• Korean Journal of Agricultural Science
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• v.37 no.2
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• pp.177-189
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• 2010

These studies were conducted to analysis for weather reaction on the growth and yield component according to meterological elements used Vector Autoregressive Regression(VAR) Model at Daejeon, Hongseong, Geumsan, Nonsan, and Yesan to core of center to Chungnam area in Rice. Reaction of cultivars according to change of meterological elements for growth and yield component effected on heading time in Gancheokbyeo and Mananbyeo, grain number of a spike in Gancheokbyeo, ratio of ripeness in Gancheokbyeo and Geumobyeo 1, amount of milled rice in Geurubyeo and Ansanbyeo, and 1,000 grains weight in Gancheokbyeo, Dasanbyeo, and Hwajinbyeo. An effect on the growth and yield components of meterological elements were influenced by heading date, 1,000 grain weight and ratio of repening as sunshine hours. The cultivars in sensitive reaction for change of weather condition were classified to 14 varieties including Gerubyeo et al., insensitive cultivars were classified to 66 varieties including Gyehwabyeo et. al.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.238-238
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• 2017

Salt stress is one of the deteriorating abiotic stresses due to the climate change, which causes over-accumulation of $Na^+$ and $Cl^-$ ions in plants and inhibits the growth and yield of rice especially in coastal Southeastern Asia. The yield components of rice plant (panicle number, spikelet number per panicle, 1000-grain weight, % of ripened grains) that are majorly affected by salt stress vary with growth stages at which the plant is subjected to the stress. In addition, the salt sensitivity of each yield component differs among rice varieties even when the salt-affected growth stage was same, which indicates that the physiological mechanism to maintain each yield component is different from each other. Therefore, we hypothesized that rice plant has different genes/QTLs that contribute to the maintenance of each yield component. Using a Japanese leading rice cultivar, Koshihikari, and salt-tolerant Nona bokra's chromosome segment substitution lines (CSSLs) with the genetic background of Koshihikari (44 lines in total) (Takai et al. 2007), we screened higher yielding CSSLs under salinity in comparison to Koshihikari and identified the yield components that were improved by the introgression of chromosome segment(s) of Nona bokra. The experiment was conducted in a salinized paddy field. One-month-old seedlings were transplanted into a paddy field without salinity. These were allowed to establish for one month, and then the field was salinized by introducing saline water to maintain the surface water at 0.4% salinity until harvest. The experiments were done twice in 2015 and 2016. Although all the CSSLs and Koshihikari decreased their yield under salinity, some CSSLs showed relatively higher yield compared with Koshihikari. In Koshihikari, all the yield components except panicle number were decreased by salinity and % of ripened grains was mostly reduced, followed by spikelet number per panicle and 1000-grain weight. When compared with Koshihikari, keeping a higher % of ripened grains under salinity attributed to the significantly greater yield in one CSSL. This indicated that the % of ripened grains is the most sensitive to salt stress among the yield components of Koshihikari and that the Nona bokra chromosome segments that maintained it contributed to increased yield under salt stress. In addition, growth analyses showed that maintaining relative growth rate in the late grain filling stage led to the increased yield under salt stress but not in earlier stages.

• Research in Plant Disease
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• v.19 no.3
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• pp.196-200
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• 2013

This study was carried out to investigate yield loss due to soybean leaf spot disease caused by Cercospora sojina Hara and to determine the economic threshold level. The investigations revealed highly significant correlations between disease severity (diseased leaf area) and yield components (pod number per plant, total grain number per plant, total grain weight per plant, percent of ripened grain, weight of hundred seed, and yield). The correlation coefficients between leaf spot severity and each component were -0.90, -0.90, -0.92, -0.99, -0.90 and -0.94, respectively. The yield was inversely proportional to the diseased leaf area increased. The regression equation, yield prediction model, between disease severity (x) and yield (y) was obtained as y = -3.7213x + 354.99 ($R^2$ = 0.9047). Based on the yield prediction model, economic injury level and economic threshold level could be set as 3.3% and 2.6% of diseased leaf area of soybean.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.218-226
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• 1984

