• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.198-208
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• 1992

Recently, a nursery mat made from rock wool has realized transplanting of the younger seedlings with the ordinary transplanting machines for Chibyo and Chubyo(3 and 4～5 leaved seedling, respectively). The seedlings defined as the 'Nyubyo' or 'Nursling seedlings' became possible to achieve economic profits from the reduction in both working time and costs. It being widely noticed as a strategy to solve the difficulties in current rice cultivation. The nursling seedlings are 1.4 to 2.5 leaves and height at 4.5 to 7cm, grown 4 to 7 days after seeding. They maintain still up to 50 to 80% of their nutrients in the endosperm, and can grow by using only their own nutrients for a certain period of time after transplanting. Nursling seedlings take 2 days in the nursery chamber at 32$^{\circ}C$ after seeding, and 2 days in the greening house at $25^{\circ}C$. This is only 4 days, all together, to make the nursling seedlings of 1.5 leaves which are ready for transplanting. Watering is only needed once at the sowing time. It only takes 1 or 2 waterings even to raise a seedlings for a period of 7 days. The number of nursery boxes can be reduced because it is possible to sow more densely(220 to 240g per box), thus it only needs seedlings of 15 to 16 boxes per 10 a which leads to a reduction in facilities and space needed. Temperature during the nursery period can be artificially adjusted more precisely which may lead to the prevention of temperature stress. The nursling seedlings can root rapid by because the crown roots from the coleoptile node begin to emerge immediately after transplanting. They show strong resistance to low temperature (12$^{\circ}C$) and deep-planting. There is no danger in the rooting of the seedlings even if half of their height is buried into the soil. Moreover, it can root at a rate of up to 65 to 80% even if the full height of the seedlings is buried. They show also strong resistance to submergence (10～15cm). The nursling seedlings tend to grow by producing tillers from lower nodes. It is therefore, necessary to control to keep the proper numbers of tillers per unit area. They have no fear in the delay of heading and their yield components can be so well balanced that the same level of yield was achieved with the nursling seedlings compared to that with Chibyo. It was further suggested that if the surplus tillers can be avoided by such cultivation practices, the number of grain per panicle can be kept greater and higher yield can be realized. Practical experiments with the nursling seedlings conducted in 1989 and 1990 by farmers in various areas showed exciting results. The nursling seedlings will become widely spread, or at least occupy an important position in Japanese and also in Korean rice cultivation techniques.tivation techniques.

• 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.

• Korean Journal of Plant Resources
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• v.11 no.3
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• pp.315-318
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• 1998

This study was carried out to investigate the effect of seedling growth with different seedling rate for machine transplanting with turf. Chosun Zoysia was sown on May 17 with three levels seedling rates. The plant charactersitics were greater in 500g/box plots than the other seedling rates on the seedling box. It ws shown that the 30-40day old seedlings of 1.000 and 2,000g/box seedling plots appeared to be proper methods for Sprigging as the high seedling density. The 70 day old seedling plant with 500g/box were shown to be propoer methods for Sprigging. The seedling periods need to be 60 days for 500g/box plots and 40 days for 1,000 and 2,000g/box plots as forming the mats.

• Korean Journal of Soil Science and Fertilizer
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• v.40 no.6
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• pp.465-470
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• 2007

To evaluate the effect of companion plant (Phlox subulata and Glechoma hederacea var. longituba) on conservation of soil in slopped highland, coverage of crops and soil erosion were investigated with 3 different conditions. The coverage rate of Phlox subulata with Chinese cabbage cultivation was kept on approximately 100% from Chinese cabbage-transplanting to -harvest. The coverage rate of Glechoma hederacea var. longituba with Chinese cabbage cultivation was low at it's early stage, however, reached to approximately 100% at the time of Chinese cabbage harvest. In contrast, the coverage rate of Chinese cabbage cultivation without cover crop, and simultaneous transplanting with Chinese cabbage and cover crop were approximately 60%. Losses of soil and nitrate nitrogen were much lower in Phlox subulata with Chinese cabbage cultivation ($0.1{\sim}0.2ton\;ha^{-1}$, $0.2{\sim}0.4kg\;NO_3{^-}-N\;ha^{-1}$) than those in Chinese cabbage cultivation without cover crop ($20.8ton\;ha^{-1}$, $2.1kg\;NO_3{^-}-N\;ha^{-1}$), and simultaneous transplanting with Chinese cabbage and cover crop ($8.9{\sim}10.5ton\;ha^{-1}$, $1.5{\sim}2.2kg\;NO_3{^-}-N\;ha^{-1}$). Cover plants suppressed the weed occurrence up to about 70%. Live mulching with cover plants set a good effects on weed suppression and reduction of soil and nutrient loss. Therefore intercropping with Phlox subulata will make great contributions to soil conservation in Chinese cabbage cultivated highland.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.246-261
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• 2023

