I have posted some comments regarding this subject on the AG 2 thread.
Most ag pilots can fly alright if they got through the training and got a seat but can they think safely. I am not saying we shouldn't do more check and training however that will mostly tidy up their flying and spraying technique, but how much safer will it make them fly.
I think we need to have at least bi-annual safety courses that teach people mental techniques to stay safe and reduce their exposure to risk. If nothing else it will promote a culture of safe thinking.
I was suprised many years ago to find a highly experienced 502 pilot never used to watch his flap go down, he'd just hit the button for a second or two. As everyone knows Air Tractor flap motors fail all the time, so what happens the day he really needs flap (which is everyday in an AT) and doesn't realise he hasn't got any until its too late. If he hadn't thought of it how many others haven't.
If we can teach people to get into the habit of saying "what if" to themselves more they should be safer.