What about simple XPath (if you have only one textarea): 
my $textarea = $mech->xpath('//textarea', one => 1);
$textarea->value("somevalue");

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In reply to Re: How to fill textarea of a webpage fetched using WWW::Mechanize::Firefox ? by Gangabass
in thread How to fill textarea of a webpage fetched using WWW::Mechanize::Firefox ? by strawperl

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