As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
(CAN) ENROUTE TO A SPRAY OPERATION THE ENGINE BEGAN TO RUN ROUGH AND LOSE POWER. THE PILOT DUMPED THE LOAD AND ATTEMPTED A RETURN TO BASE. THE AIRCRAFT COULD NOT MAINTAIN ALTITUDE AND THE PILOT FORCED LANDED IN A SWAMP. INDICATIONS ARE THAT THE NR4 CYLINDER FAILED.