• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.428-434
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• 2021

To study whether the area under the cultivation of Italian ryegrass (IRG) has increased with rise in global temperatures, we investigated the effects of climatic variables on seed productivity in different parts of Gangwon-do, South Korea. Specifically, IRG was cultivated in the western (Gangneung), central (Wonju), and northern (Chuncheon) parts of Gangwon-do. The heading date of IRG in Gangneung was earlier than that in the other regions. Moreover, the values of agronomic traits, including spikelets per spike, grains per spike, and thousand-grain weight, were lower in Chuncheon. However, there were no differences spikelets per spike and grains per spike between Wonju and Gangneung. Additionally, the thousand-grain weight and seed production were higher in Gangneung. Statistical correlation analysis between climatic variables and agronomic traits revealed that the mean daily minimum temperature was positively correlated with seed formation-related traits in April and seed maturity-related traits in May. In the light of rising minimum temperatures in Gangwon-do, Gangneung, Chuncheon and Wonju are suitable areas for IRG cultivation with optimal seed productivity.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.33 no.2
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• pp.138-145
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• 1988

The effect of directions (north to south vs east to west) of planting row, planting intensities (10/15, 15/15, 20/15, 25/15 cm/cm) and the number of rows consecutively (1,2, 3,4) for both the CMS and pollen parent in alternation, on the seed yield of CMS of rice was tested with a breeding line V20A/Iri342$\^$*8/. When the planting row was made in vertical direction to the wind direction during anthesis, the seed yield was higher than the other direction regardless the planting densities and number of rows consecutive. Seed yield increased as high as 46.9%. The higher planting intensities up to 10/15 cm/cm yielded the higher hybrid seeds. The highest yield was 81.2 kg/ha. The yield variation among plants within a plot and among the plants within a replication was relatively large. Increased pollen parent row numbers caused increased grain fertility per plant, but the seed yield was increased by reduced pollen parent row number. Reduced CMS parental row numbers caused increased grain fertility per plant, but the seed yield was increased by increased CMS parental row numbers. Considering the hybrid seed yield, parental seed yield and operational convenience, 4 rows of CMS and 1 row of pollen parent in alternate with 20/15 or 25/15 (cm/cm) planting densities seemed to be the rational layout.

• Journal of the Korean Magnetics Society
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• v.11 no.2
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• pp.63-71
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• 2001

The effects of an Ag seed layer on the magnetic properties and the microstructural evolution of SmCo/Cr thin films deposited on glass substrates were investigated. Coercivity of the films is 2.0 kOe when the thickness of Ag seed layer was 1nm thick, but it increased to 2.7 kOe when the Ag seed layer thickness is 3 nm. The increase of coercivity for film with 3 nm-thick Ag is due to roughness of Cr and grain size of Cr by the Ag microbumps. Ar partial pressure influenced on the formation of Ag microbumps, for example, they were formed at 5 mTorr when Ag thickness was 1 nm. The mechanism of magnetization reversal of the SmCo films changed from domain wall motion to domain rotation as the Ag inserted. This was thought to be due to inhibition of domain wall motion by the reduction of Cr grain size and the increase of roughness.

• Korean Journal of Agricultural Science
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• v.46 no.3
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• pp.439-449
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• 2019

The purpose of this research was to evaluate the effects of different sowing dates on growth characteristics, seed productivity and feed value of triticale in Gyeongbuk province. The experiment was conducted from September 2015 to July 2017, using triticale "Joseong" cultivar of 150 kg of seed/ha and sown at 10 days intervals from different sowing dates ($30^{th}$ September, $10^{th}$, $20^{th}$ and $30^{th}$ October) in 2015 and 2016, respectively. The emergence date in the autumn season was 8 - 18 days after sowing in 2015 and 2016. The heading, flowering and maturing periods were the fastest on $30^{th}$ September compared to the other sowing dates. The average number of stem and panicle per unit area were 409.3 - 428.5 and 330.9 - 334.0 on $30^{th}$ September and $10^{th}$ October, which were higher than those sown on $20^{th}$ and $30^{th}$ October, 2015 and 2016, respectively (p < 0.05), and the average number of grain and kernel weight was 47.1 - 48.1 and 2.2 - 2.3 g on $30^{th}$ September and $10^{th}$ October, which were higher than the late sowing dates. In case of seed yield as affected by different sowing dates, the highest yield was found on the sowing plot of late September and $10^{th}$ October, which were 5,680 and 5,918 kg/ha, respectively (p < 0.05). However, the average CP content was 10.7%, CF content was 2.8% and TDN content was 85.3. In conclusion, $30^{th}$ September and $10^{th}$ October were the appropriate sowing dates for a forage self-sufficiency system in Gyeongbuk.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.30 no.2
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• pp.146-153
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• 1985

