• Korean Journal Plant Pathology
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• v.11 no.4
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• pp.338-343
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• 1995

Incidence of blast caused by Pyricularia grisea on five new cultivars and four elite lines (C/L) of rice was investigated at different locations, Icheon, Chuncheon, Jecheon and Naju, 1992 to 1994. Disease indices of leaf blast on the tested C/L except Juanbyeo and Keumnambyeo ranged from 0 to 6 in the blast nursery. Under the field conditions, percentages of diseased leaf area of Kuemnambyeo were 6.5% in Jecheon and 2.8% in Icheon in 1993. The incidence of panicle blast on the C/L except Suweon 394 and Milyang 117 differed depending on the locations and years. In case of Unjangbyeo, panicle blast was rarely observed n the fields in Icheon and Naju, but the disease incidences were 21.8% in Jecheon in 1993 and 16.4% in Chuncheon in 1994. Race distribution of the blast fungus was variable according to the locations. The major race in the Jecheon site was KI-197, which was recently identified.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.53 no.3
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• pp.239-243
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• 2008

This experiment was carried out to elucidate the appropriate split application method of nitrogen fertilizer in infant rice seedlings which show poor seedling growth resulted from extended seedling nursery duration more than 12 days. The 16 day-old infant rice seedling (DOIRS) showed poor seedling growth than 8 day-old seedling. Early growth of transplanted 16 DOIRS was poor, compared with that of transplanted 8 DOIRS. However, the poor plant growth estimated by plant height, tiller number, and the number of newly developed roots was compensated by 70-0-30% (basaltillering-panicle initiation) of nitrogen split application. In 70-0-30% plots among split nitrogen application methods, tiller number, biomass, and leaf area at heading stage of rice showed the highest values. Sixteen DOIRS plots showed lower grain filling and 1000-grain weight, resulted in lower yield of rice than 8 DOIRS plots in the same nitrogen split application. However the lower yield in 16 DOIRS plots was recovered by 70-0-30% of nitrogen split application method to a similar level in 8 DOIRS plots in which nitrogen was split applied by 40-30-30%.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.2
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• pp.121-129
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• 1987

Indonesian varieties were compared with Korean varieties on three different sowing times, each of which had three different nursery periods, at Suwon, Korea (126$^{\circ}$ 19'E and 37$^{\circ}$ 16'S). Indica-type varieties with exception of late-maturing ones had heading regardless of sowing time and nursery period. As the Korean varieties com-pared with those, the earlier sowing plots with shorter period of nursery gave better result in yields and yield components.

• Korean Journal of Agricultural Science
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• v.4 no.2
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• pp.199-214
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• 1977

These studies were conducted to obtain basic information of the rice blast resistance in comparision with blast occurrence patterns in the blast nursery test in Korea. One hupdred and twenty nine rice varieties including several blast differential varieties and 30 combinations of pedigree lines were tested at six different locations, Suweon, Chulweon, Chuncheon, Iri, Jinan, Imsil, and Milyang, in 1976~1977. The results obtained are summarized as follows: 1. When blast resistance was tested using three sets of differential varieties at six locations, prevalent races were different depending on the location and differential variety set tested. 2. There were regional differences in blast disease reation among Japonica rice varieties and among Indica${\times}$Japonica crosses. 3. At Suweon blast disease reactions of pedigree lines were different from that at Imsil. 4. Three varietal groups were made depending on the develpment of rice blast in the nursery test. 5. In general, highly resistant varieties to rice leaf blast were also resistant to neck blast, but there were exceptions.

• The Plant Pathology Journal
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• v.32 no.3
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• pp.228-241
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• 2016

In our previous study, we reported that a novel endophytic bacterium Bacillus oryzicola YC7007 has suppressed bacterial diseases of rice via induced systemic resistance and antibiotic production. This endophytic strain, B. oryzicola YC7007 was used as a biological control agent against bakanae disease of rice caused by Fusarium fujikuroi, and its mechanism of interaction with the pathogen and the rice was further elucidated. Root drenching with B. oryzicola YC7007 suspension reduced the disease severity of bakanae significantly when compared with the untreated controls. The treatments of B. oryzicola YC7007 suspension ($2.0{\times}10^7cfu/ml$) to the rice rhizosphere reduced bakanae severity by 46-78% in pots and nursery box tests containing autoclaved and non-autoclaved soils. Moreover, in the detached rice leaves bioassay, the development of necrotic lesion and mycelial expansion of F. fujikuroi were inhibited significantly by spraying the culture filtrate of B. oryzicola YC7007. Drenching of ethyl acetate extracts of the culture filtrate to the rhizosphere of rice seedlings also reduced the bakanae disease severity in the plant culture dish tests. With the root drenching of B. oryzicola YC7007 suspension, the accumulation of hydrogen peroxide was observed at an early stage of rice seedlings, and a hormonal defense was elicited with and without pathogen inoculation. Our results showed that the strain B. oryzicola YC7007 had a good biocontrol activity against the bakanae disease of rice by direct inhibition, and was also capable of inducing systemic resistance against the pathogen via primed induction of the jasmonic acid pathway.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.428-433
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• 1989

The objective of this experiment was to determine if there were feasible to transplant infant rice seedling for machine transplanting. Cultivars tested were Sobaegbyeo and Daecheongbyeo, ]aponica type cultivars. Infant seedling, young seedling and semi-adult seedling were raised with sailor rock wool in seedling tray from 1986 to 1988. Infant rice seedling raised more than 4 days after sowing with rock wool was uniform, and low in ratio of missing hill at machine transplanting. Tiller number per m$^2$ was more in infant rice seedling, young seedling and semi-adult seedling, in that order. Heading dates were not significantly different among seedlings applied, however rice plant sown directly was later 4 or 5 days than any other seedlings. Panicle number per m$^2$ was more in infant seedling than in semi-adult seedling, but ripened ratio was lower in infant seedling due to lodging. Thus there were not greatly different in yield among seedlings tested. Therefore infant rice seedling (more than 5cm in plumule length) raised for 7 days was most optimum, and rock wool would be used as a nursery soil instead of nursery soil for raising infant rice seedling in machine transplanting.

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.04a
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• pp.168-169
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• 2000

• 한국약용작물학회:학술대회논문집
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• 2011.09a
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• pp.100-101
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• 2011

• Proceedings of the Korean Society of Crop Science Conference
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• 2000.11a
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• pp.167-168
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• 2000

• Proceedings of the Korean Society of Crop Science Conference
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• 1992.05a
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• pp.78-79
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• 1992