The aircraft was engaged in the final stages of a pasture spraying operation. The area of operation was a small field surrounded by trees. A powerline was located beyond the trees at the southern end of the field. After committing the aircraft to a low level pass towards the south, the pilot remembered the partially concealed powerline but was unsure of its exact position. When the powerline became visible against the skyline, the pilot realised that he would be unable to pull up over it and elected to fly through the tree tops beneath the powerline. Right wing impact with the trees caused the aircraft to yaw and the rudder to strike the powerline as the aircraft passed beneath it. Despite right wing and rudder damage, the pilot retained control and landed the aircraft in the adjacent paddock where he evacuated the aircraft without assistance or injury. Examination of the aircraft determined that there were no pre-existing mechanical defects, abnormalities or damage which can be considered as factors in, or contributory to, this accident. The pilot acknowledged that he did not conduct a specific check of powerline positions before commencing the clean-up run. The pilot had re-commenced agricultural flying, three weeks prior to the accident, after approximately 9 months of fish spotting operations.