菊花入秋后,锈病、灰霉病、黑斑病和烟煤病发生普遍,防治不力可引起大量落叶,影响开花,降低观赏价值。一、锈病。主要为害叶片和茎,发病初期叶片上产生淡黄色小点,后变为褐色并略凸起,后期在叶柄、叶片和茎上,长出深褐色或黑色椭圆形病斑,常造成叶片枯死和大量落花,植株生长十分衰弱。防治方 Chrysanthemum fall, rust, gray mold, black spot disease and bituminous coal common occurrence of poor prevention and treatment can cause a large number of leaves, affecting flowering and reduce ornamental value. First, rust. The main damage to leaves and stems, early onset leaves pale yellow dots, then turned brown and slightly raised later in the petiole, leaves and stems, grow dark brown or black oval lesions, often resulting in leaves withered and A large number of falling flowers, plant growth is very weak. Prevention and treatment side