The impact force with which a 1 Newton apple hits the ground depends on the height from which the apple falls and the stopping distance after impact. Since the weight of the apple is already provided, the apple is no longer in free-fall, and the answer is 1 Newton.
The apple fell from a height of zero in order for it to be described as 1 Newton. In general, impact force is a product of the work done and the time it takes to slow the object down. The work is the energy needed to slow the object down. To minimize damage to the falling object, the time to slow the object down should be as large as possible.