• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.627-638
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• 2022

This study was conducted at a village fishing farm on 4 peaks on the main island of Jeju Island and 2 peaks on an inhabited island to compare the distribution characteristics of seaweeds along the coast of Jeju Island from May to December 2018. A total of 101 species of seaweeds were surveyed, including 13 species (12.9%) of green algae, 24 species (23.8%) of Phaeophyta, and 64 species (63.4%) of Rhodophyta. The largest number of seaweeds appeared in May and the fewest in October, showing typical features of a temperate sea area. The number of seaweed species that appeared was 66 and 65 species at the water depths of 5 m and 8 m, respectively, and the largest was 74 species at 12 m. The number of seaweeds that appeared by area was the largest at 66 species on Udo Island, an eastern island near Jeju Island, and the lowest at 27 species in Pyoseon-ri, an eastern part of Jeju Island. The important values of emerging species were high in the order of, Ecklonia cavaand Corallina crassissima at 21.1% and 20.3%, respectively, Corallina aberransat 9.2%, Amphora ephedraeaat 6.2%, and Sargassum macrocarpumat 4.4%. Among seaweeds, an average of 11.2 species of coralline algae appeared, and the mean importance value was 32.6% in the sear area. The lowest importance value was 14.7% on Udo Island, and the highest was 41.0% in Pyoseon-ri. The mean ecological evaluation index (EEI) of seaweed colonies ranged from 2.1 to 10. It was the lowest at the water depth of 12 m in Pyoseon-ri in May and June and was 7.3 or higher in other areas, indicating good condition. This study rated the standardized ecological grade I for the water depth of 12 m on Udo Island and grade II for the water depths of 5 m and 8 m in Sagye-ri and on Chujado Island. Grade III was the water depth of 5 m and 12 m in Pyoseon-ri and Guideok 2-ri and the water depth of 5 m and 8 m in Pyeongdae-ri, and grade IV was the water depth of 8 m in Guideok 2-ri.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.69 no.1
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• pp.25-33
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• 2024

This experiment was conducted at the affiliated farm of the Suncheon University from 2022 to 2023 to investigate the growth, yield, and quality characteristics of soybeans based on the treatment method of Methyl Sulfony Methane (MSM) for the establishment of stable production practices. In the initial investigation of growth characteristics in 2022, an increasing trend in characteristics such as plant height, stem thickness, and branching index was observed as the treatment concentration increased from 50% to 200%. Yield components also followed the same trend, with the basal fertilization + top dressing 3 times at 200% treatment showing the highest yield at 355 kg·10a^-1, with the highest number of pods. In the subsequent study to determine the optimal concentration exceeding 200% in 2023, growth characteristics showed a trend of 400% > 200% > 800%. The basal fertilization + top dressing 3 times at 400% treatment exhibited the longest plant height (106.7 cm) and the most branches (6). In terms of seed quality, this treatment also had the highest proportion (66.9%) of seeds with a diameter over 6.7 mm. Additionally, in yield components such as pods, seeds per pod, and 100-seed weight, the basal fertilization + top dressing 3 times at 400% treatment showed the highest values, resulting in a maximum yield of 374 kg·10a^-1, representing a 23.4% increase compared to the control. Therefore, for the optimal production of high-quality soybeans, it is recommended to apply the treatment of basal fertilization + top dressing 3 times at 400% concentration, with top dressing occurring at 30-day intervals before harvest.

• Parasites, Hosts and Diseases
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• v.28 no.4
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• pp.241-252
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• 1990

In a basic attempt to develop the prophylactic and therapeutic measures on intestinal giantcystic disease of the Israel carp, C), prinks carpio nudum, the effects of physical and chemical factors on viability or survival of the spores of Thelchcnellus kiteuei were checked in vitro by means of extrusion test on the polar filament. When the fresh spores suspended with 0.45% and 0.9% scdium chloride solution and distilled water were laid at $5^{\circ}C$ and $28^{\circ}C$ for short terms, the extrusion rates increased until the 3rd day, meanwhile when son;e of them were suspended with Tyrode's solution at $-70^{\circ}C$ the rates increased gradually until the 8th day. Viabilities of the spores suspended with 0.9% saline and added antibiotics to the suspension at $5^{\circ}C$ for long terms lasted for 997 days and 1, 256 days (presumed values) at maximum, respectively. The spores suspended with distilled water at $28^{\circ}C$ for long terms survived 152.4 days, but the spores suspended with Tyrode's solution at $-70^{\circ}C$ for long terms showed almost the same viable pattern as early freezing stages up to 780 days. The spores suspended with Tyrode's solution, frozen at $-70^{\circ}C$ and thawed at $5^{\circ}C$, showed the highest rate of extrusion of the polar filament. In the case of frozen spores, the extrusion rates during heating tend to become higher in accordance with the increase of frozen period, and the critical points of 180 day-frozen spores to be killed were generally 78.5 hr. at $60^{\circ}C$, 23.4 hr. at $70^{\circ}C$, 189.1 min. at $80^{\circ}C$ or 10.5 min. at $90^{\circ}C$. The longer the spores were frozen, the more time was needed for the death of spores after thawing; 20 days-17.4 days, 100 days-33.2 days, and 400 days-37.8 days. The longer the spores were frozen, the more time was needed for the death of spores at a conventional when they were dried air drying condition, 540 days-23.5 days, 160 days-21.0 days, and 20 days-14.4 days. On the other hand, the longer the spores were frozen, the more spores were dead rapidly when they were irradiated with 10W UV-ray; 100 days-26.0 hr, 300 days-21.9 hr, and 540 days-13.9 hr. The time needed for killing 200 days-frozen spores by various disinfectants at 1, 000 ppd was 5.2 min. by calcium oxide, 10.4 min. by potassium permanganate, 27.8 min. by malachite green and 14.3 hr. by formalin. Transient inhibitory effects of the extrusion of the polar filament were observed by various antiprotozoal and antifungal agents in the descending order of ketoconazole. metronidasole and dapsone. The above results presume that full drying, followed by spraying CaO and maintaining sunny condition for a few days on the concrete bottoms of knish farm may be an effective method for the prevention of intestinal giant.cystic disease.