During an aerial application flight the aircraft engine sustained a loss of power and the pilot performed a forced landing to nearby field. During the landing the aircraft sustained substantial damage. Post-accident examination of the engine revealed that the number-two cylinder connecting rod bearing was in several pieces and the connecting rod bolts were broken. The number-two piston was removed from the cylinder and no anomalies were found with the piston or piston-rings. The cylinder wall was inspected and no scoring was noted.