• KOREAN JOURNAL OF CROP SCIENCE
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• v.23 no.3
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• pp.47-54
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• 1978

Weed control is an essential part in rice culture and has been practiced by hand. But the shortage of man power in rural area in recent years has brought about the use of herbicides. The effective use of herbicides in rice has contributed toward improving labor situation and maintaining rice production. The use of herbicides will extend more in the future. The only limitation of present uses of monoherbicides might be the predominant growth of a certain weeds in paddy field, and subsequent effect on ecology system. It is, therefore, wanted to develop a herbicide which will be effective on several kinds of weeds. In the weed control system, ecological and integrated weed control would be necessary in the future. To obtain the most effective weed control, studies on physiological ecotype of weeds and machanism of herbicides and their interactions will be necessary.

• Korean Journal of Weed Science
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• v.30 no.4
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• pp.396-404
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• 2010

Phenolic compounds, which are products of secondary metabolism, have been demonstrated to be widespread growth substances in plants. The objectives of this study were to identify the phenolic compounds in common ragweed (Ambrosia artemisiifolia var. elatior) by HPLC and to evaluate their effects on germination and seedling growth of three weed species. Under controlled conditions in Petri dishes at $25^{\circ}C$, $10^{-3}$ and $10^{-4}$ M solutions of phenolic compounds were evaluated in seed germination tests. Four phenolic compounds (caffeic acid, O-coumaric acid, ${\rho}$-coumaric acid and ferulic acid) in common ragweed plant were identified and their concentration was increased from the stage before flowering through full flowering stage. Treatment of O- and ${\rho}$-coumaric acids delayed the seed germination of Digitalia ciliaris, while the treatment of caffeic acid delayed the seed germination of Echinochloa crus-galli. In time to 50% germination ($T_{50}$), phenolic compounds at $10^{-4}$ M promoted in Cyperus microiria and E. crus-galli but the level of $10^{-3}$ M delayed the $T_{50}$ of those weeds. The O-coumaric acid inhibited seed germination and seedling growth of the tested weeds and especially it perfectly inhibited the root growth of E. crus-galli.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.1-7
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• 2013

Studies were carried out to provide basic information for establishing the weed control in Chungbuk, Korea. The present surveys targeting 260 farmers in Chungbuk province were conducted for the cultivation system, weeds occurrence and usage of herbicides. To estimate the occurring area of herbicide resistant weeds, soil samples from 400 paddy fields were collected twice on August, 2011 and April, 2012. In the results of survey, the 99.6% of farmers used the rice planting machine and the 78% of the farmers disseminated herbicides twice to control weeds before and after planting rice. The most commonly used herbicide were as follows; soil-applied herbicide : butachlor 46.6%, mid-term herbicide : mefenacet + pyrazosulfuron-ethyl 10.7%, foliar herbicides : bentazone 62%. The dominant paddy field weeds included Echinochloa crusgalli (16.2%), Scirpus juncoides (12.2%), Monochoria vaginalis (11.9%) and Sagittaria trifolia (9.5%). Occurrence area of sulfonylurea herbicide resistant weeds was 13,659 ha in 26.8% of the paddy area. Monochoria vaginalis showed the highest with 4,605 ha (36.4%) followed Scirpus juncoides (30.7%), and Lindernia dubia (10.6%) at 2011. Monochoria vaginalis and Scirpus juncoides occurred were evenly distributed and the most problematic weed in Chungbuk, Korea.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.66 no.4
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• pp.459-466
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• 2021

The present study was conducted to propose future research directions for weed management by examining the current trends of research on weed occurrence according to cropping systems. The cropping systems are developed for the efficient use of arable land, and the weed flora changes according to the management practices of a given cropping system. In particular, weed occurrence can be reduced by altering the soil environment. In addition, cultivation methods, such as tillage, affect the weed seed bank in the soil, thus altering the pattern of weed occurrence. Here, we propose three weed management practices according to the cropping system. First, it is necessary to develop a model that can classify weed species by analyzing young seedlings and can predict the flora in the field. Second, it is important to manage the cropping system history and establish a database of agricultural information, which can be linked to meteorological and geographic data. Third, it is critical to estimate the weed occurrence and soil seed bank dynamics, based on which a cropping system platform and digitalization technology can be developed. In the future, the prediction of weed occurrence and control according to the cropping system will contribute to sustainable agriculture by reducing the use of herbicides and solving the problems of resistant weeds.

• Weed & Turfgrass Science
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• v.6 no.1
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• pp.21-27
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• 2017

This study was investigated in order to occurrence of weed flora in orchard (apple, grape, peach, pear etc.) fields and to the establishment of weed control basic data in these weeds. And this study was survey on 2015. As a result of the study on orchard weeds, there were total of 492 weeds including 63 families. Among all the weeds, 159 species were annual, 97 species were winter annual and 236 were perennial. Each fruit tree patterns of occurrence weeds, 306 species 50 families in apple orchard, 304 species 50 families in pear orchard, 286 species 50 families in grape orchard, and 288 species 48 families in peach orchard. Dominance was the highest with Digitaria ciliaris followed by Artemisia princeps, Stellaria aquatica, Commelina communis, Acalypha australis etc. in order. And exotics weeds occurred 127 species. Trifolium repens was the highest in importance analysis and the followings were in order of Conyza canadensis, Chenopodium album, Taraxacum offcinale, Rumex crispus etc. Changes in weed vegetation in orchard during 30 years, did not very many changed. In 1990, D. ciliaris, Persicaria hydropiper, Portulaca loeracea were dominant. In 2003, D. ciliaris was the most abundant species, followed by A. australis, A. princeps species. And in 2015, also D. ciliaris was the most dominant, followed by A. princeps, S. aquatica.

