• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.320-320
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• 2017

Recently, the rice growing time was extended by the global warming. This study was conducted to investigate the possibility of rice double cropping system in southern Korea. The first transplanting was with six cultivars ('Kilala397', 'Baekilmi', 'Joun', 'Hanseol' and 'Jungmo1031') on April 15. All cultivars could be harvested at the end of July. Adaptable cultivars for the first cultivation were 'Kilala397', Baekilmi' and 'Joun'. The rice yields at the first cultivation was about 95% of local average yield. Although the yield was slightly less, the first cultivation was considered to have economic benefits, because of the high market price of rice. In the second transplanting was with five cultivars ('Manjong', 'Joun', 'Deabo', 'Jinok' and 'Kilala397') on April 15. All cultivars could be harvested in early November. Adaptable cultivars for the second cultivation were 'Jinok' and 'Kilala397'. The rice yields at the second cultivation was about below the 60% of local average yield, because there was the less growth than normal season cultivation. Consequently, southern Korea' annual rice double cropping system is considered to have no economic value yet. However, the research should be continued considering the temperature rise of global warming.

• Korean Journal of Poultry Science
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• v.39 no.3
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• pp.163-166
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• 2012

This study was carried out to compare the cut meat yields of Cobb and Avian and their profits at productive aspect. Two different breeds, Cobb (34,086,758 birds) and Avian (4,087,600 birds) produced from January 2009 to August 2009 were used. The whole chickens were divided into cut meats including tenderloins, breast fillets, whole wings, boneless thighs, and drumsticks. The growth performance and cut meat yield of Cobb and Avian were measured to investigate possible profit difference. Cobb was superior in the aspect of production performance to Avian with significant differences in survival rate and slaughtering age. As the weight gained, the yields of Cobb increased in breast fillets and boneless thighs as well as lean meat percentage. Significantly higher yield (%) of breast fillets was produced by Cobb at size 14 when compared with Avian. However, there was no significant difference in expected market prices for both cut meat and whole chicken meat between the two breeds in all sizes.

• Korean Journal of Remote Sensing
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• v.1 no.1
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• pp.63-87
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• 1985

Considerable experience has been reported on the use of spectral data to measure the canopy biomass of dryland grain crops and the use of these estimates to forecast subsequent grain yield. These basic procedures were retested to assess the use of the general process to forecasting grain yield for paddy rice. The use of the ratio of a multiband radiometer simulation of Thematic Mapper band 4(.76 to .90 .mu.m) divided by band 3 (.63 to .69 .mu.m) was tested to estimate the canopy biomass of paddy rice as a function of the stage of development of the rice. The correlation was found to be greatest (R = .94) at panicle differentiation about midway through the development cycle of the rice canopy. The use of this ratio of two spectral bands as a surrogate for canopy biomass was then tested for its correlation against final grain yield. These spectral estimates of canopy biomass produced the highest correlations with final grain yield (R = .87) when measured at the canopy development stages of panicle differentiation and heading. The impact of varying the amounts of supplemental nitrogen on the use of spectral measuremants of canopy biomass to estimate grain yield was also determined. The effect of the development of a significant amount of weed biomass in the rice canopy was also clearly detected.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.1
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• pp.57-66
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• 2013

