Pecan tree suckers

One of my pecan trees had, I guess you call it a sucker that grow below soil line or under ground so I dug it up had root so I cut and planted it last February come spring it leaf out so what can I except it was a grafted tree this sucker was below the graft thanks

it is statistically unlikely to be worth growing. 1 in 250 chance that it makes a decent nut, 1 in 2500 that it is a good nut on a good tree, 1 in 25000 that it is an exceptional nut and tree, and 1 in 250,000 that it is a world beating good tree that endures better than Stuart. A lot depends on the parent tree the seed nut came from. Better parents tend to produce better seedlings.

I guess it will be good shade tree then cut some limbs for smoking meat thanks