The aircraft was loaded with approximately 80 litres of fuel and 220 litres of spray. The pilot had intended to taxi to the far end of the 570 metre long paddock in order to takeoff into wind but at the last moment he noted that the wind was very light. He elected to takeoff from his current position with a rear quartering wind. Full power was applied and the aircraft accelerated normally. Approximately 50 to 100 metres from the boundary fence the pilot rotated but the aircraft failed to become airborne. He commenced to dump the load but the aircraft remained on the ground. The aircraft then ran through the boundary fence and collided with a small embankment collapsing the main gear. The pilot then noticed that the wind strength had increased to approximately eight knots which increased the tailwind component. A performance analysis estimated that under the prevailing conditions reported by the pilot the aircraft required 500 metres for takeoff. Although it was possible for the aircraft to takeoff in the available paddock length it is obvious that a small error in estimated wind velocity or paddock slope would have increased the takeoff run to more than was available. It is likely that this was the case. This accident was not the subject of a formal on-scene investigation.