• Journal of Bio-Environment Control
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• v.15 no.1
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• pp.8-20
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• 2006

This research was conducted to determine the plant growth and nutrient contents of potted chrysanthemum 'Lima Honey' as influenced by application rate of dolomite in three root media, peatmoss+vermiculite (1:1, v/v), peatmoss+composted rice hall (1:1, v/v), and peatmoss+composted pine bark (1:1, v/v). All root media contained polyacrylic acid sodium salt (PASS) at a rate of $4.5g L^{-1}$. In crop growth at 40 and 80 days after transplanting, elevated application rates of dolomite up to $6.0g L^{-1}$ in three root media increased fresh and dry weights per plant. But the treatment of $9.0g L^{-1}$ had less fresh and dry weights than those of $6.0g L^{-1}$. Tissue phosphorus content decreased and those of Ca and Mg increased by the elevated application rates of dolomite. Elevated application rates of dolomite in three root media resulted in the increase of pH, EC, and the concentrations of K, Ca, and Mg at 43 days after transplanting. Those at 80 days after transplanting were also increased, but the differences among treatments were less significant as compared to those at 43 days after transplanting. From the results of dry weight in potted chrysanthemum 'Lima Honey', the proper application rate of dolomite to three root media containing PASS at a rate of $4.5g L^{-1}$ were $6.0g L^{-1}$.

• Korean journal of applied entomology
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• v.50 no.3
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• pp.215-220
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• 2011

This study aimed to estimate control thresholds for managing common cutworm, Spodoptera litura Faricius (Lepidoptera: Noctuidae) at different larval densities and growth stages of Chinese cabbage in field conditions. The percent yield reduction (Y) of Chinese cabbage infested by different densities of S. litura (X, no. of larvae/100 plants) for three weeks were estimated by Y=-21.85X+1300 (R2=0.997) 5 days after transplanting and Y=-12.1X+1382 (R2=0.998) 20 days after transplanting. Based on the relationships between the densities of S. litura larvae and the yield index of chinese cabbage, the number of larvae (2nd to 3rd instar) which caused 5% loss of yield was estimated as 2.9/100 plants 5 days after transplanting, and 5.6/100 plants 20 days after transplanting.

• Journal of The Korean Society of Agricultural Engineers
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• v.63 no.3
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• pp.75-85
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• 2021

This study evaluated variations in the paddy rice water demand based on the continuous changing in rice transplanting period and ponding depth at the four study paddy fields, which represent typical rice producing regions in Korea. Total 7 scenarios on rice transplanting periods were applied while minimum ponding depth of 0 and 20 mm were applied in accordance with maximum ponding depth ranging from 40 mm to 100 mm with 20 mm interval. The weather data from 2013 to 2019 was also considered. The results indicated that the highest rice water demand occurred at high temperature and low rainfall region. Increased rice transplanting periods showed higher rice water demand. The rice water demand for 51 transplanting days closely matched with the actual irrigation water supply. In case of ponding depth, the results showed that the minimum ponding depth had a proportional relationship with rice water demand, while maximum ponding depth showed the contrary results. Minimum ponding depth had a greater impact on rice water demand than the maximum ponding depth. Therefore, these results suggest that increasing the rice transplanting period, which reflects the current practice is desirable for a reliable estimation of rice water demand.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.629-636
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• 2019

This study was conducted to investigate the growth characteristics and yield of whole green rice grains during the ripening period. These were investigated using Hopumbyeo and Unkwangbyeo at two transplanting times and with two kinds of nitrogen fertilization. The transplanting times were May 30 and June 20, respectively, using 30-day seedling culture and transplanting conducted with 3 - 4 plants per hill in planting space of $15cm{\times}30cm$. During nitrogen fertilization, 9 kg and 18 kg was used, respectively. The harvest of the green whole rice grains was carried out on the 15th, 20th, 25th, 30th, and 40th day after the heading date. The clum length was greater with later planting and with application of more nitrogen. The rice yield was higher with nitrogen fertilization of 18 kg/10 a when transplanted on May 30 for Hupumbyeo, and for Unkwangbyeo, was higher at 9 kg/10 a nitrogen fertilization when transplanted on May 30. The protein content of Hopumbyeo was higher when the nitrogen fertilizer was 18 kg/10 a, and that of Unkwangbyeo was lower than that when transplanting on June 20. The greenness was not related to the nitrogen fertilization level when transplanted on May 20 but for later transplanting, the greenness was higher when the nitrogen application was increased, and the greenness was the greatest about 30 days after the heading date.

• Korean Journal of Organic Agriculture
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• v.23 no.1
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• pp.59-66
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• 2015

Effect of seedling type and early transplanting of summer grown seedling on the growth and yield of tomato was investigated to minimize problems caused by legginess of seedling in summer. Grafted seedling, 20 days seedling (young seedling), 40 days seedling, and rooted cutting were raised from July 20 to Sept. 7 and young seedling was transplanted 20 days earlier than other seedling types. Young seedling growth was weaker than other seedling types and fresh weight was only 1/10 of 40 days seedling. Growth of young seedling at 20 days after transplanting was better than other seedling types and fresh weight was 3 times higher than 40 days seedling. Creased stem did not appear and trusses developed faster in young seedling. Total yield and commercial yield were highest in young seedling as 8,535 kg/10a, and 7,575 kg/10a. There is no significant difference among seedling types in fruit quality. This result shows that early transplanting of summer grown seedling is more effective to attain stable growth and yield in tomato.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.231-238
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• 1982

