• Korean Journal of Soil Science and Fertilizer
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• v.5 no.1
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• pp.33-39
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• 1972

For the increase of productivity, canopy structure and nutritional status in various productivity grades (high>700, medium>600 and low>500kg/l0a as head rice) were investigated in a study using Jinheung(Oryza sativa L.) for the increase of producticity with following results: 1. High yield plot showed greater leaf area and slow decrease of it after heading stage. While low yield plot had rapidly decrease of leaf area. 2. High yield plot showed higher light transmission ratio (LTR) durnig early grow stage, low LTR. during late grow stage, and higher leaf area per LTR. 3. Net assimilation ratio was decrease with the increase of leaf area index (LAI) and it was always higher in high yield plot. 4. High yield plant had greater amount of total nitrogen uptake, slow uptake rate, and considerable uptake after heading while low yield plant showed higher uptake of nitrogen in early stage of growth and no uptake after heading. 5. The percent ratio starch at heading to total at harvesting was 40% for low yield plant and 10% for highyield plant inderting that high yield depends much on past-heading starch synthesis. 6. Main factor determining secondary yield was ripened grain ratio.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.442-448
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• 1992

In order to determine the critical seeding date in dry paddy field at southern plain area of Gyeongbug province, dry seeds of three different rice cultivars was sown April 25 to June 20 at 15 or 10-day intervals. The number of days from seeding to emergence decreased in late seeding date : from 32 days at April 25 to 7 days at June 10 sowing. The number of seedlings showed 121-154 plants per square meter were not much differed among the varieties and seeding dates. Culm length, panicle length and ripened grain ratio decreased in late seeding date, but number of panicles per square meter, 1,000 grain weight and spikelets number per panicle were similar among the seeding dates. The cumulative effective temperature(mean air temperature-15$^{\circ}C$) from emergence to heading was very constant having 655$\pm$9$^{\circ}C$ in Keomhobyeo, 771$\pm$9$^{\circ}C$ in Donghaebyeo and 801$\pm$3$^{\circ}C$ in Milyang 95, respectively. Grain yield of Dong Haebyeo seeded in June 20 and Milyang 95 seeded in June 10 were much lower compared with other seeding dates and increased green kernel in late seeding date of Donghaebyeo and Milyang 95.

• Korean Journal of Plant Resources
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• v.19 no.2
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• pp.340-343
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• 2006

This study was conducted to find out the effect of rainfall time on growth and seed quality in safflower. Rainfall was done artificially and the treatment of rainfall time was divided into 6 parts. Each rainfall treatment was done from the first day of flowering up to the fifth day after flowering, from sixth day after flowering to the tenth day after flowering, from the eleventh day after flowering to the fifteenth day after flowering, from sixteenth day after flowering to twentith day after flowering, from the twenty first day after flowering to the twenty fifth day after flowering and from twenty sixth day after flowering to thirtith day after flowering. Rainfall time after flowering did not affect disease occurrence on the upper part and flower bud of safflower, which were infected at were 3.3 and 1, respectively. Ripened grain found on the main stem and primary branch was 37.4% and 65.0% at first day to the fifth day and sixth day to the tenth day rainfall periods after flowering, respectively. Yield was decreased by 14% in the sixth day up to the tenth day and eleventh day up to the fifteenth day rainfall periods (282-281kg/10a) compared to the one under control (327kg/10a). Hunter's L value was 73.5 and 69.9 in twenty first up to the twenty fifth day and twenty sixth up to the thirtith day rainfall periods after flowering, which decreased significantly to 79.3 under non-rainfall period. Therefore, it can be concluded that the optimum harvest time is twenty fifth day after flowering to maintain seed quality at rainfall time and before harvesting period.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.163-172
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• 1987

Results obtained from this study conducted to find the effect of wind-break net on reducing cold wind damage in the eastern coastal cold wind damaged area are summarized as follows. The rice critical safe heading date was up to Aug. 10 in the eastern coastal area, which the frequency of gale Aug. 10 to Sep. 10 is high. The frequencies of westries and cold wind from sea were 25%, respectively, in this area. The effects of wind-break net on reducing wind verocity were 26.9, 34,6% with raising air temperature of 0.4-0.7$^{\circ}C$ and water temperature of 0.3-0.5$^{\circ}C$. The effect of wind-break net was up to 10 time's distance of wind-break net's height from wind-break net. The installation of wind-break inhanced to rice growth, so showed the heading date earlier by 2-5days and increased culm length, no.of panicles per hill and no. of spiklets per panicle. The yield decrease in this area was due to sterilization, poor ripening and light 1,000 grain weight. The yields showed 20-28% increase by installation of wind-break net. The effect of wind-break net was most in the installation plot with wind-break net against cold wind from sea and westries installed in the panicle formation stage.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.458-463
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• 2015

This study was conducted to investigate the mixed seeding of 5 forage barley varieties (youngyang, yuyeon, dami, wooho, soman) with 1 malting barley variety (hopum). Yield of the mixed seeding was compared with each single seeding and variety combinations. Yield of mixed seeding combination was higher than each single seeding. In mixed seeding of 'Youngyang' and 'Hopum' (50% and 50% ratio), 'Yuyeon' and 'Hopum' (70% and 30% ratio), 'Dami' and 'Hopum' (50% and 50% ratio), 'Wooho' and 'Hopum' (50% and 50% ratio) were higher yield of dry weight than yield of other mixed ratios. Most of all, mixed seeding of 'Dami' and 'Hopum' were high yield mixed seeding (ratios of 50% each other). In generally, the yields of barley mixed seeding with malting barley 'Hopum' were high production. The forage quality of mixed seeding combination was higher than any each single seeding. 'Youyeon' 50% and 'Hopum' 50% ratio was more higher TDN content (69.2%) than any other mixed combination.

