plowdel: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/plowdel - from package: plowshare

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/plowdel - from package: plowshare4

You may install the required package with command apt-get install {package}

Error in other languages:
plowdel: bevel nie gevind nie
plowdel: comandă negăsită
plowdel: comando não encontrado
plowdel: commande introuvable
plowdel: command not found
plowdel: käsku ei ole
plowdel: không tìm thấy lệnh
plowdel: komanda nerasta
plowdel: Kommando nicht gefunden.
plowdel: kommandot finns inte
plowdel: komut yok
plowdel: nie znaleziono polecenia
plowdel: níor aimsíodh an t-ordú
plowdel: no se encontró la orden
plowdel: no s'ha trobat l'ordre
plowdel: opdracht niet gevonden
plowdel: parancs nem található
plowdel: perintah tidak ditemukan
plowdel: príkaz nenájdený
plowdel: příkaz nenalezen
plowdel: команда не найдена
plowdel: командата не е открита
plowdel: 命令找不到
plowdel: コマンドが見つかりません