禾谷类黑穗病是陕北地区的历史性病害,50年代中后期到70年代初,推广赛力散等汞制剂拌种,效果较好;1970年后停用汞制剂病害加重,1975年前后延安、榆林地区谷子黑穗率一般10—15％,高的达40％以上。 1976年开始引用“内疗素”和“公主岭霉素”到1980年发病率控制到1％以下,其后又放松防治,1985年黑穗率达10％;1986年组织用农抗769闷种,病株率控制在1—2％。1987年以后,由于拌种剂供应不及时,定边县 The cereal smut was a historic disease in northern Shaanxi. From the mid-late 1950s to the early 1970s, the promotion of Saili Powder and other mercury preparations was better, and the effect was better. After the deactivation of mercury preparations in 1970, the disease was aggravated. Before and after 1975 Yan’an, Yulin black spike rate of grains is generally 10-15%, up to 40% or more. In 1976, the quoted “Endothelin” and “Princess Merimycin” were controlled to less than 1% in 1980, and then relaxed and controlled. In 1985, the rate of black ear reached 10%. In 1986, , Diseased plant rate control in 1-2%. After 1987, due to the supply of seed dressing is not timely, Dingbian County