On July 2, 1999, at 0730 eastern daylight time, a Bell 47, N23590, collided with trees during a forced landing near Trenton, Georgia, following a loss of rotor rpm. The agricultural flight was operated by the pilot under the provisions of Title 14 CFR Part 137, and no flight plan was filed. Visual meteorological conditions prevailed at the time of the accident. The helicopter sustained substantial damage and the commercial pilot received minor injuries. The flight departed Trenton, Georgia, at an undetermined time. The pilot was conducting an aerial application for agricultural purposes. According to the pilot, the helicopter experienced a decay in rotor rpm and he was unable to maintain flight. He executed an autorotation and collided with trees on the descent. According to the FAA, the pilot attempted the autorotation with about a five knot tailwind. No mechanical deficiencies were reported by the pilot. A Pilot/Operator Aircraft Accident Report (Form 6120.1/2) was not submitted by the pilot.