• The Bimonthly Magazine for Agrochemicals and Plant Protection
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• v.12 no.5 s.104
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• pp.80-86
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• 1991

임업에서 육림(育林)은 기르고자 하는 수종과 경쟁하는 잡초목과의 싸움이라고 할 수 있다. 대개 가치있는 수종은 초기생장이 느리고, 제거 대상이 되는 잡초나 관목및 활엽수의 맹아등은 초기 생장속도가 아주 빠르고 생존력이 강하기 때문에 방치하는 경우 조림목은 피압되어 고사하게 된다. 현재 여러가지 사회적인 여건에 의하여 인력작업이 어려운 시점에서 제초제의 활용은 이러한 문제를 해결할 수 있는 가장 효과적인 방법이라고 할 수 있다. 그러나 제초제의 사용은 세심한 주의가 필요하다. 제초제의 잘못 사용은 효율적인 작업성과를 얻지 못할 뿐만 아니라 오히려 기르고자 하는 나무를 손상할 수 있으며 대면적에 대한 과다한 사용은 산지의 황폐나 또는 자연생태계에 큰 영향을 줄수도 있다. 이러한 점에서 앞으로 제초제의 산지 적용에 대한 폭넓은 연구와 검토가 이루어져야 하겠다. 또한 여기서 소개하는 몇가지 제초제에 대하여도 사용할 때는 약제의 특성에 대한 충분한 지식을 가지고 대상지의 식생이나 입지조건에 대한 면밀한 조사가 이루어진 후에 사용하여야 할 것이다.

• Korean Journal of Weed Science
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• v.30 no.2
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• pp.59-67
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• 2010

The distribution of exotic weeds in 4 island area such as Baengnyeong-do, Heuksan-do, Chuja-do, and Geomun-do in Korea was investigated. Baengnyeong-do, Heuksan-do, Chuja-do, and Geomun-do have different weed flora, 41 species included 13 families, 32 species included 11 families, 23 species included 9 families and 30 species included 12 families were observed in the 4 islands, respectively. 18 families 70 species were occurred in 4 island. Most troublesome exotic weeds were Ambrosia artemisiifolia var. elatior, Solanum carolinense, Cuscuta pentagona. Occurrence frequency of Conyza canadensis, Erigeron annuus, Dactylis glomerata, Bromus catharticus and Lolium multiflorum were the highest in each island, respectively. Also, result of divided life cycle, annual weeds were 28 species occupied 40% in total, biennial weeds were 21 species (30%) and perennial weeds were 21 species (30%).

• Korean Journal of Weed Science
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• v.31 no.1
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• pp.1-7
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• 2011

It was a method of weed removing, called as whagyeongsoonoobeob. Namely, the Hwanoobeob was the weeding method came from "Jeminyosool" in old China, and had been descended to "Wibinmyeongnonggi", "Nonggajibseong" and "Gwanongsocho" in the $16\sim18^{th}$ century of our country. The method was applied to rice paddy after applying direct-seeding, burning by unit before watering to remove weeds and to save rice plants. It would be applied with a method of using non-selective herbicide such as paraquat and oxyfluorfen, or radiation treatment, as a simple and safe weed removing method.

• Weed & Turfgrass Science
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• v.2 no.1
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• pp.38-46
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• 2013

With increasing environmental issues from synthetic chemical herbicides, microbe-originated herbicides could be a fascinating alternative in current agriculture. We isolated Streptomyces strains that produced herbicidal active metabolite(s) against a grass weed Digitaria sanguinalis. According to the result from 16S rDNA sequence comparison with the close strains, the best isolate (Code name MS-80673) was identified as Streptomyces scopuliridis KR-001. The closest type strain was Streptomyces scopuliridis RB72 which was previously reported as a bacteriocin producer. The optimal culture condition of S. scopuliridis KR-001 was $28^{\circ}C$, pH 7.0 and culture period 4 to7 days. Both of soil and foliar application of the crude culture broth concentrate was effective on several troublesome or noxious weed species such as a Sciyos angulatus in a greenhouse and field condition. Phytotoxic symptoms of the culture broth concentrate of S. scopuliridis KR-001 by foliar application were wilting and burndown of leaves, and stems followed by discoloration and finally plant death. In crops such as rice, wheat, barley, hot pepper and tomato, growth inhibition was observed. These results suggest that the new S. scopuliridis KR-001 strain producing herbicidal metabolites may be a new bio-herbicide candidate and/or may provide a new lead molecule for a more efficient herbicide.

• Agrochemical news magazine
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• v.24 no.7 s.190
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• pp.10-13
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• 2003