Chrysanthemum planted in winter is very susceptible to downy mildew. After producing a pale white to pale yellow downy layer on the leaves and leaves, the leaves turn yellow and brown and die. Therefore, winter should pay attention to the prevention of Artemisia halodendron to protect the leaves. Specific prevention and control methods: Artemisia selengensis planted in winter, after growing 3-5 true leaves, pay attention to inspection of the leaves and found that there are yellow-green to yellow-brown patches on the backs and leaves of leaves, with pale white to pale yellow. In the case of peronospora, a foliar spray of 600-800 times 58% aqueous solution of metharone Zn wettable powder, or 800-1000 times of 72% aqueous solution of urea MnZn wettable powder, or 800-1000 times 69% olefin Manganese zinc wettable powder aqueous solution, or 500-600 times 64% frost MnZn wettable powder aqueous solution, etc. to control, spraying once every 7-10 days, continuous spraying 2-3 times, evenly wet all the leaves to start Dropping drops of water is appropriate to control the disease and restore the diseased plants to normal growth. Cycas Plant,Cycas Revoluta,Natural Cycas Revoluta,Cycas Tree fanhua nursery , https://www.fanhuanursery.com