EXHIBIT 99.1

                            CERTIFICATION PURSUANT TO
                             18 U.S.C. SECTION 1350,
                             AS ADOPTED PURSUANT TO
                  SECTION 906 OF THE SARBANES-OXLEY ACT OF 2002



     In connection with the quarterly report of Monsanto Company (the "Company")
on Form  10-Q for the  period  ending  September  30,  2002,  as filed  with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Hendrik
A. Verfaillie,  President and Chief Executive  Officer of the Company,  certify,
pursuant to 18 U.S.C.  Section 1350,  as adopted  pursuant to Section 906 of the
Sarbanes-Oxley Act of 2002, that:

          (1)  The Report fully complies with the  requirements of Section 13(a)
               or 15(d) of the Securities Exchange Act of 1934; and

          (2)  The information  contained in the Report fairly presents,  in all
               material  respects,   the  financial  condition  and  results  of
               operations of the Company.


                                           /s/ Hendrik A. Verfaillie
                                           ------------------------------------
                                           Hendrik A. Verfaillie
                                           President and Chief Executive Officer
November 14, 2002