• 作者： 王錫慶
• 作者服務機構： 國立中興大學植物病理學系
• 中文摘要： 桑樹銹病在木省日趨普遍，尤以苗栗縣的大湖，南投縣的大庄，臺南縣的麻豆寮，以及臺東縣的池上等地發生最為嚴重，因此影響春蠶與秋蠶的桑葉供應甚大。桑銹病發生於幼芽、嫩葉、新梢、成葉、葉柄、花穗及桑椹上，尤以葉片被害最大。於秋季，罹病葉紛紛提前脫落，故無法達到預定的桑葉產量，因此桑農被迫減少養蠶次數。對本省蠶絲生產與外銷影響甚大。 桑樹銹病共有三種，在本省猖獗為害者係由Aecidium mori Barclay所引起。此病病原菌只產生銹子器（Aecidium）。在一年中春季與秋季均可發生。苗栗縣大湖與臺東縣池上春季發生比較普遍，南投縣大庄及臺南縣麻豆寮在秋季發生甚為嚴重。夏季可能受高溫限制發病較少，病原菌可在被害枝條上越冬，故疏於修剪的桑葉園被害最為嚴重。於不同桑樹品種中，罹病程度有顯著差異，在大湖地區發病嚴重者，計有在來桑品系208、376、176、205、175、377、236、462、277、182、61、209、590、499、157等。每一罹病葉片上的病斑均在50個以上。在來品系208發生嚴重者，一個病葉上病斑數目高達1,053個，即葉片幾全部為銹子器所遮蔽。因此罹病葉迅速脫落，影響樹勢很大。 由室內試驗，知病原菌之銹孢子於5～32℃之間均可發芽，但其發芽適溫為20～-24℃。由藥劑防治試驗結果獲知，銹克（75％ Plantvax） 1,500倍，殺普（18.6％ Saprol） 750倍，每週噴一次，對防治此病，效果甚為顯著，賽加樂（Sicarol, 50 WP）稀釋到2,500倍，雖仍有防治效果，但易於發生藥害。 利用等量的健全與發生銹病的桑葉，每天早、中、晚分別飼養數量及大小相同的兩組稚蠶，至結繭為止，每天並稱稚蠶的總體重及食後的桑葉殘餘物。結果餵健葉者蠶體大而重，所剩桑葉殘餘物少；餵病葉者蠶體小而輕，桑葉殘餘物多，發育稍差。餵健葉者所結蠶繭，其體積與重量均大於餵病葉者，餵病葉者其繭層率較餵健葉者顯著降低。
• 英文摘要： Mulberry rust, caused by Aecidium moriBarclay, has become one of the most destructiveand prevalent disease at Tahu (大湖), Tachuang(大庄), Hsiaying (下營) and Chihshang (池上) inTaiwan. The economic damage caused by thedisease is to reduce the yield and quality ofmulberry leaves in spring and autumn. The disease occurs on buds, shoots, leaves,leaf pedicels, flowers and fruits of mulberrytrees. It causes a deformation of young leavesand heavy defoliation of affected trees. Thecausal fungus appeared on both leaf surfacesand was probably to overwinter on old shootsof mulberry trees. Aecia are amphigenous,cuplate, orange yellow, 100-280μ. Pseudoperidialcells are polygonus, hyaline, 13.5-225 × 12-18μ.Aecidiospores are round or ellipsoid, orangeyellow, 12.5-27.5 × 8.5-20μ in size, cell, wallmostly 1-2μ thick finely echinulate. Diseaseincidence varies according to different mulberryvarieties. The local lines of mulberries such as208, 376, 176, 205, 175, 377, 236, 462, 277, 182,61, 29, 499, 157 are most susceptible to thedisease. According to our trials, the optium temper-ature for aecidiospore germination of the causalfungus was about 24℃. A trial of the control of mulberry rust withfungicides was carried out in 1977 at Tachuang.Plantvax and Saprol applied in one week intervalwere more effective than Antracol and DithaneM-45, but Sicarol was more or less phytotoxicto the mulberry leaves. The nutritive value of diseased leaves ofmulberries, especially in relation to their use insilkworm rearing, was more or less reduced thanthe healthy mulberry leaves, so that the growthof silkworm and the yield and quality of thecocoon of silkworm were also affected.
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