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Pine pitch canker is a virulent and incurable fungal disease of pine trees caused by the fungus ''Fusarium circinatum''.〔(Pine Pitch Canker - California Forest Stewardship Program )〕 Infected trees may exhibit a number of symptoms, including the appearance of canker: small areas of dead tissue which grow slowly, often over a period of years. Additional symptoms include discoloration on the branches, trunk and exposed roots. The fungus infects branches from the tips down, turning needles brown, and creates a flow of amber pitch that runs down the trunk.〔(Pitch Canker Diagnosis - California Department of Forestry )〕 == Background == "Pitch canker" is now found in seventeen of California's counties from Mendocino to San Diego. Scientists fear that the disease will spread to the Sierra Nevada, Coast, and Cascade mountain ranges. The fungus is transmitted by bark, cone and twig beetles whose dispersal may carry the disease to new locations. At this time, pine pitch canker cannot be eradicated. Officials in California have recommended that people avoid transporting infected trees or firewood from their region of origin, sterilize pruning tools with bleach before and after pruning operations, chip and spread or burn infected plant material, avoid using Monterey pines for landscape plantings, and report new occurrences of pitch canker to the California Department of Forestry and Fire Protection. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pine pitch canker」の詳細全文を読む スポンサード リンク
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