• Title/Summary/Keyword: bulrush(scirpus juncoides Roxb.)

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Dormancy - breaking Conditions of Bulrush(Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.) 종실(種實)의 휴면타파조건(休眠打破條件)에 관한 연구(硏究))

  • Huh, S.M.;Guh, J.O.;Son, P.K.
    • Korean Journal of Weed Science
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    • v.6 no.2
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    • pp.102-109
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    • 1986
  • To know the ecological pattern of bulrush (Scirpus juncoides) seeds in dormancy-breaking responses as affected by different ripening processes, storage conditions, germination conditions, and some of known chemicals concerned, the study was conducted. Among other conditions detected, the burial in 2 cm depth paddy soil, $5^{\circ}C$ storage temperature, pre-maturing process (Green color), high concentration of chemicals used, and flooding paddy surfaces were the most efficient conditions for bulrush seeds to break dormancy and germinate, respectively.

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Competition between Bulrush(Scirpus juncoides Roxb.) and Rice under the Different Fertilizer, Water Depth, and Light Restriction (비료성분(肥料成分)·수심(水深) 및 광제한(光制限)에 따른 올챙고랭이(Scirpus juncoides Roxb.)의 종간경합(種間競合)에 관한 연구(硏究))

  • Huh, S.M.;Guh, J.O.
    • Korean Journal of Weed Science
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    • v.9 no.3
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    • pp.177-182
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    • 1989
  • The plant height, shoot numbers and dry matter weight in both bulrush and rice were increased by high level of nitrogen fertilizer and especially the dry matter weights in both species were sharply increased by high level of nitrogen fertilizer. The plant height, dry matter weight in rice, and shoot, and dry matter weight in bulrush were increased by high level of phosphorus fertilizer. The deficient symptom disappeared with change of low level into high level phosphorus in rice. The plant height, dry matter weight and shoot numbers in rice and bulrush were increased by high level of potassium fertilizer. In the inter-specific competition in bulrush according to various water levels, the plant heights in both species elongated longer with deep water levels, and the plant height and dry matter weight in bulrush were more sharply decreased than in rice by deep water levels. The shoot numbers and dry matter weight were critically dropped above 6-8 cm water level. In case of the shoot numbers for light source, in both species were more decreased in mixed culture than each monoculture. The exserted shoot length and weight in bulrush were larger than those in rice. The shaded shoot dry weight was more decreased in mixed culture than in each monoculture, and the decrement was larger in bulrush than in rice.

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Ecological Study on the Seed Germination and Emergence of Overwintered Stump of Bulrush(Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.) 종자발아(種子發芽) 및 월동(越冬) 주기부(株基部)의 출아생태(出芽生態)에 관한 연구(硏究))

  • Guh, J.O.;Huh, S.M.
    • Korean Journal of Weed Science
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    • v.6 no.2
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    • pp.110-123
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    • 1986
  • To know the ecological pattern of bulrush (Scirpus juncoides Roxb.) seeds and overwintreed stumps in germination and sprouting responses as affected by different temperature (7 trt.), light intensity (5 trt.), shading intensity (S trt.), light quality (specturm spectrum; 6 trt.), soil acidity (7 trt.), stump sizea (weight base; 5 trt.), and molding depth (6trt.), respectively, this serial studies were conducted by use of growth chamber, incubator, Wagner pot and petri-dish. Most efficient treatment was obtained from 25-$35^{\circ}C$ temperature, higher light intensity in 2-11 klux range, 95% shading intensity, clear and yellow film for seeds/clear and blue film for stumps, soil pH 5.53, 3-4g stump weight, 0-5% wxygen concentration, 1 ㎝ flooding depth for seeds, and 1-1.5cm molding depth for seeds/0.5-1.0 cm molding depth for stumps, respectively, among others.

