• 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.

• Weed & Turfgrass Science
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• 제6권4호
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• pp.345-349
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• 2017

Herbicides are important weed control tools for increasing crop yields and the efficiency of crop production. As the use of herbicides increases, the occurrrence of herbicide-resistant weeds has been an increaing problem. In Korea, since the first occurrence of acetolactate synthase (ALS) inhibitor resistant Monochoria korsakowii was reported in the Seosan reclaimed paddy field in 1998, resistance has been reported in 14 weed species, including Echinochola spp. and their populations are gradually increasing. The objective of this study is to investigate the nationwide occurrence of ALS and Acetyl-CoA Carboylase inhibitor resistant Echinochloa spp. in Korea. In 2013, 2014, and 2015, we collected 594 accessions of Echinochloa spp. in Korean rice fields except for Jeonnam and Chungbuk provinces. They were then treated with the recommended rates of penoxsulam and cyhalofop-butyl. We harvested seeds from 45 accessions of E. oryzicola in the case of cyhalofop-butyl treatment. Also, 44 and 46 accessions of E. oryzicola and E. crus-galli survived and their seeds were harvested after penoxsulam treatment. Twenty accessions of E. oryzicola survived from both herbicides inferring possible multiple resistance. Two accessions out of 20 inferred from possible multiple resistance survived after cyhalofop-butyl treatment at a dose of $500ga.i.ha^{-1}$. Seeds of herbicide resistant populations will be provided and utilized for further research.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.357-357
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• 2017

The combined application of oil cake and rice bran into the soil surface was found useful for weed control in our previous pot study. The present study was undertaken to evaluate the performance of white clover (Trifolium repens L.) while incorporated in the paddy field and effects of combined fertilizer on weed control and rice yield. A plot was divided into two parts i.e. white clover incorporated and not incorporated. The nitrogen content of the incorporated white clover was $12.5gm^{-2}$. Chemical fertilizer and combined fertilizer plots were compared with non-fertilizer conditions. The mixed ratio of combined fertilizer was oil cake 1.35 and rice bran 1.0. Combined fertilizer was applied to the soil surface, and chemical fertilizer was mixed in the soil. Nitrogen application rate was $8gm^{-2}$ for any fertilizer. The weed numbers were significantly reduced in the white clover plot irrespective of application condition both at heading and harvest time. Also, weed control ability was improved by the use of combined fertilizer. In the not incorporated plot, the number of weeds was suppressed about 90% by applying combined fertilizer. The rice yield was markedly increased by the incorporation with white clover under all fertilization conditions. Contribution rates of increased rice yield by white clover and combined fertilizer were about 55% and about 25%, respectively. The rice yield was increased by the incorporation with white clover, and the number of weeds remarkably decreased as well. Also, these effects were improved due to combined application of oil cake and rice bran.

• 한국잡초학회지
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• 제10권4호
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• pp.305-311
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• 1990

잡초종자(雜草種子) 발아(發芽)에 미치는 광(光)의 영향(影響)을 구명(究明)하기 위하여 왕바랭이, 냉이, 털비름, 개비름, 쇠비름, 명아주, 까마중, 강아지풀, 바랭이를 공시(供試)하여 시험(試驗)을 수행(遂行)하였다. 1. 대부분의 공시잡종(供試草種)은 $25^{\circ}C$ 이상(以上)에서 강(强)한 광발아성(光發芽性)을 보였으며 낮은 온도하(溫度下)에서는 발아(發芽)가 저조(低調)하였다. 그러나 피, 강아지풀, 바랭이는 대체적으로 발아율(發芽率)이 떨어진 반면, 털비름, 개비름, 쇠비름은 높은 발아율(發芽率)을 유지(維持)하였다. 2 개비름, 쇠비름, 털비름은 적색광하(赤色光下)에서 발아(發芽)가 촉지(促進)되었으며 원적색광(遠赤色光)에서는 발아(發芽)가 현저히 억제(抑制)되었다.3. 털비름, 개비름, 쇠비름은 red/far-red 광(光)에 의한 가역반응(可逆反應)을 나타내는 것으로 보아 종자발아시(種子發芽時) Phytochrome이 관여하고 있음을 알 수 있었고 피, 왕바랭이는 적색광(赤色光) 및 자색광(白色光)과 청색광(靑色光) 연속조사하(連續照射下)에 관여하는청색광(靑色光) 색소(色素) (HIR 색소(色素))가 관여하는 것으로 추정(推定)되었다.

