for my $index2 (0..$#productarray)
{
 $Prod{$reference}->{$productarray[$index2]}++;

}

Output:
'ref261' => {                       
            'rope' => '4',
            'suit' => '1',
            'boats' => '3',
            'Gloucestershire' => '1',
             },
'ref523' => {
'pool' => '2',
            'fish' => '1',
            'polystyrene' => '1',
            },