• 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

• Proceedings of the Korean Society of Crop Science Conference
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• 2021.04a
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• pp.23-23
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• 2021

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.3
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• pp.225-228
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• 1989

Under the different conditions of planting density, maturation dates, stem length, oil contents, stem yield and seed yield of flax were investigated in 1984. The results were as followed: Wiera and Storment Goss were earlier in the maturation dates with increasing plant density, However Taijungsung #1 was delayed. Though there is a difference between the varieties stem length was getting longer with increasing plant density., Oil contents were getting higher with increasing plant density, stem yield and seed yield were increased with increasing plant density, on the contrary those were decreased by the growth of ciliary flax in the case of 1200 plants per 1.2m$^2$. Therefore optimum planting density of flax culture was 12cm x 6cm.

• Journal of Environmental Science International
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• v.21 no.5
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• pp.641-646
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• 2012

Available phosphorus($P_2O_5$) in conventionally cultivated soil was more abundant in two fold than that of organically cultivated soil. Relative density of Arbuscular Mycorrhizal Fungi (AMF) was higher in organically cultivated soil, That of welsh onion cultivated soil was the highest, that of strawberry was followed and then that of pepper, respectively. Relative density of AMF was inversely proportioned to available soil phosphorus. Phosphorus content of crop and relative density of AMF were more abundant in organically cultivated crop or soil. However available soil phosphorus content was much in conventionally cultivated soil. The phosphorus contents between soil and crop were negatively correlated. The phosphorus content of crop was increased as the relative density of AMF increased. Relative density of AMF in the organically cultivated soil and phosphorus content of the crop with organic cultivation were higher than those of conventionally cultivated.

• Korean Journal of Medicinal Crop Science
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• v.23 no.3
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• pp.198-206
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• 2015

This study was conducted to investigate the effects of sowing density, number of seeds sown per hole, and thinning treatment on growth characteristics and disease occurrence in Panax ginseng under direct sowing cultivation in a blue plastic greenhouse. Seedling were grown from 2 or 3 seeds sown, and the healthiest was only retained, while the rest were thinned out at the foliation stage. $NO_3$-N, $P_2O_5$, and organic matter content differed significantly between growth conditions in the plastic greenhouse and in conventional shade in the soil. Disease also tended to be higher in the conventional shade than in the plastic greenhouse. Plant height and stem length showed an increasing trend with increasing sowing density and number of seeds sown per hole. However, these measures noticeably decreased when thinning treatment was conducted. Growth of the subterranean part of ginseng was not markedly influenced by sowing density, the number of seeds sown per hole, or thinning treatment. Root weight, which is an important factor in yield, was significantly affected by the number of seeds sown and thinning treatment. Interestingly, root weight tended to be higher in the thinning treatment plot than the untreated control plot. Damping-off and root rot increased noticeably as the number of seeds sown increased. Disease also tended to be substantially higher in the thinning treatment plot than the untreated control. However, physiological disorder of the plants did not vary with sowing density, the number of seeds sown, or thinning treatment.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.57-57
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• 2017

Chrysanthemum is one of the most important floral crop in Korea produced about 7 billion dollars (1 billion for pot and 6 billion for cutting) in 2013. However, it is difficult to breed and to do genetic study because 1) it is highly self-incompatible, 2) it is outcrossing crop having heterozygotes, and 3) commercial cultvars are hexaploid (2n = 6x = 54). Although low-density genetic map and QTL study were reported, it is not enough to apply for the marker assisted selection and other genetic studies. Therefore, we are trying to make high-density genetic mapping using GBS with about 100 $F_1s$ of C. boreale that is oHohhfd diploid (2n = 2x = 18, about 2.8Gb) instead of commercial culitvars. Since Chrysanthemum is outcrossing, two-way pseudo-testcross model would be used to construct genetic map. Also, genotype-by-sequencing (GBS) would be utilized to generate sufficient number of markers and to maximize genomic representation in a cost effective manner. Those completed sequences would be analyzed with TASSEL-GBS pipeline. In order to reduce sequence error, only first 64 sequences, which have almost zero percent error, would be incorporated in the pipeline for the analysis. In addition, to reduce errors that is common in heterozygotes crops caused by low coverage, two rare cutters (NsiI and MseI) were used to increase sequence depth. Maskov algorithm would also used to deal with missing data. Further, sparsely placed markers on the physical map would be used as anchors to overcome problems caused by low coverage. For this purpose, were generated from transcriptome of Chrysanthemum using MISA program. Among those, 10 simple sequence repeat (SSR) markers, which are evenly distributed along each chromosome and polymorphic between two parents, would be selected.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.169-170
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• 2000

