SECURITIES AND EXCHANGE COMMISSION
                              WASHINGTON, DC 20549


                                   FORM 12b-25

                                                Commission File Number:  0-22307

                           NOTIFICATION OF LATE FILING


      (Check One): [ ] Form 10-K  [ ] Form 11-K  [ ] Form 20-F  [X] Form 10-Q
[ ] Form N-SAR

For Period Ended:  March 31, 1999
                   -----------------

[ ] Transition Report on Form 10-K      [ ] Transition Report on Form 10-Q
[ ] Transition Report on Form 20-F      [ ] Transition Report on Form N-SAR
[ ] Transition Report on Form 11-K

For the Transition Period Ended:
                                -------------------------

     Read attached  instruction  sheet before  preparing  form.  Please print or
type.

     Nothing in this form shall be  construed to imply that the  Commission  has
verified any information contained herein.

     If the  notification  relates  to a portion of the  filing  checked  above,
identify the item(s) to which the notification relates:
                                                       -------------------------

                                     PART I
                             REGISTRANT INFORMATION

Full name of registrant             Senesco Technologies, Inc.
                         ---------------------------------------------------

Former name if applicable           Nava Leisure USA, Inc.
                         ---------------------------------------------------

Address of principal executive office (Street and number)

                                   34 Chambers Street
- --------------------------------------------------------------------

City, State and Zip Code      Princeton, New Jersey 08542
                         -------------------------------------------


                                     PART II
                             RULE 12b-25 (b) AND (c)

     If the subject  report could not be filed  without  unreasonable  effort or
expense  and  the  registrant  seeks  relief  pursuant  to Rule  12b-25(b),  the
following should be completed. (Check appropriate box.)

[X]     (a)    The reasons  described in  reasonable  detail in Part III of this
               form  could  not be  eliminated  without  unreasonable  effort or
               expense;

[X]     (b)    The subject annual report,  semi-annual report, transition report
               on Form 10-K,  20-F,  11-K or Form N-SAR, or portion thereof will
               be filed  on or  before  the  15th  calendar  day  following  the
               prescribed  due  date;  or  the  subject   quarterly   report  or
               transition  report on Form 10-Q, or portion thereof will be filed
               on or before the fifth  calendar day following the prescribed due
               date; and

[ ]     (c)    The  accountant's  statement  or other  exhibit  required by Rule
               12b-25(c) has been attached if applicable.

                                    PART III
                                    NARRATIVE

     State below in reasonable detail the reasons why the Form 10-K, 11-K, 20-F,
10-Q,  N-SAR or the transition  report portion thereof could not be filed within
the prescribed time period. (Attach extra sheets if needed).

               Senesco  Technologies,  Inc.  (the  "Company")  is unable to
               timely  file its  Quarterly  Report on Form  10-QSB  for the
               Quarter Ended December 31, 1998 (the "Form 10-QSB")  without
               unreasonable  effort or expense  because  management  of the
               Company  has been  utilizing  much of its  efforts  in fully
               integrating the Company's operations after the recent merger
               of Nava Leisure  Acquisition Corp., a New Jersey corporation
               and  wholly-owned  subsidiary of Nava Leisure USA,  Inc., an
               Idaho corporation, with and into Senesco, Inc., a New Jersey
               corporation,  consummated  on  January  22,  1999.  The Form
               10-QSB  is  currently  being  prepared  and will be filed no
               later than the fifth calendar day following the May 17, 1999
               due date of the Form 10-QSB.



                                     PART IV
                                OTHER INFORMATION

     (1) Name and  telephone  number  of  person  to  contact  in regard to this
notification.

 Phillip O. Escaravage               (609) 252-0680
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      (Name)                    (Area Code) (Telephone Number)

     (2) Have all other periodic  reports  required under Section 13 or 15(d) of
the Securities  Exchange Act of 1934 or Section 30 of the Investment Company Act
of 1940  during the  preceding  12 months or for such  shorter  period  that the
registrant was required to file such report(s) been filed?  If the answer is no,
identify report(s).

                                                      [X] Yes  [  ] No

     (3) Is it anticipated that any significant  change in results of operations
from the corresponding  period for the last fiscal year will be reflected by the
earnings statements to be included in the subject report or portion thereof?

                                                      [  ] Yes  [X] No

     If so: attach an explanation of the anticipated  change,  both  narratively
and  quantitatively,  and, if  appropriate,  state the reasons why a  reasonable
estimate of the results cannot be made.


      Senesco Technologies, Inc.
- --------------------------------------------
(Name of registrant as specified in charter)

Has  caused  this  notification  to be signed on its  behalf by the  undersigned
thereunto duly authorized.

Date: May 17, 1999               By: /s/Phillip O. Escaravage
                                     -------------------------------------------
                                     Name:  Phillip O. Escaravage
                                     Title: Chairman and Chief Operating Officer


     Instruction.  The  form  may  be  signed  by an  executive  officer  of the
registrant or by any other duly authorized representative. The name and title of
the person signing the form shall be typed or printed beneath the signature.  If
the  statement  is  signed  on  behalf  of  the   registrant  by  an  authorized
representative   (other   than   an   executive   officer),   evidence   of  the
representative's  authority to sign on behalf of the  registrant  shall be filed
with the form.


                                    ATTENTION

     Intentional  misstatements or omissions of fact constitute Federal criminal
violations (see 18 U.S.C. 1001).

                              GENERAL INSTRUCTIONS

      1.  This  form is  required  by  Rule  12b-25  of the  General  Rules  and
Regulations under the Securities and Exchange Act of 1934.

      2.  One  signed  original  and  four  conformed  copies  of this  form and
amendments  thereto must be completed and filed with the Securities and Exchange
Commission,  Washington,  DC 20549,  in accordance  with Rule 0-3 of the General
Rules and Regulations under the Act. The information  contained in or filed with
the form will be made a matter of the public record in the Commission files.

      3.  A manually signed  copy of the form and  amendments  thereto  shall be
filed with each national securities exchange on which any class of securities of
the registrant is registered.

      4.  Amendments to the  notification  must also be filed on Form 12b-25 but
need not restate information that has been correctly  furnished.  The form shall
be clearly identified as an amended notification.

      5.  Electronic  Filers.  This form shall not be used by electronic  filers
unable to timely file a report  solely due to  electronic  difficulties.  Filers
unable to submit a report within the time period  prescribed due to difficulties
in  electronic  filing  should  comply  with  either  Rule  201 or  Rule  202 of
Regulation  S-T or apply for an adjustment in filing date pursuant to Rule 13(b)
of Regulation S-T.