When loading the planter last week I had a couple partial bags of seed left over from last year and I put them in first. Then started planting the field by the road, when I got done planting and cleaned out the planter I went to put the leftover seed in the shed and noticed another bag of corn in the corner. I think this is the bag left from last year and what I planted was from 2 years ago, the problem is last year I switched to round-up ready corn. so now I think I planted the first couple rounds with conventional seed, When I have it sprayed is the round-up going to kill the outside few rows? or will it just burn it some?