• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.273-278
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• 2008

This study set out to investigate the changes to the growth, yield, and flavonoid contents of mungbean according to different seeding times from mid May to mid July in the southern region of Korea. Days to first flowering, days to first maturing, and cultivation period were shorter at later seeding time than earlier seeding time. But later the seeding time was, days from first maturing to first harvesting, days required between harvesting increased. Number of pods at first harvesting and yield of mungbean were highest when seeded at late June, showing increase in yield 14% more than at early June as standard seeding time. However number of seeds per pod and 1,000-seed weight at first harvesting were highest when seeded at mid July. The number of harvesting was smallest at two times when seeded at June or mid July. The contents of average vitexin and isovitexin in mungbean were highest in the order of mid July, late June, and mid May. In particular, their contents reached its highest point in the seeds of the second harvest. Considering the results of the cultivation period, yield, harvesting times, vitexin and isovitexin contents, the proper seeding time of mungbeans in the southern region of Korea will be from late June to mid July.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.236-242
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• 1999

To examine the seedling stand and growth as affected by early seeding dates of dry direct seeded rice in the Honam plain area of Korea, Dongjinbyeo was seeded at six seeding dates from early March to late April in rice fields of silty loam soil(Jeonbuk series) at the National Honam Agricultural Experiment Station (NHAES) for two years, 1996 and 1998. Seedling stand decreased slightly. with an early seeding date, but it produced more than the optimum seedling number except for the seeding of 25 March in 1996. Days to emergence was significantly longer, as seeding date was earlier, and days to emergence by early seeding was shortened only by 8 days because the mean air temperature was lower in 1996 than average, while in 1998, the reduction effect was nine to twenty five days because the mean air temperature was higher than average. In early seeding, various weeds occurred at the emergence date of rice and dominant weeds were Alopecurus aequailis, Ludwigia prostata and Rorippa islandica. NH$_4$$^{+}$ -N content in the soil at the 5th leaf stage and maximum tillering stage were lower, as the seeding date was earlier when nitrogen was split applied as basal and top dressed in 1996, while it was not significantly different among seeding dates when nitrogen was intensively applied as a top dressing in 1998. Tiller number at the maximum tillering stage and panicle number/m$^2$ were more, as seeding date was earlier in 1996, while it was not different in 1998. Filled grain rate and 1,000 grain weight was not different among the seeding dates. Milled rice yield was significantly decreased in the seeding before the middle of March, but in the seeding after late March, it was not varied when compared with the normal seeding date in 1996, while in 1998, there was no difference among seeding dates. From the above results, in consideration of seedling stand, weed occurance, rice growth and milled rice yield, the critical optimum early seeding time in the southern plain area may lie in early April. But it was suggested that when soil moisture is proper for seeding practices, seeding amount is increased and nitrogen is applied after plumule emergence of rice, milled rice yield may not be reduced in the seeding of middle or late March, compared with the seeding in April.l.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.3
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• pp.225-229
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• 1999

Unstable seedling stand establishment of wet direct seeding culture of rice is one of the major elements preventing the extension of its culture area. In order to develop methods of seedling stand improvement in direct seeded rice on flooded surfaces, three field experiments were conducted on silty loam soil using a cultivar 'Donjinbyeo' for three years, mainly focusing on water management after seeding and seed soaking with plant growth regulators (PGRs). Under the condition of shallow flooding after seeding, seedling stand rate increased and floating seedling rate decreased in both early and normal season seeding compared to deep flooding. With earlier draining time after seeding, there was a tendency towards preferential growth of the seminal root, increase of seedling stand and decrease of the floating seedling rate. Therefore the highest seedling numbers per unit area and the lowest floating seedling numbers were found upon drainage at 1 day after seeding (DAS), while a contrary tendency was shown upon conventional drainage at 7 DAS. Seed soaking with PGRs such as Metalaxyl or mixing of Metalaxyl with gibberellic acid (GA$_3$) significantly increased the seedling stand. In addition the effects of PGR treatment on seedling stand and the early growth of plants were greater under flooded conditions than under drained conditions after seeding, although draining of water after seeding improved the seedling establishment rate more when compared with the PGR treatment. These results suggest that draining management after seeding or maintaining of shallow flooding for a week is the most effective method to improve the seedling stand rate in wet direct seeding.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.1
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• pp.115-122
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• 1996