• 한국잡초학회지
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• 제10권2호
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• pp.67-74
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• 1990

1989년(年)9월(月) 낙농강유역(洛東江流域) 38지점(地點)에서 총(總) 29과(科) 102종(種)의 잡초(雜草)가 조사(調査)되었다. 그 가운데 일년생(一年生) 광엽잡초(廣葉雜草)가 54%, 다년생(多年生) 광엽잡초(廣葉雜草)가 21%로 광엽잡초(廣葉雜草)가 전체(全體)의 72%를 점유(占有)하였다. 2차원적(次元的) 분류방법(分類方法)으로 환삼덩쿨(Humulus japonicum)군락(群落), 여뀌(Persicaria hydropiper)군락(群落), 고마리(Persicaria thunbergii)군락(群落), 사철쑥(Artemisia capillaris)군락(群落), 개여뀌 - 강아지풀 - 바랭이(Persicaria blumei - Setaria viridis - Digitaria sanguinalis)군락(群落), 갈대(Phragmites communis)군락(群落)이 조사(調査)되었다. 가장 큰 군락(群落)은 갈대 군락(群落)이었고, 총(總) 38 조사지점중(調査地點中) 15지점(地點)에서 갈대가 발생(發生)되었고 고마리, 환삼덩쿨, 개여뀌 등(等)의 잡초(雜草)들이 우점발생(優點發生)하였다.

• 한국잡초학회지
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• 제9권1호
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• pp.69-75
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• 1989

식물체에 함유된 잡초종자발아 억제 물질을 검색하기 위해 그 생물검정법에 대한 몇가지 기초조사와 더불어, 확립된 검정법에 의해 45종의 식물체의 MeOH 추출액에 대해 생물활성을 조사한 결과는 다음과 같다. 1. 생물검정에 사용될 수 있는 아세톤과 MeOH의 허용도는 각각 1% 이하 및 0.1% 이하였으며 유화제로써 Triton X-100은 공시종자에 대해 100ppm의 농도에서도 비교적 약해가 심하였으나, Tween 20은 500ppm의 농도까지 별다른 영향이 없었다. 2. 본 실험에서 식물체의 추출액을 대상으로, 그 발아억제 활성을 비교, 검색할 경우 가장 적절한 검정농도는 5,000ppm(0.5%)이었다. 3. 45종의 시료 식물체 중 공시잡초종자에 대해 가장 강력한 발아억제활성을 나타낸 것은 둥근잎가정큰나무와 독일가문비의 MeOH 추출액이었으며, 이들은 모두 5,000ppm의 농도에서 공시종자에 대해 60% 이상의 발아억제 활성을 나타내었고, 특히 쇠비름과 큰달맞이꽃의 종자에 대해서는 90% 이상의 강한 억제활성을 나타내었다. 4. 고들빼기의 MeOH 추출액에서는 공시종자들의 발아 및 생육을 촉진시키는 호르몬 유사 물질의 존재가 강력히 시사되었다.

• 한국잡초학회지
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• 제31권3호
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• pp.271-278
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• 2011

The allelopathic effects of Lantana camara L. (Family:Verbenaceae) on germination and seedling establishment of some agricultural crops and weed species have been identified. Aqueous extracts of dry leaves and contaminated soil where L. camara is grown were used to verify allelopathic effect on seed germination of five bioassay species; Raphanus sativas, Capsicum annum, Lycopersicum esculantem, Crotalaria juncia and Chromoleana odorata. Fifty seeds from each bioassay species were placed in a petri dish containing leaf extracts or contaminated soil, and seed germination were examined after 3 days. The plant house experiments were carried out to evaluate the impact of L. camara contaminated soil and leaf debris using L. esculantem as the indicator plant. Seed germination of L. esculentem, C. junica and Capsicum annum was significantly inhibited by L. camara contaminated soil. However, the degree of inhibition varied among the bioassay species. The aqueous extract of dry leaves of L. camara was highly phytotoxic and it significantly reduced seed germination of all bioassay species. There was a decline in plant height, leaf area and shoot dry weight of tomato only in early growth stages when grown in L. camara contaminated soils. However, incorporation of leaf debris into soil affected the vegetative growth of tomato in early stages when the leaf debris concentration was increased. Growth recovered at the latter part of the life cycle. On the basis of these results it can be concluded that the allelochemicals in L. camara contaminated soils are harmful to the seed germination of crop species. The adverse effect was present only during the early growth stages and it did not suppress the latter part of the plant growth. These responses are attributed to allelopathic effects which need confirmation under field conditions.

