On May 25, 2004, at 1830 mountain daylight time, a Cessna T188C, N2030J, impacted terrain 6 miles north-northeast of Lamar, Colorado. The commercial pilot on board was not injured. The aerial application flight was being conducted under the provisions of Title 14 CFR Part 137 without a flight plan. Visual meteorological conditions prevailed at the time of the accident. The flight originated from a private airstrip located 17 miles northeast of Lamar, at 1815. The pilot reported he had made several passes on a field when he noticed his airspeed was low (80 miles per hour) with a normal power setting of 32 inches manifold pressure and 2,500 rpm. The pilot said he leveled the airplane's wings and lowered the nose. He said when the airspeed did not increase he went to full power. The pilot said his airspeed continued to decay. The airplane was also descending. The pilot said he unsuccessfully attempted to dump his 125 gallons of chemical. The airplane mushed into the field. An examination of the airplane showed the propeller broken off in torsion. The airplane's left wing was bent back, and the airplane's left main landing gear was broken aft. Flight control continuity was confirmed. An examination of the airplane's systems showed no anomalies.