• KOREAN JOURNAL OF CROP SCIENCE
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• v.67 no.4
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• pp.326-334
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• 2022

This study was carried out to investigate the optimal nitrogen concentration level suitable for forage rice growth by hydroponic cultivation in the salinity concentration of 0.1~0.3% which is similar to that of Muan reclaimed paddy field, and based on this results, to estimate optimal nitrogen fertilization level by field experiment in Muan reclaimed paddy for maximum forage production by cultivation of Yeongwoo rice. As a result of the growth response to the salt and nitrogen concentrations in the hydroponic cultivation experiment, the growth amount increased as the nitrogen concentration increased in the range of 0~24 me/L in the absence of salt stress. However, at a salt concentration of 0.1~0.3%, the growth amount was the highest at a nitrogen concentration of 12 me/L, and at higher nitrogen concentrations of that, the rice growth decreased as the nitrogen concentration increased. Therefore, nitrogen concentration of 12 me/L was judged to be an appropriate concentration for forage rice growth at salt concentration of 0.1~0.3%, and a nitrogen fertilization amount level corresponding to a nitrogen concentration of 12 me/L was actually applied to the Muan reclaimed paddy field for forage rice cultivation during two years. The amount of nitrogen fertilizer was tested with three treatments, which are 18 kg/10a considered appropriate, and 1.5 times and 2 times of the appropriate amount, and the planting density was tested with 2 treatments of 15 hills/m² and 26 hills/m². As a result of the reclaimed paddy field experiment, the yield was the highest when nitrogen fertilizer was applied at 18 kg/10a in the planting density of both treatments. Looking at the yield according to planting density, the high planting density plot yielded higher than the low planting density plot. In other words, when the planting density was 26 hills/m² and the nitrogen fertilization amount was 18 kg/10, the highest dry matter yield of 1,763 kg/10a was obtained. From the results of hydroponics and reclaimed field experiments, we could conclude that the productivity of forage rice decreased more as the nitrogen concentration increased when the nitrogen concentration was higher than the optimal level under salt stress.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.64 no.1
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• pp.33-39
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• 2019

The goal of this study was to investigate how the characteristics of growth and yield are affected by various planting densities in wide-row drill seeding cultivation suitable for mechanized harvesting. Two cultivars ('Hwanggeum' and 'Leebackchal') of proso millet (Panicum miliaceum L.) were planted at varying planting densities [row spacing (20, 30, and 50 cm) and plant spacing (3, 5, 10, and 15 cm)]. The culm length was highest at the planting density of $50{\times}3cm$ and $50{\times}5cm$ for 'Hwanggeum' and $20{\times}3cm$ for 'Leebackchal'. The culm diameter became thinner as the planting density increased. The number of tillering and panicle length showed the same tendency to increase in quantity or length as planting density decreased and was highest at $50{\times}15cm$ when the planting density was lowest. The number of seeds per individual increased as planting density decreased. The thousand grain weight showed no significant differences among treatment plots. The greatest yield of 'Hwanggeum' was obtained at a planting density of $50{\times}3cm$ ($314.9kg{\cdot}10a^{-1}$) and that of 'Leebackchal' was obtained at $50{\times}3cm$ and $50{\times}5cm$ ($358-356kg{\cdot}10a^{-1}$).

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.5
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• pp.332-335
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• 2005

The three Korean wheat cultivars with different plant types; the erect, the middle and the creeping growth habit, were studied for their utilization to solar radiation, temperature changes on the furrow and to provide optimum planting space for producing the high yield in 2003. The average solar radiation rate was lowest for creeping type ($39.2\%$) and highest for erect type ($75.8\%$) The correlation coefficient between the coverage rate and the solar transmission rate was r = 0.8624 which was significant at $5\%$ level. The relative growth of the plant, tiller rate and leaf size was increased in the erect and the middle type at lower plant density, while no change on plant growth at creeping type regardless of plant density. The increase of leaf size in the lower plant density was due to longer flag and the first leaf than those of other plant types. The temperature on the furrow of growing plants was changed by the canopy. The changes in temperature pattern on the furrow according to plant types during winter season was different compared to the non plant ground. The temperature of the nonplant ground was the lowest due to solar reduction increasing the amount of cool air flowing in the furrow.