高接梨黑斑病之感染源與主要病害之防治措施

於1990－1993年間，檢測1,056個高接梨芽苞，由其中檢出Alternaria sp.與Venturia sp.之比率分別為59%與12%。具病原性之Alternaria佔12%，但對橫山梨無病原性，Venturia sp.則未測其病原性。Alternaria無法由高接梨田間徒長枝芽苞之內層鱗片檢出，而由外層鱗片檢出之比率為0.2%，但無病原性，可知本病菌無法在低海拔之田間殘存。芽穗分別浸Benlate或Iprodione再嫁接，無法防治黑斑病，而四至六週齡期之幼果，隔二星期施Iprodione，並於第二次施藥後立即套袋，則防治效果顯著。對其他主要病害之防治須清園與預防性施藥並行，依據生長期之防治策略可減少十次施藥，但是否可提前且拉長施藥間距仍須再評估。白粉病於5月下旬才開始發生，但不致影響果實肥大，因處於採收期間不適合施藥，而成為防治斷層，常在七至九月間造成葉枯。

關鍵字

高接梨；黑斑病；主要病害；防治措施

並列摘要

During 1990-1993, out of 1056 bud scales of Top-grafting pear scions, 59% and 12% of Alternaria sp. and Venturia sp. were found respectively. Pathogenicity of Venturia sp. were not examined, but 12 % of the Alternaria isolates were proved pathogenic to leaves of ”Nijuseki pear”, however all isolates were non-pathogenic to Hen-Shan pear. During the three years, 1000 buds of grafted pear trees in field were examined, and Alternaria sp. were isolated from 0.2% of the outer scale, but were non-pathogenic to pears, however none of them were isolated from inner bud scales, thus postulated, the pathogen didn't survive in low altitude level land. Healing of scions with their stocks were failed if the pear scions were dipped in Benlate or Iprodione before grafting. A two weeks interval and twice spray regimen of Iprodione to six-week age pear fruit, followed with immediately bagging, were proved effective for management of pear black rot disease. Powdery mildew were prevalence during end of June to middle July, the atrophy stage of pears, but the disease seemed non-harmful to pears fruits, however leaf blight were found after end of July. According two years evaluation program, disease management regimen were proposed better to follow with cultivation program than with calendar course.

並列關鍵字

Top-grafted pear ； Alternaria fruit rot ； Major diseases ； Management scheme

國際替代計量

高接梨黑斑病之感染源與主要病害之防治措施

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