On June 19, 1993, at approximately 1830 central daylight time, a Cessna AT188B, N4804Q, sustained substantial damage during a forced landing due to a loss of engine power near Holly Grove, Arkansas. The commercial pilot sustained serious injuries. Visual meteorological conditions prevailed throughout the area for the local aerial application flight. During interviews, conducted by the Federal Aviation Administration inspector and the investigator in charge with company personnel and relatives, the following information was revealed. The pilot had climbed to spraying altitude and started a right turn over a wooded area when a total loss of engine power occurred. The airplane entered a roll as the pilot dumped the load. The pilot stated that he released the control stick and braced for the impact. During the emergency descent the airplane hit the top of trees approximately 75 feet high and subsequently impacted the ground. On site examination by the airplane manufacturer representative revealed flight control continuity and fuel tank integrity with no fuel available in the tanks. An examination of the engine by the engine manufacturer representative and a FAA inspector did not reveal any discrepancies that would have contributed to the power loss. The airplane was released to the owner's representative following the investigation.