• Korean Journal of Weed Science
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• v.6 no.2
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• pp.168-173
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• 1986

The effects of varying concentrations and duration of fluazifop-butyl [(${\pm}$)-butyl [2- [4- [(5-(trifluoro methyl)-2-pyridinyl] oxy] phenoxy] propanate] treatment on cell division, cell enlargement, and protein synthesis were studied. Oat (Avena staiva L.) were treated from 0 to 48 hr with concentration ranging from $1{\times}10^{-6}M$ to $1{\times}10^{-3}M$ of fluazifop-butyl in the cell division study. There was a significant reduction in the mitotic indices of oat roots treated with $1{\times}10^{-4}M$ after 6 hr. After 18 hr treatment, All herbicide treatment inhibited cell division significantly. After 24 hr treatment almost 100% inhibition of cell division occurred at $1{\times}10^{-4}M$ to $1{\times}10^{-3}M$ while 20% inhibition of cell division occurred at $1{\times}10^{-6}M$ concentration at same exposure period. The greatest inhibition of cell division occurred between 0 to 18 hr. The avena coleoptile straight- growth test were used to determine the influence of fluazifop-butyl on eoleoptile growth. Significant inhibition of elongation of oat coleoptiles were observed at $1{\times}10^{-7}M$ to $1{\times}10^{-3}M$ after 24 hr incubation. Protein incorporation study showed that the $1{\times}10^{-4}M$ of fluazifop-butyl caused 60% inhibition of protein synthesis. It was concluded that the growth of inhibition of plants caused by fluazifop-butyl results from inhibition of cell division, cell enlargement, and protein synthesis.

• Korean Journal of Weed Science
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• v.17 no.4
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• pp.439-444
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• 1997

The causes of late establishment of barnyardgrass and their density effect on rice yield loss were examined in 1996 and 1977. Herbicide application on 5 to 15DAT(Days after transplanting) increased from 6% to 52.5%, 1988 to 1992, and their ingredient amount for barnyardgrass control decreased to 41.7-87.5% in Korea. Most late establishment of barnyardgrass in machine transplanted rice field were not late germinated but revived ones. The number of late established barnyardgrass were 0.5, 2.0 and 13.3/$m^2$, on direct seeded at May 10, and machine transplanted May 23 and June 9, individually. Relation on rice yield and the number of barnyardgrass at machine transplanted field showed highly significant equation, as y=543.3 4.7x, r=0.9039 in 1996 and y=515.8 10.4x+0.066$x^2$, $R^2$=0.9532 in 1997. Theoritical yield loss by regress equation showed 2% per one plant of barnyardgrass per $m^2$ and 5, 10, 20, 50, and 80 plants of barnyardgrass decreased rice to 10, 19, 35, 69 and 79%, individually.

• Korean Journal of Weed Science
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• v.7 no.1
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• pp.35-44
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• 1987

Differing in water conditions, the dry matter weight per plant was highest at 0 cm flooding depth, and was decreased at above 2 cm flooding depths. The shoot and spikes per pot developed best at flooding depths of 0 and 2 cm, but worst at -5cm or above 4cm flooding depths. The dry matter weight of shoots was linearly increased, but the weight of roots was sharply decreased according to high temperature after flower initation. The shoots and spikes per pot developed more effectively at 25$^{\circ}C$ than at 35 or 15$^{\circ}C$. The number of shoot and spike per pot were decreased according to higher shading. The effects of shading of 25-45% were not significantly small. The natural white and yellow spectra were the most effective to increase dry matter weight, shoots and spikes per pot. The dry matter weights of shoot and root per plant were not significantly different among at: 50 and 75% clay. The number of shoots were best and continuously increased at 75% clay, and the increments at 0 and 100% clays showed the lag period at early stage. The pattern of spikes was similar to shoots with less difference in various clay composition. The dry matter weight per plant in paddy field and upland field was basically similar. The numbers of shoot and spike were increased in response to increased fertilizer levels up to 20Kg per 10a of each component.

• Korean Journal of Weed Science
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• v.16 no.3
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• pp.221-229
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• 1996

