I get asked all the time about pecan trees like you see in the picture. The question, if I prune this tree back and fertilize it will it be okay? Well the blunt answer is NO. This tree has been under stress for a long time and what you see no has been going on internally for years. Trees like this have a multitude of problems including internal heart rot which is eating away at the trees insides. The internal problems are not showing themselves on the outside by killing back limbs to the main trunk. This tree is all but dead, it knows it but you don't!