• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.1
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• pp.86-91
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• 1995

This experiment was conducted to understand the response on sowing rates at furrow sowing of rice in paddy field. As sowing rates was increased, the number of seedling stand per$m^2$ was icreased, while panicie number per plant was decreased slightly. Leaf area at heading stage and effective tiller ratio were decreased with increasing of sowing rates, but heading date was not defferent among sowing rates. According to sowing rates was increased, culm length, panicle length, breaking strength, culm diameter were decreased, while lodging index was increased. Also, field lodging was observed in the higer sowing rates over 5kg/l0a. Althougth the panicle number per $m^2$ was increased with increasing of sowing rates, spike let per panicle and percent of filled spikelet were decreased. According to the result from the path coefficient analysis, percent of filled spikelets well identified to be the most influential variables on the variability in rice yield, so that improving percent of filled spikelets by inhibition of field lodging was the important matter to increase the yield. The optimal sowing rate and the number of seedling stand were estimated to be 4.5kg/l0a and 105 per $m^2$ respectively.

• Journal of the Korean Society of Environmental Restoration Technology
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• v.25 no.2
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• pp.15-22
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• 2022

This study has been conducted to investigate the appropriate mixed sowing rates with white clover (Trifolium repens) and Kentucky bluegrass (Poa pratensis) by evaluating initial growth. Six different mixed sowing rates (CT, Control Trifolium repens; CP, Control Poa pratensis; T1P3, Trifolium repens 1 : Poa pratensis 3; T1P2, Trifolium repens 1 : Poa pratensis 2; T1P1, Trifolium repens 1 : Poa pratensis 1; T2P1, Trifolium repens 2 : Poa pratensis 1; T3P1, Trifolium repens 3 : Poa pratensis 1) with three repetitions were implemented in greenhouse experiment plastic pots (50.5 length × 35.0 width × 8.5 cm height). Plant height, leaf length, leaf width, number of leaves, root length, fresh weight, and dry weight were measured after a week from the germination for three months. Initial growth of Kentucky bluegrass significantly increased as mixed sowing rates with increasing, while that of white clover kept relatively decreasing than that in Control. Initial growth strongly affected sowing mixed rates by Kentucky bluegrass and not by white clover in this experiment, indicating that grasses played a dominant role during initial growth period. However, seeding rates with white clover will be dependent on the use of a turf and the desired green cover. There remains a need to further study of the mechanisms and dynamics of legume and grass competition to underpin sustainable management practices.

• Plant Resources
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• v.4 no.2
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• pp.92-96
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• 2001

seeding rates(1.5,2.0,3.0 and 3.5$\ell$/10a). There were no differences in the yield components such as length of stem and ear diameter of stem number of branch, internode and ear, and yield of fresh and dry stem between the seeding methods with drilling and broadcasting, but yield components such as length of stem and ear, diameter of stem, number of branch, internode and ear, and yield of fresh and dry stem increased with seeding rates of from 2.5$\ell$ /10a to 3.5$\ell$/10a. Therefore potimum rates and methods of sowing were from 2.5$\ell$/10a to 3.5$\ell$/10a with seeding at the drilling and broadcasting.

• Asian-Australasian Journal of Animal Sciences
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• v.6 no.1
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• pp.123-126
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• 1993

Hand dibbling in rows produced higher (p < 0.05) fresh and dry matter (DM), fodder yield, higher plant density and cob yield than broadcasted. However, the varying seed rates (40, 50 and 55 kg/ha) did not affect (p < 0.05) the fresh and DM yield and cob yield except for 30 kg/ha seed rate which produced the lowest (p < 0.01). However, the overall average fresh fodder yield and the fresh and DM yield of cob were 24.97, 10.04 and 6.90 t/ha respectively. The overall average plant height (cm), cob/plant (nos.) plant/ha, (nos.) cob/ha (nos.) and weight (g) of one cob were 178, 1.11, 664141, 70104 and 145 respectively for both the sowing methods and the four seed rates. Crude protein contents of maize plant and cob by-products (8.12% and 7.34% respectively) indicated promising cattle feeds along with human food.