The study was done to determine the proper transplanting dates and seedling ages of rice when mechanical transplanting was attempted. Heading dates of the Milyang #23, developed from Tong-il rice was delayed by delayed transplanting and the percent of filling grain was also low. The proper heading dates for the variety should be the first part of August and the transplanting should be done by the end of May. The presumed last days for the transplantation was considered early part of June. 30 to 40 days old seedlings were very effective to have healthy rooting systems. However, the Milyang #15 had shown more tolerance to the late transplantation than Milyang #23 and the degree of delaying heading dates due to the delayed transplantation was rather smaller than that of the Milyang #23. Even when the Milyang #15 was transplanted on June 30, the heading dates were around the middle of August and the ripening percentage was comparatively high and yield was also high. Therefore, the proper heading dates of the Milyang #15 might be around the middle of August and transplanting dates should be the first part of June. The possible last dates of transplantation of the Milyang #15 was assumed to be the last days of June and the proper seedling ages would be 20 to 30 day after sowing.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.62 no.4
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• pp.304-310
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• 2017

This study was conducted over a 3-year period from 2013 to 2015 in the mid-northern inland, Cheolweon, Korea, to investigate changes in flowering date, daily mean temperature during grain filling, and yield characteristics affected by transplanting date in an early-maturing rice variety, 'Joun'. Thirty-day-old seedlings were transplanted at four different dates at 15-day interval from May 5 to June 19. Flowering dates were July 16, July 21, July 31, and August 14 when transplanting was performed on May 5, May 20, June 4, and June 19, respectively. Late transplanting resulted in higher daily mean temperature before flowering but late-transplanted rice required fewer days and lower cumulative temperature to reach flowering from transplanting. As transplanting was delayed, daily mean temperature for 40 days after flowering decreased, whereas daily sunshine hours for the same period increased, with a temperature of $24.8^{\circ}C$ and sunshine for 5.8 hours being recorded at the transplanting on May 5, and with a temperature of $21.0^{\circ}C$ and sunshine for 7.7 hours at the transplanting on June 19. With late transplanting, panicles per square meter significantly decreased, whereas spikelets per panicle showed an increasing trend. Regression analysis showed that maximum head rice yield was attained from the transplanting on May 18, for which the flowering date was July 21, and daily mean temperature for 40 days from that flowering date was $24.6^{\circ}C$. A decrease in head rice yield by 5% and 10% of the maximum was observed for rice transplanted on June 6 and June 15, which resulted in flowering dates of August 2 and August 11, respectively, and the daily mean temperatures for 40 days from flowering were 23.2 and $21.7^{\circ}C$, respectively. Therefore, in mid-northern inland, it is recommended to transplant 'Joun' on May 18 to induce flowering on July 21, when grain filling is subjected to a daily mean temperature of $24.6^{\circ}C$ during active filling stage.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.300-300
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• 2017

'Saemimyeon' a Tongil-type rice variety (Indica ${\times}$ Japonica), which contains high amylose contents is suitable for rice noodle production. Nowadays, the major parts of rice processing industry that includes products like rice flour and noodles are expected to partially replace wheat flour market. The volume of rice noodle market is getting bigger and can contribute to the rice surplus and farmer's income. This study was carried out to promote productivity and flour-making quality of 'Saemimyeon' by finding the most suitable transplanting and harvesting times. The transplanting days used were May $10^{th}$, May $17^{th}$, May $24^{th}$, May $31^{th}$, June $7^{th}$ and June $14^{th}$ and the planting distance used was 30 x 12cm. In addition, harvesting time was determined by days after heading time (40, 45, 50, 55 and 60 days). The field experiment was conducted at the experimental field in Miryang (Southern plain area of Korea) from 2015 to 2016. Our results suggest that the optimum transplanting days were from May $24^{th}$ to May $31^{th}$ which resulted to an average yield of 748~751kg/10a. Interestingly, yield was sharply decreased below 700kg/10a before May $10^{th}$ and after June $7^{th}$. The average grain filling rate before May $31^{th}$ was more than 83% but it declined to 75% after June $7^{th}$. The average temperature ranges from heading time to harvesting time was $ 21\sim25^{\circ}C$ and the estimated optimal temperature was $23.4^{\circ}C$ which is similar to May $24^{th}$ by regression equation. We found that the optimal harvest time was 45~50 days after heading time. It is hypothesized that low temperature at seed maturation time caused the lower grain filling rate therefore 'Saemimyeon' need to be transplanted before May $31^{th}$ for higher productivity. We found no statistical variation in amylose contents among experimental plots (28.2~30.4%). We conclude that the productivity of 'Saemimyeon' highly depends on temperature that is critical for grain filling stage controlled by transplanting time.

• 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.41 no.6
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• pp.625-633
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• 1996

Crude extracts of 4 Allium SPP. such as welsh onion, onion, chinese chives and garlic were purified by paper chromatography and these activities were bio-assayed with rice seedlings. The stem and leaf slices of Allium spp. were treated and rice seedlings were planted in the soil to know the effect of its application on rice growth. The weak acidic fraction of Allium SPP. enhanced the growth and rooting of rice seedlings and had greater activity in promoting than in inhibiting the growth on rice seedling. Elongation of the second leaf sheath of the rice seedlings were not influenced by the extracts of Allium SPP. The stem and leaf application 10 days before transplanting, increased the number of effective tiller remarkably. Especially, the application of 50~400g welsh onion and 50~200g onions increased the number of spikelets per panicle compared to standard fertilization. But, in application of larger amounts, the-death rate of the rice seedlings after transplanting was higher in the stem and leaf application 10 days before transplanting than the one applied on the transplanting day. In particular, treatments of chinese chives and garlic showed higher death rate than those of welsh onion or onion. The stem and leaf application of Allium SPP. resulted in high yield than standard fertilization.