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霜霉病是危害叶片最严重的病害之一,发病严重时病叶焦枯早落,当年可减产10%-20%,第二年的产量也受到严重影响。一、症状葡萄霜霉病主要危害叶片,也能侵染新梢幼果等幼嫩组织。叶片被害,初生淡黄色水渍状边缘不清晰的小斑点,以后逐渐扩大为褐色不规则形或多角形病斑,数斑相连变成不规则形大斑。天气潮湿时,于病斑背面产生白色霜霉状物,即病菌的孢囊梗和孢子囊。发病严重时
Downy mildew is one of the most damaging diseases of the leaves. When the disease is serious, the diseased leaves are scorched and jerky, with a yield reduction of 10% -20% in that year. The yield in the second year is also seriously affected. First, the symptoms Grape downy mildew main hazard leaves, young shoots and other young organizations can also be infected. Leaves were killed, the beginning of pale yellow water-like edge is not clear small spots, and later gradually expanded to brown irregular or polygonal lesions, several spots connected into an irregular big spot. When the weather is wet, there is a white downy mildew on the back of the lesion, namely the cystic terrier and sporocysts of the germs. When the disease is serious