The pilot had been engaged to spray a stubble field for Noogoora burr. After flying to the property to be sprayed and loading the required chemical the aircraft took off, about 30 minutes after sunrise, to commence the first spray run. The pilot had chosen to fly the spray runs into the east, although on the only other occasion he had sprayed the field the runs had been made into the west. About 110 metres after commencing the spray run the aircraft collided with a branch of a dead tree and struck the ground. A small fire started and witnesses reported that the aircraft appeared to explode. The tree was the only obstruction in the field and it is probable that it would have been difficult for the pilot to see because of the rising sun.