福州李贤升同志: 您的来信收到,你问到:所养的菊花,因施用粪肥而出现叶子受病并大批脱落的现象,想知道这是什么病,如何防治。我们仔细研究了你寄来的病叶,看样子是黑斑病,现将防治措施列后,供你参考。一,施肥前将盆土扦松,把施肥和填土结合起来,或在施肥后盖上一层净细沙,这样可避免粪肥大量溅到叶子上。二,雨后立即把花盆放倒,用清水冲洗叶子背面,把溅上的泥点冲掉。因为病菌潜伏在土壤中,在高温多雨的季节,随雨水溅到叶子上,叶子便会发病,病情自下向上 Comrade Li Xian Sheng Fuzhou: Your letter has been received. You asked: Chrysanthemums raised by the use of manure have caused the leaves to fall ill. They want to know what is the disease and how to prevent it. We carefully studied the disease you send the leaves, it seems is the black spot disease, prevention and control measures are listed, for your reference. First, before fertilization Pinus pocket soil loose, the fertilization and filling together, or covered with a layer of net fine sand after fertilization, so to avoid large amounts of manure splashed on the leaves. Second, immediately after the rain poured the pots, rinse the leaves with the back of the water, the mud splatters washed away. Because the bacteria lurk in the soil, in the hot and rainy season, with rain splashed leaves, the leaves will be the incidence of the disease from bottom to top