• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.92-92
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• 2022

In preparation for the ever-changing climate and unification of North Korea and South Korea, it is necessary to increase the grain self-sufficiency rate by selecting crops with good utilization in high-altitude regions. The principle is to sow pastures at the end of August. However, sowing occurs in spring because the sowing period is missed when the weather is bad or when the workforce is insufficient. Sometimes when the grassland is completely devastated, it is frequently sowed in spring. In addition, North Korea consists of a high-altitude regions, and has been devastated in a general mountainous region. As a result, the landscape is not good and it is vulnerable to natural disasters such as landslides. Therefore, to prevent this, pasture must be sowed in the high-altitude regions. The goal of this study was to evaluate and compare yield and feed value of pasture species and varieties by spring sowing in high-latitude regions. The study was conducted in Pyeongchang, Gangwon-do, which is 700m height above sea level. The pasture species and varieties was sown on April 24, 2022. Each treatment was carried out by sowing 30 kg/ha, the experiment field size was 1 m²(1m×1m), and randomized block design with tri-repeat. The total of 14 varieties was used in the study, 6 varieties of Orchardgrass (OG), 6 varieties of Tall fescue (TF) and 2 varieties of Perennial ryegrass (PRG). The grassland composition fertilization using (N:P₂O₅:K₂O at 80:200:70 kg/ha) was conducted and management fertilizer was N:P₂O₅:K₂O at 210:150:180 kg/ha. The first harvest was June 26,2022 and the second harvest was on August 16, 2022. For statistical analysis of the data, an Analysis of Variance (ANOVA) was performed using the R3.6.3 software program, and all data was subjected to analysis using Duncan's multiple range test. Significance was set at the 5% level. The dry matter yield at the first harvest was the highest in PRG, and second harvest was the highest in TF (p < 0.05). Overall, PRG showed a trend of gradually decreasing growth, OG and TF showed a trend of gradually improving growth. This showed that PRG was considerably weaker to summer depression than other pasture species. Comparing the total dry matter yield, TF was the highest (4,565.45 kg/ha), but there was no significance difference with PRG (4,487.24 kg/ha) (p < 0.05). In addition, comparing the total TDN (total digestible nutrient) yield, TF was the highest (3147.33 kg/ha), second in PRG (2975.67 kg/ha) and third in OG (2052.33 kg/ha). Since this result is the data of the second harvests, if the result is derived by the end of next year, it will be provided as basic data for selection of pasture species and varieties suitable for spring seeding in high-altitude regions.

• Phonetics and Speech Sciences
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• v.4 no.3
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• pp.43-49
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• 2012

This paper describes the categorical effects of pitch accent contrasts in a mimicry task. It focuses, specifically, on examining how fundamental frequency (f0) variation reflects phonological contrasts from speakers of two distinct varieties of Korean (i.e., North Kyungsang and South Cholla). The results showed that, in a mimicry task using synthetic speech continua, there was a categorical effect in f0 peak timing for North Kyungsang speakers, but the timing of f0 peaks and valleys in the responses of South Cholla speakers was more variable, presenting a gradient or non-categorical effect. Evidence of categorical effects was represented as the shift of f0 peak times along an acoustic continuum for North Kyungsang speakers. The range for the shift of f0 valley times was much narrower, compared to that of f0 peak times. The degree of a shift near the middle of the continuum showed variability across individual mimicry responses. However, the categorical structure in mimicry responses regarding the clustering of f0 peak points was more significant for North Kyungsang speakers than for South Cholla speakers. Additionally, the finding of the current study implies that the location of f0 peak times depends on individuals' imitative (or cognitive) abilities.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.68 no.4
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• pp.236-245
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• 2023

We investigated the basic vegetative phase (BVP), photoperiod-sensitivity (PS), and thermo-sensitivity (TS) of 40 rice varieties to characterize their heading ecology that is adaptable to North Korean rice production areas. The ranges were 12 - 43 days for BVP, 0 - 74 days for PS, and 15 - 33 days for TS, depending on the variety. The number of days from transplanting to the heading stage (DTH) was significantly correlated with PS in the 13 major rice production regions where all 40 varieties (including early-, middle-, and mid-late-maturing varieties) were tested. DTH was significantly correlated with BVP and TS but not with PS in the 10 low-temperature regions where only 28 early-maturing varieties were tested. The heading ecology of the adaptable varieties for each region could be characterized by an exponential equation between the BVP and PS of varieties that headed at the border of the safe marginal heading date (SMHD) for each of the seven regional environments (Kaesong, Haeju, Yongyon, Singye, Sariwon, Nampo, and Pyongyang). A PS of 25 - 30 days or less was an additional adaptive trait in the Sariwon and Pyongyang environments. The varieties that reached the heading stage not later than the SMHD in six regional environments (Anju, Kusong, Sinuiju, Changjon, Wonsan, and Supung) and those that reached the heading stage not later than the late marginal heading date (LMHD) in four regional environments (Hamhung, Pyonggang, Huichon, and Kanggye) had both a PS of 26 days or less and a BVP of 25 - 28 days or less. In the Yangdok, Sinpo, and Chunggang environments, varieties that reached the heading stage not later than the LMHD for each region had a BVP of 15 - 20 days or less. The results suggested that a shortened BVP trait should be introduced to existing early-maturing rice varieties to reduce the duration of growth period to reach the heading stage.

