I bought an Obilnaja on a lark from Raintree. It came on Krymsk rootstock. never had any wild, troublesome growth from it, and it has fruited perhaps 5 seasons now. Not sure if the rootstocks have anything to do with wildness or not. Fruit is very good, on the order of perfect Satsuma flavor. The one defect that I can think of is that they all drop to the ground around the end of July. So when that starts happening we pick them and let them rest on the kitchen counter until they are all gone.