets per panicle. 2. The phosphorus application increased the panicle number, grain number and filled grain ratio. Similarly the yield was also significantly increased. 3. Among the inorganic matter of plant absorbed at the heading time the nitrogen contents was highly correlated with the number of heads, grain number per head and yield, while contents of $P_2O_5$ and $SiO_2$ were significantly correlated with the grain number maturerate and yield respectively. 4. Under the lime application the silica of soil was partly correlated with yield and yield components. But there was a significant difference between contents of $P_2O_5$ in soil and yield componentas. And in the plot of double application of neutralizing lime, significance of 1% level was shown between the $P_2O_5$ in soil and the panicles number and grain number respectively, where as significance of 5% with yield. 5. The phosphorus concentration in soil was gradually increased by the increment of lime application. Also the rate of available silicate in soil was considerably increased by the increment of lime application. That is, the silicated concentration in soil was 86ppm with lime and 59ppm without lime.

• Journal of Animal Environmental Science
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• v.13 no.2
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• pp.139-146
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• 2007

Field experiment was conducted to assess the influence of liquid compost supplemented with chemical fertilizer on the rice growth and yield in 2005. Treatments consisted of liquid compost supplemented with chemical fertilize.(LCSC), liquid manure(LM), chemical fertilizer(CF), LCSC 50% + 50%CF, LCSC 75% + 25%CF. The plant height and tiller's number in plots of 100% basal application plot by LCSC and LM plot were lower than that of chemical fertilizer. But in the plot of basal application by LCSC and top dressing by chemical fertilizer, the height and tilters of rice were significantly difference with LM application plot. And the leaf color the plots by LCSC and chemical fertilizer was darker than that of the LM application plot. In plots by LCSC treatment, number of panicles per hill was higher that of LM plot. As the plot of 100% basal application by LCSC was fertilized, the yield of rice was decreased compared with chemical fertilizer. But the rice yield of basal fertilization by LCSC and top-dressing by chemical fertilizer was 7% increased compared with LM plot. The application plots by LCSC + chemical fertilizer plot were maintained productivity of rice, the rice should be fertilized with the basal application of LCSC and top-dressing of chemical fertilizer. The quality of brown rice was best in LM and LCSC plot, whereas in chemical fertilizer plot, it was the worst by increased of protein content. The results indicates that the application of LCSC + chemical fertilizer improves quality of rice rather quantity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.343-349
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• 1993

This study was conducted 1)to determine the factors responsible for the gradually increased rice yield by examining any improvements in yield-related characters and physiological characters among the historically recommended varieties of rice in Korea, and 2)to reveal the way of achieving further yield improvement by breeding in the future. Eight recommended varieties from 1911 to 1988 were selected and grown at the same conditions. The yield-related characters were observed at the harvest time, and the physiological characters such as RGR, NAR, LAR, SLA and L WR were estimated by the classical method of growth analysis. The newer varieties are shorter and those released after 1970's are greater in percent of filled spikelets and harvest index than the older varieties. There are no definite changing trends in the variations of number of panicles per hill, number of spikelets per panicle and 1000 grain weight according to the course of evolution in the recommended varieties. There is little evidence of improvement in the physiological characters such as NAR, LAR, SLA and LWR among the recently developed varieties compared with those of the older varieties. The increase in grain yield due to variety improvement, if any, is largely associated with the greater harvest index and percent of filled spikelets by breeding blight resistant and / or lodging resistant genotypes with short culm. It is suggested that increase in NAR should be carried out simultaneously with increase in harvest index to breed high yielding genotypes. I t appears to be important to breed genotypes with long culm in order to enhance light penetration into the canopy as long as they are lodging resistant. Since NAR is negatively correlated with LAR, it is unlikely to succeed to improve both characters simultaneously. The direct effect of NAR on RGR by path analysis is much larger than that of LAR, and hence it is suggested that breeding genotype with large NAR is more effective on enhancing RGR. It is also suggested that improving LAR through LWR is likely effective on increasing RGR.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.6
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• pp.422-426
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• 2002

In other to find out the basic information on cultivation and breeding for salt tolerance in rice, these studies were conducted at salinity paddy fields containing 0.2, 0.3, 0.4% of salt and normal paddy field using 6 Japonica type, 5 Tonsil type varieties and Annapurna. On these fields a series of investigation was made for the responses of rice growth and yield to salt content of saline sails. The heading dates of the rice cultivated at salinity 0.2, 0.3 and 0.4% were delayed compared by 2 or 3,5 or 8 and 10 or 13 days respectively in Japonica and Tonsil type varieties to those at the normal paddy fields. The culm length at salinity paddy fields decreased by 13-39% in Japonica type and 14-35% in Tongil type varieties. But the number of panicles per hill decreased by 16-40% in Japonica type and by 14-35% in Tongil type varieties. The number of grains per panicle in saline paddy fields decreased by 10 to 40% in all varieties, but the percent ripened grain decreased by 20-48% in Japonica type and by 19-51% in Tongil type varieties. 1000 grains weight was decreased by lower than 23% in all varieties, but yield was reduced to 20-62% in Japonica and 25-67% in Tongil type varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.361-365
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• 2000

This study was carried out to evaluate yearly variation and stability of yield and yield components of fifteen rice varieties. Yield stability and universal variety parameter of rice varieties were utilized for statistical model developed by Stroike, Grafius, and Finlay respectively. The lowest yearly variation based on coefficient of variation was found in Dasanbyeo for number of panicles/hill, in Jodongji for number of grains/panicle, in Yongmoonbyeo for ripened grain ratio, in Nagdongbyeo for 1,000 grain weight, and in Dasanbyeo for grain yield. Stability analysis by Stroike and Johnson's model revealed that Ilpumbyeo, Hwaseongbyeo, Dongjinbyeo in Japonica type, and And-abyeo and Dasanbyeo in Tongil type had the higher stability above average. Universal varieties analyzed by Grafius model were Ilpumbyeo, Dongjinbyeo, Hwaseongbyeo, Nagdongbyeo, and Jodongji in Japonica, and Dasanbyeo and Samgangbyeo in Tongil type. Damageum, Dongjinbyeo, Hwaseongbyeo and Ilpumbyeo in Japonica, and Dasanbyeo and Yongmoonbyeo in Tongil type were found to be highly stable as analyzed by Finlay ＆ Wilkinson's model. In conclusion, with reference to both grain yield and stability based on above three methods, Ilpumbyeo, Hwaseongbyeo, and Dongjinbyeo in Japonica, and Dasanbyeo in Tongil type were evaluated to be highly year-stable and high-yielding.