• Proceedings of the Zoological Society Korea Conference
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• 1999.10b
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• pp.309.1-309
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• 1999

No Abstract, See Full Text

• Korean Journal of Agricultural and Forest Meteorology
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• v.23 no.2
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• pp.108-121
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• 2021

Field studies at Suwon, Cheorwon, and Jinbu were carried out to determine the relationship between mean temperature from transplanting to heading (MT) and growth at heading stage of rice. P lant height (P H) and dry weight (DW) at heading stage were significantly correlated with MT, showing second degree polynomials. The optimal temperatures for PH and DW were 23.2 ℃ and 22.8 ℃, respectively. Little differences in rice growth among soils collected from the experimental sites and the temperature-response in a phytotron study supported that MT was the main determinant of the growth shown in the field study. Though number of days to heading increased as MT decreased, cumulative temperatures (CT) affected by sites and MT for given varieties were fairly constant. When applying specific CT for each of the varieties to the temperature in North Korea, (1) five regions (Kaesong, Haeju, Sariwon, Nampo, Pyongyang) were suitable for early to mid-maturing varieties and (2) 14 regions (Yongyon, Singye, Anju, Kusong, Sinuiju, Changjon, Wonsan, Hamhung, Pyonggang, Yangdok, Huichon, Supung, Sinpo, Kanggye) were suitable only for early-maturing varieties. In (1) regions, the similar extent of growth with that in Suwon could be achieved when mid-maturing varieties grown in Suwon are cultivated. Among (2) regions, early-maturing varieties are expected to demonstrate the similar extent of growth with that in Cheorwon in 9 regions except Hamhung, Kanggye, Pyonggang, Yangdok, and Sinpo. For Hamhung and Kanggye, the target PH was assessed as 4cm higher than that shown in Cheorwon. P lant height of 8-14cm and DW of 2-4g per hill greater than those shown in Cheorwon were the target growth for P yonggang, Yangdok, and Sinpo to attain the similar amount of growth with that in Cheorwon. It is suggested that rice varieties for North Korea could be bred by adjusting the target growth at the breeding sites in South Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.1
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• pp.1-7
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• 2008

This experiment was carried out to evaluate the agronomic stability of North Korean rice varieties using the statistical model developed by Grafius, Finlay, and Ever hart. The lowest yearly variation based on coefficients of variation was found in Hannam 29 for number of panicles per hill, in Sijoong 9 for number of grains per panicle, in Pyeongyang 3 for ripened grain ratio, in Sijoong 16 for 1,000 grain weight, and in Yeomju 1 for grain yield. By Grafius's model, Pyeongbook 3, Weonsan 66 in early maturing groups and Seohaechalbyeo in medium maturing groups show stable for 3 years. Weonsan 66 in early maturing groups and Seohaechalbyeo in medium maturing groups were found to be highly stable as analyzed by both Finlay and Wilkinson's model and Everhart & Russell's model. With reference to three models, Weonsan 66 was highly stable for 3 years with showing more yield than Odaebyeo in early maturing groups while Seohaechalbyeo was highly stable for 3 years with showing high yield than Hwaseongbyeo in medium maturing groups above $5\;t\;ha^{-1}$ of milled rice respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.65 no.3
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• pp.182-191
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• 2020

A field test and a phytotron study were performed over two years to examine whether rice varieties originated from higher altitude areas have lower optimum grain filling temperatures for yield improvement than the varieties from South Korea. Three varieties originated from North Korea and three varieties from northern China were compared to the same number of varieties from South Korea. In a field study, the optimum grain filling temperatures over 40 days after heading were 22.6 - 23.0℃, 21.5 - 22.3℃, and 21.5 - 23.6℃ for the varieties from North Korea, northern China, and South Korea, respectively, resulting in no significant difference among varietal groups. Meanwhile, the heading dates of the early maturing varieties from North Korea and China were 7 - 12 days earlier than that of the early maturing Odae variety from South Korea during the first transplant of 2017. The phytotron study, in which different temperature regimes were imposed from flowering/fertilization to harvest with constant daily mean temperatures, revealed that milled rice weight did not decrease under low temperatures, even at 16℃, compared to that at 22℃. At the fourth transplant in the field study, mean temperature lower than 10℃ appeared before rice grains were fully developed, resulting in yield reductions. It was concluded that rice varieties adaptable to high-altitude areas do not have lower optimum grain filling temperatures but, instead, possess shorter growth durations. It was further suggested that the optimum grain filling temperature of rice observed under natural conditions could be attributed to the lowering temperature at the late filling stage under temperate climatic conditions.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.79-79
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• 2017