• Proceedings of the Korean Society of Crop Science Conference
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• 1990.05a
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• pp.130-131
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• 1990

• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.4
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• pp.384-389
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• 2018

Cultivation techniques of proso millet (Panicum miliaceum L.) and foxtail millet (Setaria italica L.), such as sowing, weeding, and harvesting, are often not properly utilized, resulting in low productivity rates. The goal of this study was to develop cultivation techniques to increase millet productivity rates and reduce labor inputs. We evaluated the effects of different machine sowing methods compared with manual sowing methods from 2014 to 2016. The three machine sowing methods were dibbling, drilling, and broadcasting. Compared with manual sowing, the broadcasting method decreased labor times by 16.07 and $14.23hr10a^{-1}$ for proso and foxtail millets, respectively. Proso millet showed greater culm lengths at 138 and 125 cm with the broadcasting method for two years, whereas foxtail millet after three years had greater culm lengths from both the drilling and broadcasting methods. Both crops exhibited the thickest culm stems in the $3^{rd}$ year. The greatest number of seeds of the panicle were from the manual sowing method in both crops. Compared with manual sowing, broadcasting increased grain yields by 15-35% and 9.1-28% for proso and foxtail millets, respectively. Therefore, we suggest that the application of broadcasting in mechanical sowing will increase labor efficiency and yields of proso and foxtail millets.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.1
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• pp.11-19
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• 1999

This experiment was conducted with nine wheat geno-types to choose the wheat which has excellent early vigour. 'Vigour 18' and 'ZL 59A' are excellent in the long coleoptile genotype, while 'Amery' and 'Janz' are excellent in the short coleoptile genotype. Responding to the growth stage and nitrogen level, Vigour 18 is predominant in the long coleoptile genogype, while Janz in the short coleoptile genotype. Responding to sowing density and nitrogen level, the higher the sowing density was, the shorter the leaf area of Vigour 18 and Janz. Also the leaf area turned out to larger in the plot fertilized with high nitrogen than in the plot fertilized with low nitrogen. This is true of leaf weight and root weight. Concerning specific leaf area (SLA) and leaf area ratio (LAR), the higher the sowing density was, the SLA tended to grow larger, while the SLA grew larger in the plot fertilized with low nitrogen, as were found in Vigour 18 and Janz. The roots of long coleoptile genotype, Vigour 18, turned out to grow longest on the plot sown with 3 seeds. While the roots of short coleoptile genotype, Janz, grew longest on the plot sown with 2 seeds. The relative growth rate (RGR) was the same at low N rates and high N rates. The RGR was 0.071 and 0.072 g $g^{-1}d^{-1}$ at low N rates and high N rates. The partitioning of RGR into net assimilation rate (NAR) and LAR showed that the average LAR at low N rates was similar to the LAR at high N rates. Variation within each cultivar in the LAR and NAR was small relative to the difference between them at low N rates and high N rates. Above ground mass was 8.2 mg greater at high N rates than low N rates, whereas leaf area was 0.05 $\textrm{m}^2$$kg^{-l}$ greater at high N rates than low N rates. The NAR was similar at low N rates and high N rates, whereas LAR was greater at high N rates (0.05 $\textrm{m}^2$$kg^{-l}$); variation in SLA was responsible for the variation in NAR and LAR both at low N rates and high N rates. NAR was more closely associated with the reciprocal of SLA.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.61-69
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• 2024

Considering the threats of climate change, this study was conducted to investigate the influence of temperature and day-length on soybean growth and yield when sown late in comparison to the optimal sowing time in the southern region of the Korean Peninsula. Sowing was executed in 10-day intervals, including on July 1, 10, 20 and 30 and August 10, considering that the optimum sowing time of the three soybean varieties with different ecotypes is June 20. Emergence rates did not differ significantly between late-sowing and optimal sowing in all ecotypes; however, the number of days to emergence, flowering, and maturity was smaller after late sowing. A multiple-regression approach was used to test the effect of temperature and day length on the number of growing days after late sowing compared to the optimal sowing time. This analysis revealed that the number of days required from sowing to flowering was positively correlated with both day length and temperature, and the number of days from flowering to harvest was positively correlated with day length and negatively with temperature. A multiple regression equation can be calculated as follows: the number of days required from sowing to flowering (Y) = 3.177 + (0.030 × (sum of day length + sum of temperature)), and the number of days required from flowering to maturity (Y) = 20.945 + (0.021 × (sum of day length + sum of temperature)). Multiple growth parameters were significantly correlated with yield components, depending on growing days. Optimal sowing resulted in the best yield, while later sowing decreased yield compared to optimal sowing. To avoid a significant decrease in yield, early-maturing species should be sown by July 20, while late-maturing species should be sown by July 10.

