• Research in Plant Disease
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• v.18 no.4
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• pp.387-390
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• 2012

Rice black-streaked dwarf virus (RBSDV) was reported to occur on maize plants in Gochang-gun of Jeonllabuk-do region in 2011. The symptoms typically include stunted and deformed leaves. Virus infected plants usually produce poor or no head. RT-PCR analysis of genomic dsRNA extracted from the plant confirmed the infection. Specific primers for full length genome of segments 8 and 10 were used for RNA amplification. Full-length genomes of S8 and S10 were cloned and sequenced. Sequence analysis revealed that the S8 and S10 sequences of the maize isolate were same with rice isolate in size, 1,936 nt and 1,801 nt, respectively. In comparison with rice RBSDV, S8 and S10 showed 94.9-99.6% and 94.1-98.4% sequence identity, respectively. Phylogenetic analysis showed that RBSDV S8 and S10 of maize plants are categorized into the same group as RBSDV of rice plant.

• Korean Journal of Environmental Agriculture
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• v.24 no.2
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• pp.180-184
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• 2005

This study was peformed to assess environmental effect through rice culture with sewage irrigation using Iksan stream water from 2002 to 2003. Contents of $NH_4-N$ in irrigation water keep up one day at the tillering stage and panicle formation stage were decreased 40% and 52% respectively, but that of continued 4 days was decreased $88%{\sim}98%$. The $NH_4-N\;and\;NO_3-N$ in run off by reduction 50% fertilization were more decreased 17% and 44% respectively, than those of conventional fertilization level. Amount of K and $NO_3-N$ loss in infiltration water were more decreased 18% and 4% respectively, those of than conventional fertilization level. The Cu and Pb contents in soil of after experiment were slightly increased but other heavy metals were not accumulated. The rice yield by reduction 50% fertilization level was not significant compare with conventional fertilization level but head rice rate was increased.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.166-170
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• 2012

This research was carried out to choose the suitable seedling type to transplanting in order to stabilize rice yield. The brief of this research to transplant the seedling divided into 10-day seedling, 20-day seedling, 30-day seedling, 33-day pot seedling in the field of Saemangeum Gyehwa, newly reclaimed land were following; Average salt content in 2 years was reduced from 0.16% to 0.04% after transplanting. Heading date of seedling type was Aug. 14 at 33-day pot seedling compared to 2 days at 30-day seedling, 3 days at 20-day seedling, 5 days late at 10-day seedling. Lodging index was highest at 30-day seedling, and also, field lodging was 50%. Ripening ratio and 1,000 grain weight were similar and panicle number was higher 20-day seedling > 10-day seedling > 33-day pot seedling > 30-day seedling. Rice yield was higher 10-day seedling = 20-day seedling > 33-day pot seedling > 30-day seedling. Head rice ratio was higher in 20-day seedling > 30-day seedling = 10-day seedling > 33-day pot seedling. Amylose content and protein content was not significantly different between seedling types. With this results, the suitable seedling types in newly reclaimed land are 10-day and 20-day seedling.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.282-286
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• 1990

Currently, mechanization and automation have been introduced into rice harvest and drying process due to the shortage of man power. After rice cultivars, Chucheong and Milyang #23 were cutted with manual method (H1) or harvested with combine (H2), the threshed grain were dried in natural sun-drying (D1), in natural air in-bin system (D2), or in contineous hot-air drier (D3). We have evaluated grain losses, operation hour, and grain quality on each harvest and drying methods. Shattering loss during harvesting with combine was not dirfered significant from that of manual method, but threshing loss was 1.2% higher in combine harvest than in manual. Operation hours required for combine harvest was 3.5 times faster than for manual, even without head threshing. There was a significant difference bel ween cultivars in harvesting loss, which Milyang #23, a Tongil rice had two times more grain loss than Chucheong, a Japonica rice. Drying hours required to reduce to 14% grain moisture content were ten days for H1D1, 5-9 days for H2 D1, 2-3 days for H2D2, and only 15 hours for H2D3, respectively. In grain quality, complete grain ratio after dehulling was decreased about four percent in H2D3 compared to H1D1. while it was lower in Milyang #23 than in Chucheong, Hot-air drier increased occurence of cracked and broken grain. Combine harvest increased significantly these incomplete grain ratio of :Milyang #23, but not Chucheong.

• Korean Journal of Breeding Science
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• v.43 no.6
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• pp.611-615
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• 2011

'Manjong' is a new japonica rice cultivar developed in 2009 derived from a cross between 'Yeongdeog34' and 'Nampyeongbyeo' at the Department of Functional Crop, NICS, RDA. This cultivar is suitable for the double cropping system after the cash crop cultivation. Heading date of 'Manjong' is later than 'Keumobyeo' under the late transplanting cultivation on July 10. It has high grain fertility under cold conditions and low premature heading. One of the distinguishing characteristics of this variety is its resistance to major diseases like leaf blast and rice stripe virus disease. However, it shows susceptibility to major insect pests and bacterial blight disease. Milled rice kernels are translucent with non-glutinous endosperm and have 7.2% protein and 18.7% amylose contents. Ripening ratio and head rice ratio is very higher than those of 'Keumobyeo'. The palatability of cooked rice is also better than 'Keumobyeo'. The milled rice yield of 'Manjong' in local adaptability tests after harvest of the cash crop is $4.81MT\;ha^{-1}$. This cultivar is suitable for planting in the plain paddy fields of Honam and Yeonnam regions in Korea.

