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  • Title/Summary/Keyword: 피해엽율

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Injury Symptoms of Orchids by Sulfur dioxide Gases in Greenhouse (시설내 아황산가스에 의한 난의 피해 증상)

  • Lee, Young-Ran;Choi, Seong-Youl;Kwon, Oh-Keun;Huh, Eun-Joo
    • FLOWER RESEARCH JOURNAL
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    • v.17 no.4
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    • pp.237-241
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    • 2009
  • This study was conducted to determine injury symptoms of orchids by sulfur dioxide gases, three orchid plants (Phalaenopsis, Cymbidium, Oncidium) were exposed to sulfur dioxide gas in an enclosed growth chambers. Sulfur dioxide gases treatments consist of five different concentrations (0, 5, 10 25, and 50 ppm) and plant exposure of 18 hours with 25±5C air temperature and 50±5 relative humidity. SPAD values for chlorophyll content and percent leaf injury as well as leaf ion exudation were measured before and after the gas treatments. Phalaenopsis leaves showed 23.3% leaf injury at 10 ppm sulfur dioxide gas, whereas Cymbidium and Oncidium showed 4.0 and 4.4% leaf injury under 25 ppm or less, respectively. Major leaf injury symptoms appeared as initial water-soaking under side of the leaf, followed by rapidly progressed complete leaf discolorization or chlorosis. As the gas concentration increased, the SPAD value decreased while ion exudation increased. Cymbidium and Oncidium were resistant to sulfur dioxide gas than Phalaenopsis.

Damaged Aspects, Seasonal Fluctuations, and Attractivity of Various Colors on Liriomyza trifolii Burgess (Diptera: Agromyzidae) in Gerbera (거베라에서 아메리카잎굴파리의 가해양상, 발생소장 및 색상별 유인량)

  • 박종대;구용수;최덕수;김상수
    • Korean journal of applied entomology
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    • v.40 no.2
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    • pp.97-103
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    • 2001
  • The rate of gerbera (Gerbera jamesonii Bolus.) leaf damaged by Liriomyza trifolii larvae was lower than that by adults. The adults began to be attracted to yellow sticky trap immediately after transplanting and increased gradually up to early August followed by low population density from middle to late August. In the second year, adults began to be attracted from late April after transplanting and increased abrubtly from middle May and the high density was maintained till early truly. The density decreased, however, from middle July, and then followed by the high density again early September and late October The seasonal fluctuations of larva and pupa were similar to that of adults and the peaks of pupa occurred one week later than that of larvae. Larva infected by parasitoid were observed 4 weeks after transplanting. Parasitism was 65% in average from early July to late August but decreased to 50% from early September. Number of trapped adults was the highest in the yellow sticky trap among the five different colour raps. Catches at 30~60 cm above soil surface were significantly greater than that at 90 cm.

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Host Plants of Ectinohoplia rufipes (Coleoptera: Scarabaeidae) in Golf Courses and Effect of Damaged Leaves on the Attraction of Adults (주황긴다리풍뎅이 (Ectinohoplia rufipes)의 골프장 기 주식물과 피해 잎의 성충 유인 효과)

  • 최우근;이동운;추호렬;정재민;이상명;박정규
    • Korean journal of applied entomology
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    • v.40 no.1
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    • pp.31-40
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    • 2001
  • Host plants or Ectinohoplia rufipes (Motschulsky) (En) were investigated in golf courses and laboratory. E. rufipes adults fed on 61 plant species of 27 families out of 101 plant species of 41 families supplied in laboratory. In addition, twenty-seven plant species in 8 families were observed to be fed on from golf courses. Thus, total number of host plants of E. rufipes were 84 species in 29 families. E. rufipes adults preferred Japanese green alder (Alnus firma) , cherry apple (Malus sieholdii), cherry (Prunus serrulata var. spontanea) and sweet oliver (Osmantus asiaticus) in golf courses . The preference of E. rufipes adults with A. firma , P. serrulata vu. spontanea and O. asiaticus was bioassayed in laboratory. E. rufies adults preferred A. firma consuming 58.1% to O. asiaticus and p. serrulata vats. spontanea. The most number of E. rufipes adults was attracted to damaged leaf of A. firma by E. rufipes representing 45.3clo and followed by artificial damaged leaf representing 26.5% , untried feeding leaf representing 12.9% and undamaged leaf representing 4.0%. More E. rufipes adults were attracted to damaged leaf of A. firma by 67.5% than artificially damaged leaf by 30.5% or undamaged leaf treated with feces of E. rufipes by 2%.

