韩旺旺 聂玉洁

摘 要：采用田间系统调查、小区试验及室内病原鉴定等方法，对河西走廊杂交制种玉米苗枯病的流行规律及发病因子进行了研究。结果表明：玉米苗枯病是由镰孢菌、蠕孢菌、丝核菌及腐霉菌等多种病原复合侵染引起，其中镰孢菌是引起河西走廊玉米苗枯病的主要病原;河西走廊玉米苗枯病盛发期为4～5叶期;在高密度、NK肥条件下，病害发生重，传播蔓延速度快，尤其当密度达到8.50万株/hm2时，病害发生程度明显加重;随连作年限的增加，玉米苗枯病的发病率也随之增加。

关键词：玉米苗枯病;发生规律;发病因子;河西走廊

中图分类号 S435.131.4+9文献标识码 A文章编号 1007-7731（2021）05-0111-04

Abstract： The epidemic law and pathogenic factors of maize seedling blight in Hexi Corridor were studied by systematic field investigation， plot experiment and pathogen identification in laboratory. The results showed that maize seedling blight was caused by multiple pathogens such as Fusarium， Helminthosporium， Rhizoctonia and Pythium， among which Fusarium was the main pathogen causing maize seedling blight in Hexi Corridor. The peak stage of maize seedling blight in Hexi Corridor was 4～5 leaf stage. Under the condition of high density and NK fertilizer， the disease occurred seriously and spread quickly， especially when the density reached 85，000 plants/hm2， the disease occurred significantly. With the increase of continuous cropping years， the incidence of maize seedling blight also increased.

Key words： Maize seedling blight; Occurrence regularity; Pathogenic factors; Hexi Corridor

早在20世纪50年代国外就有关于玉米苗枯病的报道[1]，在国内始见于1988年。随着河西走廊杂交玉米制种面积的逐年增加，河西走廊玉米制种产量占全国玉米制种的50%，制种面积超过6.67万hm2[2]。紧凑型玉米品种的广泛种植、土壤多年连作及土壤贫瘠盐碱、播种过深和小粒型玉米的不断增加、播种期提前等等，导致玉米苗弱，发病率提高，形成了有利于苗枯病发生的小气候条件。一般年份田间病株率为10%～20%，严重时病株率高达50%以上[3]，且随着河西走廊制种面积的逐年增加以及受连作制度及品种混杂等因素影响，玉米苗枯病逐年加重，已成为河西走廊杂交制种玉米苗期的主要病害。国内外对于玉米苗枯病的病原鉴定、田间调查和药剂防治都有相关报道[4-7]，但针对河西走廊杂交制种玉米苗枯病的侵染规律和发病因子的系统研究尚未见报道。……