1. Dead seedlings due to seedbed soil, soil nutrient soil before sowing was not disinfected or disinfected thoroughly, and spraying prevention and treatment after emergence did not take place, as well as improper temperature and humidity management of seedbeds, causing damping-off and damping-off, resulting in dead seedlings. . 2, cold killed dead seedlings in the cold, low temperature, did not take timely measures to prevent cold, resulting in frozen seedlings died of death; or seedlings the right time, the seedbed temperature is too low, the seedlings can not take root after the seedbeds and cause dead seedlings. 3. When the seedling bed soil is sterilized, the amount of medication is too much, the seedbed is too dry after sowing, or the spraying concentration is too high after emergence, resulting in dead seedlings. 4. Air-dried dead seedlings that have not been ventilated for a long time are exposed to a relatively high humidity environment. When the seedbed is ventilated, direct convection of cold air, or sudden removal of film and ventilation, as well as cover being blown by strong winds, can cause both inside and outside the seedbed. The exchange of hot and cold air is too fast and too rapid, and the temperature and humidity of the air suddenly drop, causing the tender leaves to lose water too quickly and cause wilting. If the wilting is too long and the leaves cannot recover, it will eventually turn green and die. This phenomenon is called "drying." 5. Inadequate sprouting of seedlings at the time of sub-seedling causes too many seedlings. The seedlings are not dehydrated in time due to lack of seedlings in time, and seedlings are not easily recovered after seedlings. Dead seedlings are not well developed before seedlings, and roots are too few to die; The seedlings were too late, causing the roots to die. Anesthesia Medical Co., Ltd. , https://www.trustfulmedical.com