This study was carried out to determine the effects of growth regulators, carbon sources and silver nitrate on callus formation and plant regeneration of turfgrass. The results were summarized as fallows : Callus from Korean lawngrass (Zoysia japonica Steud.) and pencross creeping bentgrass (Agrostis palustrir Huds.) induced better in MS medium than in N6 medium and by addition of 2,4-D than by that of NAA. Callus formation from Korean lawngrass and penncross creeping bentgrass was very effective at MS medium adding 1mg/L 2,4-D and at the medium adding 2mg/L 2,4-D, repectively. Growth of callus was good at MS medium containing 2mg/L 2,4-D+0.2mg/L NAA. Callus growth of Korean lawngrass and penncross creeping bentgrass was good when kinetin was added 0.2mg/L and 0.3mg/L, individually, to MS medium containg 2mg/L 2,4-D+0.2mg/L NAA. Regeneration rate from leaf and stock callus of Korean lawngrass was 44% at MS medium adding 2,4-D 2mg/L+NAA 0.2mg/L+kinetin 0.3mg/L and 32% at the medium containing 2,4-D 2mg/L+NAA 0.2mg/L+kinetin 0.3mg/L, each and that from leaf and stock callus of penncross creeping bentgrass was 80% and 67%, each, at the medium adding 2,4-D 2mg/l+NAA 0.2mg/L+kinetin 0.3mg/L. Regeneration rate of Korean lawngrass and penneross creeping bentgrass increased by 3 to 4% and by 10 to 16%, respectively, when added $AgNO_3$ 1~2mg/L to the above-mentioned regeneration medium.

• Korean Journal of Weed Science
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• v.8 no.1
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• pp.71-89
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• 1988

This study was conducted to evaluate the effect of a growth retardant, Paclobutrazol on the growth, yield and its components. and physiological traits in peanut cv. Saeddle (early variety) and Nampung (medium variety). The results are summarized as follows : Main stem and branch length of both varieties were remarkably retarded at early growth stage application, but the retardation effect was reduced at late growth stage application. Number of branches was increased remarkably by treating 60ppm at 20days after seedling (DAS) in early variety. Lodging ill medium variety was not observed through growth period when 120ppm of Paclobutrazol was applied while lodging was not appeared between 40 DAS and 80 DAS in early variety. The numbers of riped pods in early variety was increased when application of 120ppm at 40 DAS was made while it was increased as application of 120ppm at 90 DAS in the medium variety. Cercospora leaf spot was reduced by spraying at 40 or 50 DAS regardless of concentration and varieties. Chlorophyll content and photosynthetic activity increased when paclobutrazol was applied during 40-60 DAS in early variety while these were observed at 90 DAS in medium variety. Seed weight tended to increase as paclobutrazol application was delayed. The ratio of pods to seeds was higher at 60ppm-40 DAS in early variety while it was higher at 120ppm-90 DAS in medium variety.

• Korean Journal of Weed Science
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• v.8 no.1
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• pp.64-70
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• 1988

An experiment was carried out to know the effects of paclobutrazol on the lodging related traits and yield of a japonia (Seomjinbyeo) and an indica (Samgangbyeo) rice variety grown at 3 N levels (10, 20, 30 kg/10a) and 3 N split rates [basal + top dressing 15 days after transplanting (DAT) : top dressing 25 days before heading (DBH) was 100 : 0, 80 : 20, and 60 : 40]. Paclobutrazol (3kg/10a of 0.6% G) was applied 15 DBH and lodging related traits were observed 3, 13, 23, and 33 days after heading (DAH). The results obtained summarized as follows. 1. Culm length was increased as N level increased, but decreased by application of paclobutrazol. Culm length was not affected by N split rates in both varieties. 2. Lodging was not occurred at all plots, but lodging index of Seomingbyeo was much greater than that of Samgangbyeo. In both varieties loding index increased up to 23 DAH due to an increase in fresh weight and a decrease in breaking strength and levelled off thereafter due to a decrease in both fresh weight and breaking strength. 3. Culm length of Seomjinbyeo and fresh weight of shoot and culm length of Samgangbyeo were positively correlated with lodging index, but breaking strength was not correlated with lodging index in both varieties during the most of ripening stages. Direct effect of culm length contributing to lodging index was positive and much greater than that of fresh weight and breaking strength in Seomjinbyeo, but in Samganbyeo direct effect of culm length and fresh weight was positive, but that of breaking strength was negative with similar magnitudes. 4. Yield in brown rice of Seomjinbyeo was not affected by N level, but split application of N increased yield. In contrast, yield of Samgangbyeo was increased as N level increased, but yield was not affected by N split rates. Paclobutrazol did not affect yield of rice in Seomjinbyeo, but decreased yield by 5.2% in Samgangbyeo due to a decrease in the number of spikelets per panicle.

