The media is reporting the pilot is believed to be a 51 yr old man from Victoria.
Crop dusting pilot dies in crash - The West Australian
Now, here's a curious twist. Gerald Repacholi has advised the media that the pilot (who was working for an aerial ag operation that competes with Repacholi Aviation in the same area) was flying "erratically" and "recklessly" (the precise media wording) over the area just prior to the crash. Hmmm ....