• Korean Journal of Breeding Science
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• v.40 no.2
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• pp.178-183
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• 2008

A new peanut variety "Seonan" (Arachis hypogaea ssp. hypogaea L.) was developed at the Yeongnam Agricultural Research Institute, NICS, in Milyang in 2007. It was developed from the cross between the erect short stem cultivar "SP9128" and the high-yielding cultivar "Daekwang". "Seanan" which is Virginia plant type has 18 branch number per plant with early maturing and long-ellipse shaped large kernel. Each pod has two grains with brown testa and 100 seed weight was 87 g in the regional yield trials (RYT). Especially this variety has resistance to lodging owing to short stem. The free sugar and tannin content of fresh peanut are 3.7% and 0.48%, respectively, similar to check variety. In the regional yield trials "Seonan" was outyielded than check variety by 14% with 8.59 MT/ha for fresh pod and by 7% with 3.75 MT/ha for grain.

• Korean Journal of Organic Agriculture
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• v.26 no.4
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• pp.629-647
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• 2018

This study was carried out to investigate the economic value of organic rice production using gelatin chitin microorganisms in eco-friendly complex, Gongsan, Naju city. The soil condition of experiment paddy field was Jeonbuk series and silt loam with a slightly poor drainage. Except for the high effective silicate, the chemical characteristics of soils used were included in the optimum range of paddy soils in Korea. In growth, plant length, tiller number, ear number, and ear length were observed to be higher in conventional paddy fields than organic paddy fields. However, number of grain per panicle and grain filling ratio (%) were higher in organic paddy fields than conventional paddy fields. Incidences of diseases and insect pests were slightly higher in the organic paddy fields. Water weevil, sheath blight, rice leaf roller and rice blast were more occurred in organic paddy field. On the other hand, false smut was higher occurred in conventional paddy field. There was a significant negative correlation between rice sheath blight and rice leaf roller, and rice yield. In the milled rice quality, the quality of organically cultivated milled rices was lower by the increase of broken rice than that of conventionally cultivated milled rices. The quality and palatability of rice were higher in organic cultivation with decreasing of protein content. Net income of conventionally and organically cultivated rice was 360,000 won/10a and 610,000 won/10a, respectively. Premium net income of the organically cultivated rice was 68%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.747-756
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• 1995

To find out the optimum application method of slow-releasing fertilizer(SRF) and conventional fertilizer(CF) with different fertilization rate under two culture methods[l0-day old seedling machine transplanting(MT) and direct-sowing on dry paddy(DS)] in the south-western region(clay loam soil) of Korea, used were Chosun slow-releasing fertilizer(silicate latex coated fertilizer: N-P$_2$O$_{5}$-K$_2$O =18-12-13) and conventional fertilizer. Plant height and number of tillers with different two culture methods were higher at MT than DS in early growth. The ratio of dry weight in heading stage was higher at CF than SRF in MT than DS and especially, SRF 80% + CF 20% than SRF 100% or CF 100%. Leaf area index (LAI) in heading stage was higher at CF in MT but higher at SRF in DS than their counterparts. Chlorophyll content was higher at SRF than in CF expect for heading stage(HS), especially in DS. It was highest at HS in CF without its difference during maximum tillering stage(MTS) and panicle formation stage(PFS), while highest at PFS in SRF with tendency of gradual increase and decrease before and after PFS, respectively. Heading was delayed 2~3 days at SRF in two cultrue methods and 4~5 days at SRF in DS in comparison with CF in MT with delay of 2 days at DS compared with MT. Culm length was longer at CF in MT and at SRF in DS than their counterparts. Panicle number per m was more at SRF and in DS. Filled grain ratio was higher at CF and in MT. Yield was obtained 101 and 100% at 100% and 80% level of SRF in DS respectively, and 96% at 80% level of CF in MT, compared with conventional application method (516kg /l0a), and increased 2~4% at DS and 0~3% at MT in SRF. Yield was high in order of 100%(SRF) =80%(SRF) + 20%(CF) > 100%(SRF) + 20%(CF) > 80%(SRF) at MT and 80%(SRF) + 20%(CF) =100%(SRF) > 80%(SRF) =100%(SRF) + 20%(CF) at DS.

• 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.66 no.2
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• pp.105-111
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• 2021

Rice lodging is an annual occurrence caused by typhoons accompanied by strong winds and strong rainfall, resulting in damage relating to pre-harvest sprouting during the ripening period. Thus, rapid estimations of the area of lodged rice are necessary to enable timely responses to damage. To this end, we obtained images related to rice lodging using a drone in Gimje, Buan, and Gunsan, which were converted to 128 × 128 pixels images. A convolutional neural network (CNN) model, a deep learning model based on these images, was used to predict rice lodging, which was classified into two types (lodging and non-lodging), and the images were divided in a 8:2 ratio into a training set and a validation set. The CNN model was layered and trained using three optimizers (Adam, Rmsprop, and SGD). The area of rice lodging was evaluated for the three fields using the obtained data, with the exception of the training set and validation set. The images were combined to give composites images of the entire fields using Metashape, and these images were divided into 128 × 128 pixels. Lodging in the divided images was predicted using the trained CNN model, and the extent of lodging was calculated by multiplying the ratio of the total number of field images by the number of lodging images by the area of the entire field. The results for the training and validation sets showed that accuracy increased with a progression in learning and eventually reached a level greater than 0.919. The results obtained for each of the three fields showed high accuracy with respect to all optimizers, among which, Adam showed the highest accuracy (normalized root mean square error: 2.73%). On the basis of the findings of this study, it is anticipated that the area of lodged rice can be rapidly predicted using deep learning.