One of the most laborious work in rice farming is transplanting of rice seedling which has been required preparation of nursery bed and care of seedling during one month period. In this research, direct seeding in dry paddy(DS) and direct seeding in wet paddy(WS) were practiced to compare with traditional transplanting(TP) in Suwon. Growth stages in direct seeding were delayed as its planting time was about 21 days later than those of TP. Heading stage of direct seeding at Suwon was delayed about 9 days as compared to transplanting culture. Rice yield was not different between the seeding practises. Working-hour saving was about 17％(DS) and 28％(WS). Production cost of direct seeding was decreased 20％(DS) and 32％(WS), respectively. Amount of rice production per a unit working-hour in direct seeding could increase 14％(DS) and 39％(WS) compared to that of TP, respectively. Therefore, direct seeding could save significantly working hour and production cost without reducing rice yield. WS was more effective than DS in saving labor and production cost. Direct seeding was not efficient method in input of farming energy and agricultural chemicals.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.46 no.1
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• pp.64-67
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• 2001

Snap bean is a new corp in Korea but believed to have a great deal of potentials for both domestic and overseas markets. The present study was performed to obtain the basic information about growth- and quality-related characteristics and to determinate the optimum seeding date and harvesting time for snap bean. Pod yield was significantly affected by seeding date. The highest pod yield was obtained from March 20 for determinate type and April 4 for indeterminate one, respectively, with the range of 13.0-23.7 t/ha. The pod length of indeterminate type was over 13cm, and the pod length was over 5 grams. The pod width for tested varieties was less than 1.0cm. Considering the pod growth characters such as pod length, pod width, and pod weight, the optimum harvesting time for immature pods of snap bean was supposed to be from 15 to 20 days after flowering. The daily yield of snap bean was begun to sharply increase from 15 days after the first flowering and the maximum yield was recorded at 30 days after flowering. For the accumulated yield, nearly 90% of total yield was obtained in 42 days after flowering.

• Journal of Practical Agriculture & Fisheries Research
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• v.19 no.1
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• pp.119-128
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• 2017

The field trial was performed to evaluate the rice growth and yield in different direct seeding methods. The required time for seed emergence was for 8~ 9days in the tested direct seeding methods and there was high in seedling establishment according to wet hill-seeding with iron-coated seeds> wet hill-seeding with soil coverage>water seeding with iron-coated seeds and water seeding with pregerminated seeds as the conventional treatment. The rice plant height was taller in wet hill-seeding methods than that of water seeding with broadcasting method but there was not significant difference in terms of statistical analysis at 75day after seeding except the water seeding with pregerminated seeds. The growth of tiller number in the rice plant was highest in water seeding with iron-coated seeds. The milled rice yield was highest in water seeding with iron-coated seed being with 6.4t/ha and percentage of head rice was the highest in wet hill-seeding and water seeding with iron-coated seeds.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.18
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• pp.88-123
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• 1975

