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：2019-001-0001-059

藏品描述：麥白粉病，自幼苗到抽穗均可發病。主要危害葉片，也危害莖和穗子。發病初期為白色病斑，而後顏色逐漸變為淺棕色，可通過自交或雜交形成黑色的子囊殼。病斑發生部位，一般情況下部葉片比上部葉片多，葉片背面比正面多。黴斑早期單獨分散，後聯合成一個大黴斑，如散佈麵粉狀甚至可以覆蓋全葉，嚴重影響光合作用，使正常新陳代謝受到干擾，造成早衰，產量受到損失。

Powdery mildew of wheat is characterized by white, cottony patches of mycelium and conidia on the surface of the plant. They can occur on all aerial parts of the plant including stems and heads, but are most conspicuous on the upper surfaces of lower leaves. The white colonies later turn dull gray-brown. Sever infections can cause stunting. Heads on the later, shorter tillers can become heavily diseased because they remain lower in the wheat canopy where humidity is high. As the growing season progresses, cleistothecia appear as distinct brown-black dots within aging colonies on maturing plants. When severe, individual patches often merge and cover large areas of the stem, leaf surface, or head.