论文部分内容阅读
Ⅰ.褐斑病主要为害杜鹃叶片。发病初期,叶片上产生红褐色小斑点,后逐渐沿叶脉扩展成不规则形的黑褐色斑,病斑叶片正面色深而背面色浅,叶缘的病斑能相互联结。后期病斑中央呈灰白色,上生小黑点,最后整个病叶发黄,提早脱落。此病菌借雨水或风传播,因此霉雨季节发病较严重。防治方法:(1)及时摘除病叶,清除落叶集中烧毁。夏季注意通风透光,避免湿度过大;(2)发病初期,喷施50％托布津800～1000倍液,
Ⅰ. Brown spot is the main damage to the leaves of rhododendron. Early onset, the leaves produce reddish-brown spots, and gradually extended along the veins into an irregular dark brown spots, the lesion leaves the front of the color depth and the back of the light, the leaf edge of the lesion can be linked to each other. Late lesion was gray, black spots on students, and finally the entire diseased leaves yellow, early off. The germs by rain or wind spread, so the onset of mildew season more serious. Prevention and treatment methods: (1) timely removal of diseased leaves, clear the leaves to focus on burning. Summer attention to ventilation and light, to avoid excessive humidity; (2) the onset of the disease, spraying 50% Tuobujin 800 to 1000 times,