白粉病是小麦主要病害,天气条件影响较大,特别是雨量较多的年份,病害即会流行。如果碰上小麦生长后期雨量偏多分布均匀,温度又偏低,将延长白粉病的流行期,加重病情。群体过大,氮肥施用过多的麦田,特别是感病品种的大面积种植,极易发病流行。冬季以分生孢子和潜育菌丝体形态在寄主组织越冬,第二年春天当温湿度条件适 Powdery mildew is a major disease of wheat, the weather conditions have a greater impact, especially in the more rainfall years, the disease will prevail. If run into late wheat growth in the distribution of more than partial rainfall, the temperature is low, will extend the prevalence of powdery mildew, aggravating the disease. Large groups, excessive use of nitrogen in wheat fields, especially large-scale cultivation of susceptible varieties, extremely vulnerable to epidemics. In winter, the conidia and the mycelium of hypocotyls were overwintered in the host tissues. The temperature and humidity conditions