• KOREAN JOURNAL OF CROP SCIENCE
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• v.44 no.2
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• pp.122-128
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• 1999

Three rice cultivars, Namweonbyeo (early maturing), Hwaseongbyeo (medium maturing) and Dongjinbyeo (medium-late maturing) were trans-planted with 3 different seedling ages to investigate their growth habits and to improve the cultural method in paddy fields in the southern plain area of the Honam region in 1993. The 10-day old seedlings had more vigorous elongation of plant height and higher tillering ability but lower effective tiller rate, when compared with 35-day or 40-day old seedlings. Leaf area index and top dry weight were lower in 10-day old seedlings up to 40 days after transplanting but thereafter, were not different among seedlings ages. CGR was later in 10-day old seedlings, up to 30 days after transplanting, but in 30 to 40 days after transplanting, it was reversed. RGR was the highest in infant seedlings to 40 days after trans-planting, while in 50 days after transplanting, it was reversed. Panicle number and spikelet number per square meter were the highest in 40-day old seedlings, next highest in 35-day old seedlings and the lowest and in adult seedlings up to 40 days after transplanting, while spikelet number per panicle was vice versa. Milled rice yield did not vary significantly by seedling ages, but among the varieties, it was less in Hwaseongbyeo compared with Naweonbyeo and Dongjnbyeo.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.269-272
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• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• Korean journal of applied entomology
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• v.22 no.1 s.54
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• pp.21-25
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• 1983

To develop forecasting methods of rice sheath blight caused by Rhizoctonia solani, two rice cultivars Jinheung (Japonica type) and Yushin (Tongil type) were used from 1976 to 1981. Severity of rice sheath blight disease at maturing stage was estimated by top lesion height, percentage of top lesion height vs. plant height in July and lesion index on September 11. The relationship between top lesion height on July 11 and degree of damage at maturing stage for a cultivar Yushin was represented by the equation of Y=4.64x-13.2, and $r=.840^{**}$, where Y is degree of damage by shea4h blight at maturing stage and x is top lesion height on July 11. Considering the percentage of infected hills/stems was rapidly increased from July 11 to August 1, the most effective period and time for fungicide spray were considered July 15 and July 25 or July 25 and August 5.

• Korean Journal of Agricultural Science
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• v.3 no.1
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• pp.23-30
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• 1976

This study was done to find out the effect of seeding seasons of rice varieties on the occurence of sheath blight caused by Corticium sasakii. The results obtained are summarized as follows; 1. The percentage of infected stems and susceptibilities to sheath blight wered ecreased as the transplanting dates were delayed. 2. The susceptibilities to sheath blight of early maturing varieties were high, medium maturing varieties were intermediate and late maturing varieties were least. 3. The percentages of infected stems of Indica X Japonica varieties checked on 28th July were lower than those of Japonica varieties, but the susceptibilities were not significant between them. 4. At all varieties, highly significant correlation was recognized between the susceptibilities and the heading dates. Also relatively high correlation was appeared between the susceptibilities and the accumulated temperatures from 10 days before heading date to 30 days after it. This indicates that the susceptibility was much influenced by high temperature of the latter part of the rice plants growth.

• Korean journal of applied entomology
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• v.50 no.4
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• pp.379-382
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• 2011

The damage rates of peach pyralid moth(Dichocrocis punctiferalis), which damages the chestnut fruits, were investigated annually from 1995 to 2010 according to year, region, and maturity. The damage rate by D. punctiferalis was the highest (34.5%) in 1998 and was the lowest (17.9%) in 2000. The pattern of the damage rate showed a repeating three-year cycle. There was a negative correlation ($-0.6261^*$) between rainfall and damage rate. There was a positive correlation ($0.5826^*$) between temperature and damage rate. The average damage rate of all surveyed regions was 22.2%. Of the surveyed areas, Hapcheon had the highest at 27% and Hamyang had the lowest at 15.0%. The damage rate of chestnut fruit depending on the maturity was 26.1% in an early maturing cultivar (Dantaek), and 19.3% and 21.1% in a late maturing cultivar (Eungi) and a medium maturing cultivar (Chukpa), respectively.

• Applied Microscopy
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• v.28 no.4
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• pp.447-463
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• 1998

