On July 29, 1993 about 0730 central daylight time, a Grumman AG-CAT; N8368, sustained substantial damage when the aircraft struck a hidden wooden post during roll-out of a forced landing. The pilot was uninjured during the aerial application flight operating under 14 CFR Part 137. Visual meteorological conditions prevailed at the time of the flight. No flight plan was filed for the flight originating from Blue Springs, Nebraska. According to the pilot, during the first pass of an aerial application flight, the aircraft's engine "started to backfire and lose power." The pilot elected to make a forced landing in an open field adjacent to the corn field he was spraying. The airplane rolled approximately 300 feet to the end of the open field as the pilot attempted to turn the aircraft to avoid crossing a dirt road and going into a corn field. The aircraft's bottom right wing hit a post hidden by tall weeds and grass at the end of the open field, substantially damaging the aircraft. Post-accident investigation found one engine cylinder cracked from sparkplug hole to sparkplug hole, with the top of the cylinder separating completely. No evidence of pre-impact mechanical malfunction with the airframe or accessories was found.