On July 17, 1996, at 1730 central daylight time (cdt), a Piper Pawnee, PA-25-235, N4997Y, registered to Pawnette, Inc., of Grand Forks, North Dakota, and piloted by a commercial pilot, was substantially damaged following a loss of control during the takeoff roll from a private turf airstrip located two miles northwest of Beltrami, Minnesota. The pilot reported minor injuries. The 14 CFR Part 137 flight was operating in visual meteorological conditions. No flight plan was on file. The flight originated from Beltrami, Minnesota, at 1730 cdt. According to the pilot's written statement, he loaded the airplane's hopper with 108 gallons of chemical product and conducted an engine runup at the end of the runway. The pilot advanced the throttle and proceeded to takeoff. Approximately half way down the turf airstrip, the airplane lifted off. The airplane began to settle back toward the runway as it neared the end. The pilot reduced the throttle and held aft stick to keep the tailwheel on the ground while he applied the brakes. The airplane skidded beyond the end of the runway, contacted soft terrain and nosed over. A Federal Aviation Administration (FAA) Principal Airworthiness Inspector represented the NTSB during the on-scene investigation. The Inspector interviewed the pilot and restated that the engine was developing full power. The inspector asked about the density altitude and the pilot said it was 2,700 feet with high humidity. The pilot also did not consider dumping the load because things were happening too fast and he thought the airplane was going to ground loop since it started to turn to the right.