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Degree of Injury Caused by Larva of Pyrausta panopealis Walker (Lepidoptera: Pyralidae) in Green Perilla Polyvinyl House at Chungnam Province (충남지역 잎들깨 시설하우스에서 들깨잎말이명나방 유충의 가해양상)

  • Choi, Yong-Seok;Park, Deok-Gi;Kim, Byung-Ryun;Han, Kwang-Seop;Youn, Young-Nam;Choe, Kwang-Ryul
    • Korean journal of applied entomology
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    • v.46 no.2
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    • pp.193-199
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    • 2007
  • This study was conducted to explain degree of injury caused by P. panopealis larva which is the key component to develop economic injury level or control threshold in green perilla and was carried out in polyvinyl houses at Yuseong Daejeon, Geumsan and Yesan Chungnam from 2004 to 2006. Of 5 major pests in green perilla polyvinyl house, P. panopealis larva injured green perilla leaf by 48.5% on average under no insecticides application. The peak occurrence of P. panopealis adult was early August and late September in 2004 and 2005 studies. The feeding amount of P. panopealis larva among 1st to 3rd instar was not different, but from the 4th instar the feeding amount greatly increased and this result was consistent with daily feeding experiment in which the amount greatly increased from seventh day. The degree of injury which was investigated with different larval infestation levels showed that the degree of injury increased a little but was not dim ε rent significantly as the density increased. The density of P. panopealis larva in damaged green perilla plant was less than three individuals/plant. This result indicates that P. panopealis adult lays egg on green perilla leaf dispersedly and larva hatched from egg injures only the leaf which egg is layed. These preliminary data seems to be very useful to design economic injury level and control threshold studies for P. panopealis in green perilla polyvinyl house.

Studies on the Reduction of Hydrogen Fluoride Damage to Rice Plant II. Optimum Application of Lime and Wollastonite (수도(水稻)에 대(對)한 불화수소(弗化水素)가스 피해경감(被害輕減)에 관(關)한 연구(硏究) II. 소석회(消石灰), 규회석(珪灰石)의 적정시용량(適正施用量))

  • Kim, Bok-Young;Han, Ki-Hak;Kwag, Pan-Ju
    • Korean Journal of Soil Science and Fertilizer
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    • v.14 no.3
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    • pp.163-168
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    • 1981
  • The studies were carried out to examine the effect of soil improvement agents, such as lime, wollastonite and phosphate, in reducing the damage caused by hydrogen fluoride gas to the vegetative growth of rice. The yield loss, damage rate of the plant leaves, the fluoride and silicate concentrations of the plants were measured. The results obtained are summarized as follows : 1. Of various levels of added lime and wollastonite, the best were found to be neutralized lime plus lime 150kg/10a, and wollastonite 150kg/10a. 2. Added fluoride increased the fluoride content of the plant and the damage rate of the plant leaves, and the yield was greatly decreased. 3. The silicate concentration at harvesting period was also increased by high amounts of fluoride in the plant during vegetative growth. 4. Increasing the amount of added lime increased the watersoluble silicate concentration in the soil. The silicate content of the plant showed the same tendency.

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Control Thresholds for the Management of Beet Army Worm, Spodoptera exigua (Lepidoptera : Noctuidae) on Welsh Onion (Allium fistulosum L.) (파에서 파밤나방 요방제 수준 설정)

  • Kim, Seon-Gon;Kim, Do-Ik;Kang, Beom-Ryong;Choi, Kyeong-Ju
    • Korean journal of applied entomology
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    • v.46 no.3
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    • pp.431-435
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    • 2007
  • Control thresholds for the management of beet army worm, Spodoptera exigua (Lepidoptera : Noctuidae) were evaluated on welsh onion of two different planting time. Two inoculation times were tested for each planting and the number of inoculated larva was 5, 10, 20, 40 per twenty plants. The injured rate of leaves was 33.5% to 10.9% at 7th September at 40 to 5 larva inoculation plot on the five days planting. That of leaves was 20.5% at 40 larva on the twenty days planting. The yields of welsh onion on non-inoculation plot were 4,395 kg per 10a. The rate of reduced yields was 49.2%(1,774.2 kg) and 36.5%(2,220.5 kg) at 40 larva inoculation on the 5 and 20 days planting, respectively. The linear relationships between population density and yield reduction were as following; it was Y=-43.474X + 3419.6 (R2=0.9698) for 5 days and Y=-32.977X + 3518.9 (R2=0.9928) for 20 days. Based on these results the control threshold level was estimated to be 1.8 larva for 5 days and 4.6 larva for 20 days per 20 plant. The more damaged leaves by S. exigua larva, the more yield reduction on welsh onion.

