• The Plant Pathology Journal
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• v.21 no.1
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• pp.64-67
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• 2005

The biocontrol agent Serratia plymuthica A21-4 readily colonized on the root of pepper plant and the bacterium moves to newly emerging roots continuously. The colonization of A21-4 on the pepper root was influenced by the presence ofPhytophthora capsici in the soil. When P. capsici was introduced in advance, the population density of A21-4 on the root of pepper plant was sustained more than $10^6$ cfu/g root until 3 weeks after transplanting. On the other hand, in the absence of P. capsici, the population density of A21-4 was reduced continuously and less than $10^5$ cfu/g root at 21 days after transplanting. S. plymuthica A21-4 inhibited successfully the P. capsici population in pepper root and rhizosphere soil. In the rhizosphere soil, the population density of P. capsici was not increased more than original inoculum density when A21-4 was treated, but it increased rapidly in non-treated control. Similarly, the population density of P. capsici sharply increased in the non-treated control, however the population of P. capsici in A21-4 treated plant was not increased in pepper roots. The incidence of Phytophthora blight on pepper treated with A21-4 was 12.6%, while that of non-treated pepper was 74.5% in GSNU experimental farm experiment. And in farmer's vinyl house experiment, the incidence of the disease treated with the fungicide was 27.3%, but treatment of A21-4 resulted in only 4.7% of the disease incidence, showing above 80% disease control efficacy.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.spc
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• pp.9-14
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• 2008

This experiment was carried out to clarify the effect of various transplanting dates and agroclimatic zones on quality of brown rice and yield of a pigmented rice variety ‘Josaengheugchal’. The black density of brown rice in Jecheon (central inland region) showed a slight difference among the transplanting dates, but in Cheongwon (western sobaek inland region) that had increased at the transplanting dates of June 10th to 20th. cyanidin 3-glucoside (C3G) content at the same transplanting date in Jecheon was higher than Cheongwon, and the overall C3G content was increased at the later transplanting dates. The optimum transplanting date estimated by brown rice yields and C3G content was May 11th (491 kg/10a) in Jecheon and June 16th (468 kg/10a) in Cheongwon.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• v.11 no.2
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• pp.73-77
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• 2006

• Proceedings of the Korean Society of Crop Science Conference
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• 2020.06a
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• pp.97-97
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• 2020

• Journal of Korean Society of Forest Science
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• v.77 no.4
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• pp.414-420
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• 1988

This research was performed to estimate the degree of influence of relative light intensity and planting density on the weight growth in the trans-planting bed. The Piuns koraionsis seedlings treated for different degrees of shading on seed bed were planted in transplanting bed. 1. The seedling weight growth under 100% relative light intensity and $6{\times}6$ plot(36 individual) density showed the largest growth and the best growth was found during 26th of May 25 of June. 2. As the relative light intensity decrease and with planting density increased, the weight growth decreased. And the weight growth had a tendency to decrease after 26th of May-25th of June. 3. T/R ratio showed the highest value under 63% relative light intensity and $12{\times}12$ plot (224 individual) of planting density. The highest T/R ratio was found during 26th of July-25th August.

• International Journal of Contents
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• v.13 no.3
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• pp.1-8
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• 2017

Rice plant numbers and density are key factors for yield and quality of rice grains. Precise and properly estimated rice plant numbers and density can assure high yield from rice fields. The main objective of this study was to automatically detect and count rice plants using images of usual field condition from an unmanned aerial vehicle (UAV). We proposed an automatic image processing method based on morphological operation and boundaries of the connected component to count rice plant numbers after transplanting. We converted RGB images to binary images and applied adaptive median filter to remove distortion and noises. Then we applied a morphological operation to the binary image and draw boundaries to the connected component to count rice plants using those images. The result reveals the algorithm can conduct a performance of 89% by the F-measure, corresponding to a Precision of 87% and a Recall of 91%. The best fit image gives a performance of 93% by the F-measure, corresponding to a Precision of 91% and a Recall of 96%. Comparison between the numbers of rice plants detected and counted by the naked eye and the numbers of rice plants found by the proposed method provided viable and acceptable results. The $R^2$ value was approximately 0.893.

