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Interaction between Light and other Factors Affecting Germination of Oenothera lamarckiana Ser. Seed. (큰달맞이꽃 종자발아(種子發芽)에 영향하는 요인(要因)과 광간(光間)의 상호작용(相互作用))

  • Kim, J.S.;Hwang, I.T.;Koo, S.J.;Cho, K.Y.
    • Korean Journal of Weed Science
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    • v.8 no.1
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    • pp.15-22
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    • 1988
  • In this experiment, interactions between light and other factors such as chilling, alternating temperature, moisture, content, oxygen, and seed coat which affect germination of Oenothera lamarckiana Ser. seed were investigated to study the physiological effects of light on the germination. Light induced the initial stage of seed germination before radical protrusion by affecting embryo rather than seed coat even under anaerobic condition or low water potential (-18 bars). This light effect on germinability of seed was suppressed by blue light irradiation and the effect was increased with increment of blue light intensity and irradiation time. However, the blue light effect was reversible. Chilling, alternating temperature, softening of seed coat and light showed promotive interaction in the induction of seed germination. Irradiation of filtered light (monochrome), however, reduced chilling effect on germination. Hydrogen-ion concentration and gibberellic acid treatment had no effect on light or dark germination.

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Effects of Colored Polyethylene Film Mulching on Germination, Emergence, and Growth of Weeds (착색(着色) 폴리에틸렌 필름 멀칭이 잡초(雜草)의 발아(發芽), 발생(發生) 및 생장(生長)에 미치는 영향(影響))

  • Pyon, Jong-Yeong
    • Korean Journal of Weed Science
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    • v.5 no.1
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    • pp.19-23
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    • 1985
  • Soil temperature was higher in clear or blue polyethylene film and bare soil than in black or green polyethylene film and straw mulching. Light transmission was low in black, blue or green colored polyethylene film and straw mulching. Germination of weeds was generally high under clear polyethylene film but black polyethylene film inhibited the germination. Germination of Portulaca oleracea, Setaria viridis and Amaranthus retroflexus increased under blue polyethylene film but inhibition of germination was observed in Erigeron canadensis, Avena fatua, Chenopodium ablum, Digitaria sanguinalis and Echinochloa crusgalli. Green polyethylene film mostly inhibited germination of weeds except A, fatua, C. album and E. canadensis. The greatest number of weeds emerged was obtained in clear polyethylene film, next in bare soil but green or blue polyethylene film inhibited the emergence of weeds. However, no emergence of weeds was observed under black polyethylene film. The highest dry weight of weeds was obtained in clear polyethylene film, next in bare soil, but green or blue polyethylene film and straw mulching caused suppression of weed growth. No weeds were grown under black polyethylene film.

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Determination of Allelopathic Activity in Dominant Upland Weeds (밭 주요(主要) 우점잡초의(優占雜草) ALLELOPATHY 작용성(作用性) 검색(檢索))

  • Chun, J.C.;Han, K.W.;Jang, B.C.;Shin, H.S.
    • Korean Journal of Weed Science
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    • v.7 no.2
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    • pp.156-164
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    • 1987
  • Allelopathic activity of dominant upland weed species was determined using aqueous and methanol extracts and dried residues of the weeds. Germination and seedling growth of radish (Raphanus sativus L.) and sesame (Sesamum indicum L.) were greatly inhibited by 2% (w/v) aqueous extracts of Artemisia asiatica Nakai and Portulaca oleracea L., respectively. Great phytotoxicity on both indicator plants occurred by 2% (w/v) aqueous extracts of Capsel/a bursa-pastoris (L.) Medik. A complete inhibition in germination and seedling growth of radish was caused by 2% (w/v) methanol extract of A. asiatica. There was about 90% inhibition in germination and seedling growth of sesame due to 2% (w/v) methanol extracts of A. asiatica, P. oleracea and Trifolium repens L. Phytotoxic effects varied with extract solution, weed species and indicator plants employed, indicating that the weed species contained different contents and kinds of allelopathic chemicals. Water potential and pH adjusted to those of the extracts did not affect germination and seedling growth of the indicator plants. Phytotoxicity increased with increasing concentration of the extracts obtained from four suspected alleopathic weeds. Soil-incorporated plant residues of A. asiatica and P. oleracea caused greater phytotoxicity on radish than those of C. bursa-pastoris and T. repens.

