Delvi 83: I live in a very tropical area. I have many guava trees but only 2-3 show this mottling in their braches. If I leave the branches as they are, there is no new growth in these branches. It is my impression that this problem stunts growth.
Greenman62: Thank you for your valuable hints in trying to identify nematodes and get rid of them ! Valuable info
I need to confirm by opinion of experts and examination in loco that it is nematode infection.