It is caused by the recent heavy rainfall, cold and wet soil, poor soil air permeability, and weakened root absorption, causing plant physiological deficiency. The situation in the picture mainly lacks nitrogen, iron, sulfur, magnesium, etc. It is recommended to clear ditches to drain moisture, cultivate and loosen the soil, apply an appropriate amount of nitrate-sulfide compound fertilizer, mainly apply granular fertilizer when the soil is moist, and spray large-element foliar fertilizer and trace-element foliar fertilizer on the leaves 2 to 3 times.