• The Korean Journal of Pesticide Science
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• v.3 no.3
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• pp.60-67
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• 1999

Insecticidal activities of imidacloprid to sucking type insect pests, brown planthopper (BPH, Nilaparvata lugens) and peen peach aphid (GPA Myzus persicae), to chewing type insect pests, tobacco cut worm (TCW; Spodoptera litura) and beet armyworm (BAW, Spodoptera exigua) and to spiders, Pirata subpiraticus, Pachygnata clercki and Ummeliata insecticeps, as natural enemies were investigated by several bioassay methods. $LD_{50}$ of the chemical by topical treatment to BPH was 0.015 ${\mu}g/g$(48 hrs), while $LC_{50}s$ by leaf dipping and root zone treatment were 18.1 and 21.5 ppm, respectively. There was no difference in insecticidal activities between leaf dipping and root zone treatment. Imidacloprid also showed ovicidal effect of root zone treatment and its $LC_{50}$ was 6.8ppm $LD_{50}$ (48 hrs after treatment) of imidacloprid to GPA was $0.4{\mu}g/g$ in case of topical application and $LC_{50}s$ by leaf dipping and root zone treatment were 1.9 ppm and 13.7 ppm respectively. Leaf dipping was more effective than root zone treatment in GPA At topical application $LD_{50}$ (48 hrs after treatment) of imidacloprid to chewing type insect pests, TCW and BAW, were greater than 1,492 and $312{\mu}g/g$ and $LC_{50}s$ by leaf dipping method were 4,803 and Heater than 5,000ppm respectively. This means that imidacloprid has much less effect on chewing type insect pests, TCW and BAW. $LD_{50}$(48 hrs after treatment) of imidacloprid to wandering spiders, Pirata subpiraticus, Pachygnata clercki at topical application were greater dan $2941{\mu}g/g$ and greater than $2,976{\mu}g/g$ respectively and that to webbing spider, Ummeliata insecticeps, was 357 ${\mu}g/g$. Imidacloprid showed very low toxicity to the spiders and its selective toxicity ratios between spiders and BPH were greater than 19,600, greater than 19,800 and 23,800, respectively.

• Korean Journal of Breeding Science
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• v.41 no.3
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• pp.288-291
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• 2009

A new commercial rice variety "Donghaejinmi" is a japonica rice (Oryza sativa L.) with lodging resistance and high grain quality. It has been developed by the rice breeding team of Yeongdeog Substation, National Institute of Crop Science (NICS), RDA. This variety was derived from a cross between "Milyang 64" as a resistance source of brown planthopper (Bph) and "Milyang 165" as grain quality source. The donor parent, "Milyang64" has been backcrossed three times with recurrent parent, "Milyang165" and selected by the pedigree breeding method. The pedigree of "Donghaejinmi", designated as "Yeongdeog 41" in 2003, was YR21259-B-B-68-1. It has a short culm length with 69 cm and medium-late growth time. This variety is resistant to stripe virus and moderately resistant to leaf blast disease with durable resistance. It also has tolerance to unfavorable environment such as cold, dried wind and storm. Milled rice kernel of "Donghaejinmi" is translucent, clear in chalkness and good at eating quality in panel test. The merit of this variety is high head rice ratio, which is essential element to produce an article of superior quality rice brand. The yield potential of "Donhaejinmi" in milled rice is about 6.05 MT/ha at ordinary fertilizer level of local adaptability test. This cultivar would be adaptable to Yeongnam inland plains and eastern costal area of Yeongnam province.