• 한국유기농업학회지
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• 제19권spc호
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• pp.295-297
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• 2011

Weed control is the most important issue in organic farming systems that limit crop growth and their yield. Field experiments were conducted in organic soybean (Glycine max Merrill) to evaluate the weed suppression effects of salt and seawater treatment. Weed population and fresh weight were monitored after 6 weeks of salt and seawater treatments. The most important weeds were Digitaria sanguinalis, Portulaca oleracea, Tradescantia reflexa and Chenopodium album var. centrorubrum, but also 6 other species were observed in soybean arable field. Soybean crops under seawater or their solids application were well grown. The results treated with salts and seawater indicate decreases by 13.4~30.8% in weed density and by 18.0~43.2% in their fresh weight and soil hardness increases of up to 2.1-fold. Salt and seawater provided good additional weed control, but they were caused a serious problem in deterioration of soil physical properties.

• Weed & Turfgrass Science
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• 제7권2호
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• pp.111-119
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• 2018

본 연구는 다양한 온도, 파종심도, 차광 및 토양수분함량 조건 하에서 둥근잎유홍초의 발아와 생육에 차이를 구명하여 효과적인 관리방법을 개발하는데 필요한 기초 자료로 사용하고자 수행하였다. 둥근잎유홍초 종자휴면은 1년 이상이었고, 휴면타파를 위해서는 황산에 15분 침지하는 것 가장 좋았다. 둥근잎유홍초 종자의 발아율은 $25-35^{\circ}C$에서 69-73%, $15^{\circ}C$에서 26%를 보였다. 파종 심도별 발아율은 2, 3, 5, 7, 8 cm 파종깊이에서 70-84%이었으나 12 cm와 15 cm 파종깊이에서는 각각 7%와 13%에 불과하였다. 둥근잎유홍초 종자는 무차광과 차광 정도와 상관없이 높은 발아율을 보였으나, 지상부 생체중은 차광 20%>무차광=차광 35%>차광 50%>차광 75%=차광90% 순으로 높았다. 토양수분은 포화상태의 30%와 100%조건에서는 둥근잎유홍초 종자는 발아하지 않았고, 포화상태의 60%와 80%에서 60-83%의 발아율과 최적의 생장을 보였다.

• The Korean Journal of Ecology
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• 제18권4호
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• pp.471-481
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• 1995

The weed population dynamics as affected by contrasting conventional tillege (CT) and no-tillage (NT) practices with a minimum herbicide application was studied in Athens, Georgia, U.S.A. Common chickweed (Stellaria media) was the most common spring weed while johnsongrass (Sorghum halepense), sicklepod (Cassia obtusifolia), and pigweed (Amaranthus retroflexus) accounted for 89∼97％ of net production during summers of 1983 and 1984. Total weed production in summer of 1984 was 2∼5 times greater than that of 1983. Weed production was greater in NT plots than in CT plots in summer of 1983, but reverse was the case in summer of 1984. In spring, net production in NT plots was greater than that in CT plots, especially, in 1985. Species diversity was consistently higher in NT plots, but in the wet summer of 1984 the pattern was different, with higher diversity in CT plots. Weed species diversity was higher in the spring rye crop than in the summer grain sorghum crop. The larger but less diverse weed populations in summer of 1984 indicated that these populations experienced competitive exclusion. Under the favorable summer moisture conditions the three dominant species grew so vigorously and quickly as to exclude many less common species that were able to survive under the drier conditions in 1983. The three dominant species not only excluded other weeds in 1984 but also greatly reduced crop production. The perennial johnsongrass was equally successful, or even more so, in CT plots as in NT plots. Plowing did not kill johnsongrass rhizomes but tended to break them up, thus increasing the number of individual plants that appear after the plowing. It means that johnsongrass was not controlled by the plowing. In summer of 1983, a moderate amount of weedy growth was maintained with a minimum amount of gerbicide application in NT and CT plots. It is possible that a small mixed weed population would be beneficial by providing cover for predatory and parasitic arthropods, and by reducing soil temperature and moisture losses.

• 한국작물학회지
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• 제21권2호
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• pp.269-276
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• 1976

This experiment was conducted to find out how to increase efficiency of fertilizer nitrogen and how to change the weed population with different methods of nitrogen application. Mudball deep placement, at 10-12cm soil depth, produced significantly the highest grain yield within the application methods with same amount of nitrogen (60kg N/ha). It produced also same grain yield with conventional application methods, timely split application method, with 90kg N/ha. Basal application of nitrogen increased weed population and it showed higher dry weight of weed than top dressing methods at early growth stage of rice.

