• KOREAN JOURNAL OF CROP SCIENCE
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• v.63 no.3
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• pp.186-195
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• 2018

A field study was conducted over a 3-year period from 2014 to 2016 in the central plain area, Suwon, Korea, 1) to compare the biomass production between machine-transplanted and water-broadcast seeded silage rice and 2) to elucidate the growth factors that affect the difference in biomass production between the two cultivation practices. The heading date for the water-broadcast seeded silage rice was September 11-18, which was delayed by 11-17 days when compared to that for the machine-transplanted silage rice. On average, water-broadcast seeded silage rice had a shorter plant height, more panicles per area, and a greater biomass production because of the increased straw dry weight. However, the difference in dry weight of each plant organ between the two cultivation practices exhibited yearly variation. When the data were pooled across experimental years, cultivation practices, and varieties, biomass production was highly positively correlated with straw dry weight but not with panicle dry weight. When the ratio of water-broadcast seeding to machine-transplanting was analyzed, total dry weight and straw dry weight were positively associated with each other, whereas no relationship was found between total dry weight and panicle dry weight. Despite that water-broadcast seeded silage rice produced more panicles per area than machine-transplanted silage rice, the two cultivation practices had a similar dry weight per culm. Therefore, we conclude that the silage rice from the water-broadcast seeding, compared to the machine-transplanting, produced more biomass because of the combination of the increased panicle number per area and a similar dry weight per culm. These results suggest that silage rice could be produced through water-broadcast seeding to increase biomass production with low labor and cost input.

• Journal of Environmental Science International
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• v.16 no.1
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• pp.1-8
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• 2007

Atmospheric photochemistry of $O_3-NOx-RH$ were considered theoretically, to clarify the reasons for the different trends of between the formation of photochemical oxidants (Ox) and its primary pollutants for the Low-and High-NOx regimes. Equations of OH, $HO_2$, and production of ozone ($O_3$) as a function of nitrogen oxides (NOx) and reactive hydrocarbons (RH) were represented in this study. For the Low-NOx regime, $HO_2$ radical is proportional to RH but independent of NOx. OH radical is proportional to NOx but inversely-proportional to RH. $O_3$ production is proportional to NOx but has a weak dependence on RH. For the High-NOx regime, OH and $HO_2$ radicals concentrations and $O_3$ production are proportional to RH but inversely-proportional to NOx. In addition, the Osaka Bay and surrounding areas of Japan were evaluated with the mass balance of odd-hydrogen radicals (Odd-H) using CBM-IV photochemical mechanism, in order to distinguish the Low- and High-NOx regimes. The Harima area (emission ratio, RH/NOx = 6.1) was classified to the Low-NOx regime. The Hanshin area (RH/NOx = 3.5) and Osaka area (RH/NOx = 4.3) were classified to the High-NOx regime.

• Journal of Plant Biology
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• v.14 no.3
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• pp.21-28
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• 1971

Dry matter production, leaf area growth and total nitrogen changes were studied in Glycine max. soybean communities, which were grown in sandy loam soils controlled to provide various moisture levels, i.e., 5-7%(level 1), 8-10%(level 2), 11-13%(level 3), 14-15%(lev디 4), 17-20%(level 5) and 22-24%(level 6). A summary of the results is shown. The maximum dry matter production of leaves, stems and nodules and the maximum leaf area per unit area were at level 5, but the maximum of root dry matter production was at level 4. Total nitrogen content of the soybean plant decreased with growth, but each level of soil moisture content also showed a little difference. Water content of the plant decreased with plant age and soil water deficiency, especially in roots and nodules. Nodule formation increased in proportion to soil moisture content. total nitrogen content of the soil on which the soybeans grew, increased from 0.23% before sowing to 0.30% at 100 days after sowing. It seems that soil water content acts as a linear factor in the elongation or dry weight increase of shoots and roots until increasing to level 5. Considering the pattern of plant growth through analysis of the shoot and root dry weight ratio, or the photosynthetic organ and non-photosynthetic organ dry weight ratio, the asymptote of plant growth at a high soil water content exceeded that at a low soil water content.

