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甜菜褐斑病为辽宁省甜菜生长中、后期最主要的病害。6月下旬至7月上旬,甜菜生长进入封垄时期,植株长出10～15片叶。如果这时日平均气温在19～23℃,降一两次20毫米以上的小雨,甜菜叶片、叶柄、花枝和种球上就开始出现褐色、紫褐色的圆形或不规则的小斑点,这就是甜菜褐斑病。病斑直径约1～4毫米,后期病斑中央呈灰白色霉层。(为褐斑病菌的分生孢子丛),在潮湿的天气里更为明显。后期病斑常相连成片,造成大量叶片干枯死之。
Beet leaf brown spot is the most important disease of middle and late stage of beet growing in Liaoning Province. From late June to early July, beet grows into the seal ridge period, the plant grows 10 to 15 leaves. If the average daily temperature at 19 ~ 23 ℃, once or twice more than 20 mm of light rain, beet leaf, petiole, flowering branches and bulbs began to appear brown, purple brown round or irregular small spots, which Beet leaf brown spot disease. Lesion diameter of about 1 to 4 mm, the late lesion was gray mold layer. (Conidia plexus), in the wet weather is more obvious. Late lesions are often linked into pieces, resulting in a large number of leaves died.