According to the description, dry edges of core leaves are more likely to be caused by dry heart disease. Dry heart disease is a physiological disease caused by calcium deficiency. In some cases, it is caused by excessive nitrogen fertilizer. It is recommended to pay attention to the amount of nitrogen fertilizer used and spray calcium fertilizer on the leaves. You can use chelated calcium or fluid calcium sprays to control it. Once every 7 days, spray 2-3 times continuously. It is recommended to apply calcium fertilizer in advance for prevention.