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Effect of Varous Factors on Emergence and Control of Sagittaria pygmaea Miquel (올미의 출아(出芽) 및 방제(防除)에 미치는 환경요인(環境要人)의 영향(影響))

  • Han, S.S.;Ryang, H.S.;Konnai, M.;Takematsu, T.
    • Korean Journal of Weed Science
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    • v.5 no.1
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    • pp.35-42
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    • 1985
  • This study was carried out to investigate the effect of environmental factors affecting emergence and control of Sagittaria pygmaea Miquel in greenhouse. Emergence of S. pygmaea delayed as the amount of rice straw increased. When the tuber was sowned at 5 to 7㎝ soil depth the emergence of S. pygmaea delayed more in the hard condition of soil than that of the soft condition the large size tuber of S. pygmaea showed less control rate than the small size one at the rate of 2 to 3㎏ prod/10a of butachlor-naproanilide mixtures. The tubers of S. pygmaea seeded at the deeper soil depth decreased weeding efficicy of this mixture. Butachlor-naproanilide mikture showed higher weeding effects at the high temperature and at 2 to 4cm depths of water management than those of the low temperature and at 0cm and 6cm water depths. Weed control rate increased as the rate of butachlor-naproanilide mixture increased. The rate of 4㎏ (prod.)/10a showed good weed effect regardless of application times till 7.5 leaf stage of S. pygmaea. Tuber production of S. pygmea increased as the application time of mixture delayed.

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Effects of Trinexapac-ethyl(CGA 163935) on Growth and Lodging of Rice(Oryza sativa L.) (Trinexapac-ethyl(CGA 163935)의 처리(處理)가 수도(水稻)의 생육(生育) 및 도복(倒伏)에 미치는 영향(影響))

  • Im, I.B.;Choi, W.Y.;Lee, S.Y.;Park, K.Y.;Lee, J.L.
    • Korean Journal of Weed Science
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    • v.13 no.1
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    • pp.19-25
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    • 1993
  • This study was conducted to evaluate effect of trinexapac-ethyl{4-(cyclopropyl-${\alpha}$-hydroxy-methylene)-3, 5-dioxocyclohexan carboxylic acid ethyl-ester} for lodging prevention, growth pattern of several organs and yield in machine transplanted rice with 10-day-old seedling. Elongation rate of the second internode affected the most largely by trinexapac-ethyl was 33-52, 35-56 and 42-53% of check in application of 12, 7 and 5days before heading, respectively and, culm elongation was reduced 27-34, 20-29 and 20-25% in application of the same time. Lodging in field was decreased by treatment of trinexapac-ethyl compared with check, Ripened grain ratio and yield were increased about 3-7 and 7-17% by trinexapac-ethyl, respectively.

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Herbicidal Effects on the Differential Rice Cultivation Condition and Damage of No-target Plants of Macro Granule Herbicide for Remote-controlled Aerial Application (무인헬기용 Macro granule 제초제의 벼 작형별 살초효과 및 주변작물에 미치는 영향)

  • Yoon, Cheol-Su;Bae, Chang-Hyu;Lee, Sheong-Chun;Kim, Kyung-Hyun;Lee, Kye-Hwan;Cho, Tae-Kyoung;Hwang, In-Cheon
    • Korean Journal of Weed Science
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    • v.31 no.4
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    • pp.375-383
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    • 2011
  • This experiment was carried out to confirm characteristics of macro granule (GG) for herbicidal efficacy by using remote-controlled aerial application (RCAA) to control annual and perennial weeds in rice paddy field, and phytotoxicity to rice and non target plants of formulation types. Herbicidal efficacy of GG applied by using RCAA was 93.6~96.6% in flooded direct sowing cultivation. There was no difference in phytotoxicity between the hand and the power applicator methods in terms of height, number of tiller and yield component. Herbicidal efficacy of GG applied by using RCAA was 92.7~97.3% in machine transplanting rice field. There was no difference in phytotoxicity between the hand and RCAA methods in terms of height, number of tiller and yield component. When suspension concentrate (SC) and GG were applied directly on Chinese cabbage, lettuce, cucumber, pepper, soybean and wild sesame, several symptoms of injury such as, the inhibition of growth, yellowish, leaf fall and withering was observed.

Growth of Vicia tetrasperma and V. hirsuta as Affected by Seeding Condition and Estimated N Production (피복식물용 얼치기완두와 새완두의 생장에 미치는 파종조건과 질소공급량 추정)

  • Cho, Jung-Lai;Choi, Hyun-Sug;Lee, Youn;Kim, Chang-Seok;Lee, In-Yong
    • Korean Journal of Weed Science
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    • v.31 no.1
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    • pp.84-88
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    • 2011
  • This study was established to investigate the effects of seeding depth and seeding time on the emergence, growth, and N production of Vicia tetrasperma and V. hirsuta in 2007 and 2008. All seeds of both species were gathered from Dangjin, Chungnam in late June of 2005 and stored for two year at room temperature. Both V. species began to germinate at the end of June, passed the winter with the seedling stage, rapidly increased their height in April and May, were in full bloom in May, and then withered after entering mid-June. V. hirsuta had higher emergence rate and growth compared to those of V. tetrasperma. The optimum seeding time and seeding depth for a cover cropping was from late August to early September and from 1 to 5 cm, respectively. V. tetrasperma and V. hirsuta had a satisfactory growth and provided 43.8 and $55.4kg\;ha^{-1}$of N, respectively.