• 한국작물학회지
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• 제44권3호
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• pp.221-224
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• 1999

A field experiment was carried out to observe the weed control effects of vetch and to evaluate vetch characteristics on clay loam soil in no-till direct-sown rice-vetch cropping systems. The effects of weed control, forage productivity, and N content of vetch plants were investigated. With the progress of plant growth, density of Chinese milk vetch (Astragalus sinicus L.) gradually decreased, but densities of foxtail and other weeds decreased steeply due to the depression by the over-shaded vetch canopy in a no-till direct-sown rice-vetch cropping paddy field. The vetch density in tillage systems was lower than in notillage cropping systems. Lower vetch density occurred with an increase in foxtail density and other weeds. Weed control effect increased by the progress of vetch growth, which indicated that the vetch canopy over-shaded the weeds. Vetch straw was degraded rapidly submergence after with water at the time of wet sowing of rice. Early harvesting of vetch seed resulted in lower seed germination. To acquire enough seedlings without re-sowing, the harvesting of seed should be delayed at least 28 days after the flowering stage in order to ensure the vetch population is sustainable in a no-till direct-sown rice-vetch cropping system. In order to improve the survival of vetch plants, vetch seeds should germinate from the heading .stage to before the full-ripening stage of rice plants. To enhance the percent of over-wintering survival, vetch seeds should germinate no later than the end of October in southern Korea. The dry weight of vetch plants increased with the progress of vetch growth until the flowering stage but N content decreased for 30 days from before the flowering stage (2.9%) until the ripening stage (1.8%). We concluded that Chinese milk vetch could have an effect on weed control before the flowering stage, sustainability without re-sowing of seed annually, and effective green manure for rice pre-crop in no-till direct-sown rice-vetch relay cropping systems.

• 한국작물학회지
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• 제52권2호
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• pp.169-175
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• 2007

본 실험은 강원도 영서지역에서 맥류 수확 후 가을채소 파종까지 휴경을 하게 될 경우의 여름 휴경지 관리방안으로 가을채소용 두과녹비작물의 도입에 필요한 기초 자료를 얻기 위하여 수행되었으며, 그 결과는 다음과 같았다. 1. 여름철 휴경을 할 경우 주요 잡초는 바랭이, 방동사니, 쇠비름 그리고 털비름 등 비두과 식물로, 자연적인 두과식물의 출현은 없었다. 2. 두과식물을 6월 중순 로타리 경운 후 파종할 경우 동부와 예팥은 출현율이 높았으나, 돌콩과 헤어리벳치는 출현율이 낮았으며, 동계일년생 두과녹비작물인 헤어리벳치는 하계잡초와의 경합에서 도태되는 경향이었다. 3. 만성형식물인 동부는 잡초의 생육을 가장 크게 억제하였으며, 만성 예팥이나 돌콩, 그리고 헤어리벳치보다 생육량이 많았다. 따라서 우리나라 기상조건에서 여름철 휴경을 할 경우 두과식물의 인위적인 파종이 필요하며, 동부는 여름철 휴경지의 녹비작물로서의 이용 가치가 높은 것으로 판단되었다.

• 한국환경과학회지
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• 제27권9호
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• pp.771-780
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• 2018

To develope a microbial weed control agent, HCN-producing bacteria were isolated, and their characteristics were investigated. A selected strain of WA15 was identified as Pseudomonas koreensis by morphological, cultural, biochemical and 16S rRNA gene analyses. The conditions for HCN production was investigated by a One-Variable-at-a-Time (OVT) method. The optimal HCN production conditions were tryptone 1%, glycine 0.06%, NaCl 1%, and an initial pH and temperature of 5.0 and $30^{\circ}C$, respectively. The major component for HCN production was glycine. Under optimal conditions, HCN production was about 3 times higher than that of the basal medium. The WA15 strain had physiological activities, such as indoleacetic acid that was associated with the elongation of plant roots and siderophore and ammonification inhibiting fungal growth, and produced hydrolytic enzymes, such as cellulase, pectinase and lipase. The strain was able to inhibit the growth of phytopathogenic fungi, such as Rhizoctonia solani, Botrytis cinerea and Fusarium oxysporum, by the synergistic action of volatile HCN and diffusible antimicrobial compounds. A microscopic observation of R. solani that was teated with the WA15 strain showed morphological abnormalities of fungal mycelia, which could explain the role of the antimicrobial metabolites that were produced by the WA15 strain. The volatile HCN produced by the WA15 strain was also found to have insecticidal activity against termites. Our results indicate that Pseudomonas koreensis WA15 can be applied as a microbial agent for weed control and also as a termite repellent. Furthermore, it could be applied as a microbial termiticidal agent to replace synthetic insecticides.