• 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.11
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• pp.1-9
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• 1972

For a measure against late transplanting, this experiment was conducted to investigate a reasonable seeding rate in nursery bed and a proper nursery size. The treatments applied to this experiment are as follows a) seeding rates: 0.2ι, 0.4ι and 0.6ι per 3.3$m^2$ b) nursery sizes. for 10a-field area: 39.6$m^2$, 49.5$m^2$ and 59.4$m^2$ c) transplanting dates: June 5, June 25 and July 15. The seeding date was April 26 and planting density was determined by the number of sound seedlings based on the combination of seeding rate and nursery size. The results may be summarized as follows: 1. In seedlings both increased nursery period and decreased seeding rate showed a remarkable-increase in plant height, number of leaves, dry matter weight and the ratio of dry weight to plant height. But their number of tillers and live leaves did not show such tendency. 2. Delayed transplanting date shortened culm length and panicle length as well as number of days from transplating to heading and it also delayed heading date. On the other hand the transplanting of 80-day seedlings resulted in premature heading. 3. As a result late transplanting reduced number of spikelets per panicle, maturing rate and 1000-grain weight. In the last analysis it linearly reduced grain yield. The decreasing rate of yield by late transplanting was 15.6% in June 25 plot and 41. 3% in July 15 plot, compared with the yield in June 5 plot. Such a remarkable decrease in yield of the extremely late transplanted plot was mainly due to markedly decreasing number of spikelets per panicle and 1000-grain weight. 4. Both increased seeding rate and nursery size gave a rise in number of tillers per unit area as well as number of transplanting hills but gave a fall in culm length and panicle length. 5. Accordingly, though thick seeded - dense planted plot increased number of panicles per unit area, decrease in number of spikelets per panicle and 1000-grain weight made no differences in yield between thick seeded - dense planted plot and thin seeded - sparse planted one. However, the yield in the thick seeded - dense planted plot transplanted on July 15 was reduced owing to the remarkable decrease in maturing rate and 1000-grain weight. 6. We came to the conclusion that as a measure against the extremely late transplanting the suitable seeding rate was 0.4ι per 3.3$m^2$ and the proper nursery size was 59.4$m^2$ for 10a-field area.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.5
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• pp.379-385
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• 2006

This experiment was carried out to investigate the optimum planting density in low fertilizing cultivation of machine transplanting in rice field of Honam Agricultural Research Institute, NICS for $2004{\sim}2005$. Sobibyeo which belongs to medium maturing variety and Nampyeongbyeo which belongs to medium-late maturing variety were transplanted on May 30. In this experiment, there was no significant difference in heading date between planting density and nitrogen fertilization rate, and heading dates were August 8 in Sobibyeo, and August 14 in Nampyeongbyeo respectively. In relation to lodging character, lodging Index was high where the nitrogen fertilization rate and planting density were high. As planting density increases, panicle number per $m^{2}$ increased irrespective of nitrogen fertilization rate. When nitrogen was 6 kg/10a, rice yield of Sobibyeo was more where planting density was 90 hill per $3.3m^{2}$, and that of Nampyeongbyeo was more where planting density was 80 hill per $3.3m^{2}$. When nitrogen was 9 kg/10a, rice yield of Sobibyeo was more where planting density was 100 hill per $3.3m^{2}$, and that of Nampyeongbyeo was more where planting density was 110 hill per $3.3m^{2}$. Head rice rate of brown rice was higher when planting density increased, and was higher at 6 kg/10a nitrogen rate than 9 kg/10a nitrogen rate in all varieties.

• Korean Journal of Weed Science
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• v.7 no.3
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• pp.280-288
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• 1987

The experiment was carried out to clarify the root competition between rice and paddy weed. Sagittaria pygmaea, under field condition. Rice variety Joongwonbyeo(Tongil type) and Sangpoongbyeo(Japonica type) were transplanted and Sagittaria tuber was planted artificially at planting density of untreated control, 4, 8 and 16 tubers/$m^2$, respectively. The number of roots, root fresh weight and root activity of rice and Sagittaria were measured at 30, 45, 60 and 75 days after transplanting. The results obtained were as follows. The root growth of Joongwonbyeo was decreased greatly according to the increase of Sagittaria tuber density compared with Sangpoongbyeo. On the other hand, the root growth of Sagittaria competed with Joongwonbyeo was depressed at 45 days after transplanting, and the one competed with Sangpoongbyeo was depressed at 60 days after transplanting. It was concluded that the competition ability of Sangpoongbyeo against Sagittaria was greater than Joongwonbyeo mainly due to the tall height and large tillers. And also the root growth of Sagittaria competed with Joongwonbyeo was more depressed than that of Sangpoongbyeo.