What is the yellow tip of leek leaves?

The reasons why leek leaves turn yellow and dry tip are: 1, and the excessive dose and concentration in the early winter germination period easily lead to dry tip of leaves. 2. Excessive use of urea and nitrate nitrogen. The maximum dosage of urea per mu is about 12 kg. If the amount of urea in the arched shed leek field is too large, it is easy to cause ammonia gas to damage the leaves; Too much nitrate nitrogen and ammonium nitrogen can easily cause nitrite damage and make leaves yellow and dry. PH test paper can be used to detect the pH of dew. 3. Overventilation In the case of high temperature in the shed, if the air outlet is suddenly opened, the blades may be dry and yellow. 4. Varieties related to variety characteristics, such as snow leek, small root red, Hanzhong winter leek, etc., are prone to dry tip phenomenon in summer and autumn, but this will not happen in winter protected cultivation. Solution: 1 Pay attention to the use of medicine before the shed is buckled, control the best dosage, and avoid the time of leek germination, so as not to hurt the leek buds. 2. The dosage of urea should be controlled below 12kg. In addition, more organic fertilizer or humic acid fertilizer should be applied to promote and raise roots and improve the growth of leeks. 3. Nitrate nitrogen fertilizer should be applied as little as possible or not.