Good to see you on here Willy, can’t believe you’re planting chufa in that hog infested area you’re in! But, I always have good luck by getting the field ready to plant and letting everything sprout and then spraying with roundup before I plant. The planters stir up a little weed seed but a timely plowing will take out most of it. Of course, I’m primarily battling pusley and that stuffs worse than kudzu. I’m not aware of any pre-emergent that will work.