fortran-line-length

fortran-line-length is a variable defined in `fortran.el'.
Its value is

72

• Automatically becomes buffer-local when set.
• This variable is safe as a file local variable if its value
  satisfies the predicate `integerp'.

Documentation:
Maximum number of characters in a line of fixed-form Fortran code.
Characters beyond this point are treated as comments. Setting
this variable directly (after fortran mode is loaded) does not
take effect. Use either M-x customize (which affects all Fortran
buffers and the default) or the function
`fortran-line-length' (which can also operate on just the current
buffer). This corresponds to the g77 compiler option
`-ffixed-line-length-N'.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 23.1 of Emacs.