• Title/Summary/Keyword: dry rpt

Search Result 2, Processing Time 0.042 seconds

Occurrence of Dry Rot on Cymbidium Orchids Caused by Fusarium spry. in Korea

  • Kim, Wan-Gyu;Lee, Byung-Dae;Cho, Weong-Dae;Sung, Jae-Mo
    • The Plant Pathology Journal
    • /
    • v.18 no.3
    • /
    • pp.156-160
    • /
    • 2002
  • Cymbidium orchids with blight and rot symptoms were collected, and a total of 63 isolates of Fusarium app. was obtained from pseudobulbs, roots, and leaves of the diseased plants. The isolates were identified based on their morphological characteristics. Out of the 63 isolates of Fusatium sup., 51 isolates were identified as F. oxysporum, 10 isolates as F. solani, and the rest as F. proliferatum. F. oxysporum was isolated from all the Cymbidium spp., while F. solani and F. proliferatum were isolated only from Cymbidium ensifolium and C. ginatum, respectively. Isolates of the three Fusarium spp. were tested for pathogenicity to their hosts by artificial inoculation. The strongly pathogenic isolates of Fusarium spp. induced severe dry rot of pseudobulbs and roots of the host plants. The symptoms progressed up to the basal part of the leaves, which later caused blight of the entire plant. The dry root symptoms induced on the plants by artificial inoculation with the isolates of Fusarium app. were similar to those observed in the growers'greenhouses. This is the first report of dry rot of Cymbidium spp. caused by F. oxysporum, F. solani, and F. proliferatum in Korea.

Improving Curing Rate and Physical Properties of Korean Dendropanax Lacquer with Thermal and Photo Initiator by Dual Curing (이중경화법을 이용한 열개시제 및 광개시제가 배합된 황칠도료의 경화속도 촉진 및 물성향상 연구)

  • Hwang, Hyeon-Deuk;Moon, Je-Ik;Park, Cho-Hee;Kim, Hyun-Joong;Hwang, Baik
    • Journal of the Korean Wood Science and Technology
    • /
    • v.38 no.4
    • /
    • pp.333-340
    • /
    • 2010
  • The Korean Dendropanax lacquer, made from a natural resinous sap from Dendropanax orbifera Lev., was used as a golden and transparent varnish for the traditional artifacts (armor uits, helmets, arrowheads, etc.) to make them be brilliant golden color. The cured film of the acquer has excellent protective properties such as weatherability, water resistance, and nticorrosive. But, one of disadvantages is that takes a long time and much energy to fulfill curing the lacquer. The chemical constituents of the lacquer contained conjugated diene compounds s the photopolymerizable monomers. These monomers easily polymerized in sunlight to form olden-colored, hard-coating films in a short time. Photooxidation may be one of the most mportant reactions in the chemistry of the lacquer. Although the Korean Dendropanax Lacquer hould be dried to a thoroughly dry stage to achieve optimal film properties, curing with elevated emperatures may be required for the protracted curing time at atmospheric temperature. So we ntended to accelerate the curing rate of the lacquer by dual curing of thermal and radiation uring. The effect of thermal initiator on the thermal curing reaction was evaluated by monitoring he changes in double bond peak with FT-IR. Then the curing rate of the lacquer blended with hermal initiator and photoinitiator together was measured during dual curing using a RPT with V spot curing machine. Thermal initiator not only accelerated the curing rate but also improved he physical property. And the curing rate of the Korean Dendropanax lacquer was improved by ual curing method of thermal and UV curing. According to these results, the application area of he Korean Dendropanax lacquer could be expanded to surface coatings for electronic devices uch as mobile phones or electronics.