We investigated critical temperature for early marginal transplanting (CT-EMT) of the contemporary japonica rice varieties in Korea through the field, pot seedling tray, and the phytotron experiments during 2020 to 2023. The lowest mean temperature for 10 days from transplanting (MT-10DFT) that resulted in earlier heading date was 12.4℃ and the highest MT-10DFT that did not show the earlier heading date was 12.0℃ in the field study when the MT-10DFT varied by changing transplanting date. The lowest MT-10DFT that induced the increased biomass but not the earlier heading date was 11.6℃ and the highest MT-10DFT that showed neither the increased biomass nor the earlier heading date was 11.4℃. Compared to the 10-day later transplanting, the dates of the first root development, initiation of the chlorophyll recovery, and the first tiller development were earlier when the MT-10DFT was 9.1℃ or higher, 10.5℃ or higher, and 11.6℃ or higher, respectively, in the pot seedling tray and field experiments. The earliness of the first tiller development was a practical index for the estimation of CT-EMT during the early growth stage of rice. The response of transplanted rice to temperature treatments with the diurnal change of 10℃ in the phytotron study was similar to that shown in the field study. The data shown for constant temperature without a diurnal change revealed that the extent of positive effects of high temperature at day-time was greater than the extent of negative effects of low temperature at night-time on the early growth of transplanted rice. It was concluded that the critical MT-10DFT for early marginal transplanting of japonica rice in the temperate environments was between 11.4 to 11.6℃ based on the plant growth and between 12.0 to 12.4℃ based on the plant development.

• Plant Resources
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• v.3 no.3
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• pp.194-199
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• 2000

The result of this experiment which are conducted, to improve the cultivation technology of Alisma plantago, to increase its quantity and to contribute for stable production with Yongiun local group by examining the optimal planting density and transplanting period of double cropping of Alisma plantago in the southern region. The characters of plant height, leaf width and length tend to be reduced as the seeding period is later by the order of the 10th, 20th and 30th of July. The period required for flowering is reduced as the transplanting period is later and dense planting is applied. Plant height, the number of leaves and yield of dry root have much quantity at the dense planting density of 20$\times$ 15cm as they are transplanted later in the 30th of August or the 10th of September, but they are rather less in sparse planting density of 20$\times$25cm or 20$\times$35cm.

• Journal of Practical Agriculture & Fisheries Research
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• v.21 no.2
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• pp.77-86
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• 2019

To determine none top soil covering in rice seedling nursery method for the sparse machine transplanting, four different sowing methods were tested. Shoot and root length, fresh weight, leaf number and color using leaf color chart(LCC) and SPAD were collected as the data comparison of methods. The seedling height showed the highest growth according to the conventional (230g seed rate of pre-emerged seeds and top-soil covering) > high sowing density 1 (290g seed rate of pre-emerged seeds and top-soil covering) ≥ high sowing density 2(290g seed rate of pre-emerged seeds and none top-soil covering) > high sowing density 3(290g seed rate of iron-coated seeds and none top-soil covering). There was any statistical difference between groups in root length, leaf number, LCC, and SPAD values. Thus, a high sowing density of 290g for rice nursery seedling box was recommended to the sparse machine transplanting in rice cultivation with the none top-soil covering method, enabling convenient handling in transportation and machine transplanting work.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.72-72
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• 2019

This study compared the growth characteristics of A. gigas according to the transplanting season, in the cultivation located in Yeongju, Gyeongsangbuk-do, transplanted in the autumn and spring. As a result of that the plant survival rate were observed the highest autumn transplanting (9.4%; autumn-92.2%, spring-82.8%) and bolting rate were observed lowest spring transplanting (7.1%; autumn-37.3%, spring-30.2%). Growth characteristics (height, leaf length and width, stem diameter) were observed the highest autumn transplanting in June and highest spring transplanting in August. The early growth is high growth due to long rooting time in autumn transplanting, but the difference in the ground growth between the two experiments was insignificant when the main growth period was from June to August. Further analysis of the growth characteristics and marker components of roots of A. gigas can be used to determine the optimal planting time and the establishment of high quality cultivation technology.

• Proceedings of the Korean Society of Crop Science Conference
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• 2005.10b
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• pp.156-157
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• 2005

• Proceedings of the Korean Society of Crop Science Conference
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• 2001.05a
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• pp.134-135
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• 2001