• Journal of The Korean Society of Grassland and Forage Science
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• v.10 no.3
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• pp.147-151
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• 1990

The purpose of this study is to clarify the relation of survival rates of seedling plants under grown orchardgrass populations and control by the difference cutting frequency. The orchardgrass populations investigated in this study have passed for 10 years after establishment. Cutting frequencies were 3, 4 and 5 times in a year. This experiment was conducted from April to October, 1989 at the experimental field of Institute of Agricultural Development, Yonsei University. The results are summarized as follows: 1. The survival rates of seedling plants decreased by the days after sowing. The final survival rates of seedling plants were 7.8%, 38.9% and 33.8% in 3, 4 and 5 cuttings, respectively. 2. Relative light intensity indicated highly possitive correlation with relative survival rates of seedling plants and negative correlation with plant length of orchardgrass populations in 4 and 5 cuttings. 3. The frequency distribution of survival seedling plants at 177 days after sowing were showed high values in seeding spots near the adjacent plants of 3 cutings, but in the middle of seeding spots between adjacent plants of 4 .and 5 cuttings, respectively. 4. The plant length of seedling became longer towards the seeding spots near the adjacent plants but the number of tillers increased slightly up to the middle of seeding spots between adjacent plants in all cutting frequencies.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.31 no.2
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• pp.129-142
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• 1986

Fifty-five local collections of buck wheat, Fagopyrum esculentum, were investigated their ratios of long-styled (LS) and short-styled (SS) flowers, fertility, meiosis of megaspore and microspore mother cell, female and male gametogenesis, and egg apparatus in accordance with the sowing seasons (spring, summer), altitudes (20m, 50-100m, 300m), and parent style types (L, S). Also they were embryologically investigated the fertility, fertilizing phenomenon and proembryogenesis by the legitimate and illegitimate pollination. There were no differences in the ratios of long-styled and short-5tyled flowers along with altitudes, but more irregularness was observed in plain area than that in the mountaineous or coastal area. LS versus SS ratios by sowing seasons were significantly separated into 1 : 1 in the summer sowing (P 0.1), but they were irregularly separated in the spring sowing. The segregating ratios by parent style types showed more number of short-styled flower in the spring sowing, and were statistically seperated into 1 : 1 in the summer sowing (P 0.25), regardless to parent style types. In the artificial legitimate union, the seed setting rates of the summer sowing (59-61%) were much higher than those of the spring sowing (about 30%), but in the artificial illegitimate union the seed setting rates were only fructified about 0.8-1.8% in the spring sowing. The seed setting rates in accordance with flowering stages were larger in turn early, middle, late, in the summer sowing. The grain number and grain weight per plant of short-styled flower were more than those of long-styled one regardless to style types. The 1,000 grain weight of long-styled flower was heavier than that of short-styled one in large grain, but it was lighter than that of short-styled flower in small or medium grain. The percentage of normal female and male gametogenesis in the summer sowing were higher than those in the spring sowing. The ovule was atropous and two polar nuclei were a synkarion before flowering. The pollens germinated at 30 minuts after pollination and the pollen tube grew continually and penetrated into micropyle at 1.5-2 hours and the two male nuclei fertilized with egg nucleus at 3 -5 hours after pollination. Flertilizing times in summer were shorter than in autumn. The fertilized egg was divided in a small apical cell toward the interior of the embryo sac and a large basal cell toward the micropyle cell at 15-24 hours after pollination, and division times in summer were shorter than in autumn. The proembryo began the embryogenesis at 7-8 days and formed itself into the perfect embryo at 15 days after pollination.