The purpose of this study was to investigate the effects of shifts in sowing time on the ecological responses, growth and yields of major soybean cultivars in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (latitude $35^{\circ}$ 04'N, longitude $126^{\circ}$ 54'E) for three years from 2008 to 2010. The test cultivars included Saeol-kong and Tawon-kong of the summer type, Taekwang-kong and Pungsannamul-kong, and Cheongja3 of the autumn type. Sowing took place on May 15 and 30, June 15 and 30, and July 15 of each year. Of the summer type soybean cultivars, Saeol-kong showed a smaller curtailment in days from sowing to flowering, days from flowering to maturity, and days from sowing to maturity according to sowing time postponement than Tawon-kong. Of the autumn type soybean cultivars, Taekwang-kong exhibited a lower photoperiodic response in reproductive growth period than Pungsannamul-kong and Cheongja3, both of which recorded higher level photoperiodic responses in vegetative growth stages and reproductive growth periods than other test cultivars, with the former exhibiting higher levels than the latter. Most of the test cultivars tended to decrease in stem length, node numbers of the main stem, and stem diameter according to postponed sowing time, but there were no significant differences in stem length and node numbers of the main stem of the Saeol-kong cultivar. Differences in sowing times did not affect the first setting pod node order of Saeol-kong and Tawon-kong summer type cultivars of internode lengths of all of the test cultivars. All of the test cultivars tended to show decreases in pod number per plant due to postponement of sowing time except for the Saeol-kong cultivar. The variation was more prominent in small grain cultivars such as Tawon-kong and Pungsannamul-kong with the latter autumn type cultivar showing especially large variation. Yields were the greatest for the Tawon-kong, Taekwang-kong, and Pungsannamul-kong cultivars sown on May 30 and Cheongja3 sown on May 30 and June 15. There were no significant differences in the yields of Saeol-kong for different sowing times from May 30 to July 15, with the yields lowest for the batch sown on May 15.

• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.378-383
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• 2018

This study was carried out to investigate the optimum cultivation distance for high yielding cultivation of the new variety of Gomchwi in highland and lowland. The test material was used 'Sammany' variety and the area was cultivated with a highland of 750 m above sea level and a lowland of 20 m above sea level. The planting distance was 5 treatments of $20{\times}20cm$, $20{\times}30cm$, $30{\times}30cm$, $35{\times}40cm$ and $40{\times}40cm$, and the plant was cultivated at 35% shading net in the open field. The annual growth of 'Sammany' variety was higher in the highland than in the lowland, but the number of leaves was higher in the lowland than that in the highland. The leaf number per plant was the highest in the $40{\times}40cm$ plot and the more the planting distance was, the more tendency was. However, the leaf weight per plant was higher in the highland than in the lowland. The number of leaves per 10a were higher in the lowland than that of highland and the tendency was more as the planting distance was narrower. Yields were slightly higher in the highland than that of lowland and the highest treatment plot was 2,983 kg/10a in $20{\times}20cm$. In the second year, the growth was high in the highland, and the highland was high in the leaf number and leaf weight and the same tendency in the yields. Among the planting distances, Yields in both areas were the highest in the $20{\times}20cm$ treatment, with 3,369 kg/10a in lowland and 7,257 kg/10a in highland. The growth of the third year was slightly better in the highland than that of the lowland but the difference was not significant. However, the number of leaves and leaf weight per plant were higher in the lowland than that of highland. And, in terms of leaf number and yield per 10a, it was also higher in the lowland than that in the highland. The narrower the planting distance was increased yields, and the highest yield was 6,051 kg/10a in $20{\times}20cm$. The lowland was high in yield until the third year, but the highland was the highest in the second year and decreased slightly in the third year. The narrower the planting distance in the both areas, the higher the yield, and the leaf size tended to be small.

• Korean Journal of Remote Sensing
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• v.33 no.5_2
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• pp.699-708
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• 2017

