• Proceedings of the Korean Society for Bio-Environment Control Conference
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• 2006.05a
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• pp.104-107
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• 2006

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.169-174
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• 2017

BACKGROUND:Kiwifruit growers build their vineyards using many windbreaks to protect their kiwifruit vines from defoliation injury by strong winds such as typhoon. In this study, we have compared fruit quality, budbreak rate and floral bud as affected by windbreaks. And also we surveyed several microclimate indices of kiwifruit orchard depending on the covering materials of arch-type windbreaks. METHODS AND RESULTS: Five different windbreak materials including polyethylene film (PE), blue- and white-colored nets were tested in pipe-framed archtype kiwifruit vineyards as the covering materials. Photosynthetically active radiation (PAR), annual mean temperature (AMT) and chill unit (CU) as well as fruit quality were compared among the covering materials. In all treatments, annual PAR was more than $400{\mu}mol\;m^{-2}s^{-1}$, in which kiwifruit leaf could reach its maximum photosynthesis, since the leaves were emerged. Annual mean temperature was greater in 0.1 mm-PE covering as much as $1-2^{\circ}C$ than other windbreaks. In CU calculated by three different models, all windbreaks showed more than 1400 CU that is fully fulfilled CU for kiwifruit rest completion. There were no difference in budbreak rate among the covering materials. Fruit weight was heavier in 0.1 mm-PE and white-net (4 mm) than other windbreaks. CONCLUSION: Regardless of the windbreak materials, the PAR quantity was enough for kiwifruit photosynthesis. And CU for kiwifruit rest completion was fully achieved in all treatments. However, with respect to fruit weight, quantity of PAR, and AMT, etc., It is highly recommended for kiwifruit growers to choose 0.1 mm-PE and white-net (4 mm) as for their windbreaks materials.

• Research in Plant Disease
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• v.10 no.4
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• pp.304-309
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• 2004

Girdling of trunk and rainproof installation over kiwifruit (Actinidia deliciosa) trees were turned out to alleviate bacterial blossom blight effectively in kiwifruit orchards. The disease was most effectively prevented by girdling of tree trunks with 20 mm width around April 10 before about 45 days of flowering stage of kiwifruit, but control efficiencies were not affected by height of girdling on trunks above the ground. Use of a transparent polyvinyl film to protect kiwifruit trees from rain was more effective than windbreak net to prevent the disease, irrespective of kinds of rainproof installation. Installation of partial rainproof vinyl cover over kiwifruit trees around March 10 before about 75 days of flowering stage of kiwifruit prevented most of the disease occurrence on kiwifruit. It is expected that girdling of tree trunks and installation of partial rainproof vinyl cover over kiwifruit trees will be practical as environmentally friendly control methods to manage bacterial blossom blight in kiwifruit orchards.

• Research in Plant Disease
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• v.8 no.3
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• pp.179-183
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• 2002

to investigate occurrence of kiwifruit bacterial canker disease,172 kiwifmit orchards in Jeonnam and Gyeong-nam provinces were surveyed from March to April in 1999. In the south coast region of Korea, such as Haenam, Wando, Jindo, Jangheung, and Bosuns, red-rusty brown bacterial oozes were observed in 17 kiwifvuit orchards. Disease incidences varied from 2.2% to 100% depending on various regions. Total 22.8 ha of kiwifruit orchards were destroyed by occurrence backerial canker at 1999 in Korea. Orchard in Wando, Jindo, and Goheng were severely damaged in 1999. The seasonal variation of bacterial canker incidence was also investigated from 1996 to 1997 on leaves, vines and twigs of kiwifruit. Red-rusty brown bacterial ooze was exuded from mid February or early March to late April in creaked site of vine and twig. The seasonal incidence of bacterial canker on leaves appeared from late April to late June, and rapidly increased during May, Optimum growth temperature of Pseudomonas sytingae pv. actinidiae was at $25^{\circ}C$ on King's B medium and did not grow at 33$^{\circ}C$. We suggest that spreading of bacterial canker was suppressed under the plastic flim and windbreak net house.

• Korean Journal of Environmental Agriculture
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• v.34 no.4
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• pp.288-293
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• 2015

BACKGROUND: This study was conducted to investigate the effect of the unexpected early loss of leaves on a newly-bred kiwifruit on the regrowth of axillary buds the current season and the early growth and development the following year.METHODS AND RESULTS: The vines were defoliated on Jul. 18, Aug. 16, and Sep. 17 in 2012 and on Jul. 16, Aug. 13, and Sep. 12 in 2013. The vines were defoliated 0 (control), 50, and 100% of the total number of leaves on a vine. The regrowth of axillary buds at 30 days after defoliation increased in proportion to defoliation degrees regardless of the defoliated time. Defoliation the previous season did not influence percent budbreak the next season. Percentage of floral shoots of the control vines was 27.4%, each bearing 2-3 flowers. In those vines defoliated 100% in August and September, however, percent floral shoots and number of flowers significantly reduced.CONCLUSION(S): Defoliation in July, August, and September didnot affect percent budbreak the following year regardless of degrees of defoliation. A 100% defoliation in August and September significantly reduced flowering the following year compared to the control; that in August resulted in no floral buds at all.

• Journal of Bio-Environment Control
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• v.15 no.2
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• pp.138-148
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• 2006

This study was carried out to evaluate the structural safety fur both the attached wind-protecting wall in greenhouse and the detached one installed outside. Regarding the attached wind-protecting wall in greenhouse, the analysis was conducted by doing a fluid-structure coupled field analysis using both CFX-5.7 and ANSYS 8.1 and also under the design condition of an instantaneous maximum wind velocity of $30.9m{\cdot}s^{-1}$. Three kinds of the width ranged from 30 to 90cm were considered in this study. With regard to the detached wind-protecting wall, the structural saffty was analyzed under the pressure difference of 1,117 Pa which corresponded to a wind velocity of $50m{\cdot}s^{-1}$ and the analytical results were also compared with theoretical ones. The result showed that there was little difference in the distribution of velocity overall and total pressure on the lateral side according to the width of the attached wind-protecting wall, but greenhouse with wind-protecting widths of 30 to 60cm has been reinforced to the extent of about 11% when compared with the case of being without the wall. The result also showed that the detached wind-protecting wall with a main-column interval of 3m was not stable so that it was necessary for the detached wind-protecting wall to be adequately reinforced to secure structural stability. Finally, there was great difference between analytical results and theoretical studies. The difference meant that there was some possibility of including errors when a theoretical study was done in three dimensional structure.