To obtain useful fundamental informations for improving cultural practices of barley, an investigation was made on the influences of different fertilizer level and seeding rate as well as seeding date on yield and yield components and their balancing procedure using barley variety Suwon ＃ 18, and at the same time, 8 varieties including Suwon ＃ 18 were also tested to clarify the varietal responses in terms of their yield and yield components under different seeding date at Crop Experiment Station, Suwon, during the period of 1969 and 1970. The results obtained were summarized as follows; 1. Days to emergence of barley variety Suwon ＃ 18 at Suwon, took 8 to 19 days in accordance with given different seeding date (from Sept. 21 to Oct. 31). Earlier emergence was observed by early seeding and most of the seeds were emerged at 15$0^{\circ}C$ cumulated soil temperature at 5cm depth from surface under the favorable condition. 2. Degree of cold injury in different seeding date was seemed to be affected by the growth rate of seedlings and climatic condition during the wintering period. Over growth and number of leaves less than 5 to 6 on the main stem before wintering were brought in severe cold damage during the wintering period. 3. Even though the number of leaves on the main stem were variable from 11 to 16 depending upon the seeding date. this differences were occurred before wintering and less variation was observed after wintering. Particularly, differences of the number of main stem leaves from September 21 to October 11 seeding date were occurred due to the differences of number of main stem leaves before wintering. 4. Dry matter accumulation before wintering was high in early seeded plot and gradually decreased in accordance with delayed seeding date and less different in dry matter weight was observed after wintering. However, the increment rate of this dry matter was high from regrowth to heading time and became low during the ripening period. 5. Number of tillers per $\m^2$ was higher in early seeding than late one and dense planting was higher in the number of tillers than sparse planting. Number of tillers per plant was lower in number and variation in dense planting, and reverse tendency was observed in sparse planting. By increasing seedling rate in early seeding date the number of tiller per plant was remarkably decreased, but the seeding rate didn't affect the individual tillering capacity in the late seeding date. 6. Seedlings were from early planting reached maximum tillering stage earlier than those from the late planting and no remarkable changes was observed due to increased seeding rate. However. increased seeding rate tends to make it earlier the maximum tillering stage early. 7. Stage of maximum tillering was coincided with stage of 4-5 main stem leaves regardless the seeding date. 8. Number of heads per $\m^2$ was increased with increased seeding rate but considerable year variation in number of heads was observed by increased fertilizer level. Therefore, it was clear that there is no difficulties in increasing number of heads per $\m^2$ through increasing both fertilizer level and seeding rate. This type of tendency was more remarkable at optimum seeding time. In the other hand, seeding at optimum time is more important than increasing seeding rate, but increasing seeding rate was more effective in late seeding for obtaining desirable number of heads per $\m^2$. 9. Number of heads per $\m^2$ was decreased generally in all varieties tested in late seeding, but the degree of decrease by late seeding was lower in Suwon ＃ 18. Yuegi, Hangmi and Buheung compared with Suwon ＃ 4, Suwon ＃ 6, Chilbo and Yungwolyukak. 10. Highly significant positive correlations were obtained between number of head and tillers per $\m^2$ from heading date in September 21 seeding, from before-wintering in October 1 seeding and in all growth period from October 11 to October 31 seeding. However, relatively low correlation coefficient was estimated between number of heads and tillers counted around late March to early April in any seeding date. 11. Valid tiller ratio varied from 33% to 76% and highest yield was obtained when valid tiller ratio was about 50%. Therefore, variation of valid tiller ratio was greater due to seeding date differences than due to seeding rate. Early seeding decreased the valid tiller ratio and gradually increased by delaying seeding date but decreased by increasing seeding rate. Among the varieties tested Suwon ＃ 18, Hangmi, Yuegi as well as Buheung should be high valid tiller ratio not only in late seeding but also in early seeding. In contrast to this phenomena, Chilbo, Suwon ＃ 4, Suwon ＃ 6 and Yungwolyukak expressed low valid tiller ratio in general, and also exhibited the same tendency in late seeding date. 12. Number of grains per spike was increased by increasing fertilizer level and decreased by increasing seeding rate. Among the seeding date tested. October 21 (1969) and October 11 (1970) showed lowest number of grains per spike which was increased in both early seeding and late seeding date. There were no definite tendencies observed along with seeding date differences in respective varieties tested. 13. Variation of 1000 grain weight due to fertilizer level applied, seeding date and seeding rate was not so high as number of grains per spike and number of heads per $\m^2$, but exhibited high year variation. Increased seeding rate decreased the 1000 grain weight. Among the varieties tested Chilbo and Buheung expressed heavy grain weight, while Suwon ＃ 18, Hangmi and Yuegi showed comparatively light grain weight. 14. Optimum seeding date in Suwon area was around October 1 to October 11. Yield was generally increased by increasing fertilizer level. Yield decrease due to early seeding was compensated in certain extent by increased fertilizer application. 15. Yield variations due to seeding rate differences were almost negligible compare to the variations due to fertilizer level and seeding date. In either early seeding or law fertilizer level yield variation due to seeding rate was not so remarkable. Increment of fertilizer application was more effective for yield increase especially at increased seeding rate. And also increased seeding rate fairly compensated the decrease of yield in late seeding date. 16. Optimum seeding rate was considered to be around 18-26 liters per 10a at N-P-K=10.5-6-6 kg/10a fertilizer level considering yield stabilization. 17. Varietal differences in optimum seeding date was quite remarkable Suwon ＃ 6, Suwon ＃ 4. Buheung noted high yield at early seeding and Suwon ＃ 18, Yuegi and Hangmi yielded higher in seeding date of October 10. However, Buheung showed late seeding adaptability. 18. Highly significant positive correlations were observed between yield and yield components in all treatments. However, this correlation coefficient was increased positively by increased fertilizer level and decreased by increased seeding rate. Significant negative correlation coefficients were estimated between yield and number of grains per spike, since increased number of heads per m2 at the same level of fertilizer tends to decrease the number of grains per spike. Comparatively low correlation coefficients were estimated between 1000 grain weight and yield. 19. No significant relations in terms of correlation coefficients was observed between number of heads per $\m^2$ and 1000 grain weight or number of grains per head.

• Journal of The Korean Society of Grassland and Forage Science
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• v.5 no.3
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• pp.212-219
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• 1985

The field experiment was conducted to study on the growth analysis of early variety, MTC-1, and late variety, Suweon 19, in response to seeding time at Suweon. The results summarized as follows: 1. Days required for Leaf-Formation(L-phase) of MTC-1 and Suweon 19 was same but that of Node-Thickening(N-phase) was quite different, e.g. late variety has two times longer. The period of Ear-Development (E-phase) in MTC-1 was 41 days and 53 days in Suweon 19. L-and N-phase were shortened by late seeding but E-phase was not influenced by seeding time. 2. Leaf Area Index(LAI) was decreased and Leaf Area Ratio(LAR) was increased by late seeding. Days required to maximum LAR was less by late seeding. Net Assimilation Rate(NAR) of L-, N-, and E-phase was decreased but its tendency in E-phase was remarkable at late seeding. 3. Crop Growth Rate(CGR) was increased gradually in the process of plant growth and it was the highest at Husk-stage. Relative Growth Rate(RGR) was increased in L-phase and was decreased in N- and E-phase, but its tendency in N-phase was great. 4. The period required to the maximum dry matter yield was shortened by late seeding and dry matter yield was increased by early seeding.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.102-102
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• 2022