• Korean Journal of Weed Science
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• v.18 no.2
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• pp.171-178
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• 1998

Growth response and acetolactate synthase(ALS) activity were examined to determine the resistance of corn cultivars to primisulfuron when primisulfuron and/ or insecticide Terbufos were applied. Pioneer 3571 IR showed resistance to primisulfuron regardless of Terbufos treatment, but Pioneer 3571 was greatly injured with primisulfuron plus Terbufos treatment. Suwon 118 was relatively tolerant to primisulfuron compared to Chalok 2, but crop injury was occurred at both cultivars by primisulfuron plus Terbufos treatment. ALS activity at Pioneer 3751 IR was very high in primisulfuron and/ or Terbufos treatment. Suwon 118 also showed higher ALS activity compared to Pioneer 3751 and Chalok 2, but ALS activities were greatly decreased by primisulfuron plus Terbufos treatment at Suwon 118 and Chalok 2. The $I_{50}$ concentration for 50% inhibition of the ALS enzyme was 10.0, 0.06, 7.75, and 0.04${\mu}M$ for Pioneer 3751 IR, Pioneer 3751, Suwon 118, and Chalok 2, respectively. Consequently, resistance of corn cultivars to primisulfuron was significantly related to ALS activity. Crop injury and lower ALS activity were recognized in susceptible corn cultivars by primisulfuron plus Terbufos treatment.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.132-143
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• 1992

The study was conducted to find out synergistic effects by interaction on the basis on anatomical changes between paddy rice and weed species by mixture use of oxyfluorfen and bensulfuron at 0, $10^{-6}$ and $10^{-4}$M, respectively. Tissues were sampled at 72 hrs after soaking treatment and prepared for light microscopic examination and sectioned longitudinally and transversely stem into $8{\mu}m$ thick. As the results of microscopic examination, the major response of treated plant involved rupture and constrict in mesophyll cells and epidermal cells, and shrinks in bundle sheath cells by oxyfluorfen and disorganization and swelling in meristems by bensulfuron. Anatomical changes in rice was the least affected by even high concentration and two herbicide mixtures, whereas Echinochloa crus-galli was severely disorganized in meristem regions and ruptured in epidermal cells by mixture use. Monochoria vaginalis was completely ruptured by any treatment concentrations and mixtures. Scirpus juncoides was considerably tolerant to both herbicides and their mixture and was similar to those that occur in rice. Perennial weed, Sagittaria pigmaea was observed vacuolation, non-nucleation of cell, and irregular cell layering but in mixture injury was slight. Cyperus serotinus was severely shrunk and ruptured by mixture treatment. Eventually anatomical variations in all weed species was shown synergistic effect by use of herbicide mixtures.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.124-131
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• 1992

Not only reducing the carry-over effects of quinclorac [3, 7-dichloro-8-quinoline carboxylic acid] used in paddy field to some following vegetable crops but also rationalizing agro-ecology conservation and farm economy, the reducing feasibility of application rates by various cropping patterns and application timing after rice seeding and transplanting. Four cropping patterns namely dry direct seeding(DDS), flooded direct seed(FDS), transplanting of 8 days old early seedlings(EST) and 25 days old machinery seedling(MST) were experimented with 7 application timings as 0, 5, 10, 15, 20, 25, 30 days after seeding/transplanting and 9 levels of application rates as 0, 75, 150, 225, 300, 375, 450, 525, and 600g ai/ha of the chemical, respectively. Within the maximum permitted limit of rice phytotoxicity, the minimum application rate of quinclorac to complete control of Echinochloa crus-galli as influenced by various cropping patterns with application timing could be evaluated as follows : A. Dry direct seeding : The minimized application rate at application timing upto 10 days after seeding (DAS) was counted 150g ai/ha, and delaying upto 15-30 DAS, the rates were increased upto 225-525g ai/ha. B. Flooded direct seeding and transplanting : The application rates were minimized 75g ai/ha at application timing upto 10 days after seeding/transplanting(DAS/T), 150g ai/haupto 15 DAS/T, and 225g ai/ha at later than 20 DAS/T, respectively.

• The Korean Journal of Archival Studies
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• no.21
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• pp.283-322
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• 2009

Legislation and enforcement of the Presidential Records Management Law was an important turning point in Korean archival management history. In the past, the notion of presidential records was vague. The law was a starting point of establishing presidential records management. The Presidential Records Management Law provides the definition of presidential records and its scope, and establishes the protection of presidential records through restricted access to the records. The key to the law is to enable a president freely to produce records and transfer them to the next administration without omission. In other words, it aims to stop the practice that presidential records are produced but never be left. But, 'disputes over the release of presidential records' and the disclosing of access-restricted presidential records presented a crisis to national records management as well as the prospect of presidential records management, even if they were 'legal procedures.' The instability of presidential records management could give a serious impact on the national records management and its operation. Amid this situation, it is required to review the presidential records management system and provide recommendations for improvement, even if the enforcement of law has just started. The most urgent things in improving presidential records management are to secure its independence, specialty, and to complement restricted access to presidential records. For securing independency, presidential records management should be done by a separate organization other than the National Archives of Korea while for promoting specialty, a newly established organization could serve as a professional archive. And for complementing restricted access to the presidential records, the access should be more limited. In other words, more discretion is needed in permitting access. And more specific regulations should be applied to the permitted records. However, these regulatory actions may not have effects unless independency is not secured. Thus, more fundamentally, independency of the National Archives of Korea should be first established.