On September 6, 2000, approximately 1415 central daylight time, a Cessna 188B single-engine agricultural airplane, N21635, was substantially damaged during a forced landing following a reported loss of engine power while maneuvering in the vicinity of Farwell, Texas. The airplane was registered to and operated by Rhodes Crop Care Inc., of Bovina, Texas. The commercial pilot sustained minor injuries. Visual meteorological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations Part 137 aerial application flight. The flight originated from a private agricultural airstrip near Bovina, Texas, at 1328. The pilot reported on NTSB Form 6120.1/2, that he had completed spraying about two-thirds of a cornfield when he pulled up and entered a downwind to re-enter the field. He then "felt heat", and smoke "filled" the cockpit. He stated that the smoke smelled like a "hot iron." At the same time, the engine "quit" producing power. The pilot turned into the wind, lowered the flaps and impacted the ground, which was a rough/uneven, crop field. He observed what appeared to be a "large flame" coming from the right side of the cowling, and then exited the aircraft. He estimated that the time elapsed from when he first smelled the smoke, to ground impact, was about 2-3 seconds. The pilot was utilizing smoke generating equipment to mark his swath runs. Examination of the accident site by an FAA inspector and the operator did not reveal evidence of an on-ground fire (It was noted that the crop field was very dry). There was no evidence of a sustained fire in the wreckage; however, the feeder tube, which supplies oil to the smoke generator, was found to be burned adjacent to the outside of the right exhaust stack. Both wings were structurally damaged, both main landing gear were torn loose, and the empennage was buckled. Examination of the engine by the FAA inspector and the operator, did not disclose any anomalies that would have caused the reported loss of power. Work order number 910958, dated September 15, 2000, which was found in the maintenance records, showed that an alternator bracket, engine lord mounts, and exhaust stacks were installed 12 hours prior to the accident flight. The work required the engine to be removed and replaced on the airframe. The airplane was returned to service, and flew 12 hours prior to the accident. The operator stated that the previously installed smoke generating equipment, specifically the hose which supplies oil to the exhaust stacks, would have been removed and replaced during this maintenance procedure. The smoke generator kit, which had an FAA approved Supplemental Type Certificate, had been operated prior to the aforementioned scheduled maintenance with no reported problems.