More than 74% of forage crops in Korea are cultivated in winter rice fields. Italian ryegrass (IRG) can be said to be a representative forage crop, but over 70% of its seeds are dependent on imports. In addition, there are concerns that the stable supply of research fees may be disrupted due to the effects of climate change, war, and other factors. Therefore, it is necessary to secure a large production area for stable supply. Korea's reclaimed land area is 135,000 ha and its agricultural area is 112,000 ha. Therefore, this study attempted to apply IRG to the domestic IRG seed industry through stable cultivation techniques on reclaimed land. In this study, IRG 'Kowiearly' varsity was cultivated in late October 2020 and early October 2021 in the Saemangeum reclaimed land. The seeding methods were conventional drill sowing seeding, new technology spot seedling (30 × 18 cm) and new technology drill sowing seeding. The amount of sowing was conventional drill sowing seeding 2.0(kg/10a), new technology spot seedling 1.5(kg/10a), and new technology drill sowing seeding 1.5(kg/10a). Fertilizer application amount is conventional drill sowing seeding(N-P₂O₅-K₂O) 9.0-12-12(kg/10a), and new technology spot seedling and drill sowing seeding were(N-P₂O₅-K₂O) 4.5-12-12(kg/10a) respectively. Fertilizer was applied accordingly. After that, in February, the conventional drill sowing seeding, new technology drill sowing seeding and spot seedling applied 4.0 and 2.2(kg/10a) of nitrogen supplement fertilizer, respectively. Before wintering, plant length was higher in 2022 than in 2021, but leaf number was higher in 2021. Heading time was April 30, 2021 and April 25, 2022. In heading time, plant length was 74 cm in 2021 and 67 cm in 2022, lower than in 2021. On the other hand, There was no difference in the number of panicle and the number of seeds in the 2021 harvester in all treatment plots, and, thus seed yield was no differ. However, the drill sowing seeding and spot seedling of the new technology were somewhat higher than the conventional drill sowing seeding. On the other hand, seed yield was decreased in all treatment plots compared to 2022 because of raifall deficiency in 2021.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.45 no.6
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• pp.400-404
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• 2000

Hairy vetch (vicia villosa Roth), leguminous green manure crop, can increase soil fertility and reduce chemical nitrogen application for cash crop such as spring corn. More yield of hairy vetch is needed at planting cash crop to obtain higher effect of green manure. Hairy vetch waa seeded on Sep.10, Oct.1, and Oct. 20 and at 10, 20, 30 and 40 kg/ha of seeding rate respectively, in 1996 and 1997, Dry matter and nitrogen yield of hairy vetch were measured on May 1 in 1997 and 1998. Proper seeding rate of hairy vetch was 30 kg/ha irrespective of years and seeding dates. Above-ground dry matters of hairy vetch on May 1 in 1997 and 1998 decreased according to delayed seeding, and those were 5.5-7, 4-4.5, 1.3-2.2 ton/ha on Sep. 10, Oct. 1 and Oct 20 of seeding date, respectively in seeding rate 30-40 kg/ha. Also nitrogen yield of hairy vetch on May 1 decreased according to delayed seeding, and those were 220-280, 160-180, 60-100kg/ha on Sep. 10, Oct. 1 and Oct 20 of seeding date, respectively in seeding rate 30-40kg/ha. Therefore, we suggest that hairy vetch has to be seeded earlier in autumn to obtain high green manure yield in spring. To determine the detailed optimum seeding time in autumn, hairy vetch was seeded on Aug. 20, Aug. 31, Sep. 10, Sep. 20, and Sep. 30 in 1999 and was harvested on April 22, April 27, and May 2 in 2000, respectively. Dry matter and nitrogen yield of hairy vetch by seeding in late August were higher than those by seeding in September indicating that dry matter of hairy vetch were 7-8, 6-7, 4-5, 2-3 ton/ha and nitrogen yield were 240-290, 200-260, 150-220, 70-120 kg/ha, respectively when seeded on Aug. 20, Aug. 31, Sep. 10, Sep. 20 and Sep. 30 and harvested on April 22-May 2. Increase of dry matter and N yield of hairy vetch by 10days delayed harvest was higher in late August seeding than in September seeding. So hairy vetch should be seeded in late August if possible to obtain much more green manure yield and be seeded until September because green manure yield decrease rapidly when seeded after October.