On May 31, 1997, at 1435 central daylight time, a Grumman G-164A agricultural airplane, N842KG, was substantially damaged during a forced landing following the loss of engine power while maneuvering near Woodsboro, Texas. The non-instrument rated commercial pilot, sole occupant of the airplane, was not injured. The airplane, owned and operated by a private individual, was being operated under Title 14 CFR Part 137 at the time of the accident. Visual meteorological conditions prevailed for the aerial application flight for which a flight plan was not filed. The airplane departed from the operator's private airstrip at approximately 1345. The pilot told the FAA inspector that responded to the scene of the accident that the airplane departed on the first flight of the day from the operator's private airstrip with 125 gallons of pesticides. The pilot further stated that while spraying his second field, as he started the pull up for the turn to reverse direction, the engine "began sputtering and coughing and continued to lose power." The pilot added that he considered landing on a one-lane country road with power lines on the north end; however, he elected to land on the cultivated field adjacent to the road in order to avoid the wires. The pilot reported that "because of recent rains, he suspected that the field might be soft and muddy, so he slowed the airplane as much as he could." During the landing roll on the waist high milo field, the main landing gear tires sank in the soft ground, and the airplane nosed over, coming to rest in the inverted position. The FAA inspector stated that the physical evidence found in the cultivated field was consistent with the heavy application of wheel brakes towards the end of the airplane's landing roll. The operator reported to the NTSB investigator in charge that when he briefed the pilot on the work that was contracted for the day, he told the pilot that the airplane was serviced with about one hour of fuel which was enough fuel to spray one field. The operator did not know why the pilot elected not to refuel the airplane prior to initiating the second field. Examination of the airplane by the owner and the pilot revealed that the airframe and wings incurred structural damage. Inspection of the fuel system by the FAA inspector revealed that both fuel cells were empty and that there was no evidence of any fuel spills near the resting place of the airplane. Further examination of the engine did not reveal any evidence of pre-existing anomalies that would have contributed to the loss of engine power. Numerous attempts, albeit unsuccessful, were made by the investigator in charge to obtain a completed Pilot/Operator Report (NTSB 6120.1/2) from the pilot and the operator. The pilot did not make himself available for a telephone interview.