• Journal of the Korean Society of International Agriculture
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• v.23 no.5
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• pp.485-490
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• 2011

In Southeast Asia, Myanmar is the largest country of the continent with land area 676,577 km² that is three times higher than Korea. Nonetheless, a lot of diversity in agricultural enterprises is available in Myanmar as different climatic zones are available due to its unique location from north to south and east to west. Agriculture is considered the most important industry in Myanmar that largely relies on rice production. During 2009-10, rice and black gram are also among the major export items of Myanmar. Wheat, maize and sorghum are among the other major crops of the country and cultivation area of wheat and corn has been steadily increasing. Sesame is an important oilseed crop of Myanmar that is cultivated on the largest area. Presently, Myanmar has trade relations with Thailand, India and China.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.4
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• pp.511-516
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• 2007

This experiment was conducted to evaluate the effects of differently maturing corn hybrids on silage production and milk production per unit area in the northern part of Japan, where grain development occurs under decreasing ambient temperature. Both hybrids were harvested at the same time. The stages of maturity for the early-maturing hybrids (EH; 80 d relative maturity) and the mid-maturing hybrids (MH; 93 d relative day) were early dent and late dough stage, respectively. The plant yields for MH were higher than those for EH. The dry matter (DM) content of MH was lower than that for EH, and the effluent loss for MH silage was greater than that for EH silage. Therefore, the DM yields of prepared silage per area were similar for both treatments. Twelve multiparous mid-lactation Holstein cows ($58{\pm}13$ days in milk) were fed diets based on EH or MH silage in a crossover design with two 3-week periods. Cows were fed 3 kg of hay crop silage (DM basis) and either EH or MH silage ad libitum, and concentrates were supplied to meet NRC requirement for dairy cows. Silage DM intake for EH was found to be higher (p<0.05) than that for MH (10.0 vs. 9.1 kg/day). Milk production and milk composition for EH were similar to those for MH. Feed efficiency per total feed intake was similar in both treatments, although the feed efficiency per concentrate intake tended to be higher for the EH than that for the MH diet. These results indicate that differences in maturation in corn hybrids affect the effluent production of silage and the silage intake of dairy cows. It may be advantageous to plant early hybrid corn with a reduction in effluent production of silage as well as a reduction in purchased feed costs for dairy cows under the climatic conditions of the northern part of Japan.

• Journal of Korean Society of Forest Science
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• v.89 no.2
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• pp.232-240
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• 2000

Correlation between Songyi(Tricholoma matsutake, pine mushroom, matsutake) production and the annual pine tree growth in Korea was analyzed with 18 years data of the mushroom production in Sangju area and the annual ring-growth of pine trees at Mt Sogni in the area. The two parameters were not significantly related to each other(r=0.408). A possible reason of this low relationship is that September and October climate affected annual Songyi production through mushroom primordial formation, continued growth of the primordia, while May and June climate did the annual tree-ring growth. Songyi production at Mt. Wolak in Chungcheongbukdo peaked while the minimum daily air temperature ranged about $7^{\circ}C$ to $13^{\circ}C$ during the first week of October in 1999. These show that Songyi production variation is not a simple trend depending on the energy the pine trees have accumulated. Rather, controlling soil moisture and air temperature during Songyi fruiting season can be a significant management option for improving the mushroom production.

• Korean Journal of Agricultural Science
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• v.44 no.1
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• pp.40-49
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• 2017

Cultural practices for adzuki bean and the distribution of weed species in the south-west regions of Korea were surveyed to provide information on effective weed management. Approximately 27.5% of the farm households were growing adzuki bean in an area larger than 1 ha while the rest grew the crop in an area smaller than 1 ha. Of all adzuki bean growers, 17.1% seeded in early June, 8.6% in mid June, 34.3% in late June, 17.1% in early July, 20.0% in mid July, and 2.9% in late July. The average planting distance was $71.0{\times}29.5cm$. From the 40 surveys in adzuki bean fields, 35 weed species in 17 families were identified. According to the occurrence frequency, the dominant weed species were Digitaria sanguinalis, Acalypha australis, Cyperus amuricus, Echinochloa crus-galli, and Amaranthus nangostanus in decreasing order of dominance. However, based on dry weight, Chenopodium album (34.4%) was the most dominant followed by Acalypha australis (21.9%), Amaranthus nangostanus (19.1%), Digitaria sanguinalis (7.5%), and Portulaca oleracea (6.1%). The exotic weeds found in the field of adzuki were Ipomoea hederacea, Abutilon avicennae, and Celosia argentea. The plant heights of I. hederacea, A. avicennae, and C. argentea were 259 cm, 98 cm, and 76 cm, respectively, while the fresh weights were 850 g, 66 g, and 101 g, respectively. Integrated weed management systems utilizing mechanical, chemical, and biological control techniques need to be developed for effective weed management in adzuki bean production.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.167-167
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• 2022

