• Korean Journal of Weed Science
• /
• v.32 no.3
• /
• pp.188-194
• /
• 2012

Field experiments were conducted to investigate the competition relationships of main paddy weeds with transplanted rice grown in paddy conditions. Data were used to predict crop yield as a function of weed density using a rectangular hyperbola model and determine weed economic threshold (ET) levels. The rectangular hyperbola (equation 2) was fitted to rice yield to estimate weed-free rice yield ($Y_o$) and weed competitivity (${\beta}$). Its competitivity for M. vaginalis was 0.0007445, 0.0005713, 0.000988 and 0.0008846 in Daejeon, Suwon, Iksan and Naju, respectively. The competitivity at harvest represented by parameter ${\beta}$ ranged from 0.001611 in Naju to 0.002437 in Iksan for S. trifolia. The ET levels of main paddy weeds in machine transplanted rice cultivation were well estimated based on the herbicides applied and its application cost. Therefore, our results can be used to support decision-making on herbicide application for weed management in transplanted rice cultivation.

• Weed & Turfgrass Science
• /
• v.2 no.1
• /
• pp.23-29
• /
• 2013

This study was conducted to clarify effects of weed control methods on damages from agricultural chemicals of pear trees, growth of weeds and states of pear trees after treating pear orchards with different methods of weed controlling, density of GLU and application times. The growth and occupation rate were investigated after 10, 20 and 40 days of weeding treatment. According to a result of the first treatment conducted when weeds in the lower parts of crown in a pear orchard began to grow and grew about 20 cm, unwoven cloth covering showed the highest control value with 100% in all 14 kinds of grasses. In comparison, Stellaria aquatica and catchweed bedstraw showed 96.7% and 97.3% respectively in the 20 DAT investigate after the first treatment of GLU 540 g a.i. ha-1 and the high control value of 100% in other all kinds of grasses. According to an investigation of stalk enlargement, length of new shoot and the number of new shoot made to know differences in tree growth following treatment of the lower part of crown, to use weed killers two or three times a year or to eliminate grasses with machines have positive effects on cross growth of pear trees.

• The Korean Journal of Archival Studies
• /
• no.50
• /
• pp.177-229
• /
• 2016

Archival reference service is the ultimate goal and outcome of records management. It encompasses a whole range of activities to connect records with the demands for them. Intellectual needs for records are met by the procedure of information disclosure to guarantee the people's right to know and to provide active responses to archival information needs. Thus, it is required to establish an efficient search system by unifying search tools for archives used in information disclosure and sorting out the classification systems and description items according to the archive types. The qualitative enhancement of information disclosure can be expected when there is a harmonious circulation of attributes-such as applicants, records, search tools, and information providers-for the smooth implementation of reading processes in the context of archival reference service. Therefore, the present study holds its significance in the following aspects. First, it presented a picture of pending issues and the reality of reading service processes from an internal perspective by examining the factors and characteristics that influence "reading service."Second, it demonstrated the phenomenon of close interactions among information providers, applicant, search tools, and records in the process of requesting, searching, and providing records. Third, it proposed the need for a total integrated search tool around the pending issues of reading processes at the National Archives of Korea. Fourth, it promoted an understanding of archival information utilization at the working level among information providers. Finally, it showed major differences in the quality of information provision of "reading service" according to the "perceptions" and "attitudes" of information providers.