This study was conducted to establish fundamental of cultivation system in the southern warm region of Korea by investigation of variation of yield component and yield under the different nitrogen fertilizing levels. And that levels in this experiment were 10, 15, 20 and 25 Kg/10a. Optimum fertilizing level of nitrogen was 20 kg/10a in Seokwang variety and 25 kg/ 10a in Dongjin variety. On the optimum fertilizing level (Seokwang; 20 kg/10a, Dongjin; 15 kg/10a), the correlation coefficient between No. of panicles per unit area and the rate of ripened grains were showed negative correlation (Seokwang; r =-0.6023$\^$*/, Dongjin; r=-0.858l$\^$**/). In the primary, secondary branches and spikelets, the degeneration ratio was increased significantly under the level of N=25 kg/10a in Seokwang, N$\geq$20 kg/10a in Dongjin. In Dongjin, the rate of ripened grains was decreased with increase in nitrogen fertilizing levels and that caused to decrease the yield.

• Korean Journal Plant Pathology
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• v.14 no.6
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• pp.720-724
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• 1998

Open-top field chamber study was carried out to investigate effect of ambient ozone level on the yield of rice cultivar 'Dongjin' in Kwangyang area located in the vicinity of the industrial complex of Yechon petrolium refinery and chemical works or Kwangyang Iron and Steel works during the summer of 1997. mean ozone concentration of ambient air during daytime (9:00∼17:00) was revealed to exceed over 40 ppb which is defined to be a critical level causing plant injury and yield reduction in Europe. Yield component analysis showed that there was no significant difference in rice yield between ambient air and charcoal-filtered air. The results suggest that the ambient ozone levels during the exposure period had no effect on yield reduction of rice cultivar 'Dongjin' and it is likely that the cultivar is tolerant to ambient ozone levels.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2001.04a
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• pp.51-53
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• 2001

• Transactions of Materials Processing
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• v.31 no.6
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• pp.351-364
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• 2022

The yield criterion, or called yield function, plays an important role in the study of plastic working of a sheet because it governs the plastic deformation properties of the sheet during plastic forming process. In this paper, we propose a modified version of previous anisotropic yield function (Trans. Mater. Process., 31(4) 2022, pp. 214-228) based on J2 and J3 stress invariants. The proposed anisotropic yield model has the 6th-order of stress components. The modified version of the anisotropic yield function in this study is as follows. f(J₂⁰,J₃⁰) ≡ (J₂⁰)³ + α(J₃⁰)² + β(J₂⁰)^3/2 × (J₃⁰) = k⁶ The proposed anisotropic yield function well explains the anisotropic plastic behavior of various sheets such as aluminum, high strength steel, magnesium alloy sheets etc. by introducing the parameters α and β, and also exhibits both symmetrical and asymmetrical yield surfaces. The parameters included in the proposed model are determined through an optimization algorithm from uniaxial and biaxial experimental data under proportional loading path. In this study, the validity of the proposed anisotropic yield function was verified by comparing the yield surface shape, normalized uniaxial yield stress value, and Lankford's anisotropic coefficient R-value derived with the experimental results. Application for the proposed anisotropic yield function to AA6016-T4 aluminum and DP980 sheets shows symmetrical yielding behavior and to AZ31B magnesium shows asymmetric yielding behavior, it was shown that the yield locus and yielding behavior of various types of sheet materials can be predicted reasonably by using the proposed anisotropic yield function.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.354-354
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• 2017

