Probably won't help your situation, but Milestone does a great job of controlling it in chufas. I don't know what you want to grow, so it may not be a herbicide that you can use. I used a bean herbicide years ago that also eradicated the sicklepod, but it damaged the chufas and I quit using it. Can't remember the name of it right now.

But once you have made a crop of sicklepod in a field, there is no getting rid of it. You have got to either grow a warm season crop and use herbicides, or grow nothing but winter crops. I cleared a field in 2006 that had been in pine trees since the 50s and that first summer it grew a solid stand of sicklepod. The seed had to have lasted for decades in the ground; no other way it could have gotten there. Same field is solid sicklepod now and it will be when I'm dead and gone. Just put some on my grave and say that it won.