• 한국잡초학회지
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• 제15권4호
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• pp.247-253
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• 1995

The herbicide butachlor [N-(butoxymethyl)-2-chloro-N-(2,6-di-methylphenyl) acetamide] is widely used by farmers as a tool for weed management of transplanted rice(Oryza sativa L.) in Taiwan. The herbicide did not stop germination of rice and weed seeds, but strongly inhibited the subsequent growth of young shoots and roots. The inhibition was also strong on established seedlings. However, they could recover to normal growth after the herbicide effect disappeared. Butachlor greatly decreased the endogenous indole-3-acetic acid (IAA) but increased the endogenous abscisic acid (ABA) contents of rice seedlings. Addition of lAA into growth medium (Hoagland's solution) partly relieved growth inhibition. Pretreatment of both gibberellic acid ($GA_3$) and IAA 24 hours before butachlor treatment almost completely alleviated the butachlor-interfere with GA and/or IAA metabolism or their action resulting in the growth inhibition of rice. Butachlor was readily absorbed by rice roots. During 24 hours of uptake experiment, 32% of the applied herbicide was absorbed. Pretreatment of the herbicide for 2 days did ncx affect the absorption. Of the absorbed herbicide, 80% remained in roots, only 20% transported into shoots, and more than 50% was metabolized to water soluble substances. Thin-layer chromatographic (TLC) analysis indicated that the Rf value of the most abundant metabolite was butachlor-glutathione conjugate. Rice, barnyardgrass (Echinochloa crus-galli (L.) Beauv.), and monochoria (Monochoria vaginalis Presl) seedlings contained relatively high level of non-protein thiols, while the glutathione S-transferase (GST) activity was found highest in rice, barnyardgrass the next, monochoria the lowest. The difference in GST activity among these species might be related to their sensitivity to butachlor.

• 한국잡초학회지
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• 제6권2호
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• pp.124-129
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• 1986

보리밭의 잡초방제(雜草防除)를 위하여 몇 가지 겨엽처리형제초제(莖葉處理型除草劑)를 공시(供試)하여 시험(試驗)한 결과(結果)를 보면 1. 공시약제중(供試藥劑中) 살초력(殺草力)은 Bromoxynil + MCPA와 Bromoxynil이 Ioxynil 보다는 효과적(效果的)이었다. 2. 이들 약제(藥劑)들의 시용량(제품)(施用量(製品))은 100g/10a 보다는 200g/10a 시용량(試用量)에서 살초효과(殺草效果)가 높았다. 3. 약제(藥劑)의 살포시기(撒布時期)는 이들 3엽제(葉劑) 모두 3월(月)보다는 4월(月) 초순(初旬)에 살포(撒布)되는 하잡초(夏雜草)도 방제(防除)할 수 있었기 때문이었다. 4. 보리 파종직후(播種直後) 토양처리제(土壤處理劑)로서 Butachlor를 처리(處理)하고 4월(月) 초(草)에 경엽처리제(莖葉處理劑)로서 Bromoxynil 이나 Bromonynil + MCPA를 처리(處理)한 구(區)에는 거의 완전방제(完全防除)가 가능(可能)하였다. 5. Bromoxynil+MCPA 약제(藥劑)로 30여(餘) 초종(草種)들의 살초력(殺草力)을 본 결과(結果) 주(主)로 광엽잡초(廣葉雜草)에 효과(效果)가 있어 답이작(畓裏作)보다는 전작맥류포(田作麥類圃)에 발생(發生)되는 잡초(雜草)를 대상(對象)으로 방제(防除)하는 것이 좋을 것으로 본다. 6. 잡초발생량(雜草發生量)(잡초건물중(雜草乾物重))과 보리 수량(收量)과의 회귀식(回歸式)은 y=593.112-0.41x(r=$-0.918^{**}$)로서 고도(高度)의 역상관(逆相關)을 보였다.

• 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.