自60年代后期以来,小麦赤霉病已逐渐成为关中灌区的常发性病害和主要防治对象。本文从生态条件、品种抗性和侵染菌源诸方面论述了关中灌区小麦赤霉病流行因素。分析表明,关中农田灌溉事业的发展引起农田生态条件的变化和大面积栽培感病品种是赤霉病流行的基本前提:复种夏玉米面积扩大,田间遗留大量带菌玉米残秆,提供了赤霉病流行的菌源基础。在以上条件下,气象因子,特别是5月份降雨,便成为决定各年流行程度的主导因子。 Since the late 1960s, wheat head blight has gradually become a frequent disease and the main control target of Guanzhong Irrigation District. This article discusses the epidemic factors of wheat scab in Guanzhong irrigation area from the aspects of ecological conditions, variety resistance and bacterial sources. The analysis shows that the development of Guanzhong farmland irrigation cause the changes of farmland ecological conditions and the cultivation of susceptible cultivars in large area are the basic prerequisites of the epidemic of scab: the enlargement of summer maize area and the presence of a large number of residues of corn residues in the fields provide scab Popular source of bacteria. Under the above conditions, the meteorological factors, especially the rainfall in May, have become the dominant factor in determining the prevalence of each year.