template.php

<?php

/**
 * Default theme function for all RSS rows.
 */
function YOURTHEME_preprocess_views_view_row_rss(&$vars) {
  $item     = &$vars['row'];

  // Default item_elements to empty string.
  $vars['item_elements'] = '';

  if (!empty($item->elements)) {
    // If there are item_elements, format them as xml elements.
    $vars['item_elements'] = format_xml_elements(
      // But first filter out any unwanted element.
      array_filter($item->elements, function($element) {
        // Some other keys: 'dc:creator', 'category'
        return !in_array($element['key'], array('pubDate'));
      })
    );
  }
}