Rate of Ground Cover and Weed Occurrence in Pepper Cultivation as Affected by Seeding of Ground Covers (고추재배 시 피복작물에 의한 피복율 변화와 잡초발생 양상)

  • Cho, Jung-Lai;Choi, Hyun-Sug;Lee, Youn;Lee, Byung-Mo;An, Nan-Hee;Park, Kwang-Lai;Lee, Ji-Hyun
    • Korean Journal of Weed Science
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    • v.31 no.4
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    • pp.355-359
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    • 2011
  • This study was conducted to evaluate the effects of seeding of Vicia tetrasperma and V. hirsuta on the rate of ground cover as well as growth and yield of organic pepper plants in 2008 and 2009. All seeds of both species were gathered from Dangjin, Chungnam in late June of 2006 and stored for two year at room temperature. Capsella bursapastoris, Echinoloa crus-galli, Digitaria ciliaris, and Commelina communiswas were observed as main weeds during the winter and summer, respectively, at the field of V. tetrasperma and V. hirsuta. C. bursapastoris did not affect growth and yield of pepper plants. Seeding of V. tetrasperma and V. hirsuta maintained high percentage of ground cover later in the growing season of pepper plants and reduced significant amounts of weed in 2009. V. tetrasperma and V. hirsuta, therefore, produced more pepper yield compared to that of control but similar yield to the conventional system (polyethylene film).

Effects of Storage Period and Germination Condition on Germination Rate of Vicia tetrasperma and V. hirsuta (피복식물용 자생잡초 얼치기완두와 새완두 종자의 저장방법이 발아에 미치는 영향)

  • Cho, Jung-Lai;Choi, Hyun-Sug;Lee, Youn;Kim, Chang-Seok;Lee, In-Yong
    • Korean Journal of Weed Science
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    • v.31 no.1
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    • pp.78-83
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    • 2011
  • This study was conducted to evaluate germination rate of Vicia tetrasperma and V. hirsuta as affected by storage duration, temperature, and light. All seeds of both species were gathered from Dangjin, Chungnam in the late June of 2004 and 2005, stored for a certain period of time, and then exposed for 20 days to the alternating temperatures ($15/^{\circ}C,\;20/10^{\circ}C,\;25/15^{\circ}C$, and $30/20^{\circ}C$) for evaluating the germination rate. Both 2004 and 2005, two species stored at room temperature for 3 months had germination rates less then 30% with applying various alternating temperatures for 20 days although the highest germination rate was obtained with $25/15^{\circ}C$ treatment. V. tetrasperma at 12 month storage after seed gathering in 2005 had 82% of germination rate with $25/15^{\circ}C$ treatment and showed the increased rate as time passed. V. hirsuta at 6, 9, and 12 month storage after seed gathering in 2005 ranged, however, from 33 to 53% of the germination rate at alternating temperature treatments for 20 days and did not seem to be affected by the elapsed time of the storage. Storage at room temperature was more effective for increasing germination rate of both species compared to those of the storage at low temperature. The germination rate of both species was not significantly affected by either exposure of light or short period of high temperature.

Heat-treatment Effects of Agricultural Imports for Devitalization of Quarantine Weed Seeds (검역잡초종자 발아력 제거를 위한 수입농산물 열처리 효과)

  • Moon, Kwang-Ok;Oh, Jin-Bo;Kyoung, Eun-Seon;Lee, Yong-Ho;Hong, Sun-Hee;Kang, Byeng-Hoa
    • Weed & Turfgrass Science
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    • v.2 no.2
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    • pp.170-175
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    • 2013
  • Korea is carrying out weed quarantine by plant quarantine regulations including heat-treatment method to prevent the influx of exotic weeds. In order to confirm suitability for current heat-treatment criteria and find field-applicable methods which can completely devitalize quarantine weed seeds, the conditions for heat-treatment with/without 40% relative humidity were studied with 9 species among quarantine weed seeds and one weed species similar to quarantine weed. Dry heat-treatments had been tested under various temperatures and time conditions. All seeds were dead at the conditions of $95^{\circ}C$ for 48 hours, $100^{\circ}C$ for 36 hours, $110^{\circ}C$ for 24 hours, $121^{\circ}C$ for 4 hours and $130^{\circ}C$ for 30 minutes. Heat-treatments at 40% relative humidity resulted in complete seed death at the conditions of $85^{\circ}C$ for 36 hours and $90^{\circ}C$ for 16 hours. The above results show that current heat-treatment criteria are not suitable for several quarantine weeds and these conditions could be applied as a quarantine method to prevent the influx of quarantine weeds along with agricultural imports. More specific conditions for heat tolerant species such as Picris echioides and heat susceptible species such as Cuscuta spp. are necessary and will improve plant quarantine process in devitalizing quarantine weed seeds with different heat tolerances.