There is an easier way to do what you want. DBI has a bunch of utility methods which replace common actions. In fact, more than half your code can be replaced with a single method call.

You should try replacing this:

$sth5 = $dbh->prepare("SELECT round,department,score FROM  trees WHERE
+ sport = \'$sport\' AND year = \'$year\' ORDER BY round DESC")|| die 
+"couldn't  prepareSQL statement";
$sth5->execute || die "can't execute sql statement";

$rowcount = 0;
while (@row = $sth5->fetchrow_array()) {
  $round = $row[0];
  $teamname = $row[1];          
  $Score    = $row[2];          

  push @list_of_teamdata, qw("$round $teamname $score");
    $rowcount++;

  }

[download]

With this: (Note: code is spread out for better formatting)

my $statement = q{
    SELECT round
         , department
         , score
      FROM trees
     WHERE sport = ?
       AND year = ?
  ORDER BY round DESC   
};

my $list_of_teamdata = $dbh->selectall_arrayref(
  $statement,
  {},
  $sport,
  $year,
);

[download]

Here's what I did: