join node value which have same node name with PHP

How to join node value which have same node name with PHP? My output:

<SHOP> 
 <SHOPITEM>
  <title>BERMUDY FRANKLIN</title>
  <text>6skladem 3 kusů</text>
  <text>7skladem 8 kusů</text>
  <text>22skladem 33 kusů</text>     
  <unit>0</unit>
 </SHOPITEM>
 <SHOPITEM>
  <title>FRANKLIN 14221</title>
  <text>6skladem 3 kusů</text>
  <text>7skladem 8 kusů</text>    
  <unit>0</unit>
 </SHOPITEM>
</SHOP>

And i wish this:

<SHOP> 
 <SHOPITEM>
  <title>BERMUDY FRANKLIN</title>
  <text>6skladem 3 kusů<br>7skladem 8 kusů<br>22skladem 33 kusů</text>    
  <unit>0</unit>
 </SHOPITEM>
 <SHOPITEM>
  <title>FRANKLIN 14221</title>
  <text>6skladem 3 kusů<br>7skladem 8 kusů</text>  
  <unit>0</unit>
 </SHOPITEM>
</SHOP>

How improve this code which do first block of code? I am totaly lost..thx:

foreach ($items as $item) 
 {
 $pieces = $item->getElementsByTagName("STOREPIECES");
 $sizename = $book->getElementsByTagName("SIZENAME"); 
 $sizenamevalue  = $sizename->item(0)->nodeValue; 
 $piecesvalue = $pieces->item(0)->nodeValue; 
 $query = $xpath->query('DESCRIPTION',$item);
 $text = $query->nodeValue .= ($sizenamevalue.'stock '.$piecesvalue.' pc'); 
 $node = $dom->createElement("text","$text");
 $item->parentNode->parentNode->appendChild($node);
 }