If you have a genuine Morus nigra the main thing with a developing specimen is to retain a leader for as long as possible - older plants may develop low heavy branches in danger of splitting. Selecting a leader a keeping it trained to a tall, secure stake for some years might be a good idea. Cutting away parts of it, especially with such a small specimen is not likely to be productive. Some thinning can be undertaken to take weight off of plants that have begun to bear heavy limbs, but care must be taken not to spoil the shape in the process.

And fruit is born on current seasons small wood.

Hi BBoy,

The trees I got had no leader more like a bush which is fine as I try to keep the fruit low.

Harvestman thank you I though it grew on new wood.

Bucky