Remember the two most critical aspects of left turning tendency - high power and high angle of attack. It is negligible in straight and level flight because all forces are in equilibrium.

Because single engine turbo-props have such high levels of power output (the PC-12 is 1270 ESHP I thnk) it is necessary to trim the airplane to the right to compensate for all the torque and p-factor, otherwise it would be a wild ride down the runway. Once you've leveled out and the forces are all neutralized the rudder centers up for coordinated flight.

If you started a climb from cruise you would see the rudder move to the right to keep the ball centered, but when you land it's centered up because there is no left turning tendency when the engine isn't accelerating the plane.

The green marks on the trim indicator are for take-off only.