近年来,水稻纹枯病在徽州地区不断加重,山坞田发生普遍,为害较烈。调查如下: 一、几种最常见的杂草寄主:大刺草、小刺草(它们又名白茅),扁茅、三梭草、狗尾草、蟋蟀草、水兰花、竹叶草和稗草等十多种均有纹枯病发生。其中扁第、三梭草和小刺草分布极广,感病率高、甚至生长在没有水源的山上,感病株和发病中心也处处皆是。例如,以扁茅为主的水稻田梗上,杂草发病率高达69.7—75％,一般为20％,少则5％以下。 In recent years, rice sheath blight in Huizhou area continue to increase, Hill dock Tian common, more harmful. The investigation is as follows: First, several of the most common host weeds: barbed grass, barbed grass (they also known as white grass), broom, three shuttle grass, Setaria, cricket grass, water orchid, bamboo grass and barnyard grass More than ten species have sheath blight occurred. One flat first, three shuttle grass and small spines are widely distributed, the rate of infection is high, and even grow in the mountains without water, susceptible strains and centers of disease are everywhere. For example, the crop of paddy-dominated paddy fields has a high prevalence of weeds of 69.7-75%, typically 20%, or less than 5%.