Seed production of italian ryegrass has a problem of lodging during ripening and a decrease in quality due to difficulty in drying seeds during harvest. Therefore, in order to produce high-quality Italian ryegrass in paddy fields, it was carried out to reduce the density and solve the lodging problem through transplanting. In this experiment, Lolium multiflorum cv. Kowinearly was transplanted in autumn from a paddy field in Sindong-ri, Gwansan-eup, Jangheung-gun, Jeollanam-do. var. Kowinearly was made into a bed at 90 g/box and stacked in boxes. It was transplanted on October 27th after 2 days of germination at 30℃ and 15 days of seedling and greening. When transplanting, they were transplanted at intervals of 30×14cm. The existing cultivation method, drill seedling, was sowed at a level of 50 kg/ha, and both transplanting and drilling were carried out at a nitrogen fertilization rate of 45 kg/ha. The number of ears during transplant cultivation was 1,016/m² and the drilling tended to be higher at 2,278/m², but this was probably due to the difference in seeding amount. The seed number of an ear tended to be 56% higher in transplantation, which had a significant impact on yield. The seed yield was 2,096 ka/ha in transplantation, which was 21% higher than that of drilling. When looking at the relationship with weed occurrence, there were areas where all the weeds, such as amul foxtail, occurred due to the low density. Even in the same transplanting area, the seed yield was about 1,000kg/ha less in the area where the weeds were abundant. It seems that weed management is important in paddy cultivation. Therefore, it seems necessary to develop an exclusive herbicide for Italian ryegrass cultivation.

• The Journal of Fisheries Business Administration
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• v.15 no.1
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• pp.58-80
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• 1984

The classification of islands is prerequisite for establishing a development policy to vitalize many-sided function of islands. We try to classify the 440 inhabited islands which exist in Jeon-Nam area and Kyong-Nam area by means of PCA. PCA begins with making correlation matrix of orignal variables. From this matrix we can comprehend the rough relationships between two variables. Next, we look for the eigenvalues which are roots of characteristic equation of correlation matrix. The number of eigenvalues is equal to that of original variables. We choose the largest eigenvalue λ$_1$among them and then look for the eigenvector of correlation matrix corresponding to the largest eigenvalue. Linear combination of eigenvector obtained above and original variables is namely first Principal Component (PC). Using an eigenvalue criterion(λ$\geq$ 1), we choose 3 PCs in Jeon-Nam area and 2 PCs in Kyong-Nam area. But we decide to consider only two PCs in both areas to faciliate a comparative analysis. Now, loss of information is 31.7% in Jeon-Nam area and 26.64% in Kyong-Nam area. PCs extracted by preceding procedure have characteristics as follows. The first PC relates to aggregate size of islands in case of both areas. The second PC relates to income per household, factors of agricultural production and factors of fisheries production in Jeon-Nam area, but in Kyong-Nam area it means distance from island and income per household. A classification of islands can be attained by plotting component scores of each island in graph used two PCs as axes and grouping similiar islands. 6 groups are formed in Jeon-Nam area and 5 groups in Kyong-Nam area. The result of this study in kyong-Nam area accords with prior result of study.

• Korean Journal of Agricultural Science
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• v.43 no.3
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• pp.330-339
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• 2016

The effect of transplanting and harvest timing was evaluated for the production of high quality pigmented rice in the Yeongnam plain area. Rice was transplanted on June $2^{nd}$ and $14^{th}$ and harvested between 35 - 55 days after panicle heading at 5 - day intervals. Three black- and 3 red-pigmented rice cultivars (such as early cultivar : Josengheugchal, Jeogjinju; medium cultivar : Heugseol, Hongjinju; and mid-late cultivar : Sintoheugmi, Geongganghongmi) were studied. Yield components like spikelet number, ripened grain ratio, and 1,000 - grain weight of the black- and red-pigmented rice cultivars were similar for both the June 2 and June 14 transplantings but panicle number per $m^2$ was higher for the June 14 transplanting than for June 2. This contributed to a higher brown rice yield for the June 14 transplanting, by 6 - 19% for black-pigmented rice, and by 10 - 21% for red-pigmented rice than the yield for the June 2 transplanting. Total anthocyanin and polyphenol productions of the pigmented rice were also higher in the June 14 transplanting than that in the June 2 transplanting due to high brown rice yield. Based on the combined pigmented brown rice yield, we concluded that the optimal harvest timing would be 40 - 45 days after panicle heading (DAH) for the black-pigmented rice and 45 - 50 DAH for the red-pigmented rice. This study suggests that optimum transplanting and harvest timings play an important role for production of high quality pigmented rice in the Yeongnam plain area.