Green onions can be used to remove bacteria and prevent diseases of vegetables in greenhouse.

Spring onions are Liliaceae, biennial, hardy and adaptable vegetables. The leaves of Welsh onion can volatilize propylene sulfide with pungent smell, and its roots can secrete bactericidal substances, which can effectively inhibit the transmission, infection or killing of a variety of pathogens in air and soil, and significantly reduce the incidence of vegetable plants. Use the soil that has been planted with scallions to prepare the bed soil, generally choose the field soil, it is best to choose the soil that has been planted with scallions. If there is no soil planted with green onions, the soil can be transported into the greenhouse and spread into a 15 cm thick, and green onions can be planted. After growing for about a month, green onions can be pulled out and the bed soil can be prepared with its soil, which can reduce the occurrence of soil-borne diseases in the seedling period. Many green onions are planted in the seedling greenhouse during the period of raising seedlings in the greenhouse, make use of the surrounding areas and open spaces in the greenhouse as far as possible to plant more green onions. In a well-sealed greenhouse, if you can smell the pungent smell of propylene sulfide when entering the greenhouse in the morning, the germicidal effect is better. After interplanting cucumber, tomato and other vegetables with green onions in the solar greenhouse, immediately plant a green onion 4-6 cm next to the cucumber, tomato and other vegetable plants, so that cucumber, tomato and other vegetables grow together with green onions. Mixed sowing with leafy vegetables or intersowing into autumn and winter, Welsh onion seeds were mixed with leafy vegetable seeds or sown green onions between the ditches sown with leafy vegetables. When harvesting leafy vegetables, leave the green onions and turn them into the soil during the next soil preparation, which can play the role of soil disinfection.