手机尾号为0258的用户问:怎样防治苹果紫纹羽?专家解答:紫纹羽病一般在树龄较大的老果园发病重,是根部病害,难防治。病株地上部分的症状是叶片变小、黄化,枝条节间缩短,植株长势衰弱。根部受害则从小根开始向大根蔓延,病势一般缓慢,病株要几年才会死亡。病根初期形成黄褐色斑块,较健部略深,内部则发生褐色病变,病部表面密生紫黑色绒状菌丝层,并长出暗色菌索,在病健交界处甚为明显。在腐朽根上形成半球形菌核,大小为1～2毫米。在多雨季节菌丝层表面可产生担子孢子,外观呈粉状。各种农药防治效果差。 Mobile tail number 0258 users Q: How to prevent and cure apple purple pattern feather? Expert’s answer: Purple pattern feather disease is generally in the older age old orchard incidence, is the root disease, difficult to control. The symptoms of the diseased plants are that the leaves become smaller, yellowing, shorten the internodes, and the plants grow weak. The roots of the damage from the root of a small root to the root of the spread, the general slow disease, disease will take years to die. Pathological root formed early brown patches, slightly deeper than the Department of Health, the internal occurrence of brown lesions, diseased parts of the surface of dense black and purple velvet mycelium and grow dark color strain, in the junction of disease is very obvious. In decayed roots formed hemispherical sclerotia, the size of 1 to 2 mm. In the rainy season mycelial surface can produce basidiospores, the appearance of powder. Poor control of various pesticides.