How to prevent and control retting roots with green onions?

How to prevent and control retting roots by planting green onions? Please advise that root retting is one of the common diseases in vegetable seedlings, and it also occurs in the adult stage of green onions. Control measures: (1) stabilize the ground temperature, promote the development of strong seedlings, improve the ability of disease resistance, and increase the temperature of seedling field by more than 20 ℃. (2) decreasing field humidity and high field humidity are the key factors leading to retting roots. After watering the soil moisture in the seedling field, irrigate little or no water as much as possible, and frequently irrigate the small water when necessary, and avoid flooding. In cloudy and rainy days or when the humidity in the field is too high, plant ash or fine dry soil can be scattered on the seedling field to reduce the humidity in the field. (3) to improve soil aeration conditions, planting Welsh onions on sandy soil as far as possible, and apply a large amount of rotten organic fertilizer, improve soil structure, improve soil buffering capacity, improve ventilation and air permeability conditions, so as to reduce the occurrence of retting roots. Click to get more green onion planting techniques click to get more vegetable planting techniques