• Korean Journal of Breeding Science
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• v.41 no.4
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• pp.520-524
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• 2009

A newly developed rice variety "Pungmi 1" is a japonica rice(Oryza sativa L.) with high grain quality and multi-resistant to diseases. It was developed by the rice breeding team of Yeongnam Agricultural Research Institute (YARI), RDA. in 2004. This variety derived from a cross between "YR13616Acp 1", having short culm and multi-resistance to biotic stresses and "Milyang 122" with good grain quality. It has short stature of 73cm in culm length and mid-early flowering date of Aug. 13. This variety is moderately resistant to leaf blast showing durable resistance of lower 10% diseased leaf araea in sequential planting meothod. Milled rice kernel of "Pungmi 1" is translucent, clear in chalkness and good at eating quality in panel test. Milling recovery and head rice ratios were comparable to Milyang 122, while it has low protein content. The milled rice yield potential of "Pungmi 1" is about 5.59 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to Yeongnam inland plains and southern coastal areas of Yeongnam province at ordinary transplanting as well as after barly cultivation.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.1
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• pp.49-59
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• 2019

The field trial was performed to evaluate the rice growth and yield in different direct seeding methods after Italian Ryegrass Harvest The required time for seed emergence was for 7 ~ 8days in the tested direct seeding methods and there was high in seedling establishment in order of wet hill-seeding with iron-coated seeds > water seeding with iron-coated seeds > wet hill-seeding with soil coverage with pregerminated seeds. The rice plant height was shorter in the tested direct seeding methods than that of machine transplanting until 45day after seeding but there was not significant difference in terms of statistical analysis at 63day after seeding. The growth of tiller number in the rice plant was high in water seeding with iron-coated seeds and wet hill-seeding with soil coverage and low in wet hill-seeding with iron-coated seeds compared to machine transplanting. The yield component in the tested direct seeding methods was not significant difference in terms of statistical analysis. The milled rice yield in the tested direct seeding methods was higher 2 ~ 8% being with 4.94 ~ 5.24t/ha than that of machine transplanting but there was not significant difference in terms of statistical analysis. The percentage of head rice was low in the tested direct seeding methods compared to machine transplanting. The weedy rice was not occurred in the tested rice cultivation methods. In conclusion the direct seeding method would be recommended to be a suitable to in following by Italian ryegrass harvesting in southern area of Korea in terms of reduction in production cost and high income basis for rice growing farmers.

• Korean Journal of Agricultural and Forest Meteorology
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• v.25 no.4
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• pp.337-345
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• 2023

Estimating the rice heading date is one of the most crucial agricultural tasks related to productivity. However, due to abnormal climates around the world, it is becoming increasingly challenging to estimate the rice heading date. Therefore, a more objective classification method for estimating the rice heading date is needed than the existing methods. This study, we aimed to classify the rice heading stage from various images using a CNN classification model. We collected top-view images taken from a drone and a phenotyping tower, as well as slanted-view images captured with a RGB camera. The collected images underwent preprocessing to prepare them as input data for the CNN model. The CNN architectures employed were ResNet50, InceptionV3, and VGG19, which are commonly used in image classification models. The accuracy of the models all showed an accuracy of 0.98 or higher regardless of each architecture and type of image. We also used Grad-CAM to visually check which features of the image the model looked at and classified. Then verified our model accurately measure the rice heading date in paddy fields. The rice heading date was estimated to be approximately one day apart on average in the four paddy fields. This method suggests that the water head can be estimated automatically and quantitatively when estimating the rice heading date from various paddy field monitoring images.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2003.02a
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• pp.131-136
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• 2003

쌀은 우리 국민의 주식이자 단일 작물로써 재배면적이 가장 많은 105-110만㏊ 수준에 연간 생산량도 500만톤 이상을 꾸준히 유지하고 있는 중요한 식량작물이자 농가의 주 소득원이다. 그러나 이렇게 쌀의 생산량은 꾸준한데 비해 국민의 식생활이 점차 인스턴트 화되고 육류소비가 증가하면서 연간 쌀 소비량이 1990년 119.6kg에서 2002년 87.0kg으로 급격히 감소추세를 보임으로써 2002년도 기준으로 약 1,190만석의 재고가 발생하고 있다. 더욱이 WTO출범이후 MMA 물량이 2002년 125만석에 이르렀고, 2005년 이후 더욱 증가 할 것으로 예상되고 있어 국내 쌀 시장은 이제 과잉공급시대에 직면하고 있다. (중략)

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 1993.10a
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• pp.298-306
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• 1993

A portable torque and power measurement system for small farm equipment based on instrumented pulley was developed. The prototype pulley was machined from mild steel, with spokes serving as strain beams. Strain gages mounted to the spokes sense the bending strain due to the torque and convert this into millivolt output. Calibration results showed the torque-millivolt relationship was linear, while hysterisis and error were less than 1% fs. For power measurements, an additional tachmeter with dcvoltage output is necessary. With the tachometer , error in power measurement was +-1.03W or 0.2% fs. Field tests showed that for ease of installation, no machine alteration needed and safety, this system had advantage over other methods for small farm equipment.