What can I do about bark spli ing on a quince?

ASplitting of bark is always a concern. It can be due to environmental factors, such as cold winters, but it may indicate fungal infection. If on a branch, the damage can be pruned back to healthy wood. There’s nothing that can be done about splits on main trunks – trees will either repair the damage themselves or not.

Branch problems can be pruned out, but wait and see on the main trunk