AHMEDABAD: A 75-year-old man and his son were assaulted with a spade by his brother over a dispute of cutting a branch of an asopalav tree in their house in Vasna on Saturday. Rohit Kadia, a resident of Rajratn Society, told police on Sunday that the incident took place when his son Nikul was cutting a branch of the tree as it was obstructing their way to the house.