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在大葱生长过程中，最常见的病害是紫斑病、霜霉病、锈病。虫害是蓟马、葱蝇、潜叶蝇。一、主要病虫种类及发生特点１．紫斑病。秋季主要危害大葱叶片，病斑多从叶尖处开始，随即向叶下部蔓延。初为白色，稍凹陷，中央微紫色的小斑点。扩大后病斑成椭圆形至纺锤形，后期病...
In the growing process of green onions, the most common diseases are purple spot, downy mildew, rust. Pests are thrips, onion fly, leaf miner. First, the main types of pests and occurrences 1. Purple spot disease. Major green onions in autumn leaves, lesions and more from the beginning of the leaf tip, then spread to the lower part of the leaf. The beginning of the white, slightly depressed, central purple spots of small spots. Enlarge the lesion into an oval to spindle-shaped, late disease ...