The present study was to develop an approach for predicting soybean yield using a crop growth simulation model at the regional level where the detailed and site-specific information on cultivation management practices is not easily accessible for model input. CROPGRO-Soybean model included in Decision Support System for Agrotechnology Transfer (DSSAT) was employed for this study, and Illinois which is a major soybean production region of USA was selected as a study region. As a first step to predict soybean yield of Illinois using CROPGRO-Soybean model, genetic coefficients representative for each soybean maturity group (MG I~VI) were estimated through sowing date experiments using domestic and foreign cultivars with diverse maturity in Seoul National University Farm ($37.27^{\circ}N$, $126.99^{\circ}E$) for two years. The model using the representative genetic coefficients simulated the developmental stages of cultivars within each maturity group fairly well. Soybean yields for the grids of $10km{\times}10km$ in Illinois state were simulated from 2,000 to 2,011 with weather data under 18 simulation conditions including the combinations of three maturity groups, three seeding dates and two irrigation regimes. Planting dates and maturity groups were assigned differently to the three sub-regions divided longitudinally. The yearly state yields that were estimated by averaging all the grid yields simulated under non-irrigated and fully-Irrigated conditions showed a big difference from the statistical yields and did not explain the annual trend of yield increase due to the improved cultivation technologies. Using the grain yield data of 9 agricultural districts in Illinois observed and estimated from the simulated grid yield under 18 simulation conditions, a multiple regression model was constructed to estimate soybean yield at agricultural district level. In this model a year variable was also added to reflect the yearly yield trend. This model explained the yearly and district yield variation fairly well with a determination coefficients of $R^2=0.61$ (n = 108). Yearly state yields which were calculated by weighting the model-estimated yearly average agricultural district yield by the cultivation area of each agricultural district showed very close correspondence ($R^2=0.80$) to the yearly statistical state yields. Furthermore, the model predicted state yield fairly well in 2012 in which data were not used for the model construction and severe yield reduction was recorded due to drought.

• Microbiology and Biotechnology Letters
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• v.47 no.1
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• pp.105-115
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• 2019

Saline or alkaline condition in soil inhibits growth of most crop plants and limits crop yields in many parts of the world. Augmenting an alkaline soil with alkali-tolerant bacteria capable of promoting plant growth can be a promising approach in expanding fertile agricultural land. Near-shore environments of Dokdo Island, a remote island located in the middle of the East Sea, appear to have patches of seawater-influenced haloalkaline soil that is unsupportive for growth of conventional plants. To exploit metabolic capacities of alkali-tolerant bacteria for promoting plant growth in saline or alkaline soils, we isolated of alkali-tolerant bacteria from near-shore soil samples in Dokdo and investigated properties of the isolates. Alkali-tolerant bacteria were selectively cultivated by inoculating suspended and diluted soil samples on a plate medium adjusted to pH 10. Fifty colonies were identified based on their $GTG_5$-PCR genomic fingerprints and 16S rRNA gene sequences. Most isolates were affiliated to alkali-tolerant and/or halotolerant genera or species of the phyla Firmicutes (68%), Proteobacteria (30%) and Actinobacteria (2%). Unlike the typical soil bacterial flora in the island, alkali-tolerant isolates belonged to only certain taxa of terrestrial origin under the three phyla, which have traits of plant growth promoting activities including detoxification, phytohormone production, disease/pest control, nitrogen-fixation, phosphate solubilization or siderophore production. However, Firmicutes of marine origin generally dominated the alkali-tolerant community. Results of this study suggest that haloalkaline environments like Dokdo shore soils are important sources for plant growth promoting bacteria that can be employed in bio-augmentation of vegetation-poor alkaline soils.

• The Korean Journal of Mycology
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• v.17 no.3
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• pp.124-131
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• 1989

Some factors effecting on mycelial growth and cultural substrates using pine sawdust were investigated to develop an artificial cultivation technique. The optimal temperature and media pH for the mycelial growth were at $25^{\circ}C$ and 4.0, respectively. The mycelial growth was not different among three isolates tested. Among them ASI 19003 isolate showed the highest mycelial density and fruitbody yield. Among supplements added into pine sawdust, wheat bran was the best and its appropriate percentage was 20 for the mycelial growth. The mycelial densities were uprisen according to the amounts of the supplement. The highest yield, 107g/bottle of the sporophores of the mushroom was obtained from the substrates supplemented by 30% of wheat bran, but no fruitbody was formed on non supplemented one. Optimal moisture contents of the substrates was different for the mycelial growth, pinheading and fruitbody yields. Sixty five, 60 and 75% of moisture contents of the substrates were optimal for the mycelial growth, pinheading and fruitbody yields, respectively.

