• Title/Summary/Keyword: Damaged seed ratio

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Effects of Mixed Seeding of Main Revegetation Plants Treated with Different Seeding Amounts of Pennisetum alopecuroides on Cut-Slope Revegetation (수크령 파종량에 따른 주요녹화식물의 혼파가 비탈면 녹화에 미치는 영향)

  • Ham, Kyung-Sik;Shim, Sang-Ryul
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.18 no.1
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    • pp.25-35
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    • 2015
  • Pennisetum aloperculoides is a key revegetation species mixed with other plants species and used for revegetating cut-slopes. The purpose of this research is to identify the effects of mixed seeding of revegetation plants on cut-slope revegetation with respect to the quantity of Pennisetum aloperculoides seeds. The coverage ratio and appearance frequency of Pennisetum aloperculoides, and other revegetation species were measured to assess the cut-slope revegetation. We divided Pennisetum treatments into four groups with different Pennisetum seed quantities of $0g/m^2$, $5g/m^2$, $10g/m^2$, and $15g/m^2$. For each treatment group, we mixed identical quantities of seeds from herbaceous flowers (bird's-boot trefoil, aster, chrysanthemums, golden coreopsis and china pink), cool-season turfgrasses, and woody plants (korean lespedeza, indigo and silk tree). The increase in the quantity of the Pennisetum seeds resulted in the higher coverage ratio for Pennisetum, but in the lower coverage ratio for herbaceous flowers, cool-season turfgrasses, and woody plants. We observed a short-term succession process in which the dominant species shifted in the following order: the initial species Pennisetum, herbaceous flowers, and then lastly woody plants. In case of the appearance frequency, we also observed the higher appearance frequency for Pennisetum and the lower appearance frequency for the other plants due to the increase in the quantity of Pennisetum seeds. Pennisetum, bird's-foot trefoil and china pink showed the tendency to decrease the appearance frequency from one month after seeding while cool-season turfgrasses became extinct due to summer drought. In the woody plants, the appearance frequencies of korean lespedeza and indigo were high due to the decrease in quantity of Pennisetum seeds. The silk trees were damaged from winter frost and none emerged at all in 2013 (the following year after the seeding). Korean lespedeza and indigo appeared to have the short-term rapid dominance over other treated revegetation plants.

Occurrence of Insect Pest from Organic Seed Producing Field of Minor Grain Germplasms (잡곡유전자원을 이용한 유기종자생산 포장의 해충발생 소장)

  • Kim, Jeong-Soon;Ko, Ho-Cheol;Yoon, Sung-Tag;Cho, Yang-Hee;Kim, Jung-Gun;Shim, Chang-Ki
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.55 no.1
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    • pp.58-64
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    • 2010
  • This study was carried out to screen the occurrence of insect pest on the organic seed producing field of minor grain germplasms, Pearl millet (Setaria italic L.), Sorghum (Sorghum bicolor L.), and Common millet (Panicum miliaceum L.) in Gangwon-do from 2008 to 2009. The artificial pheromone traps successfully attracted an Oriental corn borer, Ostrinia furnacalis (Guenee) on Pearl millet, but the Army worm, Pseudaletia separata, was not attracted in all of the minor grain fields. The ratio of damaged plants of Oriental corn borer and Army worm were appeared in order with Pearl millet, Common millet, and Sorghum. The morphological diversities of plant bug were shown as four kinds of species, Eastern green stinkbug (Nezara antennata), Brown-marmorated stinkbug (Halyomorpha halys), Sloe bug (Dolycoris baccarum), and Bean bug (Riptortus clavatus), on the organic seed producing field of minor grain. The average occurrence density of Eastern green stinkbug was the highest level in the three kind of minor grains, Pearl millet, Common millet, and Sorghum in 2008 and 2009. The dominant species are the Eastern green stinkbug and the Bean bug in Pearl millet and Common millet. The Sloe bug and the Bean bug possessed the highest population density in Sorghum.

Effects of Development Time and Severity of Rice Ear Blight on Rice Yield and Quality (벼 이삭마름병 발병시기와 정도가 수량 및 품질에 미치는 영향)

  • Shim Hong-Sik;Hong Sung-Jun;Hong Sung-Gi;Kim Yong-Ki;Ye Wan-Hae;Sung Jae-Mo
    • Research in Plant Disease
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    • v.12 no.1
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    • pp.5-9
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    • 2006
  • Grain discoloration, caused by several microorganisms, is a minor disease, but it is gaining importance in almost all rice growing areas of the world in recent years. Such grains are of low market value and consumption appeal in addition to their abnormal performance as seed of source of nutrient value. When the casual agents were inoculated on rice plant,'Ilmi-byeo'(at right before heading time and on heading time), the incidence of rice ear blight caused by Alternaria alternate and Nigrospora oryzae was higher in a plot inoculated at right before heading time than (in n plot inoculated) on heading time. Meanwhile, the incidence of rice ear blight caused by Bipolaris oryzae and Curvularia lunate was higher in a plot inoculated on heading time than in a plot inoculated at right before heading time. In rice quality, the ratio of imperfect grains was increased at right before heading time or on heading time by Nigrospora oryzae or Alternaria alternata, respectively. As discoloration rate of rice grains increased on 'Ilmi-byeo', the percentage of perfect grains decreased proportionally and the percentage of damaged rice grains increased remarkably.