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Competitiveness and Yield Loss Prediction of Water-seeded Rice by Densities of Scirpus juncoides Roxb (담수직파논 올챙이고랭이 발생밀도에 따른 경합 및 쌀 수량예측)

  • Won, Jong-Gun;Ahn, Duok-Jong;Kim, Se-Jong;Kwon, Oh-Do;Moon, Byeong-Chul;Park, Jae-Eup
    • Korean Journal of Weed Science
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    • v.30 no.1
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    • pp.43-49
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    • 2010
  • This study was conducted to predict the rice yield loss and determine the economic threshold levels for water direct seeded rice from competition of the most serious weeds, Scirpus juncoides Roxb. (bulrush) and Echinochlor crusgalli L. (barnyardgrass) in Daegu of Korea. To predict crop yield as a function of weed density used a rectangular hyperbola, and determine their economic threshold levels used the equation developed by Cousens. The rice yield loss model of S. juncoides was predicted as y = 466 / (1+0.00188x), $R^2$ = 0.933 and that of E. crusgalli was y = 458 / (1+0.02402x), $R^2$ = 0.973. In comparison of the competitiveness represented by parameter ${\beta}$, it was 0.001884 in S. juncoides and 0.02402 in E. crusgalli. Economic threshold calculated using Cousens' equation was negatively related to the competitiveness of weed. So that the economic threshold of S. juncoides was 13.4 and that of E. crusgalli was 1.07 plants per $m^2$.

Intra- and Inter-specific Competition of Bulrush(Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.)의 종내(種內) 및 종간경합(種間競合)에 관한 연구(硏究))

  • Guh, J.O.;Huh, S.M.
    • Korean Journal of Weed Science
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    • v.9 no.2
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    • pp.168-173
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    • 1989
  • In the characteristics of intra-specific competition according to bulrush density, the intra-specific competition in plant height began at 5 and 15% per pot in mixed culture and bulrush monoculture, respectively. The intra-specific competition in the shoot began at 5 plants per pot in both mixed culture and bulrush monoculture. The competition in dry matter weight began at 15 plants per pot in monoculture, and at 10 plants in mixed culture. On the rice density, the plant height, and numbers of shoot and dry matter weight in rice were rapidly increased up to 2.6, and 2.5 plants per pot, respectively, And then the increments were slow, The critical intra-specific competition of bulrush with rice was 2.5 to 3 plants per pot in their traits of rice, and especially the number of shoots and dry matter weights per pot showed significant decrements. In the different transplanting time in rice, the plant heights in both rice and bulrush elongated longer in mixed culture than in monoculture. The plant height of bulrush became shorter but the height of rice longer with late transplanting. The ratio of shoot number in rice to the number in bulrush was about 1 : 3 in all plots, and shoot numbers became less by late transplanting. The dry matter weight in both species were decreased by late transplanting, and the decrements were more prominent in bulrush than in rice.

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Reproductive Growth of Seeds and Overwintered Stump of Bulrush (Scirpus juncoides Roxb.) (올챙고랭이(Scirpus juncoides Roxb.) 종실(種實) 및 월동주기부(越冬株基部)의 번식생장(繁殖生長)에 관한 연구(硏究))

  • Huh, S.M.;Guh, J.O.
    • 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.

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Regrowth of Bulrush (Scripus juncoides Roxb.) by Seasonal Mowing (올챙고랭이(Scirpus juncoides Roxb.)의 예취(刈取)에 따른 재생력(再生力)에 관한 연구(硏究))

  • Huh, S.M.;Guh, J.O.
    • Korean Journal of Weed Science
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    • v.7 no.1
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    • pp.29-34
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    • 1987
  • The number of regrown shoots per plant for 2 weeks after mowing sharply increased in response to late mowing until June 6, and then the increments were slow. The number of regrown shoots for July 30 were many with early mowing until May 14, and then the numbers were rapidly decreased. The plant height regrown for 2 weeks after mowing was increased until May 14, and then decreased. The plant height regrown for July 30 was not sensitive to mowing time and the development was linearly shown. The fresh weight regrown for July 30 was only increased by late mowing. The regrowth rate of shoots for 2 weeks after mowing was much higher than untreated control and the ratio was decreased with late mowing and the ratio to untreated for control for July 30 was decreased up to 50% by late mowing. The regrowth rate of plant height for 2 weeks after mowing was rapidly decreased, but slowly decreased for July 30 mowing. The regrowth rate of fresh weight was higher until May 22, and then rapidly decreased by late mowing. The decreasing tendency for 2 weeks after mowing was more prominent them for July 30. The annual regrowth rates in shoots and plant height were slowly decreased, but the decreasing rate in fresh weight was rapidly done until May 15, and then decrement became up to 30% by late mowing.

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