• The Korean Journal of Archival Studies
• /
• no.79
• /
• pp.271-303
• /
• 2024

In our country, which has a strong presidential system, the power and responsibilities of the president are truly enormous. He is the head of state and diplomatic representative, and at the same time exercises authority over all areas of the country, including the legislature, judiciary, and constitutional institutions, along with his responsibilities as head of the executive branch. Considering these aspects, it can be said that presidential records created during the president's rule have a high level of national and historical significance and value compared to other public records. Considering these importance of presidential records, the Presidential Records Management Act was enacted in 2007 to establish an institutional mechanism to systematically manage presidential records. However, the current institutional basis for appraisal of presidential records is very weak. In this regard, there is a need to begin discussions on the appraisal of presidential records in earnest. Considering the national importance and symbolism of presidential records, it is necessary to establish a new direction for appraisal of presidential records that is different from general public records. Accordingly, in this paper, as part of reestablishing Korea's presidential records appraisal system, this article analyzed the status and problems of the current presidential records appraisal system and presented directions needed to find future improvement measures. To this end, as a premise for discussing the importance and value of presidential records, it examined the powers and responsibilities of the presidency as defined in our country's Constitution.Next, we looked at the appraisal system and method for presidential records that are currently in operation, and then analyzed the problems that emerged here in connection with the characteristics of presidential records. Based on this, it presented five perspectives on issues that need to be discussed publicly in the records management community in order to reestablish Korea's presidential records appraisal system in the future.

• Korean Journal of Weed Science
• /
• v.32 no.3
• /
• pp.159-169
• /
• 2012

Hormesis is a dose-response phenomenon that is characterized by low-dose stimulation and high-dose inhibition. This biphasic dose-responses have had a long and extensive history in the fields of chemical toxicology, radiation biology and pharmacology. Hormesis has been found from bacteria, fungi, plants and animals, but hormesis in plants has received relatively little attention. Thus principles, occurrence, factors affecting the expression of hormetic responses, and their mechanisms in plants induced by herbicides are reviewed to provide the potentials for crop enhancement. Bromacil, bromoxynil, chloramben, propachlor, terbacil, EPTC, MSMA, and glyphosate at low doses showed stimulatory response in growth. Subtoxic dose of glyphosate increased sucrose content in sugarcane that is used worldwide in sugarcane production. Low dose of protoporphyrinogen-inhibiting herbicides induced increased pathogen defence, and low dose of triazine herbicides improved nitrogen metabolism and increased protein content in some crops. Further researches on potential benefits and risks of hormesis and its mechanism are needed for application of crop enhancement in agriculture.

• Weed & Turfgrass Science
• /
• v.4 no.4
• /
• pp.348-359
• /
• 2015

Total 443 isolates of actinomycetes were isolated from turfgrass rhizosphere as potential biological control agents. The two isolates (S11 and S4) showed highest cellulase activity with compared to the other isolates that exhibited a clear zone of 1.2 mm around the colony on cellulose agar medium. S12 strain appeared the most active chitin degrading, which exhibited a 1.2 mm of clear zone. The highest proteolytic activity on skim milk agar was which exhibited a 7.5 mm of clear zone by S2 strain. S1 strain from the soli showed siderophore production ability, which exhibited a 0.6 mm of large clear zone on chrome azurol S agar. The antifungal activity of the volatile compound producing by 4 selected actinomycetes was investigated that inhibition rate against Rhizoctonia solani AG2-2 and Sclerotinia homoeocarpa. Growth inhibition effect of S8 isolate against S. homoeocarpa was appeared to 94.8%, S2 to 76.9%, S5 to 46.1% and S12 to 43.5%. The significant inhibition effects on mycelial growth of S. homoeocarpa were shown on media with four strains. The inhibition effect was the highest with S8 strain treatment at 94.8%.

• Weed & Turfgrass Science
• /
• v.2 no.3
• /
• pp.221-229
• /
• 2013

This paper reviews current status of weed control practices in herbicide-resistant crops to examine weed management strategies in cope with cropping herbicide-resistant crops in the near future. Herbicide-resistant crops were rapidly adopted weed management technologies due to broad-spectrum weed control without crop injury. Transgenic glyphosate-resistant cultivars in soybean, corn, canola, and cotton were adopted to manage weeds at lower cost in a simplified weed management system. Dual stack crops with glyphosate and glufosinate resistance were developed to control glyphosate resistant weeds in corn, soybean and cotton. New multiple herbicide-resistant crops with resistance to glyphosate and glufosinate, acetolactate synthase (ALS) inhibitors, synthetic auxin herbicides, 4-hydroxyphenyl pyruvate dioxygenase (HPPD) inhibitors or acetyl Coenzyme A carboxylase (ACCase) inhibitors will expended the utility of existing herbicide technologies to manage the evolution of resistant weeds. However, herbicide resistant crops alone cannot solve weed problems and thus studies on diverse weed managements using an array of alternating herbicides of mode of action, mechanical, and cultural practices are needed for integrated weed management systems in the future.