To investigate the possibility of improvement of seed mustard varieties, these experiments were conducted at Muan in Chonranamdo for three years with five local seed mustard varieties and seeding dates. Local varieties collected from Seoul, Cheju and introduced from Japan showed earlier bolting date while Yungsanpo and Suweon varieties bolted later and Suweon variety exhibited the latest maturity. Suweon variety had the shortest plant height with higher number of grains per pod. Seoul and Yungsanpo varieties had more total branch numbers than others. There was no varietal difference in grain weight, pod length and one liter weight. Grain yield per 10a was highest in Seoul variety by 247.5kg. Late seeding date delayed the bolting and flowering date while plant height, total branch numbers, pod numbers per ear and grain number per pod were decreased. The magnitude of varietal response to seeding date was varied greatly with traits. Grain weights per liter, 1,000 grain weight, pod lengths, oil contents, and fatty acid compositions were not affected by the different seeding dates.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.5
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• pp.571-578
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• 1997

The development of new approaches for wheat grain hardness assessment may impact the grain industry in marketing, milling and breeding. This experiment was to develop a new method for fast identification between softness and hardness, and for maintaining germinability of seed after measurement in wheat. Results from the comparisons of accuracy and significance between image analysis and conventional methods(NIRS and textrometer) were summarized. Data obatined from image analysis for grain hardness did not show any difference from those of the conventional methods. The protein content analyzed by micro-Kjeldahl method was significantly correlated with the grain hardness measured by image analysis, textrometer, and NIRS. The analysis for wheat grain hardness using image analysis may be used as an alternative method to the conventional methods. This method also takes the seeds after analysis can be utilized as breeding materials in early generations.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.55 no.3
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• pp.195-199
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• 2010

This experiment was conducted to develop optimum sesame cultivation practices as succeeding cropping system of watermelon in the greenhouse condition. We also compared major components in sesame seed cultivated in the greenhouse and open field condition. The adaptable varieties under the greenhouse condition were white sesame 'Pyoungan' and black sesame 'Jinki' which showed higher yield and disease resistance. We also conducted several experiments to determine optimum sowing date, planting density and pinching time. Grain yields were statistically different according to the several sowing dates. In general, sesame sowing on June 30th showed higher grain yields than July 10th, July 20th and July 30th in the greenhouse. We also found out sesame cultivation practice with the row spacing of 40 cm and interplant spacing of 30 cm (a few branch type) or 40 cm (many branch type) showed higher yield than other treatments. Optimum pinching time was 25 days after first flowering in main stem when thousand seed weight and grain yield were highest. In the comparison of major components of sesame at the different cultivation conditions, sesame seeds cultivated in the greenhouse contained 4% much more oil content than open field condition. The lignan compounds, sesamin and sesamolin were also higher by 6% in the greenhouse than open field condition. It was concluded that sesame cultivation practices as succeeding cropping system of watermelon in the greenhouse condition guaranteed higher grain yield with less labor input which is now emerging alternative farming practice system in present aging rural society and will also give sesame cultivation farmers to increase net income in Korea.

• Molecules and Cells
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• v.42 no.10
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• pp.711-720
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• 2019

