Ask for expert guidance: yellow leaves are dead branches and roots are normal! What's going on here? thank you

I'll consult the punk teacher for you. My suggestions are as follows:

The root system is normal, which eliminates the possibility of retting, root rot and stem borer damage; Pay attention to branches with withered leaves. It is suggested that the typical branches be cut vertically and horizontally to observe the pith. If the color changes, the catheter is blocked, which is caused by Fusarium wilt.

Mainly to prevent Fusarium wilt. Once the disease is not well treated, it is suggested to clean up the seriously ill area, then disinfect the soil, and do preventive treatment for those who are not sick.

I hope it helps you!

Reference scheme:

1. The cleaned plants were treated with metalaxyl+hymexazol or ferrous sulfate, and the soil was disinfected and sterilized.

2. If there is no disease and no symptoms, spray with hymexazol+Zhongshengmycin for prevention, and combine with nutrition to improve the resistance of the tree itself.