On August 4, 1996, at 1410 central daylight time, an Emroth-Emair MA-1B, N9918M, registered to and operated by Robbie's Flying Service, was substantially damaged during takeoff near Clayton, Louisiana. The commercial pilot, sole occupant of the airplane, was not injured. The flight was operating under Title 14 CFR Part 137, and a flight plan was not filed. Visual meteorological conditions prevailed for the aerial application flight. The flight was originating at the time of the accident. The pilot reported that during the takeoff roll on a wet, grass runway, the airplane began to skid and drift left. The pilot stated he was unable to correct for the drift. The airplane contacted a ditch with about 4 to 6 inches of water in it and nosed over. The wings were structurally damaged, and the engine separated from the fuselage.