Why do spring onions die in summer and autumn?

Why did summer onions die in autumn? Please give an introduction to the other causes of onion death: 1. The air humidity is too high. There is a layer of wax on the surface of scallion leaves, which has the effect of preventing water loss, and transpiration is small. Summer and autumn rainy days more, air humidity is larger, inhibit transpiration. Therefore, the absorption of roots is reduced, and the nutrient elements-nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, zinc and other fertilizer elements brought to leaves by absorbing water are also greatly reduced. Long-term lack of fertilizer elements can also cause dead plants and aggravate the occurrence of diseases, resulting in dead plants. 2. The disease is serious. Due to continuous cropping for many years, soil-borne diseases are serious, resulting in a large number of soft rot, blight and root rot. In addition, the soil moisture is too large, which exacerbates the damage of the disease, so the number of plants killed by the disease is extremely large. 3. Insect infestation is serious. In the past two years, it has been forbidden to burn wheat straw and wheat husks in the field, and a large number of scarabs have given birth and survived in wheat husks. In this situation, we should strengthen the trapping and killing of adults and early spraying to eliminate larvae. Many vegetable farmers neglect the prevention and control of pests, resulting in serious occurrence of underground pests such as grubs, killing many plants and aggravating the harm of diseases. Click to get more green onion planting technology Click to get more vegetable planting technology