• Title/Summary/Keyword: field extension

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ON THE SOLUTIONS OF EQUATIONS OVER NILPOTENT GROUPS OF CLASS 2

  • Kim, Seong Kun
    • East Asian mathematical journal
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    • v.29 no.3
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    • pp.349-353
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    • 2013
  • In this paper, we study equations over nilpotent groups of class 2. We show that there are some overgroups which contains solutions of equations with exponent sum 1 over nilpotent groups of class 2. As known, equations over a field has a solution in an extension field which contains a copy of the given field. But it is not easy to find that a solution of equations over groups. In many cases, even if equations over groups has a solution, the overgroup is not concrete but very Here we find the concrete overgroups in case of nilpotent groups.

Difference in Growth, Yield and Isoflavone Content among Soybean Cultivars under Drained Paddy Field Condition

  • Chon, Sang-Uk;Kim, Dong-Kwan
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.51 no.1
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    • pp.48-52
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    • 2006
  • Naturally occurring soybean isoflavones are known to be influenced by various genetic and environmental conditions. Growth, yield, and isoflavone content were determined in four different cultivars of soybean grown under drained paddy and upland fields. Most of growth characteristics and yield components of four different soybean cultivars harvested in drained paddy field were greater than those in upland field, regardless of cultivar. By means of high performance liquid chromatography, total daidzein and genistein contents of soybean in drained paddy field were increased up to 40 and 35%, respectively, compared with those in drained paddy field. Besides isoflavone contents, the growth and yield of soybean were significantly affected by cultivar and field conditions, indicating the necessity of genetic program for soybean cultivars appropriate to drained paddy field conditions. In conclusion, converting paddy field into upland may effectively improve soybean cropping system, especially in terms of isoflavone increment under paddy field conditions.

Comparison of the Surface Chemical Properties of Plastic Film House, Upland, and Orchard Soils in Gyeongbuk Province

  • Park, Sang-Jo;Park, Jun-Hong;Kim, Chan-Yong;Seo, Young-Jin;Kwon, Oh-Heun;Won, Jong-Gun;Lee, Suk-Hee
    • Korean Journal of Soil Science and Fertilizer
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    • v.49 no.2
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    • pp.115-124
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    • 2016
  • The objectives of this study were to evaluate the soil fertility about plastic film house, upland, and orchard in Gyeongbuk Province, Korea. The surface chemical properties of soil samples were investigated every 4 year from 2000 year at upland, 2001 year at orchard, and 2002 year at plastic film house. During 12 year's monitoring, mean soil pH was increased by 0.7 and 0.8 pH unit from pH 5.7 in upland and orchard, respectively, 0.5 pH unit from pH 6.5 in plastic film house. About 50% of all the field samples occupied within the recommended pH range (pH 6-7). Although soil organic matter (SOM) was gradually increased by about $10g\;kg^{-1}$ for 12 years, 40% of orchard, 49% of plastic film house, and 77% of upland soil samples were still below the 3% SOM. The mean concentration of available phosphate for 12 years in upland, orchard, and plastic film house were 530, 600, and $760mg\;kg^{-1}$, respectively. The relative frequencies exceeding the recommended available phosphate range ($300-550mg\;kg^{-1}$) were 43%, 53%, and 66% at upland, orchard, and plastic film house soils, respectively. $NH_4OAc$ exchangeable $K^+$ of upland, orchard, and plastic film house in the last soil test were 0.8, 0.9, and $1.6cmol_c\;kg^{-1}$, respectively. The relative frequencies above the recommended K level were 56% and 70% of orchard and plastic film house soil samples, respectively. The levels of crop nutrients except exchangeable Ca and Mg in upland soil were tended to increase gradually in the three fields. Exchangeable Mg, EC, available phosphate, organic matter and soil pH could be used as principle components to differentiate the chemical properties of three land fields. This analysis revealed that the soil fertility was affected by cropping method and field management, although additional research is needed to assess the importance of management on soil chemical properties and many fields indicate an opportunity for improvement in fertilizer management.

Growth characteristics comparison per planting density on the waxy corn early-planting culture for the paddy field in the southern province

  • Kim, Yong-Soon;Choi, Jin-Gyung;Kim, Dong-Kwan;Park, Heung-Gyu;Kim, Myeong-Seok;Kim, Hyun-Woo;Kim, Sung-IL;Kim, Sang-Yeol
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2017.06a
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    • pp.88-88
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    • 2017
  • The study was conducted to analyze the growth characteristics comparison per planting density on the waxy corn early-planting culture for the paddy field in the southern province of south Korea. The cultivation period of early-planting culture for the paddy farming of the waxy corn are sown on February 15, 2016years, transplanting March 15 and harvest June 20. And it grew 126 days. The weather change according to the cultivation period of unheated plastic house early-planting culture, it was average temperature $14.6^{\circ}C$ and humidity 62.5%. And the temperature was 5.6 degrees Celsius warmer compared with the outside temperature and the humidity was 0.7 percent higher tendency. At the growth per planting density of waxy corn, culm length was average 224cm, the more it is high density culture the more was high trend. Stem diameter and ear length the more it is high density culture the more was lowed trend. The node number of $60{\times}20Cm$ was 12 nodes, fruit seting 5.7 nodes, tasseling number 94 days and silking number 96 days. In the ear characteristics per planting density, the size of ear length, seed setting length, ear width and ear weight the more planting density is high the more lowed that trend. The commodity percentage of planting density $60{\times}35Cm$ was the highest among other treatment as 69.1%. But, marketable yield was the highest planting density of $60{\times}20Cm$ as 4,543 ears/10a, and appeared in order $60{\times}25Cm$ 95%> $60{\times}30Cm$ 93%> $60{\times}35Cm$ 92%. The planting density on the waxy corn early-planting culture for the paddy farming in the southern province, the planting density analyzed to be effective planting of over 25% than normal season culture.

