The young spring onion that just emerged died, which may be caused by insufficient nutrition. If trace elements such as calcium and magnesium are lacking in the growth process, the onion tip will dry up and turn yellow. Therefore, in the growth period of shallots, in addition to phosphorus and potassium fertilizer, dilute calcium nitrate solution and magnesium chloride spray should be applied to alleviate it.
Onions need a lot of water during their growth. If the soil is too dry, the seedlings will die. Therefore, water every 15 ~ 20 days during the growth of seedlings. In order to keep the green growth of shallots, we can supplement fertilizers while watering them.
Onions are suitable for growing in sunny environment, but if exposed to high temperature or strong light for a long time, the seedlings will wither and die. Therefore, when the light is too strong in summer, it is necessary to build a sunshade net above to shade the room temperature at 12 ~ 25℃. When the temperature is higher than 25℃, it is necessary to spray water around the blades to cool down.
If onion seedlings are attacked by aphids and scale insects during the growth period, the tip will wither and die, so it is necessary to spray diluted bully spirit in time for treatment. In order to improve the disease resistance of shallots, diluted carbendazim solution should be poured into the soil for disinfection and sterilization before planting.