Avocado growth under the graft? Should I cut 1/2" from trunk? Pics included

[saltyreefer]

Planted it last October, Its grown great this spring and just realized a few wayward branches were growing from under the graft. Can I just cut them about a 1/2' from the trunk? Less or more? It was tagged as a Florida Hass.
 I'm thinking since its growing so well that it wouldn't hurt it but...


This was it last October.


Here it is now and that lower branch sticking out at the bottom is the larger of the three.







Here are the limbs at the graft.

[spaugh]

Yeah cut them or they will start taking all the energy.  I cut those low branches up 1.5ft off the ground at least or it will be on the ground when it fruits. 

Cut the branches nearly flush with the trunk so thry dont resprout.