• 한국잡초학회지
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• 제12권3호
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• pp.230-260
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• 1992

The paper was reviewed the research results on weed dynamics and effective control methods in direct-seeded rice crop. Direct seeding method resulted in drastic increment of weed growth compared to transplanting method and also changed in troublesome weed flora. Two to three fold more weeds were harvested at the direct seeded rice and weed flora of dominant species shifted toward $C_4$type grass weeds. Some of the important troublesome weeds in direct seeded rice were Echinochloa crus-galle, Oryza saliva ssp spontanea, Leptochloa chinensis. Setaria viridus. Digitaria adsendens, Sesbania exaltata, Aeschynomene indica, Algae, etc. Yield loss due to weed competiton was about 40-60% for water-seeded and about 70-100% for dry-seeded rice while these for transplanted rice were about 25-35% for mechanical transplanting and about 10-20% for manual transplanting, respectively. Integrated weed management concept was neede to approach weed control effectively. Several cultural technologies were very effective to suppress the weed growth. These were tillage operation, water management, seeding date and seeding rate. Crop residues of barley, rice, wheat, oat and italian ryegrass were also effectivly suppressed the paddy weeds particularly to Potamogeton distiuctus, a perennial broadleaf weed. A pathogen of Epicoccosorus nematosporus identified from Eleocharis kuroguwai was an excellent potential bioagent to control the most troublesome perennial sedge weed of E. Kuroguwai without arising any detrimental effect. The herbicidal efficacy of this pathogen was as high as bentazon herbicide. Plant growth regulator of paclobutrazol (pp-333) was another possible alternative to reduce the herbicide use. In current, herbicide exhibited the most conspicuous results to control weeds in direct-seeded rice even though the application technologies were not fully established. Recommendations for herbicide application were suggested for in both water-and dry-seeded rice in USA, Japan and Korea, respectively. To make better and comprehensive recommendations further studies on weed ecology and herbicide development were emphasized.

• 한국작물학회지
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• 제50권2호
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• pp.79-83
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• 2005

Rice and weed interference in the paddy field caused by resource competition and allelopathy. Evaluation method of active weed suppressive behavior of rice to weed was developed by eliminating light competition at soil condition. Twenty eight days old rice seedlings (6-7 leaf stage) which was grown at saturated, no drainage pot were clipped above $3\~4cm$ from the soil surface. Weeds seeded around clipped rice stem, named ratoon seeding screening method, showed varietal suppressive difference to Echinochloa crus-galli, Echinochloa crusgalli var. praticola and Monochoria vaginalis. Potential allelopathic rice varieties, Sathi, AC1423 and PI312777 showed better suppressive activity to weed seedling growth than Nonganbyeo and Keumobyeo. Weed suppression of one plant of rice cultivars could be evaluated by the cell size of $2.5\times2.5cm$ at rice clipping of seedling 29 days after rice seeding.

• 한국유기농업학회지
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• 제19권spc호
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• pp.119-122
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• 2011

Among the developed bio-degradable polymer films as compared with transparent film(White), black polymer film was significantly more effective for controlling weeds in red pepper. Also, we found that white and black polymer mulching had 81.8% and 97.9% of managing weed controlling effects in rice, respectively. Compared to non-mulched rice paddy with water supply, the non-mulched rice paddy without any water supply has stopped its growth at 41 days after transplanting, while polymer-mulched rice paddy without water supply had about 60% of normally growing rice plants. This shows the polymer treatment has a remarkable effect on water and power saving, solution of herbicidal resistance, avoidance of herbicidal influence to eco-system etc. When the naturally decomposing polymer was used, a temperature was elevated as high as $4.7^{\circ}C$ on maximum and $2.6^{\circ}C$ on average. Also the naturally decomposing polymer accelerated rooting by 7 days and lowered a stress level from transplanting. The weed control effect mulched by polymer was remarkable as 98.7%. The polymer now, after 294 days treated on the rice paddy, has been completely decomposed.

• 한국잡초학회지
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• 제32권1호
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• pp.10-16
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• 2012

이 연구는 비타민 A 강화벼(GM 벼)와 모품종인 낙동 및 일반품종을 대조로 농업적인 생육특성과 잡초를 대상으로 유전자 전이 정도를 조사하였다. GM 벼의 농업적인 특성에서 모품종인 낙동과 차이를 보이지 않았으며, 우점 잡초군과 건물중에서 유의성이 보이지 않았다. GM 벼와 모품종인 낙동 재배구의 우점 잡초는 물달개비, 올방개, 좀개구리밥, 물피 등의 10여 종이었다. 잡초의 유전자 전이 정도를 PCR 분석 결과, GM 벼와 낙동 그리고 우점잡초 8종에서 유전자 전이가 나타나지 않았다. 그러므로 비타민 A 강화벼의 화분이 비래하여 비표적 다른 품종의 벼 또는 주변 잡초에 유전자 이동이 일어나 외래유전자가 함유된 잡초가 출현하는 경우는 거의 없을 것으로 사료된다.

