大葱紫斑病发病初期喷75%百菌清可湿性粉剂500~600倍液,或58%甲霜灵锰锌可湿性粉剂500倍液,64%杀毒矾可湿性粉剂500倍液,或50%扑海因可湿性粉剂1500倍液,隔7~10d喷1次,共喷3~4次。