This study was carried out to investigate the histomorphological changes and the electrophoretic patterns of egg components, obtained from 100 of 2-year-old female catfishes (Silurus asotus). Female Korean catfishes collected in the vicinity of Chollabukdo have synchronous ovaries which discontinously ovulate eggs during the breeding season (from late May until early July). The fishes were killed by severing the spinal cord just posterior to the head after immobilization with tricaine methanesulfonate (MS 222). Especially, the light microscopic and ultrastructural changes of ooplasm and follicular membranes of oocytes, were examined by means of light and transmission electron microscopy. The size of the nucleoli and number of the yolk granules increased as the oocyte groved. Yolk granules were deposited in the oocyte as fluid Due to tile presence of large early and late maturing oocytes, their ovaries were enlarged, transparent, granular and greenish in color. As the percentages of fish in late maturing oocyte (LMO) and ripe oocyte (RO) stage increased from March to April, mean gonadosomatic index (GSI) values (19.95%) increased. Zona radiata changed from squamous into cuboid in shape in the early maturing oocyte (EMO) stage. Processes, microvilli, from the zona radiata and from the oocyte grow, and make contact with each other in the pore canals of the zona radiata during vitellogenesis, but are withdrawn as the zona radials becomes more compact and devoid of pore canals during oocyte maturation. Seasonal changes in the microscopic appearance of the ovaries were well correlated with those in both gonadosomatic index and macroscopic appearance. The main cytological changes such as increase in size of cell, nucleus, nucleolus, and increase in number of nucleoli and mitochondria demonstrated with electron microscopy in the previtellogenic oocytes of Korean catfish, provided evidences for important synthetic processes in an early preparatory phase of oocyte development. The electrophoretic pattern of major band in mature stage was much thicker (24 k, 66 k, 90-110k dalton) than that in previtellogenic phase.

• Korean Journal of Agricultural and Forest Meteorology
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• v.2 no.4
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• pp.148-155
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• 2000

The typhoon and flooding injury in rice were investigated both the region of downpour at the middle of August and the region of typhoon 'Yanni' at the late of September, 1998 in Kyongbuk provincial of Korea. More than 10% of rice stem were buried by soil inundation, the heading was delayed and the high node tiller was brought out. Yield components were deteriorated and yield was reduced. As the clay in the muddy water was attached on grains of rice, the yield was greatly reduced by reason of low grain filling ratio and polished rice ratio. The injury of muddy water was less at yellow ripening stage than at early ripening stage. On the other hand, the muddy water injury was reduced by the fungicide 'Benomyl' and 'Daconil' treatments. The degree of lodging according to varieties and ripening stages was not made a great difference, while the lodging was mainly occurred in the early transplanting time. In a week after lodging, viviparous spikes were occurred in almost all varieties, the degree of viviparity was shown highly in order of early maturing, middle maturing and late maturing varieties in the field as well as in laboratory test. The viviperous spikes were greatly occurred in the lodging toward hill space within row than row space because the more grains were touched on the ground.

• Korean Journal of Organic Agriculture
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• v.10 no.4
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• pp.69-78
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• 2002

This experiment was conducted to investigate the changes of sugar contents and chip color during 104days storage after harvesting of five potato varieties. The potato varieties were planted on 1st April in 1999 and harvested on 10. July in 1999. $No_2$ contents in potato petiole tended to decrease repidly at tuber maturing stage. $K^+$ contents in potato petiole tended to in crease at 70 days ofter planting on medium maturing varieties, and at 90 days after planting on late maturing variety. Snowden variety was no desirable cultivar for processing on spring cultivation due to long growth period. Contents of solid and sugar in potatoes affected on potato chip color. Higher contents of solid in potato varieties showed low sugar contents and no change on chip color during storage.

• Journal of The Korean Society of Grassland and Forage Science
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• v.42 no.3
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• pp.188-194
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• 2022

This study was conducted to investigate the forage characteristics of very early-maturing Italian ryegrass (IRG) three cultivars within September, 2021 to July, 2022 in Cheonan, Korea. We used three different cultivars of Italian ryegrass in this study "Greenfarm" "Greenfarm2ho" and "Greenfarm3ho" The results of heading date in this study, "Greenfarm" was recorded 3 days earlier than the other two cultivars, and its lodge tolerance score was the highest among the three. However, in case of plant length, there was no significantly difference in whole cultivars, in addition disease resistance, insect resistance and cold tolerance were not significantly different in three cultivars. The forage productivity of "Greenfarm2ho" was recorded the highest, especially the 1^st harvesting of "Greenfarm2ho" yielded significantly the highest and superior to other varieties. As a result of feed value analysis, three cultivars were generally superior to overseas varieties and in particular, "Greenfarm2ho" was recorded to have excellent value because of the lowest NDF and ADF content. On the other hand, there was no significant difference in crude protein content among three varieties. In case of the monosaccharides content "Greenfarm3ho" had significantly higher glucose content than other two varieties, therefore the "Greenfarm" has advantage for preparing high quality of silage. In contrast, there was no significant difference among three varieties in fructose content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.20
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• pp.100-106
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• 1975

Germinating ability of green seed in maturing period was investigated to develop the technics on generation shortening. Rapeseed did not germinate until 40 days after flowering (=DAF) in green seed and 50 DAF in dried seed. Effective germination to be utilized for generation shortening came on 55 DAF for dried seed by heating and on 75 DAF for green seed. The periodic time of seed dormancy in maturing period had two cycles and rest period was considered that it was different according to the ecological types of early, middle and late maturity.