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Influence of Soil Flooding on Control of Pink Root Disease in Onion Crop (양파 연작지의 분홍색뿌리썩음병 방제를 위한 담수처리 효과)

  • Moon, Jin-Seong;Lee, Jong-Tae;Ha, In-Jong;Whang, Seon-Gyeong;Song, Wan-Doo;Cheon, Mi-Geon;Lee, Chan-Jung
    • Research in Plant Disease
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    • v.13 no.2
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    • pp.104-109
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    • 2007
  • Pink root disease of onion, a known worldwide constraint upon onion production, significantly reduces crop levels in the main Korea cultivation area. In order to examine the effect of flooding on incidence of pink root disease caused by Pyrenochaeta terrestris and on onion growth and on populations of soil fungi, field experiments were conducted during two seasons, 2003/04 and 2004/05 at Onion Research Institute. Populations of soil fungi from fields were assayed on selective media. Flooding treatment was effective in reducing populations of P. terrestris, Pythium spp., and Rhizoctonia sp. in soil; fungal populations in soils flooded for 90 days were reduced to 1/2 to 1/3 of those in non-flooded soils. In nursery bed, protective activities of soils flooded for over 60 days were 93.5 to 99.2% and their pink root incidences were less than 5%, which were 1/11 to 1/18 of that in control. Increased yield of onion bulbs was associated with control of soil borne pathogenic fungi by flooding treatments. As flooding period was prolonged, bulb grade showed the tendency to increase. Soil flooding for over 60 days resulted in effective disease control, facilitated accurate planning of plant population in the field, extension of the growing-season and consequently higher yields of better quality.

A Study on the Development of Greenhouse Management System Based on Internet (인터넷 온실경영관리시스템 개발에 관한 연구)

  • Shim, Keun-Seop;Kang, Jeong-Ok;Lee, Hee-Ju
    • Journal of Agricultural Extension & Community Development
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    • v.11 no.1
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    • pp.191-207
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    • 2004
  • This study was focused on the development of greenhouse management and environmental control system using internet. The essence of this system were remote automatic control unit connected with greenhouse environmental control according to the growth stages of crops, The specific objectives of the study were; 1) to analyze need of greenhouse environmental remote control system, 2) to investigate the important functions related to greenhouse management program, 3) to explore the possibility of diffusing the system using internet.The study was carried out through review of related literature and need assessment from the research and extension workers in charge of greenhouse management using questionnaire survey, interview and field study. The results of the study were summarized as fallows: 1) About 89% of respondents responded positively on the need to establish automatic control system using internet. 2) The greenhouse management and environmental control system using internet was possible to control the greenhouse in remote, automatic, and simultaneous manner, and additionally by cellular phone in emergent situation. 3) The system was possible to precisely control the greenhouse environment, and it was able to connect the environmental control data with information on growth of crops. 4) By networking the farmer, extension educator of agricultural technology center and researcher, web based farm consulting was possible through the system. Based on the results of the study recommendations were suggested as follows: 1) Thorough spot inspections and field trials should be performed before the diffusion of this system. 2) The costs of the system installation and maintenance should be moderate. 3) The operation of the system should be simple and easy for tamers to adopt. 4) National support should be made to build better internet infrastructure in rural areas.

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Effects of Paclobutrazol and Prohexadione-Ca on Seed yield, and Content of Oils and Gibberellin in Flax Grown in a Greenhouse

  • Kim, Sang-Kuk;Han, Chae-Min;Shin, Jong-Hee;Kwon, Tae-Young
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.63 no.3
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    • pp.265-271
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    • 2018
  • We investigated the effect of paclobutrazol (PB) and prohexadione-Ca (PC) on seed yield, and the content of oils and endogenous gibberellin in flax grown in a greenhouse. Flax seedlings were cultivated in a greenhouse with average ambient temperature ranging from $35^{\circ}C$ to $38^{\circ}C$ during the growing period, and then PB and PC were applied on the leaves. The height of flax plants was reduced significantly by the foliar application of PB and PC. The highest ripening seed rate recorded was 94.5% with 2000 ppm PC; a 10.3% increase compared with that of the control. Both PB and PC markedly increased the fructification of flax seed. The application of two plant growth retardants resulted in higher seed production in flax seedlings grown in open field than in those grown in a greenhouse. The highest oil content was observed in flax treated with PC, whereas, the lowest oil content was observed in flax treated with PB. The oil content and ratio of unsaturated fatty acids were higher in flax seedlings grown in greenhouse than in those grown in open field. The level of two endogenous bioactive gibberellins ($GA_1$ and $GA_4$) in flax seeds decreased with the application of PB and PC. The flax plants treated with PB and PC presented higher secoisolariciresinol diglucoside content than that of the control. The optimal concentration of PC was found to be 2000 ppm. In conclusion, the foliar application of 2000 ppm PC might be useful in increasing oil content and seed production in flax plants.