The Prevention and Control Techniques of Artemisia halodendron
First, the field identification: Artemisia halodendron downy mildew, from the seedling stage to the adult stage can occur. At the initial stage, chlorotic yellow spots with indistinct edges were generated on the leaves, and the lesions were densely white to yellowish-white moldy layers on the back of the lesions, and the diseased leaves rapidly withered. With the development of the disease, the front of the diseased leaves is also densely covered with white to yellowish-white mold. In severe cases, the leaves dry and die. Second, the cause of the disease: the bacteria in the Artemisia halodendron residues, but also in the field perennial Compositae weeds host perennial overwintering. In the following year, mycelia produce sporangia, which are spread by wind and rain, irrigation water, and released by zoospores or buds that grow directly from the stomata. The disease rapidly expands and spreads. The temperature is 15-20°C, and relative humidity above 95% is suitable for onset. The germination of the sporangium requires the presence of water droplets on the leaf surface. Third, prevention and control points: 1 Choose land plots with high topography and well-drained land. 2 The density is suitable to avoid excessive density and poor ventilation between the plants. 3 Apply manure, increase phosphorus, potash fertilizer, timely and appropriate amount of top dressing, irrigation to make plants robust, and improve disease resistance. 4 timely control of water, timely exclusion of water after the rain. Protected areas enhance ventilation and reduce the frosting time of the blades. 5 Eradicate field weeds early, especially in the Asteraceae weeds. 6 In the early stage of disease prevention and control in a timely manner, you can use 58% metalaxyl Mn-Zn 500 times, or 25% metalaxyl 800 times, or 40% EB 300 times spray, interval 6? 7 days after the spray , spray 2 to 3 times. Medical Ear Thermometer,Ear Thermometer,Infrared Ear Thermometer Dongguan Keyutai Mask Co., Ltd. , https://www.maskkytai.com