Unfortunately - the answer is no. Disk harrow is not designed to chop surface weeds. It may knock some down and chop some, but it will - overall - do a very poor job.
By the way - Mervyn - complete your profile and tell us where you live. Also - what type of weeds. A flail mower might do the job the best.
I hesitate to recommend any type of weed killing chemicals because I'm not familiar with your situation.
What do others do in your location - in similar situations?
Welcome to TBN and the forum.