• Parasites, Hosts and Diseases
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• v.27 no.4
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• pp.261-270
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• 1989

The present study is intended to observe the chronologic changes of experimental sparganosis by histopathological observation and detection of circulating anti-sparganum IgG antibody using ELISA. Each of 25 mice was infected with aye spargana, and they were examined after 1, 2, 4, 10 weeks or 6 months from infection. The followings are summarized results. - 1. The plerocercoids were detected in the subcutaneous tissue of the trunk, neck or axilla, but a few often extended into the skeletal muscle. The recovery rates were 72% at the first week, 80% at the second week, 95% at the fourth week, 92% at the tenth week and 100% at .the sixth month. The larvae grew slowly in both length and weight until 6 months. 2. Histopathologically, most of the larvae were observed alive in the soft tissue or skeletal muscle. Numerous eosinophils, neutrophils, Iymphocytes and plasma cells were infiltrated focally around the worms by the second week, but they surrounded the worms to form a layer of inflammatory reaction after 4 weeks of infection. Also histiocytes and fibroblasts began to appear around the inflammatory cells at 4 weeks. After 10 weeks, the worms encircled by a thin fibrous layer were found. After 6 months, the worms were surrounded by either fibrous tissue or active inflammatory cells. The inflammation looked more severe in the tracks left by the worms, rather than around the worms. 3, The level of anti-sparganum IgG antibody in the serum showed an increase by the fourth week, and a rapid and continuous increase was observed thereafter by the tenth week after infection. The high level of the IgG antibody was maintained up to 6 months forming a plateau curve. The present results suggest that the tissue reaction and antibody production in subcutaneous sparganosis become distinctive by the fourth week after infection.

• Journal of Korean Society of Forest Science
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• v.49 no.1
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• pp.6-10
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• 1980

The witches' broom disease of Paulownia tomentosa (Thunb.) Steud with which mycoplasmalike organisms are associated is widespread throughout Korea and poses serious threat to the cultivation of paulownia. Attempt was made to investigate the feasibility of field control of the disease with oxytetracycline hydrochloride (OTC). A total of 84 paulownia trees (6 year-old, DBH: 10-15cm) exhibiting severe symptoms of witches' broom were selected and treated during March to September. Solution of 1-10g of OTC dissolved in 0.1­2.0 of water was transfused into infected trees with gravity flow method from a dark-brown colored plastic reservoir (11 volume) through plastic tubes (1.2m long) connected to 2-4 holes (5 mm in diameter and 4-5cm in depth) bored in the basal part of the tree trunks (Fig. 1 and 2). Of 60 diseased paulownia trees injected with 2g of OTC in 0.1-2.0l of water during May to September, 1979, 58 trees resulted in complete remission of symptom development and resumption of healthy new growth at least up to September, 1980 when the last observation of the effect of OTC treatment for this experiment was made. The rest of two trees were dead probably due to too severe infection. Of 24 paulownia trees treated in March and April, 1979 complete remission of symptom development was obtained with 8 trees, and nine trees were partially prevented from symptom development in the following season. The remaining 7 trees were dead due to failure in uptake of OTC and partly because the trees were in too far advanced stage of infection. Application of highly concentrated solution of 2g of OTC dissolved in 0.1-0.2l of water per tree was just as effective as the 2g/1-2l treatment. Injection of 2g/1-2l required 3-4 days while treatment of 2g/0.1-0.2l reduced the time for injecting one tree down to less than 24 hrs. The result of this experiment demonstrates that basal trunk injection of 2g OTC/0.1-0.2l/tree is feasible for field control of paulownia witches' broom, provided that tree injection is performed in actively growing season (May-September) and at the initial stage of disease development.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.53-57
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• 2013

A severe defoliation by typhoon in early autumn reduces fruit quality for the current season and reserve accumulations for the next season. This study was conducted to determine the effects of foliar applications during the autumn on alleviating the damages after defoliation. Leaves of 2-year-old 'Fuyu' trees, grown in 50-L pots under a rain-shelter, were 75%-defoliated on September 9. In mid-September and early October, trees were treated either with eight foliar applications of urea or with four alternating applications of urea and $KH_2PO_4$ (urea + KP application), all at 0.5% (w/v). Trees untreated after the defoliation served as the control. The urea applications slightly increased N and P concentrations of the leaves collected on November 6, while urea + KP applications significantly increased P and K concentrations. Foliar applications did not affect fruit growth, but tended to decrease skin coloration. Fruit soluble solids increased by 1.5 and $1.0^{\circ}Brix$ for urea and urea + KP applications, respectively. There was a significant increase in dry weight of fine root for the foliar application treatments but not in those of aerial woods and larger roots. With the foliar applications, N concentration tended to increase in the permanent organs but not P and K, whereas soluble sugars and starch notably increased in shoot, trunk, or fine root regardless of the different applications. Results indicated that the foliar applications could partially help to restore fruit quality and carbohydrate accumulations in the defoliated trees.

• Journal of the Korean Institute of Landscape Architecture
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• v.46 no.6
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• pp.111-119
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• 2018

This study was carried out to investigate the growth characteristics and propagation methods of the Korean native Amelanchier asiatica, A. arborea, and A. alnifolia as fruit trees for gardens. Due to the lack of recent research on Amelanchier spp., their superficial classification is still unclear and the names are being used interchangeably. The results are obtained as follows : A. arborea and A. alnifolia were globular type multi-stemmed shrubs. A 20-year-old tree of A. asiatica was 7.8m in height, with a 5.2m crown width, with one trunk. As for the morphological characteristics, leaves of A. asiatica were oblong, with an acuminate of, 6.1cm and 3.6cm width, but A. arborea and A. alnifolia had acute obovate leaves. The leaf size of A. alnifolia was the largest among the three species. The flower size of A. asiatica was bigger than that of A. arborea and A. alnifolia. In addition, its petals and flower clusters were also the largest among the three species. The flowering of A. asiatica initiated on April 21 and then bloomed for a duration of 24 days in Osan, while that of A. arborea and A. alnifolia initiated flowering on April 12 and then bloomed for a duration of 22 days in the same location. The fruit of A. arborea and A. alnifolia were green on May 10~12, it changed into purplish red on May 24~26, and its matured on June 1~3. The duration of fruit persistence of A. arborea and A. alnifolia were 48~50 days. On the other hand, A. asiatica showed greenish fruit on May 20, it became red on September 4, and had fallen by October 3. The fruit size was the largest at 1.03cm of height and 1.12cm of diameter in the A. arborea, followed by the big berry of A. alnifolia and the smallest fruit in the native, A. asiatica. It was difficult to root due to the hardwood cutting of A. arborea at a 40% rate of rooting. In the softwood cutting, the rooting rate of A. arborea was increased by the treatment with concentrated IBA, especially at 5,000 and 7,000ppm. The optimum date for cutting was on June 27, when the rooting rate was more than 80%. The most effective method for rooting of A. arborea was rootone or 7,000 ppm IBA treatment on June 27 softwood cuttings, which showed a rooting rate of over 80%.