On August 23, 2003, at 1800 central daylight time, a Cessna 188B, N5647G, operated by a commercial pilot collided with a ditch following a loss of control during an aborted takeoff. The takeoff was being performed to the south from a private airstrip in Monette, Arkansas. The pilot was not injured and the airplane was substantially damaged. The agricultural application flight was operating under 14 CFR Part 137. Visual meteorological conditions prevailed and no flight plan was filed. The local flight was originating at the time of the accident. According to the pilot's written statement, the right brake failed during the takeoff roll. The pilot reported he applied right rudder to keep the airplane on the runway centerline. He reported the airplane veered to the left at which time he reduced the engine power to idle. The pilot stated the tail of the airplane came down and the airplane veered across several rows of cotton and impacted a drainage ditch. Inspection of the airplane revealed a hole in the right brake line which allowed brake fluid to leak out of the system.