• Weed & Turfgrass Science
• /
• v.4 no.3
• /
• pp.199-208
• /
• 2015

This study was conducted to provide basic information for weed control by surveying the occurrence of weed species in upland crop fields in Gyeongnam province of Korea. The result of this survey, 55 weed species 21 families in barley fields, 56 weed species 22 families in garlic fields, 47 weed species 19 families in onion fields, 68 weed species 26 families in Chinese cabbage fields, 54 weed species 22 families in potato fields, 62 weed species 25 families in sweet potato fields, 87 weed species 29 families in red pepper fields, 79 weed species 28 families in corn fields, 84 weed species 29 families in soybean fields. The most dominant weed species in upland crop fields of Gyeongnam province were Alopecurus aequalis var. amurensis 20.7% (barley fields), Cardamine flexuosa 12.3% (garlic fields), Chenopodium ficifolium 18.7% (onion fields), Portulaca oleracea 8.1% (Chinese cabbage fields), Chenopodium ficifolium 13% (potato fields), Digitaria ciliaris 12.6% (sweet potato fields and red pepper fields) and Digitaria ciliaris 11.3% (corn fields), 13.2% (soybean fields). This information could be useful for establishment of future weed control methods in Gyeongnam province.

• Weed & Turfgrass Science
• /
• v.6 no.2
• /
• pp.130-135
• /
• 2017

In the current study, we surveyed the status of graveyard lawn maintenance in Korea. The lawn maintenance information was obtained from the vicarious companies registered on the internet portal site and the Forestry Federation of Korea, and the questionnaire investigation from Primary Agricultural Cooperatives (Nonghyup). In all provinces surveyed, individual graves were maintained on a $66m^2$ (20 Pyeong) basis. The vicarious maintenance of graveyard lawn was carried out 1~5 times a year, and the maintenance cost increased as the number of times increased. Mowing the grass around a grave (Beolcho) was mainly done before the Korean Thanksgiving Day (Chuseok). The number of Beolcho was steadily increased from 2013 to 2015, and the price was getting higher and higher. Gyeonggi province had the highest cost, and Jeolla had the lowest cost. Regardless of the year, the number of orders received were higher in Gyeongnam > Gyeongbuk > Jeonnam province in order. Most of the reason for requested Beolcho was because the client lives in the area far from the graveyard. The direction of the cemetery was very varied. According to the survey, the all grass were zoysiagrass (Zoysia japonica), and grass coverage rate of the graves was 35.4~71.9%. Through questionnaire investigation, the reason why the density of grass was lowered was because the periodic management of weeds and fallen leaves was insufficient. Further research on the maintenance of graveyard in the future will be necessary.

• Korean Journal of Weed Science
• /
• v.31 no.2
• /
• pp.175-182
• /
• 2011

This study was conducted to evaluate the growth inhibition of weeds and selectivity of crop species by hairy vetch residues. The growth of all the weed species was suppressed greater than 90% at the ratio 60 : 40 of hairy vetch residues and no weeds were emerged at 90 : 10 mixture in the greenhouse. It was noticed that broadleaf weed species were more suppressed compared to grass weed species. Growth of weeds was significantly reduced and the inhibition percent was increased with increasing application depths of hairy vetch mixture both in vinylhouse and in field conditions. Among the different application depths of hairy vetch mixture, 0.75 cm depth of application tended to inhibit more, but statistically no significant difference was observed between 0.5 cm and 0.75 cm application depth. The growth of weed species such as Galium spurium, Chenopodium album, Plantago asiatica, and Rumex japonicus was greatly suppressed in the vinylhouse and the growth of G. spurium, R. japonicus and Amaranthus retroflexus was suppressed significantly in the field condition. The growth inhibition of all the above mentioned sensitive weed species was approximately 80% at the application depth of 0.5 cm. Crop growth was not hampered by using the residues of hairy vetch. This study demonstrated that rotation crop residues of hairy vetch contained high allelopathic potential to different weed species without hampering the growth of crop species.