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牡丹的常见病害较多,下面举几例说明其特征及如何防治。 1.灰霉病:此病为害幼苗,及成苗的叶、茎及花等部位。幼苗被害时茎基部初产生不规则病斑,后呈水渍状腐烂,褐色倒伏;叶片受害多从叶尖或叶缘开始。病斑近圆形,褐色或紫褐色,具不规则轮纹。天气潮湿时受害部位均产生灰色霉状物。此病常在施氮肥过多、植株
Peony common disease more, give a few examples below to explain its characteristics and how to prevent. 1. Botrytis cinerea: the disease damage seedlings, and seedlings of leaves, stems and flowers and other parts. When the seedlings were killed, there were irregular spots at the base of the stems, which were water-rotted and lopsided brown after the seedlings were killed. Most of the leaves began to suffer from the tip or leaf margin. Lesions nearly round, brown or purple-brown, with irregular round pattern. Wet mildew gray mildew are generated when the weather is wet. This disease often nitrogen fertilizer too much, plants