Disable block with taxonomies at post page

Use remove_meta_box

remove_meta_box( 'categorydiv', 'post-type-name', 'side' ); 

And hook it to ‘admin_menu’ as in the Codex.

function my_remove_cat_box() {
     remove_meta_box( 'categorydiv', 'post-type-name', 'side' ); 
}
add_action( 'admin_menu', 'my_remove_meta_boxes' );

I am guessing a little at the first parameter–‘categorydiv’–, but that is what it looks like based on your screen shot.