farm-2.x-dev/modules/core/ui/dashboard/farm_ui_dashboard.module

<?php

/**
 * @file
 * The farmOS Dashboard module.
 */

/**
 * Implements hook_toolbar_alter().
 */
function farm_ui_dashboard_toolbar_alter(&$items) {

  // Rename home item to "Dashboard".
  if (!empty($items['home'])) {
    $items['home']['tab']['#title'] = t('Dashboard');
  }
}