• 농업과학연구
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• 제42권2호
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• pp.111-116
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• 2015

Combined applications of rice bran with pine leaves were tested to examine the inhibitory effects to paddy weeds and increased yield of rice for developing techniques of environment-friendly weed management in paddy rice fields. Weed control efficacy at 60 days after treatment was improved to 88.8% by combined application of rice bran with pine leaves, while weed control efficacy by single application of rice bran showed 67.5%. The other weed control efficacy combined with chestnut leaves and barley straws were 76.3% and 69.9% respectively. Combined application of rice bran with pine leaves was more effective to broadleaf weeds such as Monochoria vaginalis. Weed control efficacy by combined application with pine leaves was 100% until 70 days after rice transplanting and maintained weed control effect up to 90 days after transplanting. Rice yield by combined application of rice bran with pine leaves was 526 kg/10 a, which was higher yield than by combined application with barley straws, single application of rice bran, natural snail application and hand weeding.

• Journal of Crop Science and Biotechnology
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• 제10권2호
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• pp.79-85
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• 2007

Rice bran application just after transplanting has been increasingly practiced as an herbicide-substitute for organic rice production in Korea. However, this practice is frequently reported to be unsatisfactory in weed suppression. An experiment with five treatments that combines flooding depth, rice bran application dose, and herbicide treatment was done in the paddy field to evaluate whether rice bran application under deep flooding can lead to a successful weed control in compensation for the single practice of rice bran application. Rice bran was broadcasted on the flood water surface just after deep flooding of 8 to 10cm that was started at seven days after transplanting. In the shallow flooding plot without herbicide six weed species were recorded: Monochoria vaginalis, Echinochloa crus-galli, Ludvigia prostrate, Cyperus amuricus, Aneima keisak, and Bidens tripartite. Among the first four dominant weed species, deep flooding significantly suppressed the occurrence of Echinochloa crus-galli and Cyperus amuricus while did not suppress the occurrence of Monochoria vaginalis and Ludwigia prostrate. On the contrary, rice bran application under deep flooding suppressed significantly Monochoria vaginalis and Ludwigia prostrate while didn't exert an additional suppression of Echinochloa crus-galli and Cyperus amuricus compared to deep flooding alone. Rice bran application and deep flooding suppressed complimentarily all the six weed species to a satisfactory extent except for Monochoria vaginalis of which suppression efficacy was 31.9%. Deep flooding reduced the panicle number substantially by inhibiting the tiller production, increased the spikelet number per panicle slightly, and leaded to a lower rice grain yield compared to shallow flooding with herbicide. Rice bran application under deep flooding mitigated the panicle reduction due to deep flooding, increased the spikelets per panicle significantly, and thus produced even higher grain yield in the rice bran application of 2000kg $ha^{-1}$ as compared to the shallow flooding treatment with herbicide. In conclusion, this practice applying rice bran under deep flooding would be promising to be incorporated as an integral practice for an organic rice farming system.

• 한국잡초학회지
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• 제15권4호
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• pp.305-312
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• 1995

벼-콩 답전윤환재배지에서의 잡초발생동태를 구명하기 위하여 수행하였던 결과를 요약하면 다음과 같다. 1. 벼 건답직파재배지에서는 피의 우점현상이 두드러졌으며, 연작에 의해서 계속 증가하는 경향이었고, 콩재배지에서는 피, 좀명아주 및 (좀)바랭이가 문제잡초로 제기되었다. 2. 벼 건답직파재배에서 콩 재배로 또는 콩재배에서 벼 건답직파재배로 답전윤환(畓田輪換)을 함으로써 잡초의 발생량을 크게 감소시킬 수 있었으며, 너도방동사니, 올방개, 올챙이고랭이, 벗풀 및 수생잡초의 발생이 크게 억제되는 경향이었다. 3. 답전윤환재배시(畓田輪換栽培時) 동일 작물을 2년 이상 연속재배(連續我培)하면 잡초의 발생량이 크게 증가하였다.

