Why does my outfile put out a trailing "," at end of each line ?

The below code snippet  generates a extra "," at end of each line.
The first line prints out without the comma at end of line. The extra "," occurs from second line onward..

How to prevent the trailing , ?

      
my @allrows;
      my @columns;
      my $getfilename = join '', $partition_key,'.csv';
      my $rc  = $genextract->fetchrow_hashref() or $nodata = 1;
               my @row = @{$genextract ->{NAME}};

      foreach my $col (@row) {
          my $name = $col;
          $name =~ s/\s+//g;
          my $data = $rc->{$name};
          push @allrows, $data;
          push @columns, $name;
      }
      my $dumpdir = "$wkdir/RECgen_$getfilename";

      open (OUT, ">$dumpdir") or die(" - Could not open $dumpdir for export. $!");

      # List out all the columns/rows with header information and generating a csv outfile..
      $" = ",";
      print OUT "@columns\n";
      print OUT "@allrows\n";

      while (my $row = $genextract->fetchrow_hashref()) {
      
        foreach my $col (@columns) {
     
           print OUT $$row{$col},",";        
        }
        print OUT "\n";
      }
      close(OUT);

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output given

10/01/2015,0784626443000,ACACIA,ACACIA_UNIT_1,BRYAN SOLAR LLC (RE),RN,80.743461
10/01/2015,0432268853000,AUSTPL,BOULDERPL_DENV2,LOWER COLORADO RIVER AUTHORITY (RE),OS,7.656099,
10/01/2015,930187393,AV,AV_DG1,TX LFG ENERGY LP (RE),RN,94.34616,
10/01/2015,0791659493000,BAFFIN,BAFFIN_UNIT1,BAFFIN WIND LLC (RE),RN,101.595611,
10/01/2015,0791659493000,BAFFIN,BAFFIN_UNIT2,BAFFIN WIND LLC (RE),RN,110.031439,

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EXPECTED OUTPUT

10/01/2015,0784626443000,ACACIA,ACACIA_UNIT_1,BRYAN SOLAR LLC (RE),RN,80.743461
10/01/2015,0432268853000,AUSTPL,BOULDERPL_DENV2,LOWER COLORADO RIVER AUTHORITY (RE),OS,7.656099
10/01/2015,930187393,AV,AV_DG1,TX LFG ENERGY LP (RE),RN,94.34616
10/01/2015,0791659493000,BAFFIN,BAFFIN_UNIT1,BAFFIN WIND LLC (RE),RN,101.595611
10/01/2015,0791659493000,BAFFIN,BAFFIN_UNIT2,BAFFIN WIND LLC (RE),RN,110.031439

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