(39(1):47-54)Dissemination of White Root Rot Disease of Loquat and Its Control

白紋羽病菌（Rosellinia necatrix）在本省已發現能感染枇杷、葡萄、梨、桃、蘋果及茶樹等作物。將這些不同寄主來源的白紋羽病菌製成麥粒菌種接種枇杷，於二至四個月內皆能使其萎凋、死亡。枇杷白紋羽病菌在田間之存活與傳播主要是依靠罹病的枇杷根，病原菌藉埋置土中的罹病根至少可存活三年以上。而田間雜草「香附子」在受到病原菌拓殖後亦可能有利於病原菌之傳播與存活。本病之防治首要挖除罹病植株的根部。經室內藥劑篩選及盆砵試驗得知，罹病跡地灌以貝芬替（Bavistin 50％WP）、免賴得（Benlate 50％ WP）或邁隆（Basamid 85％ WP）等藥劑之500倍液，再於土表覆以透明之塑膠布可得良好的殺菌效果。 White root rot disease caused by Rosellinia necatrix can make many plants wilt and die, particularly on fruit trees. Based on our survey, the fungus had been found to infect loquat, grape, pear, peach, apple and tea plants in Taiwan. The pathogens collected from these six host plants can all infect loquat seedlings and make them appear the same wilting symptom within two to four months. The pathogen harbouring in the natural infected roots of loquat underground can survive for at least three years. While the bare mycelia and microsclerotia of the fungus can not survive in soil or shading condition for more than one month. Moreover, the weed (Cyperus rotundus) may also facilitate the pathogen survival and dissemination for the mycelia of the pathogen can easily colonize on its roots. Field sanitation by digging out the disease roots would greatly decrease the inoculum source in orchard. Fungicide trials with soil plate method and pot test showed that drenching the soil with 500X diluted solution of Bavistin 50% WP, Benlate 50% WP or Bamamid 85% WP and then tarping with transparent polyethylene on the soil surface were potential measures for controlling this disease