Which factor is most influential in the learning of a child, Nature or Nurture ?

Nurture is much more influential.

Nature and nurture are two sides of a coin in children's pedagogical experience. A child placed on the wrong environment finds it difficult to maximize his/her learning capabilities. On the other hand, a child that is not well nurtured stands the risk of being retarded or not well developed physically to grasp all that is been taught.

Nature cannot be controlled so much. It is naturally what a child inherits from the parents biologically, genetically. Nurture, yes. The child can be nurtured to develop certain interest, character (e.g brave or timid etc) even future career prospect.