In recent years, there has been a spreading trend of leeches in greenhouses. Rainy weather, flood irrigation, shed indoor humidity, when the wind is not timely heavy onset. Now we introduce its prevention and treatment methods to everyone. First, the harm symptoms The disease mainly damages the pseudo-stem and bulbs of leeks, while leaves, roots, and flower buds can also be harmed. Injury leaf lesions mostly occur from the lower part and initially produce dark green water-spotted lesions. When they spread to about 1/2 of the leaves, the whole leaf turns yellow, sagging, and soft rot. When wet, the diseased part produces pale mould. When the pseudo-stem was victimized, it was a water-stained, light-brown, soft rot, and the leaf sheath was easily peeled off. When the bulb was damaged, the root plate showed a watery brownish to dark brown rot, and the bulbs showed a light brown inner color and the growth was inhibited. The damage to the roots was brown rot, the root hair was significantly reduced, few new roots were found, the growth potential was significantly weakened, and the life span was shortened. Second, control methods 1. Increase the application of decomposed organic fertilizers, phosphorus and potash fertilizers, avoid partial nitrogenous fertilizers, and increase plant immunity to disease. 2. Poor water pouring. The epidemic is spread by the currents, such as flooding, which can easily cause excessive humidity in the shed and spread the epidemic. 3. Pick up the dead leaves. When the diseased leaves are dry and fall on the ground, they must be picked up and ventilated in time to reduce the source of germs in the shed. 4. Ventilate immediately after watering. The humidity in the shed is too high and it is prone to epidemics. So after each watering, ventilation should be timely to reduce the temperature inside the shed. Exhale should be selected at noon on sunny days, ventilation time is 23 hours. 5. Chemical control. In the early stage of onset, spray 40% EB aluminum wettable powder 200 times, 25% metalaxyl wettable powder 600 times or 64% antivirus M8 wettable powder 400 times, 4050 kg per acre, separated by 710 days One spray, continuous control 23 times. The above liquid leek root can also be used and then planted to prevent disease. Portable strong light explosion-proof searchlight,strong light explosion-proof searchlight,Portable explosion-proof searchlight joho(HK) Technology Co. , Ltd. , https://www.joho-safety.com