Absorption of sulfur dioxide gas with various crops and it's relation to leaf injury (아황산가스에 의(依)한 작물별파해엽율(作物別破害葉率) 및 가스흡수량조사(吸收量調査))

  • Kim, B.Y.;Han, K.H.
    • Korean Journal of Soil Science and Fertilizer
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    • v.13 no.1
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    • pp.39-44
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    • 1980
  • To study the effects of sulfur dioxide on the plant; Barly, wheat, soybean sweet potato, cucumber, egg plant, red pepper, tomato, lettuce, water melon, castor bean, grape and lily were exposed to the different levels of sulfur dioxide gas(0.1, 0.25, 0.50, 1.0mg//hr) The symptoms of damage, ratios of destroyed leaf, sulfur content and absorption amounts of the gas by leaves were investigated 1. According to the increasing concentration of the gas ratios of destroyed leaf were increased in all plants. The ratios of destroyed leaf were shown by egg plant at 0.1mg//hr of SO2 were 30 percent, and no visible injuries were shown by the wheat potato, castor bean, water melon, lily at 0.25mg//hr. 2. Gray and red brown spots between the vein nerve shown by barly and wheat leaf; leaf burn by soybean, potato, sweat potato, castor bean, egg plant, red pepper, tomato and grape; leaf withering from the leaf tips by the lettuce, water melon, lily. 3. The volums of the gas absorption by cucumber, egg plant, red peper, castor he an were more than 10/hr, however less than 2/hr, be lettuce, water melon, grape, barly and wheat. 4. According to the increasing concentration of sulfur dioxide gas, sulfur contents in leaf were increased in all plants, however volums of absorption gas were decreaed. 5. According to the increase of sulfur content in leaf, ratios of destroyed leaf were increased. 6. Positive correlation was shown between total and water soluble sulfur content in leaf.

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Seasonal Occurrence and Damaged Aspects of Frankliniella occidentalis Pergande (Thysanoptera: Thripidae) by Cultural Environments and Varieties of Chrysanthemum (국화 재배환경과 품종에 따른 꽃노랑총채벌레의 발생 및 가해양상)

  • 박종대;김도익;김선곤
    • Korean journal of applied entomology
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    • v.41 no.3
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    • pp.177-181
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    • 2002
  • This study investigated seasonal occurrence of Frankliniella occidentalis and its damage on chrysanthemum from 1999 to 2000. F. occidentalis adults were attracted to yellow sticky traps from early April to harvesting time in the field. The highest densities were observed from late April to mid-June in spring culture and from mid-August (just after transplanting) to early September in autumn culture respectively. Seasonal fluctuation in a PVC green house was similar to that in the field. Number of insects per flower were higher in the green house than that in the field. Leaf damages due to the insects were observed from mid-May and increased as chrysanthemum grows (R2 = 0.9200-0.9887\^**/, p> 0.01).

Varietal Difference of Resistance to Ozone Injury in Rice Plant (벼 품종별 오존 피해 저항성 차이)

  • 손재근;이상철
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.42 no.3
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    • pp.338-343
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    • 1997
  • The response of seventy-five rice cultivars to ozone (O3) were tested in the open-top chamber with ozone producing and monitoring system to determine the varietal difference of resistance to O3 stress. Ozone was produced by electrostatic discharge in oxygen and was monitored by UV absorption ozone analyzer. Difference in response of rice to ozone was more clearly appeared on rice plants treated for 2 to 4 hours at 0.3 ppm concentration of O3. Varietal resistance of rice to ozone was more distinctly classified at 21- to 35-day seedlings compared with 14-day rice plants. Most of indica and Tongil(indica×japonica) type rice cultivars were more resistant than that of japonica cultivars based on the leaf injury to O3. Eight Korean cultivars belong to japonica groups showed highly resistant reaction to O3. Ozone exposure during booting stage caused lower grain fertility than exposures during seedling, maximum tillering and heading stages of rice.

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