• Journal of The Korean Society of Grassland and Forage Science
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• v.22 no.3
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• pp.213-220
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• 2002

The growth characteristics, forage yields and nutritive values of heading and headless types of sorghum $\times$ sudangrass(Sorghum bicolar L.) hybrids were examined to evaluate the adaptability of new cultivars at Suwon and Chunahn for two years from 2000 to 2001 in a randomized complete block design with three replications. Eleven cultivars of heading type and 4 cultivars of headless type were used in this study. The dry matter(DM) yield of AG 2501 was highest in the heading type cultivars, and PAC F8350 in the headless type cultivars, respectively. The DM yields of heading types were slightly higher than those of headless types but there were not significantly different. Early growth and regrowth characteristics of heading type was highest in AG 2501 and GW 9110G, respectively. GW 9110G and DMD were early heading types, and AG 2501 and GW 9161F were middle heading types. AG 2501 was longest and GW 9161F was shortest in plant height. Cultivars with long leaf length were appeared to be larger fur leaf width and stem diameter. Brix content was highest in DMD as 9.7%, and disease and insect resistances were not significantly different among the heading types. Early growth of headless type cultivar, PAC F8350 was slightly lower than that of Jumbo but stronger in regrowth, wider in leaf width and stem diameter, and stronger in lodging. Comparisons of growth characters between heading and headless types of cultivars were not easy in general but between them, brix contents of heading types ranging from 6.7 to 7.9% were greatly higher than those of headless types ranging from 3.6 to 3.9%. Nutritive values such as crude protein, ADF, NDF and digestibility of headless type cultivars were higher than those of heading types. In conclusion, of heading type cultivars, GW 9110G, AG 2501, DMD and GW 9161F, and of headless type cultivars, Jumbo and PAC F8350 were recommended as high yielding cultivars with good adaptability in domestic environment.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.2
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• pp.47-58
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• 2023

The quality and yield of crops produced using field cultivation are expected to decrease due to the recent global climate change caused by extreme weather. The plant reproductive stage associated with crop yields is a highly vulnerable period to global warming caused by high temperatures. This study analyzed the adzuki bean's yield properties, antioxidant contents, and pollen viability of adzuki bean (Vigna angularis L.) under high-temperature stress and growth periods in a temperature gradient greenhouse that forms 0 to 4℃ above the outside temperatures. As the main variety of red beans cultivated in Korean farms, the "Arari" red bean was grown in the rain shield greenhouse and the temperature gradient greenhouse from 2021 to 2022 in Milyang, Korea. Compared to 2022, it showed a 0 - 1.0℃ lower temperature during the whole growth period in 2021. However, its average temperatures were 0 - 3.7℃ higher in the vegetative stage and 0.4 - 2.4℃ higher in the anthesis stage in 2021. The lowest yield (6.8 ± 0.7 g) was at the highest temperature (T4: low, 23.6℃; average, 28.5℃; high, 35.8℃) during the anthesis stage in 2021. The temperatures of the mature stage were 1.7 - 3.9℃, which were higher in 2022 than in 2021, although the low temperatures of 2022 were lower than in 2021. The yields of the mature stage in 2022 increased more than in 2021 because of the high temperature of the mature stage. The growth and yield were good at 40.5℃ in the vegetative stage. However, growth was poor when the average temperature was 27.0℃ or higher, and yields decreased during the flowering period. Total polyphenol and flavonoid contents were increased, and the pollen viability was 40.75% in the whole growth period at high temperature (T4: low, 22.9℃; average, 28.8℃; high, 36.9℃). These results showed that the antioxidant levels increased when the antioxidant component was affected at higher temperatures than at normal. In contrast, the pollen viability-related yield decreased as the temperature increased. Our results are the basic data for field growers and the breeding of thermos-tolerance in adzuki beans to prepare for the changeable future climate.