On September 9, 2003, about 1300 central daylight time, an Ayres S2R-G6, N3299X, operated by Forest Flying Service Inc. collided with a ditch during takeoff to the south on a 2,300 foot long private grass airstrip in Cash, Arkansas. The commercial pilot was not injured. The airplane was substantially damaged. The 14 CFR Part 137 aerial application flight was operating in visual meteorological conditions without a flight plan. The local flight was originating at the time of the accident. The pilot stated that during takeoff roll the airplane never reached the proper rotation airspeed. The pilot reported that he waited too long to abort the takeoff, and realized that the airplane was not going to rotate before it reached the end of the runway. The pilot stated that all instruments were showing full power during the takeoff roll. The airplane made contact with a ditch at the south end of the runway.