This is a follow-up to @Geoff's excellent answer, but fitted for a more dynamic and real-live scenario.
I imagined this being a nice little post, but I realize now that it got a little out of hand.  However, the code is all there and I find it really useful, though it covers a lot more than just how to disable transition animations.
Usually, when I work with Fragments I like to have a BaseFragment that attaches to a BaseActivityCallback.  This BaseActivityCallback can be used by the my Fragments to add a new Fragment on top of itself, or even to pop Fragments beneath it, hence the desire to disable pop animations -- or pop silently:
interface BaseActivityCallback
{
    void addFragment ( BaseFragment f, int containerResId );
    void popFragment ( boolean silently );
}
class BaseActivity extends android.support.v4.app.FragmentActivity implements BaseActivityCallback
{
    public void addFragment ( BaseFragment f, int containerResId )
    {
        FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
        ft.setCustomAnimations(R.anim.enter, R.anim.exit, R.anim.enter, R.anim.pop_exit); // http://stackoverflow.com/a/17488542/2412477
        ft.addToBackStack(DEFAULT_FRAGMENT_STACK_NAME);
        ft.replace(containerResId, fragment);
        ft.commitAllowingStateLoss();
    }        
    public void popFragment ( boolean silently )
    {
        FragmentManager fm = getSupportFragmentManager();                
        if ( silently ) {
            int count = fm.getFragments().size();
            BaseFragment f = (BaseFragment)fm.getFragments().get(count-1);
            f.setDisableTransitionAnimations(true);
        }
        fm.popBackStackImmediate();
    }
}
public abstract class BaseFragment extends android.support.v4.app.Fragment
{
    private static final String TAG = "BaseFragment";
    private final String STATE_DISABLE_TRANSITION_ANIMATIONS = TAG+".stateDisableTransitionAnimations";
    protected BaseActivityCallback baseActivityCallback;
    private boolean disableTransitionAnimations;    
    @Override
    public void onCreate ( @Nullable Bundle savedInstanceState )
    {
        super.onCreate(savedInstanceState);
        disableTransitionAnimations = (savedInstanceState==null ? false : savedInstanceState.getBoolean(STATE_DISABLE_TRANSITION_ANIMATIONS, false));
    }
    @Override
    public void onAttach ( Context context )
    {
        super.onAttach(context);
        baseActivityCallback = (BaseActivityCallback)context;
    }
    @Override
    public void onSaveInstanceState ( Bundle outState )
    {
        super.onSaveInstanceState(outState);
        outState.putBoolean(STATE_DISABLE_TRANSITION_ANIMATIONS, disableTransitionAnimations);
    }
    @Override
    public Animation onCreateAnimation ( int transit, boolean enter, int nextAnim )
    {
        if ( disableTransitionAnimations ) {
            Animation nop = new Animation(){};
            nop.setDuration(0);
            return nop;
        }
        return super.onCreateAnimation(transit, enter, nextAnim);
    }
    public void setDisableTransitionAnimations ( boolean disableTransitionAnimations )
    {
        this.disableTransitionAnimations = disableTransitionAnimations; // http://stackoverflow.com/a/11253987/2412477
    }
}
Now you can create your MainActivity and have that show a Fragment1 which can add another Fragment2 which may in turn pop Fragment1 silently:
public class MainActivity extends BaseActivity
{
    protected void onCreate ( Bundle savedInstanceState )
    {
        setContentView(R.layout.main_activity);
        ...
        if ( getSupportFragmentManager().getFragments() != null && !getSupportFragmentManager().getFragments().isEmpty() ) {
            addFragment( FragmentA.newInstance(), R.id.main_activity_fragment_container );
        }
    }
    ...
}
public class FragmentA extends BaseFragment
{
    public View onCreateView ( LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState )
    {
        ViewGroup root = (ViewGroup)inflater.inflate(R.layout.fragment_a, container, false);
        ...
        root.findViewById(R.id.fragment_a_next_button)
            .setOnClickListener( new View.OnClickListener() {
                 public void onClick ( View v ) {
                      baseActivityCallback.addFragment( FragmentB.newInstance(), R.id.main_activity_fragment_container );
                 }
             });
    }
}
public class FragmentB extends BaseFragment
{
    public View onCreateView ( LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState )
    {
        ViewGroup root = (ViewGroup)inflater.inflate(R.layout.fragment_b, container, false);
        ...
        root.findViewById(R.id.fragment_b_pop_silently_button)
            .setOnClickListener( new View.OnClickListener() {
                 public void onClick ( View v ) {
                      baseActivityCallback.popFragment( true );
                 }
             });
    }
}