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：2019-001-0001-067
藏品描述：早春梨葉出現淡紅色小點，擴大後成紅褐色，表面稍凸出，產生精子器。不久其背面突出數公厘毛絨狀淡色春子器，頗為顯目。至後期病斑處轉黑，嚴重時引起落葉，腔內春孢子可危害龍柏。早春遇雨時龍柏上的冬胞子堆膨脹呈褐色膠狀物，內生擔胞子侵害梨樹。主要為害葉片，但幼果及嫩枝亦可被害，嚴重時全部落葉，病果畸形或落果。
Pear rust is caused by the fungus Gymnosporangium sabinae. The disease affects common pear and several species of juniper. In early spring, round and orange galls will form on juniper twigs. Spores are then disseminated to pears by wind and rain. Impacted pear trees will display conspicuous yellow to orange leaf spots and spindle-shaped lesions on petioles and twigs. By late summer, fruiting structures will form on the pear trees. Spores from these fruiting structures will then further disseminate to infect juniper. Pear rust is a serious disease that can significantly impact the health and survival of pear trees.