Grain Sorghum varieties grown in Korea have low productivity and are constrained by the fact that farmers' choice of improved varieties is limited. Hybrid cultivars have been demonstrated to be more productive and food security than pure line varieties. However, There's no available hybrid cultivars and never planted before in Korea. This study was, therefore, conducted to determine combining ability of Korean landrace varieties and cultivar, the level of heterosis of experimental hybrids depending on environments. Two cytoplasmic male-sterile lines were crossed with six male-fertile lines in accordance with North Carolina II mating scheme to generate 12 experimental hybrids. The hybrids were evaluated in replicated row-column alpha designs at two sites in Texas and South Korea under on-season production conditions. For each trait, general combining ability (GCA) and specific combining ability (SCA) effects were estimated using the line-tester method of analysis. Results indicated significant differences among genotypes for both grain yield potential and secondary traits. Hybrids were predominant for grain yield, and displayed up to 127% heterosis of A03017 ${\times}$ Sodamchal in Korea. Positive GCA for yield was observed for Donganme, Hwanggeumchal and Jungmo4002 in Korea. Among them Jungmo4002 and Donganme had highly positive for yield (227.90 and 84.90 kg ha-1), while it showed negative GCA for yield in College station (-40.90, -189.60 kg ha-1). ATx630 ${\times}$ Sodamchal had the greatest SCA for yield (468.10 kg/ha) in College station but at South Korea its SCA effect was -302.40 kg/ha. A similar trend was observed, followed by A03017 ${\times}$ Donganme (SCA effect = 215 kg ha-1 at College station vs. -44.20 kg ha-1 at South Korea). At South Korea the greatest positive SCA effect for grain was observed in ATx630 ${\times}$ Jungmo4002 as 322.20 kg/ha. Both GCA and SCA effects significantly interacted with site effects demonstrating the need for region adaptation of potential cultivars and test for developing Korea suitable cultivar.

• Asian Journal of Turfgrass Science
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• v.13 no.1
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• pp.37-54
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• 1999

This study was initiated to evaluate the seasonal turf performance in a tree shade and to suggest shade-tolerant turfgrasses suitable for domestic climate conditions. Atotal of 21 trufgrasses were tested, comprising of Korean lawngrass, shade-tolerant fine fescues, and newly-developed, shade-tolerant varieties of cool-season grasses. Dirrerences in shade tolerance were observed among varieties, species, and genera. Overall turf performance of C3 turfgrasses was better than that of C4 Korean lawngrass under a tree shade. Coarse-type fescues were excellent in shade tolerance, bluegrasses good, ryegrasses medium, fine-type fescues fair, and zoysiagrasses poor, respectively. Inter-species comparison in relative index of shade tolerance(IRST) demonstrated that tall fescue and fough bluegrass were greatest of 7.3, Poa supina 6.4, perennial ryegrass 5.0, Kentucky bluegrass 4.8, and fine fescues least, respectively. A great variation in RIST was observed with fine fescues; creeping red fescue was 3.6, chewings fescue 2.5, hard fescue 2.1, and sheep fescue 1.4, respectively. Among 21 turfgrasses evaluated, tall fescue 'Rebel Jr.', 'Era', and 'Oixie' and rough bluegrass 'Sabre' were the shade-tolerant varieties under a tree shade in Korea. Tall fescue, 'Rebel Jr.' was considered as the most shade-tolerant variety in the experiment. Fine fescues as creeping red fescue, chewings fescue, hare fescue, and sheep fescue, used as the shade-tolerant species in a cool climate of Europe and North America, were not suitable under domestic climate conditions.

• Applied Biological Chemistry
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• v.32 no.3
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• pp.203-208
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• 1989

Eight samples of Korean two-rowed barley, 9 samples of North American barley and 3 samples of Korean six-rowed barley were analysed for 1,000 kernel weight, steeping time, germinative capacity, and protein content. The barley samples were malted with the same malting schedule and analyzed for malting loss, protein content, soluble protein, percent extract, wort viscosity, and diastatic power. The American barleys were higher in germinative capacity, percent extract and diastatic power than the Korean two-rowed barleys. The protein content ranged from 11.8 to 14.2% for the North American barleys and 9.7 to 15.5% for Korean barleys. The three Korean six-rowed barleys were lower in germinative capacity, percent extract and diastatic power, but were higher in wort viscosity than the Korean two-rowed barleys.