The green onions have dry tips. What's going on here?

Onion is a drought-tolerant plant, and there is also a saying that cucumber can't be watered and onion can't die of drought. However, in the years with severe drought, the dry tip of Welsh onion will also appear under the condition of long-term water shortage, and the environment in the slow seedling stage after transplanting is not suitable, or the physiological dry tip caused during the growth process is related to high temperature, strong light, drought or waterlogging. The tip of green onion loses water under the baking of high temperature and strong light, which is easy to cause whitening and drying.

According to the water demand of different growth stages of green onions, water them timely and appropriately, and control the water appropriately at the seedling stage of green onions. It is recommended to water it after it is dry, once every 15 ~ 20 days. In the vegetative growth period of Welsh onion, topdressing should be combined, and the growth temperature of Welsh onion is 7~35℃. Above 35℃, the tip is dry, below 7℃, the tip turns white after frostbite. Prevention and control measures: pay attention to watering the green onions cultivated in the open field to cool down; Strengthen the fresh air in greenhouse cultivation.

The key point of dry tip caused by calcium deficiency and boron deficiency is that there is no calcium deficiency in the soil, but a large number of calcium ions combine with phosphate ions in the soil, and the plots lacking calcium are generally accompanied by soil hardening problems. In addition, element deficiency can also cause dry tip. Element deficiency has three nutrients that can cause dry tips. One is calcium, the other is magnesium and the other is potassium fertilizer. After downy mildew of scallion, yellow spots first appeared on the leaves of the plant, and then the leaves bent down and dried. After the occurrence of gray mold, white spots first appeared on the leaves of Chinese onion, and then the leaves slowly curled and dried up, which could be controlled by drugs such as pricking. It should be noted that because there is a layer of wax on the surface of onion leaves, silicone auxiliary should be added when spraying the medicine to improve the adhesion of the medicine.

Reasonable farming, choose high-lying and well-drained plots; Choose a sunny morning to water, drain water in time after rain, and try to use drip irrigation; Apply more decomposed organic fertilizer, 4000 kg per mu, and add phosphorus and potassium fertilizer.