Rice grain yield is determined by crop dry matter production that is sensitive to temperature. Our objective was to determine whether the difference in temperature between years had an impact on the relationship between yield components and grain yield. Field experiments were conducted under machine transplanting cultivation by using yield data of two japonica rice varieties, Odaebyeo (early maturing) and Nampyeong (mid-late maturing), in 2013 to 2016 in Suwon, Korea. Plant height, dry weight, and yield components were examined by analysis of variance, correlation. The milled rice yield of the two varieties were the highest in 2016, however the lowest yields were observed in the different years. In 2016, Odaebyeo produced $0.96t\;ha^{-1}$ greater milled rice yield than in 2015, and Nampyeong produced $1.11t\;ha^{-1}$ greater yield than in 2013. The correlation analysis indicated that spikelet per panicle (R = 0.53) was associated with grain yield of Odaebyeo. In Nampyeong, biomass at heading date (R = 0.74), 1000-grain weight (R = 0.71), spikelet per panicle (R = 0.58), and panicle number per $m^2$ were associated with grain yield. Sink size (spikelet number per $m^2$) of the two varieties responded to accumulative temperature from transplanting to panicle initiation stage. In this experiment, optimal accumulative temperature before panicle initiation has effect on increased spikelet number and/or number of panicle that were mainly responsible for yield difference. Rice production research to increase grain yield should consider all yield components, but increased emphasis on biomass production before heading is also necessary as well as grain ripening conditions.

• Korean Journal of Plant Resources
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• v.34 no.6
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• pp.542-554
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• 2021

In this study, we cultivated 115 Soritae and 86 Yakkong black soybean landraces collected from ten different locations in Korea. Then, the variations of three yield components (one-hundred seeds weight (HSW), number of seeds per pod (SPP), and yield per plant (YPP)) and three anthocyanins (cyanidin-3-O-glucoside (C-3-O-G), delphinidin-3-O-glucoside (D-3-O-G) and petunidin-3-O-glucoside (Pt-3-O-G)) were investigated according to landrace type and collection area. Both yield components and anthocyanin contents significantly varied between the soybeans demonstrating genetic differences. Soritae landraces had the highest average HSW and TAC, whereas Yakkong landraces displayed the highest average SPP irrespective of collection area. Relatively, Yakkong landraces from Gyeongsangnam-do (1697.29 mg/100 g) and Soritae landraces from Gyeonggi-do (2340.94 mg/100 g) had the highest average TAC. Principal component analysis clearly separated Soritae and Yakkong landraces. Moreover, TAC and C-3-O-G showed positive and significant associations in both Soritae (r = 0.972) and Yakkong (r = 0.885) landraces, while yield components showed negative or weak correlations with each other. Overall, ten landraces were identified as important resources owing to their high yield (>150 g/plant) and high level of TAC (>2300 mg/100g). This study could lay foundations to molecular level investigations and reinforce the use of Yakkong and Soritae landraces during cultivar development.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.3
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• pp.209-217
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• 1984

This study was conducted to establish fundamental of rice cultivation system in the southern warm region of Korea by investigation of variation of yield component factor and yield under the different transplanting dates which was at interval of 15 days, from May 20 to July 5. In the variation of leaf age, the leaf of July 5 transplanting was less 1.1 leaves than that of May 20 transplanting in Seokwang. However in Dongjin, the leaf of May 20 transplanting was more 1.7 leaves than that of July 5. According to transplanting date delay, the shorten ratio of flag leaf was showed an increasing tendency. Period from transplanting to heading under the different transplanting in Seokwang, required about 75 days in May 20 transplanting and 68 days in June 5, 67 days in June 20, but 71 days in July 5, it was a cause of decrease in grain yield, because of increase in the period from transplanting to heading date. The maximum yield under the different transplanting gathered on May 20 transplanting in Seokwang variety, and on June 20 transplanting in Dongjin variety, and then, on the accumulated temperature 1017$\pm$24$^{\circ}C$ in Seokwang, 952$\pm$15$^{\circ}C$ in Dongjin, from 10 days before heading to 30 days after heading, it was appeared the high yield. It was showed linearly negative correlation between the No. of panicles per unit area and transplanting date (Seokwang; r=-0.6768$^{**}$, Dongjin: r=-0.5182$^{**}$). There were more differentiation of spikelets per panicle in the late transplanting in Seokwang, however in Dongjin, it was decreased in differentiation of spikelets per panicle in the early and the late transplanting.ing.