Welsh onions are native to Central Asia and other places and are resistant to drought and moisture. Especially in the period of high temperature growth, drought will not cause death, and excessive soil moisture will often cause damage and die. This is what the saying goes, “Scallion does not die to death.†Continuous rainy days caused continuous high soil moisture, and suffocation of roots of scallions suffocated. Other reasons for the death of green onions:
1. The air humidity is too high. There is a layer of wax on the surface of the onion leaves, which has the effect of preventing the water from dispersing and the transpiration is small. In summer and autumn, there are more rainy days, and the air humidity is relatively high, which inhibits transpiration. Therefore, the absorption of the root system is reduced, and the nutrient elements such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, zinc and other fertilizer elements brought to the leaves by absorbing water are also greatly reduced. The long-term lack of fertilizer elements also causes dead plants and intensifies 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 occurrences of soft rot, blight, and root rot. In addition, the excessive humidity in the soil further exacerbates the hazards of the disease. As a result, the number of plants causing the disease to die is extremely high.
3. Serious pests. In the past two years, wheat straw and wheat husks have been prohibited from burning in the fields. A large number of beetles have survived in the wheat husks. In this situation, the trapping of adult worms should be strengthened, and larvae should be eliminated by spraying as soon as possible. Many vegetable farmers neglected the prevention and control of insect pests, resulting in serious occurrence of underground pests such as cockroaches, killing many plants, and exacerbating the harm of diseases.
1. The air humidity is too high. There is a layer of wax on the surface of the onion leaves, which has the effect of preventing the water from dispersing and the transpiration is small. In summer and autumn, there are more rainy days, and the air humidity is relatively high, which inhibits transpiration. Therefore, the absorption of the root system is reduced, and the nutrient elements such as nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, zinc and other fertilizer elements brought to the leaves by absorbing water are also greatly reduced. The long-term lack of fertilizer elements also causes dead plants and intensifies 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 occurrences of soft rot, blight, and root rot. In addition, the excessive humidity in the soil further exacerbates the hazards of the disease. As a result, the number of plants causing the disease to die is extremely high.
3. Serious pests. In the past two years, wheat straw and wheat husks have been prohibited from burning in the fields. A large number of beetles have survived in the wheat husks. In this situation, the trapping of adult worms should be strengthened, and larvae should be eliminated by spraying as soon as possible. Many vegetable farmers neglected the prevention and control of insect pests, resulting in serious occurrence of underground pests such as cockroaches, killing many plants, and exacerbating the harm of diseases.