• Journal of Korean Society on Water Environment
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• v.21 no.2
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• pp.169-175
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• 2005

This study was carried out to investigate the effects of irrigation water pollution on the yield and grain quality of rice. It acquires fundamental data to set up water quality standards for irrigation and produce agricultural safety products. The correlations of BOD, T-N, T-P, pH, ECw of the irrigation water with yield, grain appearance quality, and the protein content were evaluated. The field and pot experiments were conducted by using Japonica of Oryza sativa L. during 2 years. BOD concentration in irrigation water effects strongly on grain appearance quality and yield of rice. T-N in irrigation water has strong effect on the yield, appearance, and quality of rice. T-P concentration in irrigation water have not any correlation with yield and quality of rice. pH showed strongly negative correlation with maturity ratio(MTR), 1000 grain weight(TGW), and yield of rice(YLD) as r=-0.803~-0.828(p<0.001) and have no effect on the appearance quality of rice. $EC_w$ indicating salt content showed strongly negative correlation with MTR, TGW, number of grains per panicles(NGP), and number of panicles per unit area(NPM) as r=-0.759~-0.798, and with YLD as -0.753.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.317-317
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• 2017

We performed this experiment to select high quality rice adapted to wheat-rice double cropping system. We sowed barley and wheat seed in November 2, 2015. After harvesting barley and wheat, we transplanted high quality rice cultivars: 'Unkwang', 'Hopun', 'Haepum', 'Hyunoum' in June 17 and 24. We used 'sindongjin' rice as a control. As a result, 'Hyunpum' had a highest head rice yield regardless of transplanting date. Head rice yield of 'Hyunpum' was 488.1kg/10a when transplanted in June 17, and 453.6kg/10a when transplanted in June 24. The reason for this highest head rice yield was not percentage of head rice but milled rice yield. Milled rice yield of 'Hyunpum' was 526.5kg/10a when transplanted in June 17, and 490.0kg/10a when transplanted in June 24. Percentage of head rice had little differences between rice cultivars. Among yield components, only number of panicle per $m^2$ had an effect on the differences of yield between rice cultivars. The other yield components didn't have an effect on the differences of yield between rice cultivars. Compared to June 17, only 'Unkwang' had higher head rice percentage and head rice yield in June 24. Head rice percentage of 'Unkwang' changed from 67.3% to 85.0% and head rice yield changed from 324kg/10a to 393.8kg/10a when transplanting date delayed from June 17 to June 24. When transplanting date was delayed, heading date of 'Unkwang' was more delayed than other rice cultivars. By delay of heading date, mean temperature for 40days changed from $25.0^{\circ}C$ to $22.9^{\circ}C$ which improved temperature condition during grain filling stage. This improved head rice percentage and head rice yield of 'Unkwang' transplanted in June 24. If transplanting date is more delayed than June 24, 'Unkwang' could have higher head rice percentage and head rice yield. Therefore, if you transplant rice before June 24 in rice-wheat double cropping system, 'Hyunpum' is recommended as adequate rice cultivar. But if you transplant rice after June 24, further research is needed to find out adequate rice cultivar.

• Korean Journal of Food Science and Technology
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• v.22 no.2
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• pp.199-205
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• 1990

With a view to improving the method of rice marketing quality estimation, vaietal milling characteristics and apparent qualities were studied and their statistical interrelationships were computed for 2 years crops, using 22 varieties of Japonica type and Japonica x Indica type (Tongil). The milling yield was the highest for Japonica, while the broken rice yields was the highest for Japa.xInd. type. But bran yield did not show any significant differences among rice types. Milling factors were volume weight of brown rice, dehulling yield, and Polishing yields; the better these factors, the higher the yield. High apparent quality milled rice with high milling yield were produced from rice types whose broken rice, chalked rice, husk yield and bran yield were little and/or low.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.49 no.3
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• pp.199-206
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• 2004

Typhoon "MAEMI", happened in September 2003, hit the great damage to Gyeongnam province area. Especially, rice plant was lodged or severe leaf damage was caused. This study was conducted to find out the extents of leaf damage among different rice cultivars, and to evaluate rice yield and eating quality due to leaf damage after typhoon. Rice cultivars torn off over half of the flag leaf length (FLL) were one medium-late maturing cultivar (Donginl), medium maturing cultivar (Yeonganbyeo), eight early maturing cultivars (Samcheonbyeo, Jounghwnbyeo, Munjangbyeo, Taebongbyeo, Odaebyeo, Samhaegbyeo, Sobaegbyeo, Sinunbongbyeo), two long-il type cultivars (Samgangbyeo, Namcheonbyeo), and three special use cultivars (Heukseonchalbyeo, Jinbuchalbyeo, Yangjobyeo). Cultivars torn off below 1/10 FLL were eight medium-late maturing cultivars (Chucheongbyeo, Daecheongbyeo, Saechu cheongbyeo, Donganbyeo, Daeyabyeo, Hwamyeongbyeo, 방eongsanbyeo, Dongjinbyeo) and two medium maturing cultivays (Donghaebyeo, Gumobyeo2). The rest cultivars were tore off by 1/10∼1/2 ELL. In yield components, the longer was flag leaf damage, the lower was ripened grain ratio, grain weight and brown/rough rice ratio, which was severly impacted to late than to ordinary season cultivation. However, rice yield did not decrease up to tearing by 1/10 ELL. Head rice ratio decreased from flag leaf tearing over 1/10 ELL in late season cultivation. The longer was flag leaf damage, the lower was eating quality, which could not show significantly different.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.2
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• pp.130-136
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• 2006