• 한국작물학회지
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• 제48권1호
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• pp.1-7
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• 2003

In spite water direct seeding cultivation of rice has advantages in terms of laborsaving and cost-down, it demonstrates uneven seedling establishment and difficult weed management. To select an applicable mat for mulching system of water seeded rice, weed occurrence, growth and yield performances of rice, and soil temperature were evaluated in several kinds of biodegradable mulching material. Field studies were conducted at the experimental farm of National Crop Experiment Station in 1999 and 2000. Among the mats tested in 1999, Safer-mat had the greatest effect on inhibiting weed occurrence and Lawn-mat demonstrated the least efficacy of weed control (EWC) value. In Safer-mat treatment, Ludwigia prostrata was the dominant weed species but Echinochloa crus-galli was not observed. Different kinds of mulching material from the mats studied in 1999 were tested in 2000. Biodegradable polyester (PES) coated on the recycled paper for newspaper press (RP) treatments showed similar or higher EWC values than non-mulched broadcast seed rice with 2 times of herbicide application (BC-herbicide) and Safer-mat that was the most effective mat on preventing weed appearance in 1999. Immediately after mat mulching on the surface of paddy soil, five pregerminated rice seeds were manually sown in each 3cm-hole formerly punctured at 30${\times}$14 cm spacing in 2000. All the 3 kinds of mulching material tested in 2000 had better seedling stand than BC-herbicide treatment. Rice yield in PES coated with 10 thickness on RP (PES10 $\mu\textrm{m}$＋RP) was a little higher than in BC-herbicide treatment but the former produced less panicles in unit land area than the latter. PES10 $\mu\textrm{m}$＋RP demonstrated a great effect on raising soil surface temperature than non-mulching treatment throughout the period of seedling establishment.

• Journal of Biosystems Engineering
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• 제31권1호
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• pp.59-64
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• 2006

Application of herbicide for rice cropping is inevitable but notorious for its side effect of environmental pollution. Precision fanning will be one of important tools for the least input and sustainable fanning and could be achieved by implementation of the variable rating technology. If a device to detect weeds in rice field is available, herbicide could be applied only to the places where it is needed by the manner of the variable rating technology. The study was carried out to develop an algorithm of image processing to detect weeds in rice field using a machine vision system of multi-spectral digital images. A series of multi-spectral rice field picture of 560, 680 and 800 nm of center wavelengths were acquired from the 27th day to the 39th day after transplanting in the ineffective tillering stage of a rice growing period. A discrimination model to distinguish pixels of weeds from those of rice plant and weed image was developed. The model was proved as having accuracies of 83.6% and 58.9% for identifying the rice plant and the weed, respectively. The model was used in the algorithm to differentiate weed images from mingled images of rice plant and weed in a frame of rice field picture. The developed algorithm was tested with the acquired rice field pictures and resulted that 82.7%, 11.9% and 5.4% of weeds in the pictures were noted as the correctly detected, the undetected and the misclassified as rice, respectively, and 81.9% and 18.0% of rice plants in the pictures were marked as the correctly detected and the misclassified as weed, respectively.

• 한국잡초학회지
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• 제18권1호
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• pp.12-19
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• 1998

벼 직파재배시 가장 문제가 되고 있는 잡초 방제법을 확립하고자 농가답 잡초분포조사, 벼 직파재배 유형에 따르는 잡초발생 및 건답직파재배에서 파종기 이동에 따른 우점초종, 무제초시 재배유형별 수량감소 정도 등을 어린모 기계이앙재배와 비교분석하였다. 1. 벼 직파재배 농가답의 주요 우점잡초는 피, 바랭이, 너도방동산이, 여귀바늘 등으로 피는 44%로서 가장 많이 발생되었으나 Simpson 우점지수는 0.185로서 낮아 여러 초종이 다양하게 분포된 결과를 보였다. 2. 건답직파에서는 피 > 알방동산이 > 너도방동산이 > 여뀌바늘, 담수직파답에서는 피 > 올방개 > 올챙이고랭이 > 물달개비 순으로 우점되어 벼 직파재배시에는 피가 공통적으로 우점초종이었다. 3. 벼 재배유형별 건물중으로 나타낸 잡초발생량은 건답직파답에서 1,074g/$m^2$로 가장 많이 발생되었으며, 담수직파답에서는 723g/$m^2$으로 어린모이앙답의 218g/$m^2$ 보다 각각 3.3~5배 정도 더 많았다. 4. 무제초시 잡초발생에 따른 벼의 수량감소는 건답직파답에서 96%로 거의 수확량이 전무한 상태였으며 담수직파답에서는 61%, 그리고 어린모이앙답에서는 40% 감수되었다.