作者：曾惠中
類別：圖書文獻類 - 手稿
材質：紙質
年代：1969~1969
尺寸：長:24.6 x 寬:20.5 (cm)
藏品來源：曾惠中捐贈
登錄號：2019-001-0001-018
藏品描述：由病毒Citrus tristeza virus (CTV)造成，Tristeza是系統性病害，感染後，苗株轉黃，從頂端開始向下枯死或木質部凹陷，影響生長及果實品質。CTV存在組織內，隨著罹病組織(枝條)傳播，藉由扦插或嫁接後立足新園，成為初次感染源。植株間的自然傳播則靠蚜蟲。蚜蟲從罹病株獲毒，隨後無潛伏期即可傳播病毒，傳毒時間24～48小時，CTV不在蟲體內繁殖。CTV雖然可利用機械接種傳播，但在田間經由機械傳播之機會可能很少。CTV也不經種子傳播。目前台灣所種植之柑橘幾乎普遍感染CTV，且大部分均無呈顯著病徵，而果農自行自果園選穗嫁接繁殖之柑橘苗木，可能都帶有本病。
Citrus tristeza virus(CTV) is a viral species of the genus Closterovirus that causes the most economically damaging disease to the Citrus trees . The disease has led to the death of millions of Citrus trees all over the world and has rendered millions of others useless for production. Farmers in Brazil and other South American countries gave it the name "tristeza", meaning sadness in Portuguese and Spanish, referring to the devastation produced by the disease in the 1930s. The virus is transmitted most efficiently by the brown citrus aphid.