Growth and quality of rice are affected by various factors including the location of cultivation. This study was conducted to investigate the effects of altitudinal locations on the growth and yield-related components of rice. Nineteen Japonica type varieties were grown at Iksan (altitude, 10 m), Imsil (altitude, 150 m), Jinan (altitude, 275 m) and Jangsu (altitude, 430 m) at a similar latitude in Jeonbuk province in the south western Korea. Minimum air temperature showed a strong negative correlation with altitude. The morphological traits and yield-and quality-related components were analyzed. Longer days to heading was required at higher altitudes. However, culm length, panicle length, panicle number, grain number and rice yield were reduced at higher altitudes. Protein content of brown rice increased but fatty acid content decreased at higher altitudes. Amylose content was affected by neither the altitude nor the ecotype. Palatability of polished rice tends to be improved at higher altitudes and in early-maturing ecotypes but its relationships with altitude and ecotype were not significant. Head rice ratio was lower at higher altitudes but broken rice ratio vise versa. These results indicate that growth and quality of rice are affected significantly by changes in temperatures at the locations of different altitude. Also, the characters related to yield and quality of rice often respond incompatibly to the changes in altitudes. These results could provide valuable information for the strategic planning of rice production in geographically diverse areas.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.78-83
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• 2013

The excessive and indiscriminate use of chemical fertilizers in the past has brought serious soil and other environmental problems so alternatives over this agrochemical are being searched. Our study focuses on the effects of expanded rice hull inoculated with selected beneficial microorganisms on growth (through agronomic characters), yield and yield components, and grain quality indices of rice. Results showed that favorable effects of different expanded rice hull preparations were not readily apparent at vegetative stage and only treatments with supplemental chemical fertilizer application were comparable with the conventional practice. Expanded rice hull combined with 50% rate of chemical fertilizer exhibited a significantly higher yield (6,471 kg $ha^{-1}$) over conventional practice (5,719 kg $ha^{-1}$). Good milling quality indices were observed in treatments having 50% chemical fertilizers plus alternatives from expanded rice hull. Finally, we demonstrated that chemical fertilizer rate can potentially be reduced into 50% if combined with expanded rice hull, and show even better output than chemical fertilizer alone.

• Research in Plant Disease
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• v.13 no.1
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• pp.20-23
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• 2007

We investigated the first symptom emerging date of rice bacterial leaf blight disease during four years from 2002 to 2005. The disease occurrence date was earlier 20$\sim$30 days in 2005 than that of 2002. The damage in different rice growth stage by the bacterial disease on rice yield and grain quality in southern part of Korea was examined. The disease decreased rice yield following by increased infection rates. Slight loss in rice yield and brown head rice rate were observed at below 10% level of infected leaf area, while over 25% infected leaf area caused the significant decrease in rice yield and brown head rice rate. More than 50% of the infected leaf area rate caused 29% yield reduction in case of infection at panicle formation stage and 18% of brown head rice rate. Cooked rice quality was also affected in the diseased rice by damage in palatability score and viscosity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.259-262
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• 2002

Relationship between yield and palatability value measured by vice taster among 9 rice varieties was investigated to obtain basic information for production of rice with high quality in reclaimed paddy field. The rice yield showed a highly negative correlation with palatability value of milled rice (r=-0.49$^{**}$). The varieties of high palatability value tend to show low yield. The protein content of milled rice grown in reclaimed paddy field was higher than 7.5% mainly due to heavy fertilization of nitrogen and irrigation of eutrophicated water, The rice varieties such as Daeanbyeo, Jinpumbyeo and Sindongjinbyeo were recommendable only for higher yield, but in view of rice quality, Kwanganbyeo, Surabyeo and Nampyoengbyeo were more recommendable because of their lower protein content and higher palatability value.e.

• Journal of The Korean Society of Agricultural Engineers
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• v.46 no.1
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• pp.99-105
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• 2004

The present agricultural water quality standards are set by a policy goal. This is intended for water quality management of public water resources, but not for the use of water resources. These standards were not determined by considering the influence of water quality on the safety of agricultural produce and the growth, yield and quality of agricultural crops. Thus, this study was carried out to investigate the influence of irrigation water quality on the growth, yield, and grain quality of rice and acquire fundamental knowledges to set up irrigation water quality standards. The pot experiment was conducted with 4 treatments using irrigation waters with various total nitrogen concentrations (control, 1, 5, 10, 20mg/L) and replicated four times with randomized block design. The results of this study showed that plant height, number of tiller, plant dry weight, the uptake of N, P, and K, and rice protein contents tended to increase as the T-N concentration in irrigation water was increased. In addition, grain yield at T-N 20 mg/L was significantly higher than in the control, but the percentage of head rice was slightly lower due to the increase of green kernel and white belly/core kernel.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.330-339
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• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.