No name pecan tree


is there any way to tell what variety my two pecan tree are. I planted them 12 years ago one gets nuts others dose not .also one is 30 feet tall other is only 12 feet tall how can I get it to grow bty I gave my neighbor one it is 30 feet tall it bares nuts to thanks


Grafted trees, or seedlings?
If seedlings… they are their own ‘variety’…kind of like… your children are not you.
If grafted… you might be able to identify some varieties by nut characteristics.

Productive pecans are heavy nitrogen feeders. Soil testing and appropriate fertilization may help ‘push’ growth on your 12 ft tree, but it’s also possible that it’s on an inferior rootstock, or planted in a less-than-ideal spot.