• 한국잡초학회지
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• 제17권4호
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• pp.375-381
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• 1997

볏단이 있던 곳이나 콤바인 수확한 볏짚이 피복된 곳은 잡초 발생인 생육이 감소하는 현상이 관찰되고 있다. 이는 볏짚에 함유한 allelopathic 물질에 의한 것으로 추정되어 볏짚을 80% 메칠알콜로 추출후 둑새풀로 생물검정, 10종의 표준 유기산이 둑새풀의 생육과 발아에 미치는 영향, 볏짚추출물을 silicagel column 으로 분획후 HPLC, GC/MS로 분석한 결과는 아래와 같았다. 1. HPLC분석에 의하여 볏짚에는 fumaric acid와 4종류의 미확인 유기산이 확인되었다. 2. fumaric acid를 포함한 7종의 유기산은 $10^{-2}$의 농도에서 둑새풀의 생육을 상당히 억제하였고 특히 발아를 100-90% 억제시켰다. 3. 볏짚에 함유한 물질중 억제효과가 가장 큰 것은 GC/MS분석에 의하여 II-4-4Rf 0.5에 함유한 물질로 분자량 253인 치환된 유기산인 신물질로 Octadecanoic acid, 2-oxo-, methyl ester에서 methyl ester가 유리된 물질로 추정되었다.

• 한국작물학회지
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• 제40권6호
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• pp.738-746
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• 1995

인공안개처리에 따른 보리의 생장, 잡초경합양상 및 제초제반을을 검토코자 온실내에서 일련의 pot시험이 수행되었다. 안개조건에서 보리의 초장, 엽령, 엽폭 및 지상부 생체중은 증가하였으나 출수가 지연되고 출수율과 수량 구성요소인 수당영화수, 천립중 및 발아율은 감소하였다. 안개조건으로 초종수의 차이는 없으나 잡초발생량은 유의적으로 증가하였고, 주요한 발생초종은 둑새풀, 새포아풀, 벼룩나물, 점나도나물, 황새냉이 및 갈퀴덩쿨등이었다. 안개조건에서는잡초와의 경합기간이 길수록 초장의 감소가 인정되었으며 1,000립중은 초기경합에서만 감소하였으며 그밖의 보리의 생장은 경합의 영향을 받지 않았다. 안개조건에서 제초제처리에 따른 보리의 생체중은 공시 제초제 공히 증가되었으나 1,000립중은 오히려 감소되었으며, 그 중 Butachlor 및 Thiobencarb의 약해가 상대적으로 크게 나타났다. 처리 후 25일째 생체중에 의한 잡초방제가는 75∼90%로써 안개조건이 비안개조건보다 3∼15% 낮게 나타났으나 60일째는 96%이상으로 대등한 방제가를 보였다.

• 한국자원식물학회지
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• 제24권2호
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• pp.260-266
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• 2011

잔디 실생묘를 이식하여 조성된 잔디밭에서 초봄의 생육 초기에 많은 피해를 주고 있는 월년생(동생) 잡초를 방제하고자 예초실험을 실시한 결과 요지는 다음과 같다. (1) 전체 예초 시험구별 잡초발생율은 평균 17.9%였다. (2) 저 예초 시험구인 12.5 mm 구에서 잡초발생율은 24.7%로 높게 나타나, 4개의 예초 시험구 가운데 잡초억제효과가 가장 낮은 것으로 나타났다. (3) 22.5 mm 구에서는 10.6%의 잡초발생율을 보여 가장 높은 잡초억제효과를 나타내고 있다. (4) 고 예초 시험구인 32.5 mm 구와 42.5 mm 구에선 각각 평균보다 다소 높은 18.2%와 18.3%의 잡초발생율을 나타냈다.