Sink strength optimizes sucrose import, which is fundamental to support developing seed grains and increase crop yields, including those of rice (Oryza sativa). In this regard, little is known about the function of vacuolar invertase (VIN) in controlling sink strength and thereby seed size. Here, in rice we analyzed mutants of two VINs, OsVIN1 and OsVIN2, to examine their role during seed development. In a phenotypic analysis of the T-DNA insertion mutants, only the OsVIN2 mutant osvin2-1 exhibited reduced seed size and grain weight. Scanning electron microscopy analysis revealed that the small seed grains of osvin2-1 can be attributed to a reduction in spikelet size. A significant decrease in VIN activity and hexose level in the osvin2-1 spikelets interfered with spikelet growth. In addition, significant reduction in starch and increase in sucrose, which are characteristic features of reduced turnover and flux of sucrose due to impaired sink strength, were evident in the pre-storage stage of osvin2-1 developing grains. In situ hybridization analysis found that expression of OsVIN2 was predominant in the endocarp of developing grains. A genetically complemented line with a native genomic clone of OsVIN2 rescued reduced VIN activity and seed size. Two additional mutants, osvin2-2 and osvin2-3 generated by the CRISPR/Cas9 method, exhibited phenotypes similar to those of osvin2-1 in spikelet and seed size, VIN activity, and sugar metabolites. These results clearly demonstrate an important role of OsVIN2 as sink strength modulator that is critical for the maintenance of sucrose flux into developing seed grains.

• Korean Journal of Agricultural Science
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• v.12 no.1
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• pp.47-54
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• 1985

An investigation was made to find regional differences and seed characteristics of buckwheats collected from 36 areas in Chungnam province in 1984, and the results obtained are summarized as follows; 1. Grain types of the collected buckwheats were classified as winged, semi-winged and common types. All collections were on the average composed of 50.1 % of common grain types, 26.8 % of semi-winged type and 23.1 % of winged types, respectively. However, there was a great regional difference in components of each grain type among collections. 2. The mean 1000 grain weight was 24.9 gr. The regional differences in 1000 grain weight showed that a collection (collection no. 30) from Susan was 17.4 gr and a collection (collection. no. 16) from Suchon was 31.9 gr. There wasn't any significant relationship between grain types component and 1000 grain weight. 3. Germination of seeds was accelerated as temperature goes up from $5^{\circ}C$ to $30^{\circ}C$. However, interesting germination pattern was observed. That is, seeds from Suchon (collection no. 16), Hongsung (collection no. 23), Cheonweon(collection no. 35), and Yesan (collection no. 27) showed abrupt decrease of germination rate at the temperature of $15^{\circ}C$. The seeds collected from Suchon (collection no. 29), Dangjin (collection no. 32) and from Chungyang (collection no. 21) showed decrease of germination rate at $25^{\circ}C$. These seeds showed, however, the increase of germination percentage at temperature higher than $15^{\circ}C$ and $25^{\circ}C$, respectively. The germination rate for the most collections at $5^{\circ}C$ was less than 10%. However, seeds from Asan (collection no. 33) and Daeduk (collection no. 3) showed 20% and 30% of germination rate at $5^{\circ}C$, respectively. 4. Color of seed coat could be classified into two maj or colors, dark and dark brown. Based on the seed coat color and grain types, all the collections could be classified into the following six categories: winged-black, semi-winged-black, common-black, winged-dark brown, semi-winged dark brown and common-dark brown. The different light absorption rate was found within the UV light zone (190-390 nm) depending upon the two different major seed coat color.

• Korean Journal of Plant Resources
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• v.19 no.3
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• pp.397-400
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• 2006

The objectives of this experiment was to evaluate the effect of seeding and transplanting date on yield and quality of rapeseed experiment were conducted in the research field of Chungcheongnam Do(Taejun) Agricultural Research and Extension Services with Yudal, one of the rapeseed cultivar of different growth characteristics among the six treatments were examined and recorded. Results showed that yield components such as plant height, length of ear and pod, number of branches and pods and percentage of pod setting and seed set were highest at the plot with direct seeding in Sep. 10. In this treatment yield of seed, 1,000 grains weight and weight of $1{\ell}$ were highest. On the basis of vegetative and yield parameter of direct seeding in Sep. 10 was the best sowing date of rapeseed crop in Chungcheongnam Do region of Korea. Experiments were conducted in the research field of Chungcheongnam Do(Taejun) Agricultural Research and Extension Services with Yudal variety, which showed different growth characteristics. Yield components such as plant height, length of ear and pod, number of branches and pods and percentage of pod setting and seed set were highest at the plot with direct seeding in Sep. 10. Yield of seed, 1,000 grains weight and weight of $1{\ell}$ were highest at the direct seeding in Sep. 10. Judging from the results reported above, seemed to be direct seeding in Sep. 10.